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A20A1
09-25-2005, 11:33 AM
INTRODUCTION & LINKS
First I think we should be able to find the parts we need so this is the main reason I posted this new thread, the rest is pretty much going back through old threads and searching the internet for way to manage your ignition and fuel. The rebuilding of the engine internals can be carried over from the rest of the EFI turbo rebuild threads and doesn't need to be gone over again. The exception is that we don't use an intercooler however there are still ways to cool the air charge, I'm working on a list and will post it later.

TURBOCHARGING A CARBURETOR


An easy way to turbo a carb is via a Holley 4 barrel with vacuum secondaries, A draw-through setup in which air flows through the carb prior to the turbo. This gets rid of pressurizing the carb. When boost comes on you need more fuel to keep from a lean condition. This is where the vacuum secondaries come in. The diaphragm that controls the secondaries operates on the presence of vacuum, but if you disassemble the diaphragm and move the spring to the other side of the rubber, you can run straight manifold pressure to the diaphragm and when boost comes on, it will open the secondaries and utilize the secondary fuel system, giving fuel enrichment and a closer to Stoich mixture. two things you need are an air/fuel gauge and different rate spring to dial out your boost/secondary opening crossover point...... another diaphragn that needs swithing to boost signal is the powervalve.

In the case of a 2BBL you would either have to jet extremely fat at idle and low RPMs to make up for the much denser charge of air when the snail is boosting', or jet it so that it doesn't instantly foul plugs (leaner) and risk detonation and eventually a burnt piston. There has to be enrichment at boost. Supercharger is not a bad idea (a20a1 and I through this one around), and because it builds boost so low in the rpm curve, jetting can be set accordingly(no "boost/no boost situation)

RELATED LINKS
TURBOCHARGING CARBURETORS (http://www.dune-buggy.com/turbo/carbureted.htm)
http://www.smbaker.com/rail/monsterturbovw.html
http://0--1.net/tom/turbo_motor.html
BLOW THRU HOLLEY (http://www.hangar18fabrication.com/blowthru)



A while back I took some notes on turbo charging a carb
Turbo & Carb Placement
The longer the air fuel charge has to travel the more heat it picks up and also the more chances for the fuel to seperate form the air.
I was thinking a single 4bbl holley and have it bolt to the turbo with a 45 or 90 degree elbow that feeds the carb mix to the tubo... add a heat spacer to protect the carbs fuel source from boiling. But hot enough so the carb doesn't ice

This isn't the final Turbo orientation... but it gives you and Idea of what I was thinking of.
http://www.3geez.com/forum/attachment.php?attachmentid=3638

Turbo Manifold / Exhaust Routing
One thing that must be done is protection of all parts in the area from heat. So lots of heat shielding to the brake lines and trans and coolant lines is helpful
Also wrapping the turbo manifold and downpipe in key areas to protect the distributor and ignition parts... is a good idea, fully wrapping could be bad or good, excessive heat may damage the turbo, and can cause metal fatigue in turbo manifolds but loss of heat can lower the exhaust energy.
The downpipe for the turbo will need to be wrapped depending on where it routes to protect the oil pan from getting heated by the downpipe

Here is a SU carb on a Draw-Thru Setup, I like the way the manifold and turbo are situated with the turbo outlet facing upwards, I never figured the fuel would flow well upwards... I wanted my air/fuel charge to exit the turbo with the outlet facing down. Also water was injected in front of the carb instead of port injection.
http://www.3geez.com/forum/forum/attachment.php?attachmentid=3633

Here is a Draw-Thru Setup, it uses a 4bbl 390 cfm double pumper on a rotary motor
http://www.3geez.com/forum/attachment.php?attachmentid=3639

Here is a list of some problems and links to possible solutions

DRAW THRU CARB
- Extreme vacuum condition if the turbo is at boost and throttle is closed could suck the oil out of the turbo bearings
- If oil gets into the air / fuel mix, it lowers your octane immediately, and pinging will start at lower boost pressures.
-FIX- Need turbo with a positive (Carbon) seal on the compressor side of the turbine
-FIX- Run a oil cooler before the oil inlet into the turbo.
This will cool the oil down and help it from being sucked through the seals or blown through the exhaust side (cooler oil is thicker).
Also makes the turbo run cooler and last longer.

- Restricting the intake to the turbo will lose compressor efficiency.
- Air-Fuel mixture must pass through the turbo
- Fuel must stay suspended in the intake charge
- Compressor turbine will throw the fuel against the turbo shell, causing a lean-out condition, thus turbo lag.
- Fuel is denser than air and tends to separate in the turbo and puddle up
- Turbo less efficient because it has to pump heavier mixture
When carb causes a pressure drop and the turbo tries to increase the pressure there is a loss in efficiency, which translates into a hotter mixture in the engine which limits the boost you can run and your power.
-FIX- Water / Alcohol Port Injection
-FIX- Avoid Extra Intake bends
- Heat needed to keep the carb from Icing

Air Charge Cooling
- Draw thru Intercooling, Not possible since intercoolers are dry flow
- Water / Alchohol Injection
-- SMC (http://www.smcenterprises.com/subaru.htm)
-- RSR (http://www.rbracing-rsr.com/waterinjection.html)
-- AQUAMIST (http://www.aquamist.co.uk/index.html)
-- ERL AQUAMIST (http://www.wrxevolution.com/alcoholinjection.asp)

Turbo Cooling
Different turbos will use different methods of managing heat such as water or oil
- Oil coolers with fan
-- B&M Oil Cooler (http://www.prostreetonline.com/buy/b&m_hi-tek_engine_oil_cooler_kit/)

Oil Cooling
- Oil coolers with fan
-- B&M Oil Cooler (http://www.prostreetonline.com/buy/b&m_hi-tek_engine_oil_cooler_kit/)

Engine Cooling
- 160 Degree Thermostat
- Aluminum Radiator Dual fans with shroud

PCV System
???

VACUUM
On a draw through motor vacuum below the carb is giving the parts that operate off of ENGINE VACUUM false vacuum readings.

Vacuum below the carb 24"
Actual engine vacuum 14"
As you open the throttle vacuum is supposed to drop to allow the power valve to open... however...
Vacuum below the carb is 12"
Actual engine vacuum is 2"
Under actual engine vacuum the power valve should be open all or most of the way @ 2"
but because of the boost you get 12" so the valve doesn't open all the way or not at all and your mixture ends up being lean.

The POWER VALVE needs to be OPEN in order to RICHEN the fuel mixture, you do this by converting to a boost sensitive powervalve, which operates the power valve based on positive pressure, instead of negative pressure.


TURBOS W/ CARBON SEALS

Now there were RAYJAY turbo's with carbon seals already installed but I went to a few sites that say RAYJAY no longer exists.
Anyone have experience with this turbo?


Airesearch TO4B35 from CB Performance Products
$800
(http://www.cbperformance.com/catalog.asp?ProductID=290)
damn a full airesearch kit on ebay
$15
link (http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=270209972248&_trksid=p3984.cWAT.m240.lVI)

more carbon sealed turbos from VWTurboKits.com

- T25/T3
- T3
- T3/T4 TO4E
- T3/T4 48
- GT33
$550 and up
(http://www.thesamba.com/vw/classifieds/detail.php?id=191401)

A20A1
06-26-2006, 01:30 AM
ignition Management



In theory this will be a nice way to cover upgrading the distributor to an electronic advance one, may offer more then that if you add some ignition programmable/adjustable contorls. I don't feel so bad about converting to the F-Series OBD-1 Distributor. Also this should help with turbo or supercharging setups... though the same boost mods to EFI sensors will need to be done to any sensors still in use on the carb setup, so that includes the Missing Link mod.
I found some promising info on: REDPEPPERRACING.COM (http://www.redpepperracing.com/forums/index.php?)
Here is the original thread: Dis Ignition System Conversion?, didnt know where to post this question. (http://www.redpepperracing.com/forums/index.php?act=ST&f=33&t=15591)
Just in case you were wondering, you can toss the internal coil an external ignition coil with an adapter from:
MSD (http://www.msdignition.com/sci_8.htm)
* Honda Accord 2.2L 90-91 TEC Distributor
PN 8292 - Modified Distributor Cap
PN 82921 - Red Cap
PN 82922 - Modified Extreme Honda Power Cap
PN 8296 - Stock Cap
The Cap Is The Same For These Engines As Well:
* Accord DX (Only) 2.3L 98-02 w/TEC Dist
* Civic del Sol 1.5L/1.6L 93-97 w/TEC Dist
* Civic/Si (Exc. 96-00 HX) 1.5L/1.6L 92-00 SOHC/DOHC
* CRV 2.0L 97-01 w/TEC Dist
* Acura Integra (All Models) 1.7L/1.8L 92-93 w/TEC Dist
* Integra GS,LS,RS 1.8L 94-01 w/TEC Dist
CRANE (http://www.cranecams.com/index.php?show=browseParts&lvl=4&prt=2012)
* Part Number: 730-0694
* Part Number: 730-0794



I'm too lazy to read thru all that... Here is what I got when I was researching doing this...
Im running the MSD-6AL for extra spark, considering the newly found air and fuel. The stock ECU is still in place. Distributor legs are cut to allow me to run more static advance (around 26 DEGREES) to be exact. Also running stock coil still as well.
To be honest I was skeptical about the STATIC TIMING figure all the way through the RPM RANGE. Bisi told me based on his research, timing changes after 3,000 RPM didn't reward him with any power advantages so he opted to keep it simple. He still runs this configuration but with the MSD DIGITAL-6AL which allows him to have a 20 DEGREE start RETARD for easier starting due to the HIGHER COMPRESSION.
In addition, the guys from the RCREW road race team in NorCal schooled me on another carb configuration, that allowed a timing curve. They got the set up from SSWORKS, who also runs the KEIHIN FCR CARBS on their B18C VTEC powerplants.

- Keep ECU still in place
- Let the TPS hang, but keep it plugged in to the HARNESS and rig it so its at WOT all the time.
- Get a VACUUM SOURCE from the BRAKE BOOSTER line, etc. etc. and run this to the MAP SENSOR.
- Stock distributor timing
- INJECTORS, IAT, IACV, etc. etc. disconnected of course.

Both of the guys I talked to running this spoke on the great power and drive ability this method gave. I never got a chance to try it though. Some how even though the computer is in LIMP MODE, the MAP reading and the WOT TPS enable the ECU to give a TIMING CURVE much like stock. (some how some way)..lol
-------------------------------------------------------------------------------
Leave the ECU in the car, don’t mess with it. It will stay put for starting and spark. Leave the HARNESS alone, except what you need to disconnect to get the carbs on, for example, MAP, IAT, IACV, TPS, INJECTORS, all get unplugged. You can roll all these up and zip tie em, or whatever. Install an MSD unit. Something with a REV LIMITER would be nice seeing how you no longer have a ECU controlled FUEL CUT-OFF. The MSD also helped clean up my idle. Good thing to have the extra spark to along with the extra fuel and air. Still running the stock coil also.
Picture your stock distributor at FULL ADVANCE. It would probably only get around 19 DEGREES max if that. So you cut slots in the distributor legs to allow you to rotate the son of a bitch way past what Honda intended. This is done because with all those VITAL PGMFI SENSORS being disconnected, the ECU doesn't know what the hell is going on, and thus RETARDS the IGNITION TIMING. The cut distributor allow you to run higher STATIC ADVANCE so this isn’t a problem anymore. I am running 26 DEGREES as it is right now. This was recommended by 'Bisi. 'Bisi told me that research he'd done didn't show anything beneficial to having an ADJUSTABLE TIMING CURVE past the 3,000 RPM mark, so his advice to me was keep it simple when I told him about other methods I had heard.
Fuel wise. From the stock FUEL FILTER run a FUEL LINE through both carbs. The FUEL LINE coming out of the last carb then goes into the FUEL INLET PORT of a Holley 1-4 PSI REGULATOR. Bisi told me I need to get something that sits at a solid 5 PSI so I need to take care of that. This REGULATOR has two FUEL OUTLET PORTS. On one OUTLET PORT get some fittings and install a FUEL PRESSURE GAUGE. On the other side, run a FUEL LINE from this OUTLET PORT and out to the stock FUEL RETURN LINE. This allows you to keep the original FUEL INJECTION PUMP in place. Bisi and my friend Teren used to run the streets like this for years with out any problems to the FUEL PUMP. Because the excess FUEL PRESSURE is running back to the FUEL RETURN LINE, it doesn't put much stress on the FUEL PUMP.
About the CHECK ENGINE LIGHT, either get used to it, or pull the bulb out.


see there are different setups you should read the thread here:
http://www.redpepperracing.com/forums/index.php?act=ST&f=33&t=15591



BTW:

SU = Skinners Union

Skinner being the one who pantented the design

lots of good SU info, even software for needle selection.
http://www.teglerizer.com/sucarbs/index.html

here is a place to buy the carb, but there is always ebay.
http://www.burlen.co.uk/

Funniest and probably the most interesting thing I've seen for CV carbs... if you know what usual CV carbs look like you'll see why.
http://www.american-made.com/mcadvantage/pages/carbs.html



i'm not used to a carb looking like that.

It's a Constant Velocity Carb... it much simpler than other carbs.

I found a little animation of the carb in action.
http://su-filters.com/sucarbs.html

HondaBoy
07-03-2006, 11:38 PM
well i have a pair of SU carbs stitting in my parts car 280Z. i may think about using them for the accord instead of webers. looks like i could easily tune them and make them work well on my car.

colinnicholson86
07-03-2006, 11:48 PM
Hey guys thought you might be interested in my turbo setup. Its the CB3 Accord with the F20A3 engine (comes with keihin carb same as 3g one standard) Ive gone suckthrough turbo using a 1.75" SU carb running 10psi.
Still got to tune it and setup a boost retard.
http://memimage.cardomain.net/member_images/1/web/325000-325999/325443_47_full.jpg
Pics as requested.
Pic of 1.75" SU carb mounted BEFORE turbo aka suckthrough.
More info for those interested.
Turbo exhaust manifold off 4G63 engine.
TD04L turbo.
2 inch intake/charge piping increasing to 2.5 inch before intake manifold flange.
Thermoflex joiners (suitable for fuel/air mix)
Vacuum advance currently disconnected, Running 6' at idle with full advance of 19'.
9.5mm fuel line reducing to 6mm after engine bay filter.
Standard exhaust except for rear muffler with 4.5" tip.
Redesigned throttle linkage.
Custom turbo oil feed/return lines and coolant lines.
http://memimage.cardomain.net/member_images/1/web/325000-325999/325443_42_full.jpg
Pic of turbo and manifold
http://memimage.cardomain.net/member_images/1/web/325000-325999/325443_39_full.jpg

EDIT: Fitted fuel system this weekend.
New fuel setup, includes Civic fuel pump (on original accord bracket) and Holley fuel pressure regulator.
Currently set at 5psi fuel pressure.

http://memimage.cardomain.net/member_images/1/web/325000-325999/325443_48_full.jpg

http://memimage.cardomain.net/member_images/1/web/325000-325999/325443_49_full.jpg

Still trying to work out where the noise is coming from and wether or not it is actually detonation.
Running standard fuel pump and regulator if It has one?? Its the New Zealand model so It doesn't have EVAP canister or fuel return line, only fuel feed to carb, so as far as I know It just runs constant 3psi, Not sure how its regulated though.


well i have a pair of SU carbs stitting in my parts car 280Z. i may think about using them for the accord instead of webers. looks like i could easily tune them and make them work well on my car.

Never overestimate the tuning ability of carbs, In theory they will work, but actually tuning them is not as easy as it sounds. . . Be prepared for unable to drive unless at least 1/2 operating temp, crappy idle/no idle when cold (no choke) and various other problems.


On a side note, suspected fuel bowl was being drained too fast when on boost.
Checked fuel pressure with engine running, had no pressure. Fuel flowing but no pressure. Pulling tank out this weekend and removing pump, so I can arrange to fit civic 40psi EFI pump with a holley fuel regulator to bring pressure back down to 6psi.

gfrg88
07-04-2006, 09:00 AM
nice!!! wouldnt it be better if he had an intercooler though??? :dunno:

colinnicholson86
07-04-2006, 09:40 PM
nice!!! wouldnt it be better if he had an intercooler though??? :dunno:

Yes It would be awesome if I COULD use an intercooler . . . fuel air mix going through an intercooler??? intercooler cools air and uses narrow passages, which can cause fuel to condensate inside, and if you were to get a backfire up the intake . . . well you can work that out. It also means the mixture has to travel through a much longer passage.

gfrg88
07-04-2006, 10:05 PM
Yes It would be awesome if I COULD use an intercooler . . . fuel air mix going through an intercooler??? intercooler cools air and uses narrow passages, which can cause fuel to condensate inside, and if you were to get a backfire up the intake . . . well you can work that out. It also means the mixture has to travel through a much longer passage.


wait im lost... so theres already air/fuel mixing before it actually goes into the engine??? where can i see how a suckthrough setup works, i feel like n00b :Owned:

colinnicholson86
07-04-2006, 10:12 PM
wait im lost... so theres already air/fuel mixing before it actually goes into the engine??? where can i see how a suckthrough setup works, i feel like n00b :Owned:

Yep fuel air mix goes from carb through turbo and then into engine

http://memimage.cardomain.net/member_images/1/web/325000-325999/325443_46_full.jpg

HondaBoy
07-08-2006, 04:35 PM
here where i live we rarely have cold weather. when i start my car cold, it usually just makes it run overly rich. if i open the choke it runs fine and i guess i really dont need the choke too badly. is there no chokes on the SU carbs? if i was to do a dual setup i would probably have a manual choke setup, thats what i have been wanting to do anyway. i have a friend that can help me out with tuning the carbs. he's had many cars with dual and tripple carb setups like on datsuns and toyotas.

colinnicholson86
07-09-2006, 10:07 PM
here where i live we rarely have cold weather. when i start my car cold, it usually just makes it run overly rich. if i open the choke it runs fine and i guess i really dont need the choke too badly. is there no chokes on the SU carbs? if i was to do a dual setup i would probably have a manual choke setup, thats what i have been wanting to do anyway. i have a friend that can help me out with tuning the carbs. he's had many cars with dual and tripple carb setups like on datsuns and toyotas.

No the SU carb doesn't have a choke as such, it has the option of a simple fuel enrichment by lifting the fuel needle, but thats about it.

Checked out my fuel problem tonight-Getting about 0.25psi fuel pressure. So I checked the pump by running it directlt off a 12v source, It went up to 1.0psi. went for a drive like that, get to about 3000rpm and 0psi, So the detonation is simply due to running out of fuel. Hopefully going to sort that out this weekend. Ill be sure to let you guys know how it goes.

Finally got around to doing the fuel system this weekend. Damn taking out the tank and putting it back isnt easy. Ended up having to do it 4 times!!
So any way, fitted the civic fuel pump and holley fuel reg. Got It currently set at 5psi fuel pressure at the carb, Detonation has definatly gotten much less. Now the next thing is to replace the valve guide seals, and hopefully that will be the last of my detonation woes :)

colinnicholson86
07-16-2006, 09:43 PM
Cool couple of questions though
1. How is the turbo setup to the manifold? and what is that vac line from the turbo going to?
2. About this SU carb, does SU stand for anything? and can you buy a new one? will it work with my A20A1 without all the vac lines?
thanx!

How Is the turbo setup to the manifold?
the turbo just bolts onto it with 4 bolts.
As for the vac line, I'm assuming you mean the black lead going across the manifold? Thats the oxy sensor wiring.
All vac lines removed except for:
The vac line that goes from the charge pipes to the wastegate actuator.
And The brake booster Line.

A20A1
07-16-2006, 10:01 PM
Is that an EFI civic pump or Carb Pump?

I've seen stock efi pumps running carbs before but they usually need a return line for the fuel.

colinnicholson86
07-16-2006, 11:34 PM
Is that an EFI civic pump or Carb Pump?

I've seen stock efi pumps running carbs before but they usually need a return line for the fuel.

EFI pump off a 1996 civic, The pump has its own regulator in it, where it bypasses at about 80psi i think. I have no idea how long the pump will last, but when/if it does die, Ill be adding a return line, Although there is another way to do it . . . drill a 1mm hole in the steel tubing above the pump to releive the excess pressure.

Been having a few problems lately, namely oil being sucked through the turbo at idle causing excessive smoke out exhaust.
So I disconnected the SU carb, and charge pipes and refitted the original honda carb. It felt really gutless with standard carb.
Drove it into work today, and carried out a compression check, Results as follows: (should be around 175 psi)
#1 - 90 psi
#2 - 125 psi
#3 - 130 psi
#4 - 70 psi

So as you can see . . . bye bye engine, sorry guys I really wouldve liked to have had it fully up and running, so you could see some results.


DRAW THRU CARB
- Extreme vacuum condition if the turbo is at boost and throttle is closed could suck the oil out of the turbo bearings
- If oil gets into the air / fuel mix, it lowers your octane immediately, and pinging will start at lower boost pressures.
-FIX- Need turbo with a positive (Carbon) seal on the compressor side of the turbine
-FIX- Run a oil cooler before the oil inlet into the turbo. This will cool the oil down and help it from being sucked through the seals or blown through the exhaust side (cooler oil is thicker). Also makes the turbo run cooler and last longer.

Also, enough oil in the airfuel mix will increase the compression.
Was going to get my turbo converted to carbon seal, but no point now lol
Hmmm diddnt think of an oil cooler before turbo, although I was using a thick oil any way.

Removed #4 piston today . . .
http://memimage.cardomain.net/member_images/1/web/325000-325999/325443_50_full.jpg

FyreDaug
08-14-2006, 10:49 AM
oh shit whered the rest of it go

colinnicholson86
08-14-2006, 09:31 PM
Was still there when i removed it, then moved the rings, and the 2 peices dropped off. . . oh well thats the cost of boost

2oodoor
05-13-2007, 01:10 PM
this topic indeed is worth some study and worth keeping
I have thought of DIS as well as COP (coil on plug) being used in applications other than with ECU fuel managment, so that the mechanical factor in ignition timing control could be upgraded.
I have seen Electomotive Ignition systems that uses crank triggered signal for two coils, sort of like a magneto set up and wondered why couldn't a similar thing be done with generic parts. I never thought of using Honda OEM existing hardware, and using cam trigger thru distributor. Controling the amount of advance with the FI distributor by using current inputs to the OEM ECU is going to the the ticket.


Early various other makers of port fuel inj cars used little if any ties to ignition other than timing controls. (electronic controled carb cars uliltized that as well. but not 3 gen accords)

This is a project that has a lot of potential, but I don't know if anybody with a FI car would convert to carb. I would consider it especially with the older LXi black box cars.
Those that want real fuel delivery and use multiple carb setups take notice!!!

Ok I would like to post a shopping list for JY, for this application. Easy to read /model/year vehicles to get these OEM parts from.
This can be edited or add to thread for addtional information.
The purpose of this would be for someone wanting to do this conversion on factory carbed car rather than otherwise.


Also, what has to be removed from Original Carbed vehicle for these items to be placed.

Incomplete List
_____________
ECU from LXi
Distributor from LXi
Wire Harness LXi
TPS sensor
Coolant temp sensor (ECU)

lostforawhile
05-22-2007, 04:26 PM
did anything come out of this? this is very interesting. i would like to be able to change the advance curve when i do my carb setup. has anyone had good luck with standalone ignition control boxes,that change the timing curve?

2oodoor
05-23-2007, 08:15 AM
see there are different setups you should read the thread here:
http://www.redpepperracing.com/forums/index.php?act=ST&f=33&t=15591
Wow, thanks I found another carbie talk place, old school mods on new engines, ... :) matter of fact I ran across two other forums among these links that never came up as many times as I have searched Honda/carb/Accord/Civic/Weber

Right now it looks like using JY parts may not necessarily be the most economical source for stand alone ign or computer controlled ign. I need some time to study this and explore resources.

A20A1
02-08-2008, 01:03 AM
bump, added new info

2oodoor
02-08-2008, 04:42 AM
thanks, you have my undivided attention now.
I was thinking blow thru, but I am reading this information and thinking I could go with different carbs than DCOE < $$$ on the pull thru.

A20A1
02-08-2008, 09:36 AM
thanks, you have my undivided attention now.
I was thinking blow thru, but I am reading this information and thinking I could go with different carbs than DCOE < $$$ on the pull thru.

for sure
http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&ssPageName=STRK:MEWAX:IT&item=270209972248&_trksid=p3984.cWAT.m240.lVI


besides I would really enjoy the visual aspect of a shiny anodized carb and polished turbo in close proximity, and the sound the carb would make, vs making more power with Blow thru or efi :D

2oodoor
02-14-2008, 09:56 AM
would sound kinda like an early buick T type, deep loud-raggedy but hauling a$$

that turbo set up went for $222.50, and Yes I missed it.

colinnicholson86
05-08-2008, 10:01 PM
Wow. Been quite a while since I've been around here - Usually on CB7Tuner now.
This thread hasn't progressed very far though. Has anyone else gone through with the carb draw-thru design??
Btw good to see your still around here A20A1. Hows things been?

And for those interested, after I blew that engine. I couldn't afford the engine build downtime on the car, so just put in another block.
I then brought another CB7 (fuel injected) then turboed that.

2oodoor
05-09-2008, 03:27 AM
the thread was assembled from various others I guess because I have never seen the first part of it.
Even since the last post I put on it.

There is still interest in the topic absolutley, but the largest part of the forum seems to be anti-carb, too bad for them huh.
welcome back

evil88accordLX
05-09-2008, 02:26 PM
There is still interest in the topic absolutley, but the largest part of the forum seems to be anti-carb, too bad for them huh.
welcome back

funny how we hate what we dont understand!

has anyone ever played with the idea of using the stock exhaust manifold, or possibly an aftermarket header, and cutting it right before the firewall for turbo placement? the intake tube could draw air from the vacated black box area, and your charge pipe would only have to be like 2'-0" in length, if going sans intercooler. just a thought, especially since finding a turbo header is almost impossible.

2oodoor
05-09-2008, 04:57 PM
I have wanted to say that cliche for a long time to certain members, thanks
Your idea is not too far off base I guess, Ive seen turbos way back further than that before.

turabaka
05-09-2008, 05:48 PM
As much as I'm interested in this idea. I'd really rather try to find a supercharger that could work with our engines. I just don't like the idea of fuel going so close to the hot ass exhaust. Maybe it's just me, but heat + flammable stuff = fucking eek.

89T
05-09-2008, 07:07 PM
funny how we hate what we dont understand!

has anyone ever played with the idea of using the stock exhaust manifold, or possibly an aftermarket header, and cutting it right before the firewall for turbo placement? the intake tube could draw air from the vacated black box area, and your charge pipe would only have to be like 2'-0" in length, if going sans intercooler. just a thought, especially since finding a turbo header is almost impossible.

i have done that before on a past turbo project with good result.the turbo seemed to spool very quickly almost at idle and the turbo was high enough to drain oil back to the pan. the car was throttle body injected though.

i remember reading somewhere that there are a few shops in Cali that specialize in draw-thru set ups on sand rails. i am thinking there using Holley 4 barrels on 4 Cly. applications.

colinnicholson86
05-09-2008, 09:49 PM
funny how we hate what we dont understand!

has anyone ever played with the idea of using the stock exhaust manifold, or possibly an aftermarket header, and cutting it right before the firewall for turbo placement? the intake tube could draw air from the vacated black box area, and your charge pipe would only have to be like 2'-0" in length, if going sans intercooler. just a thought, especially since finding a turbo header is almost impossible.

Yep I saw it quite a few years back on a 3rd gen accord. (I'm sure it was on here) Turbo mounted at the back of the engine bay and it was carbed too :wave:

Accordtheory
05-11-2008, 12:30 PM
funny how we hate what we dont understand!

Well, I for one, understand. I also understand how easy it is to convert to obd-1, and how the improvement from doing so is exponentially better than a carbed setup.

Usually when you deliberately set out to half ass something, it costs more because you have to completely redo it in the future. Almost everything automotive you buy and sell, you only make a small percentage of what you paid back. You also have the original time invested, which is just wasted. The only good that comes from it is knowledge, but why not just read more instead..

A slightly cheaper initial investment, but offset by less accurate fueling and ignition, drastically less reliability , driveability, and fuel economy, no intercooling (resulting in very limited boost, and therefore power) and still requiring some type of ignition control box, ($) and still requiring a wideband for tuning. Why not just convert to obd-1, run a freeware rom editor, and have actual potential, for not even spend much more money. It's 2008, for fuck's sake, why use technology that hasn't been used in most regular production vehicles for about 30 years. Or you could build a carbed setup and blow your motor while getting your ass handed to you by a completely stock pontiac g6 driven by some hot girl laughing at you like you just left the special ed class for building cars.

ghettogeddy
05-11-2008, 12:46 PM
Well, I for one, understand. I also understand how easy it is to convert to obd-1, and how the improvement from doing so is exponentially better than a carbed setup.

Usually when you deliberately set out to half ass something, it costs more because you have to completely redo it in the future. Almost everything automotive you buy and sell, you only make a small percentage of what you paid back. You also have the original time invested, which is just wasted. The only good that comes from it is knowledge, but why not just read more instead..

A slightly cheaper initial investment, but offset by less accurate fueling and ignition, drastically less reliability , driveability, and fuel economy, no intercooling (resulting in very limited boost, and therefore power) and still requiring some type of ignition control box, ($) and still requiring a wideband for tuning. Why not just convert to obd-1, run a freeware rom editor, and have actual potential, for not even spend much more money. It's 2008, for fuck's sake, why use technology that hasn't been used in most regular production vehicles for about 30 years. Or you could build a carbed setup and blow your motor while getting your ass handed to you by a completely stock pontiac g6 driven by some hot girl laughing at you like you just left the special ed class for building cars.
well played my good man well played

2oodoor
05-11-2008, 02:47 PM
Could have done without your input/comments AccordTheory. We all know what you said probably holds water ok, that is not even the point here. This is not a FI vs carb *thread my friend. I appreiciate your knowledge (no doubt you are a smart mofo ok bro) and vague intellectual transfer of knowledge via talking down to anybody that may be opposite the debate table from you, I say vague because half the time you mix it up with so many emotional triggers it often becomes offensive to read.
Some of us are pretty resourceful and can achieve these projects without paying top dollar. We can barter and trade and hell just give uneven trades sometimes in the name of commeradery to keep each other's dream cars going. So the name of the game is fun, originality, and making friends who are also into cars. If we want to love blown carbed cars, is that so wong (jon lovitz)

Edit: *ok fair enough I did mention something about carb haters, maybe I bent a obd 1 nerve..... But my statement stands ^^

Accordtheory
05-11-2008, 03:46 PM
Could have done without your input/comments AccordTheory.

half the time you mix it up with so many emotional triggers it often becomes offensive to read.

So you liked my comment about getting smoked by the hot girl in the g6? :)

No one has really gotten into the drawbacks of the carbed setup. I'm just bringing the big picture back into focus. Also, why the thread is emphasizing draw through, a clearly inferior setup compared to blow through? Draw through has inferior fuel distribution/atomization/keeping the fuel in suspension/whatever, the lack of intercooling possibilty, and the requirement that the compressor side of the turbo can tolerate vacuum. People on this forum seem to love ITBs, for what reason I still don't know, but this is one case where I agree. 4 individual boost referenced carbs would work a hell of a lot better than one big one before the turbo.

So let's say you can tune that to run at 14.7 for most of the part throttle, get it to idle, start, rev and run right, and then enrich to about 11.8:1 for most of the boost, (how well can you really do that? To how many pounds of boost/how much hp?) Then what about the ignition part of the equation. What type of ignition box gives you a 3d map of rpm and manifold press? How else would you do it? An msd boost timing retard? Not very good. I think msd makes a programmable box, but I also think it's more expensive than a chipped obd-1 computer + the obd-1 distributor.
So you have the cost of the carbs (how much is that realistically? And you know they don't just bolt up to the a20 head..more fab work involved there..) + the ignition setup, + the wideband, + all the turbosystem components, and the tuning.
I just really don't think there is going to be much of a difference in cost between the 2 setups, and one of them provides a much better result. You do have to build a subharness for the obd-1 wiring, but there's fab work for carbs too. For instance, how would you even connect them to the intake piping?
What kills the idea for me is mostly the ignition thing. Whatever you use to (accurately)control that can also control the fuel for probably the same cost. I also doubt you'd be able to make the carbs run right across the motor's wide variety of operating conditions while accomodating more than about 10lbs of boost, but I don't really know.

Accordtheory
05-11-2008, 03:50 PM
Another thing, just an example of carbed vs injected, look back at the buick grand nationals of the 80s..they started out carbed, but then the injected setup came out, and it was a world apart in terms of performance and function.

AccordEpicenter
05-11-2008, 04:38 PM
carbs are the suck when it comes to turbo setups, the tunability and driveability leave alot to be desired when it comes to suck through and blow through setups. Ive seen some really fast blow through turboed race cars which is fine (only thing you care about is WOT tuning) nobody gives a damn in those cars about driveability. If you want a cheap turbo header, (like, flat rate styles) you can make an up pipe going from the stock exhaust manifold pretty much making a u turn and then up to the front of the engine or trans into a turbo flange. Not the greatest setup but it will work, probably better than a log manifold, but will work fine for budget setups if you can make it fit. Big thing is having clearance in the engine compartment so you dont start fires

2ndGenGuy
05-11-2008, 08:07 PM
Blah blah blah... fucking seriously.

2oodoor
05-12-2008, 07:42 AM
Another thing, just an example of carbed vs injected, look back at the buick grand nationals of the 80s..they started out carbed, but then the injected setup came out, and it was a world apart in terms of performance and function.

good example, I was going to use that myself. Those first t types were the shizzle weren't they I guess that is why they continued development on the Grand National since it was such a success out from the get go ( in carbed form, you said it)
I for one would appreciate any positive feedback, experiences, and information of builds on any forced induction carbed powerplant. It may not be the latest and greatest but it is the topic of this thread.

Accordtheory
05-12-2008, 02:18 PM
Well, you're not really going to get that, because it doesn't really exist. Standards are higher nowadays, and that's a good thing. Look how nicely even the previously mentioned mass marketed non particularly performance oriented new g6 v6 drives. My point was the carbed GN/t types were a joke compared to the SEFI distributorless MAF car of 86/87. The 86/87 GN was one of the few times GM actually let their engineers build something they wanted to build. They showcased the latest technology at the time, and it made the carbed version obsolete. And that was 21 years ago. Another example, obviously not as good, but Nissan's Z cars first came out with carbs, then they went to efi with their turbo versions in the late 70s. Even back then with their extremely primitive efi, they knew it was better than carbs. Anyway, that's not even my main point. My main point was about cost vs function, and that you still need expensive electronics for ignition control, so why not use that money and get fuel control also.

But seriously, whatever, like 2ndgenguy said, who cares. Like anyone on here is actually going to build a carbed turbo setup anyway.
That's like using your head to break a brick wall instead of a hammer. This whole thread should just be deleted. Sorry if anyone finds that offensive, but seriously.

2ndGenGuy
05-12-2008, 03:09 PM
That wasn't what I was trying to say at all. Mostly that this was an informational thread and not yet another carb'd vs EFI thread. Some people aren't always looking for what's the best most high tech, and what's far superior... or are worried about what everybody thinks of them if they don't come in first place.

For people like us, this is fun to read about. Good, insightful information about alternatives is always welcome, but the "holier-than-thou" attitude toward not running the latest and most high tech "far-superior" stuff is irritating... It's just the same annoying crap you see on so many other forums that makes them just god awful to read.

turabaka
05-12-2008, 03:11 PM
^^ I'm with ya 2ndgenguy. Although, I'm wondering something. If FI really is the best thing ever, then why do so many of the guys on onecamonly talk about using carbed setups? I mean they may not be the best for boost, but you can make some pretty good power with a carb.

Accordtheory
05-12-2008, 08:10 PM
the "holier-than-thou" attitude toward not running the latest and most high tech "far-superior" stuff is irritating... It's just the same annoying crap you see on so many other forums that makes them just god awful to read.

I'm not advocating an i-vtec k20 swap with a garrett twinscroll ball bearing turbo, am I? I wish someone would have told me everything I did wrong or should have done differently when I was 21 and built my first turbosystem. Yet when I post shit that is true and will actually save people regrets, I'm referred to as "holier than thou"? Fuck that.

colinnicholson86
05-12-2008, 09:09 PM
Well, you're not really going to get that, because it doesn't really exist. Standards are higher nowadays, and that's a good thing. Look how nicely even the previously mentioned mass marketed non particularly performance oriented new g6 v6 drives. My point was the carbed GN/t types were a joke compared to the SEFI distributorless MAF car of 86/87. The 86/87 GN was one of the few times GM actually let their engineers build something they wanted to build. They showcased the latest technology at the time, and it made the carbed version obsolete. And that was 21 years ago. Another example, obviously not as good, but Nissan's Z cars first came out with carbs, then they went to efi with their turbo versions in the late 70s. Even back then with their extremely primitive efi, they knew it was better than carbs. Anyway, that's not even my main point. My main point was about cost vs function, and that you still need expensive electronics for ignition control, so why not use that money and get fuel control also.

But seriously, whatever, like 2ndgenguy said, who cares. Like anyone on here is actually going to build a carbed turbo setup anyway.
That's like using your head to break a brick wall instead of a hammer. This whole thread should just be deleted. Sorry if anyone finds that offensive, but seriously.

Wow so arrogant.

If you don't like the thread then why post.
As you can see on the first page I DID build a carb turbo setup - Although it diddn't last as long as I'd hoped, It really was more a case of inexperience with tuning that caused its short life.
Plus there is also a few others that have done it as I stated earlier.

Mitsi built a carbed turbo car OEM as have a few others car manufactures - And they were reliable, and driveable.

Yea sure PGM-Fi is better because of blah, blah, blah. We all KNOW that. Sometimes it's nice to step outside the box every once in a while, and try something new.
Its like saying Why would you ever want to build that RWD Accord, that Vector is building? - Its not because you think its a dumb idea, but because HE WANTS to.

oscwrestler
05-15-2008, 08:57 PM
why do these always turn into arguments? seriously accept the ideas or keep quiet.

Hauntd ca3
05-16-2008, 01:54 AM
draw thru turbo set ups work fine
seen it heaps and no horror stories
blow thru would be the way if you want to intercool but otherwise draw thru is cool
just have to make sure the carb is far enuff away from the compressor so that the fuel doesnt errode the wheel away
dont laff, seen people do just that with water injection.
they had the nozzle to close and guess what
after a while they had bits of compressor wheel flyin thru there motor

2oodoor
05-16-2008, 03:46 AM
bump

oscwrestler
05-16-2008, 04:31 PM
what is better for reliability? draw or blow through?

A20A1
05-16-2008, 04:37 PM
This thread is about draw-tru which is why there is more one sided approach. I seperated it from the other thread that talks about blow-tru... I think that was my intention when making this thread, but I did it a while back so I'm not sure.

oscwrestler
05-16-2008, 05:04 PM
can you post the link for the blow through? i search and it was no dice

Hauntd ca3
05-16-2008, 10:44 PM
what is better for reliability? draw or blow through?

dont really think there is much dif betwen the two
before aftermarket ecus came along, everyone just used an su or 45dcoe in a draw thru set up and had no worries with reliablity either way
a draw thru would be easier for an experianced tuner to set up as they can look down the carb while its runing and see how the fuel is atomising and the god ones can make decisions on what jets and what not to use

89T
05-17-2008, 05:33 AM
dont forget that the turbo acts like a blender also.
the only real problem would be fuel pooling in the turbo at idle if you use too big of jets.

lostforawhile
02-09-2009, 05:16 AM
where did all the SU stuff come from? i'm waiting on my long awaited book how to build and power tune SU carbs, so there should be info to add to this thread, took me two years to finally get my hands on one. as far as the SU's,why aren't they being run blow through? they are easy to pressurize,since the fuel bowl is external. they respond to the amount of air going through the carb, the more air,the higher the needle lifts,and the more fuel. they would seem to solve the problem of making all the power valves work right,and secondaries work right,etc. there is a lot of knowledge out there on running them under boost too. with something like one of the small eaton supercharger units,that is belt driven, and the new msd boxes that control ignition in proportion to boost,it seems like it would be a pretty easy setup. was i seeing things,or was there a bunch of jerry springer stuff deleted out of this thread just now?

lostforawhile
02-09-2009, 05:29 AM
does anyone know what kind of horsepower those rhinos make? they actually have a supercharger for one, hmmmm. picture. http://www.rc-trucks.org/Yamaha-Rhino-Supercharger.jpg

lostforawhile
02-09-2009, 05:53 AM
here's an excellent article on superchargers great read for anyone http://www.502motorsports.com/PerformanceParts4.html

Hauntd ca3
02-10-2009, 12:03 AM
where did all the SU stuff come from? i'm waiting on my long awaited book how to build and power tune SU carbs, so there should be info to add to this thread, took me two years to finally get my hands on one. as far as the SU's,why aren't they being run blow through? they are easy to pressurize,since the fuel bowl is external. they respond to the amount of air going through the carb, the more air,the higher the needle lifts,and the more fuel. they would seem to solve the problem of making all the power valves work right,and secondaries work right,etc. there is a lot of knowledge out there on running them under boost too. with something like one of the small eaton supercharger units,that is belt driven, and the new msd boxes that control ignition in proportion to boost,it seems like it would be a pretty easy setup. was i seeing things,or was there a bunch of jerry springer stuff deleted out of this thread just now?

you'd have to pressurise the float bowl aswell as the dash pot to make an su work as a blowthru set up.
ts a fairly fine balance to make them work spot on at the best of times.
the needles look like a straight taper but are far from it in reality.
they can be barrel shaped,hour glass shaped or anywhere in between.
the springs in the dash pot vary in strength and the amount and grade of oil in the dash pot can change the speed the needle moves in the jet.
the jet size itself.
i reacon that su's are prob a harder carb to tune than a weber even tho they are quite poss the simplest carb in the world to rebuild at home.
they prob run better than a weber once tuned aswell
its hard to explain how an su works without writing a novel eh.
rjudgey being a pom should have su experiance, i know i was rebuilding them for fun at age 12. a slotted screw driver and a 6 inch cresent are all you need to field strip them.

colinnicholson86
02-10-2009, 12:47 AM
you'd have to pressurise the float bowl aswell as the dash pot to make an su work as a blowthru set up.
ts a fairly fine balance to make them work spot on at the best of times.
the needles look like a straight taper but are far from it in reality.
they can be barrel shaped,hour glass shaped or anywhere in between.
the springs in the dash pot vary in strength and the amount and grade of oil in the dash pot can change the speed the needle moves in the jet.
the jet size itself.
i reacon that su's are prob a harder carb to tune than a weber even tho they are quite poss the simplest carb in the world to rebuild at home.
they prob run better than a weber once tuned aswell
its hard to explain how an su works without writing a novel eh.
rjudgey being a pom should have su experiance, i know i was rebuilding them for fun at age 12. a slotted screw driver and a 6 inch cresent are all you need to field strip them.

X2.
The boost psi / fuel psi relation would have to be very accurate. Some form of rising rate regulator would have to be used, a Malpassi MIGHT work.
One of the issues I had was that too high fuel pressure would result in fuel leakage through the jet at low to mid throttle, and too low pressure would result in lean conditions at mid to high throttle.

As far a blowthrough goes with an SU. I'm not sure what would happen when you were at full throttle in boost and you closed the throttle - Would the jet close, or remain open due to the pressure acting on the needle? which could mean that the throttle would be WOT with no way of stopping it.

Hauntd ca3
02-10-2009, 12:57 AM
As far a blowthrough goes with an SU. I'm not sure what would happen when you were at full throttle in boost and you closed the throttle - Would the jet close, or remain open due to the pressure acting on the needle? which could mean that the throttle would be WOT with no way of stopping it.

worst nightmare, a runaway motor
would want a kill switch handy eh
which part of nz you at colinnicholson86

lostforawhile
02-10-2009, 08:42 AM
worst nightmare, a runaway motor
would want a kill switch handy eh
which part of nz you at colinnicholson86thats a good question, all the boosted setups i've seen have had the output of the supercharger connected directly to the carbs. it's done all the time on mini's this way. my book i've been waiting on forever should be here this week. this one is supposed to be the bible of SU performance. been trying to get my hands on one for a couple of years,now it's on the way here. oh and my SU tool set got here yesterday, the original 1970's era one. looks brand new still. probably never used. i was going to rebuild these myself,but the cost of the rebuild kit, is just a little bit less then the cost to have them done,besides these need throttle shaft bushings, and i don't have the special reamer to ream them oversize. i can't justify the 100 dollars for it eithier.

lostforawhile
02-10-2009, 09:04 AM
um these do have throttle plates lol. as far as venting the domes the dome vents are the extra holes in the air intake side of the air cleaner flange. those are the air passasges that go back to the top. the fuel bowl is a good question though. i would think the more air went through the carb,the more fuel would be pulled out of the jet. but i see the issue. the needle is supposed to be tapered on these, i've seen it changed into all kinds of wierd configurations before, but on these it's supposed to be a taper.

Hauntd ca3
02-10-2009, 09:31 PM
tru on the throttle plate bit.not thinkin
on the float bowl bit, if you are blowing thru them, you'd have boost pressure at the jet which would try and push air into the float bowl, and boost at the aircleaner side and the throttle side, and since from memory an su takes a vacum from the engine side of the throttle to the top of the dash pot and atmo presure from the aircleaner side of the dash pot, you'd have to try and replicate this somehow otherwise the dash pot wont lift and airflow wil be restricted and the needle wont come outta the jet.
i've never seen a blo thru su set up b4, only draw thru, maybe because of this

Rendon LX-i
02-10-2009, 11:27 PM
A little off topic but i love how the 4g63 manifolds bolt right up to a f22 on a 93 accord and you can basicly use the gst stock set up lol...Im a dummy when it comes to carbs i know little bout chevys thats bout it. Its confusing how a carb works when it comes to forced induction. But anyways lol

cubert
02-15-2009, 03:03 PM
does anyone know what kind of horsepower those rhinos make? they actually have a supercharger for one, hmmmm. picture. http://www.rc-trucks.org/Yamaha-Rhino-Supercharger.jpg


Do you mean Rhino as in a Yamaha Rhino?


Ive driven a supercharged one, and they go pretty decent. The one i drove was tuned poorly though

lostforawhile
02-15-2009, 04:29 PM
Do you mean Rhino as in a Yamaha Rhino?


Ive driven a supercharged one, and they go pretty decent. The one i drove was tuned poorly thoughi was just wondering about the supercharger

89T
02-15-2009, 05:00 PM
If you want to do a blow through turbo setup, take notes from those toyota corolla guys running their 1970's round backs with turbocharged 3TC engines.

Yeah, there isn't too much information regarding blow-through weber turbo systems on the internet. I was lucky enough to hook up with a guy in Hawaii that built some fast corolla's. At the time he had a corolla that broke into the 9's with a blow through setup. He was running 30+ lbs of boost through a set of 45 DCOE's.

There is no real trick with boosting a weber setup except for these few key components:

1. Make sure to pressurize the fuel bowl of the carburator. This will ensure that fuel will still flow out of the jets into the intake runner and not the otherway around.

2. Be sure to use plastic floats. Those old brass floats will crush under boost and will take on fuel eventually flooding the carb/engine.

3. You must use a rising rate fuel regulator. It sounds odd to run more than 4 psi of fuel pressure through the carbs but it is needed to compensate for boost pressure.



You don't need to build a box around the entire weber carburator to pressurize the float bowl. You pressurize the float bowl via the vent hole on the backside of the carb.


Or if you use the stock carbs, there's the vent tube that connects between the carbs. Could just tap into there.... :D
here is some info i found on P.P.

colinnicholson86
02-18-2009, 10:16 PM
um these do have throttle plates lol. as far as venting the domes the dome vents are the extra holes in the air intake side of the air cleaner flange. those are the air passasges that go back to the top. the fuel bowl is a good question though. i would think the more air went through the carb,the more fuel would be pulled out of the jet. but i see the issue. the needle is supposed to be tapered on these, i've seen it changed into all kinds of wierd configurations before, but on these it's supposed to be a taper.

That was the main problem - SU's have piston/needle for fuel and plate for air.
A piston carb has no way of forcing the piston to close. If you tip an SU upside down the piston can open w/o the throttle rotor moving.
This means that when you suddenly close the throttle, The engine will still have a vacuum acting on the piston and fuel which won't necessarily force it to close, meaning that fuel could still be sucked in (without air, potentially causing fuel pooling)
For a blowthrough setup you have to remember the fuel being pulled through the jet relies on airflow AND vaccum to pull it through, not just airflow as such. E.g You have massive airflow at 10psi but you have to remember that there is now 10psi pushing back on the fuel jet, so you would need over 10psi fro ANY fuel to flow into the carb.

BTW - What was your original SN name and also Rendon LX-i's?
As you probabally know I havn't been on this forum for a while since I found CB7Tuner.
http://www.mgexperience.net/article/images/su-hs4-section.gif


worst nightmare, a runaway motor
would want a kill switch handy eh
which part of nz you at colinnicholson86

I'm originally from Wellsford, but living in Auckland now.


A little off topic but i love how the 4g63 manifolds bolt right up to a f22 on a 93 accord and you can basicly use the gst stock set up lol...Im a dummy when it comes to carbs i know little bout chevys thats bout it. Its confusing how a carb works when it comes to forced induction. But anyways lol

I take it you've visted CB7Tuner before? That setup is more commonly know as the DSM setup. Its what I have on my CB Accord.

A18A
02-18-2009, 10:32 PM
wow someone from north of auckland :O thats a first. sorry for the off topic

colinnicholson86
02-18-2009, 10:53 PM
wow someone from north of auckland :O thats a first. sorry for the off topic

Damn another NZ'er, I really have been away for a while haha

AccordB20A
02-18-2009, 11:25 PM
and another

Rendon LX-i
02-18-2009, 11:26 PM
That was the main problem - SU's have piston/needle for fuel and plate for air.
A piston carb has no way of forcing the piston to close. If you tip an SU upside down the piston can open w/o the throttle rotor moving.
This means that when you suddenly close the throttle, The engine will still have a vacuum acting on the piston and fuel which won't necessarily force it to close, meaning that fuel could still be sucked in (without air, potentially causing fuel pooling)
For a blowthrough setup you have to remember the fuel being pulled through the jet relies on airflow AND vaccum to pull it through, not just airflow as such. E.g You have massive airflow at 10psi but you have to remember that there is now 10psi pushing back on the fuel jet, so you would need over 10psi fro ANY fuel to flow into the carb.

BTW - What was your original SN name and also Rendon LX-i's?
As you probabally know I havn't been on this forum for a while since I found CB7Tuner.
http://www.mgexperience.net/article/images/su-hs4-section.gif



I'm originally from Wellsford, but living in Auckland now.



I take it you've visted CB7Tuner before? That setup is more commonly know as the DSM setup. Its what I have on my CB Accord.


AHhh i know cb7tuner.com well but i also boosted a 4gen with a stock gst setup...i tryed it on a 5gens but had to drill out the holes...But My original name is Joshua but im just josh lol...known as Rendon since its my last name lol....I like your setup also...May i ask why Carbs?

colinnicholson86
03-11-2009, 09:35 PM
AHhh i know cb7tuner.com well but i also boosted a 4gen with a stock gst setup...i tryed it on a 5gens but had to drill out the holes...But My original name is Joshua but im just josh lol...known as Rendon since its my last name lol....I like your setup also...May i ask why Carbs?

Joshua, now I remember, Maybe you know me too http://www.cb7tuner.com/vbb/showthread.php?t=62581
I went carb simply because I had an addiction to carbs haha, That and I wanted to step out side the box.
Plus I can't deny the experience I got from it all.

Rendon LX-i
03-12-2009, 07:51 AM
Good to know. I had a buddy boosted a civic that was carbed. was a pain lol...Oh yeah i remember. Didnt know that was you. Very nice bro. mad props

colinnicholson86
03-12-2009, 10:07 PM
Good to know. I had a buddy boosted a civic that was carbed. was a pain lol...Oh yeah i remember. Didnt know that was you. Very nice bro. mad props

Haha carbs will always be a pain, But if done right they can be great.
Thanks Man :thumbup: