DISCUSSION , TURBOCHARGING YOUR CAR

[89T]

this is a little something i found to help those who want to know.
http://www.beesandgoats.com/boostfaq/g2icturbo.html#Engine

I know it is for a integra but the basics are the same...

[frankie89]

man thats some good info..

[A20A1]

http://www.beesandgoats.com/boostfaq/g2icturbo.html

I just added your link to the turbo FAQ, but then I realized I already had the link there.
Anyways, it's worth it to have two links.

[Cheeseburger]

dam thats really good info. i got alot from reading it. good find 89turbo'ed?

[racerx]

holy buttloads of good info batman! ...but i didn't like how every engine he listed could do between 300 and 500+hp.... i thought the stock bottom numbers would vary a little, and some torque numbers would have been nice, cuz that would be the largest difference.

good stuff. and now I finally know what the AFC hack is, and I can tell my friend that he's got it all wrong, and that's why his car runs a like a 3 cylinder Metro firing on only 2 cylinders... lol

[gr3k0sLaV]

man thats some good info..

OMG! Who is that woman? I must have photo's of her!

[halxi]

After reading this, i still have a couple questions.

If the springs on the BOV's are rated at 7psi, 8psi, etc, whatever you chose, and your only planning on getting 300hp, what would be better, a smaller turbo but higher PSI rating, or a larger turbo but lower PSI rating? (IE a t25 @ 15lbs or a t3 at 10?)

[racerx]

if all you care about is max horsepower on the dyno (not even the curve) than a big turbo is your way to go.

however, as you say, if 300hp is all you want, it would be best to find the turbo that can barely produce that much power. you don't want a 1000hp turbo taking 3 years to spool up to 30% of it's max efficiency, unless you just want to show your friends your semi-truck turbo which is larger than your engine...

you don't, however, want a "small" turbo that's going to strain until 5500rpm to put out a decent CFM.
get a smallER turbo with ball bearings, or one of those crazy super-efficient diesel turbos. I'll look it up...

[smufguy]

thats the same website that i took the idea for my turbo manifold from. it was great in its explanation of the physics behind the whole thing.

[racerx]

mmmmm equal length snake orgy header please...

[halxi]

i do care about the curve and acceleration, so something ideal would be something thats going to spool fast, and produce power through at least 6k rpm (even though i probably wont ever take it that high) and i definatly dont want max boost to hit at anything above 4500rpm (so that kind of limits me to a boost controller, if im not mistaking) i want to do it once, and do it right the 1st time. Btw i found a picture of that one intercooler setup he was talking about, with both pipes comming from the drivers side of the car, then one looping back up and over.

http://www.jtuned.com/media/gallery%2Flab%2Fdcfred%2Fturboinstall%2F024%2Ejpg

[smufguy]

if you are gonna do a daily driver on ur car with a turbo, the intercooler set up is not recommended. the reason being that it sits in front of the radiator and its pretty much covering the whole thing. The best thing to do is to get the smallest height as possible and then get a long length on the core. the size of the intercooler increases as your power increases and you can use something like a DSM side mount intercooler or an Audi intercooler or even a supra stock side mount intercoolers to start out.

I hope you wanted to NOT hit max boost under 4500rpm, the reason is you wanna build boost around 3500 or even 4000 rpm for daily driving. This is possible if you are running a internal wastegated turbos like a 14b or a 16g turbos. buildup of boost is related to when the wastegate opens and closes and they are directly hooked up to the engine's vaccum, hence their stock waste gates start to close around 3500 to 4000 rpm which is an optimal engine speed/rev band to build up boost for city driving.

The lag is directly related to the distance of the air travel from the turbo to your throttle body, the shortest way is to have the air come in on one side and go thru the other side of the intercooler and pass thru the passenger side of ur car and directly to the throttlebody. Even tho this is the conventional method, its ideal for our cars and pretty much every honda motor uptil the new K series, because our Throttle body faces the passenger side unlike the RSX above which has the K20 with its throttle body facing the driver side, hence its piping is ideal. But if you are gonna do that for our accord, not only will you heat soak your piping from the intercooler to the throttle body, you will also lengthen the piping distance and hence increase the air temperature and also experience below normal lag for the turbo u maybe using.

[halxi]

im definatly not going to be running my piping that way, so if i do choose to run an intercooler it would be best to get the shortest (height wise) longest one i could possibly fit? or did i misunderstand that part?

Im just starting to dig into this turbo stuff, so forgive my stupid questions, but, wouldnt it be better to hit max boost at a lower rpm so you can utilize max boost longer, oppose to hitting maxboost like 500rpm before redline?

[smufguy]

yes, an intercooler with the CORE dimensions close to our bottom grille dimensions is perfect if you are gonna use the stock front bumper.

You do not want to hit max boost at a lower rpm because of the following reasons.

1. max hp is achieved under max boost and hence if you hit max boost, lets just say at 3000rpm, you will loose traction and also have your head bobble like a bobbing doll everytime u shift in city driving.

2. if you make max boost in low rpm and have a redline of lets say 6.5K rpm, it gives you an extra rev band of 3.5K rpm which is not good because once you exceed the turbo's max spool speed, it will start to surge if its pushed any higher or made to spin any higher, this will destroy the turbo.

3. you wanna know how much hp you want and then wanna look at the compressor map of the turbo that can support it, and then decide what you want as your redline (on a standard turbo streetable rebuilt motor, a good 7 or 7.5K is good) then match it up to your turbo's efficiency area and then have the upper 2000 to 2500 rpm to be your spool up region. So in a sense, with a motor that can redline at 7K rpm, you do not wanna build boost till its like 4.5 or 5K. this usualy for a motor that can do about 300 to 500 hp, for a motor that can have about 200 to 250hp a good solid 6.5 - 7K redline and a spool up of 3.5K to 4K will be good.

NOTE: even tho boost build up is related to intake manifold vaccum, you do not wanna make boost anywhere around your average cruize rpm, which is like 3 to 3.5K for normal driving.

[superaccord]

If you have a built motor your redline should be higher. Dont ya think?

[smufguy]

If you have a built motor your redline should be higher. Dont ya think?

it all depends on ur preference. me persoanlly, i would have a redline of atleast 7.5K, anything beyond on our motor is defenitely hell to drive as a daily driver cause with that kinda lift on the cams, its not gonna be running smooth at idle. of course we can tune it and get the cam that has a lot of overlap and richen the mixture up to help it idle, but you dont wanna consume too much gas just idling either. When you want to consider daily driving under snow, rain and what not, you wanna be practical about how much hp you want, unless you have a greater idea of how to make a 350hp daily driver just on turbo, outta these.

[halxi]

Well im going to be buying a motor thats been slightly built, i just need to strengthen a few things in the head, and maybe new pistons, then im set. Its a brand new block thats bored over .040 i think it is with 9:1 pistons, im not sure exactly what it is ill have to look it up here in a min, but i THINK thats right.

The head is just rebuilt to stock specs, so im going to be buying a new cam, what else would you recomend? should i use aftermarket valves, valve springs? anything? or just the cam?

My goal is at least 250hp with a decent curve, 300 would be killer though.

Yea thats whats what im planning to do with the intercooler, something thats going to fit in the lower part of the bumper, then cutout that black mesh type thing in there and mount the intercooler down there, i dont think it will take away TOO much air in the radiator.

[racerx]

P&P that head if you're gonna do anything, and get titanium anything that you can for the valve train.

rods would be good too, but not necessary under 250hp. but at 300, i'd start gettin worried.

anyway, doesn't the wastegate control the speed of the turbo? like, if you're hitting max boost at 2500rpm (like some crazy ass built dsm's), it's the wastegate that keeps that turbo from producing more pressure, correct?
this is also why an external wastegate gives you so much extra power, since it's letting the excess exhaust gases directly into the atmosphere, instead of creating more traffic in the exhaust.

at least that's what i thought...

i'm new to the turbo stuff myself too. or at least the technical parts of it.
what exactly does "heat soaking" mean, btw? i asked a friend and he gave me some rediculous BS answer cuz obviously he didn't know either...

[smufguy]

for 250hp you can get away with stock valves and retainers, but you defenitely need to change the valve springs and you can get the intake valves replaced with the exhaust valves (stock ones). One of the european members started this trend you could say and it seems like a very easy option to get the head to flow good. all you need is just some forged pistons, balanced and stress relieved stock rods and you can cryo treat them (even some good places charge like 200 bux for all 4 rods) and a balanced crank. Just these mods to the motor will give you a peace of mind. Buying a rebuilt motor from a user is highly unadvised just for the sole reason that you do not know what and how it was rebuilt. Unless you get a warrenty or gurantee on it, dont jump in.

external wastegates or internal wastegates, they all do the same thing. the problem with internal wastegate is that they induce what is called a 'boost creep'. This is a street slang often used to define a sudden boost peak with aftermarket boost controllers. External wastegate does not exit the exhaust gases into the atmosphere the so called 'external dump' is what discharges the exhaust gas directly into the air and helps to spool up the turbo even faster.

When there is more vaccuum, the wastegate is closed, when there is less vaccum the wastegate is open. There is more vacuum at WOT and low engine speed, there is less vaccum at wot and high engine speed.

Heat soaking means, heat absorption. when the intake pipe is said to be heat soaked, it means that it is exposed too much to the engine bay heat, that it starts to absorb the heat and hence raising the air temperature inside it. The cooler the intake charge air, the better the fuel mixture and combustion and hence more power.

[halxi]

i definatly trust buying a motor from racer, well its not directly him, but one of his friends that used to have an accord. I dont think hed BS me on anything that has/hasnt been done to that motor for the soul fact that it wouldnt be all that hard to find out for myself what has/hasnt been done. But thats beside the point lol

Do you have any tips on where i could find aftermarket springs for these cars? Since you say i can put th exhaust spring on the intake side, that would mean i only need to find aftermarket springs for the exhaust valves correct? I looked at the thread he posted and there wasnt any info on the piston compression, but ive read around the site that 9:1 is the best compression for boost. To achieve this id only need to buy 9:1 forged pistons right? Last n00b question, what exactly is Cryo? ive heard that term before, but ive never understood what it is, heat protection or?

[smufguy]

no not the springs, i meant the intake valves being replaced with two of the exhaust valves. this is because the face of the exhaust valves are larger and hence u will have bigger intake valves to flow more.

Cryo treatment is a shortned term for Cryogenic treatment. Also a similar method is called nitrating. both methods fast/flash freeze a metal yielding in higher strength of a given material. all this does is bring the molecules of the metal close together in the matrix and hence yielding a greater strength given for a square area. its purely strength related, not heat dissipation. For heat dissipation, you can get it ceramic coated and SCAT industries does ceramic coatings for piston tops to acheive higher thermal efficiecny of combustion chamber and limit heat transfer to the rods.

[racerx]

one more question... when the engine was rebuilt, the machinist said he "mag'ed" the rods and crank... i'm not sure what that means... magnesium coated? magnetically charged? magneeto inspected? lol

oh, and the pistons were apparently stock compression, and with the head mill and block decking, i've confirmed a 0.2 compression increase, so the pistons are the same, but the compression has been bumped up a little. I'm told that the stock A20A3 compression ratio was 9.3:1, but that seems a little high... and i don't know if A20A1 and A20A3 had the same compression... does anyone know?

[smufguy]

the A20A1 had 9.1 and A3 had 9.3 compression ratio stock. and with this rebuilt block of a 9.3:1 compression ratio, you should be okay running around 6 to 8psi of boost without any problem. the machinist said it was maged? i would have thought magnesium coated, but why would he do that? i am not sure and never have i heard that term before.

[racerx]

nor have i, but then i saw something in a magazine about engine treatments, and there was this big word that started with "mag" and I think he might have meant that...
i know he took all the rods and had them balanced and checked for any imperfections or bends, and then they were specifically matched up to a particular journal...

[racerx]

okay i googled the term and got a lot of results of people saying
"maged and shot peened" and i remember him saying exactly that.
he did it to the rods, block and also the crank i believe...
still don't know what that means...

[smufguy]

i dont know if shot peened and stress relieved are the same terms, but in one of my posts in this thread i mentiond it. Why dont you ask the machinest how much boost one can safely run on this motor?

[halxi]

Yea, that would probably be helpfull.

So smufguy, if i put exhaust valves on the intake side, will i need to port out the intake side to allow them to fit, or will they fit without porting?

Also, would it be wise to get a regrind cam from someone? Who would you recomend buying one from?

[ABC]

Maybe he meant magnafluxed? This is a process where they check for cracks near/at the surface that are not visible with the naked eye. Just call up your machinist and ask.

[racerx]

ok he meant magnafluxed, as pointed out above.
here's a little info i got on it:

"You've heard the term Magnafluxed. To most, it means taking a part and checking it for cracks. Typically, the teardown guy brings a part to the "Mag" unit, wets it down with solution, presses the button a couple of times, then shines the black light on the part, checking it for cracks. The process seems simple enough, but there is much more to inspection than most racers realize.

Magnaflux is actually the name of the company that began building magnetic particle inspection (MPI) equipment in the '30s, and is still the leading manufacturer of the equipment."


and he shot peened the rods. here's a litte more info on that too:
"Today, Shot Peening involves bombarding a material with small spherical media called shot. Each piece of shot is the modern day version of the hammer/ stone used in the past. As the Shot Peening is performed, the atoms on the surface of the metal become crowded and try to restore the metal's original shape by pushing outward. This pulls, towards the surface, the atoms in the deeper layers, which resist the outward pull, thereby creating internal tensile stress that keeps the part in equilibrium with the compressive stress on the surface. The tensile stresses, resulting from Shot Peening, deep in the part are not as problematic as tensile stresses on the surface because cracks are less likely to start on the interior.

Shot Peening increases resistance to
……fatigue failure
…corrosion fatigue
…hydrogen assisted cracking
…cavitation erosion
…stress corrosion cracking
…galling
…fretting

Shot Peening Helps with
……surface texturing
…intergranular corrosion resistance
…closing of porosity
…testing of bond coatings
…work hardening
…increased strength
…increased durability"

Well, there you have it. i guess a little more was done to this engine than we had hoped! which would explain the insanely high price he was originally going to charge.

[smufguy]

Yea, that would probably be helpfull.

So smufguy, if i put exhaust valves on the intake side, will i need to port out the intake side to allow them to fit, or will they fit without porting?

Also, would it be wise to get a regrind cam from someone? Who would you recomend buying one from?

its part of the head work. when the head is being worked on, just tell the machinest that you want the exhaust valves in place of ur intake valves so when he switches them, he will cut new seats and stuff and make he valve fit right.

Cams, well we do not have off the shelf cams, you have to tell the machinist who works on the head how much power u want and he will put the head on the flow bench and tell u how much u need it to flow to make it produce the power u want. then get that number, lift, duration and such, call up delta or colt cams, and tell them u want ur cam reground to this specs. and they will do it, also let them know the specs of your motor and the compression you have with the info that ur head is being worked on.