PROJECT , TURBO ( SITE )

[Civvy]

Just a thought on the ignition side...as a cheap ass mod, maybe this would work but, it would annoy the r+r tuner!..if it worked!! If i could reverse the role of the vacume advance diapragm and have it push instead of pull...taking it apart and somehow putting the spring under the valve causing it to result push rather than pull! and using the boost guage line to push the diapragm and retard the timing under boost!! Also, then i could control the amount of retard by having an inline tap..which could then have a additional under hood pressure guage to show how much pressure is coming thru the tap, if ness'ry!! What do u think could it work? maybe i'm overthinking this and my worlds too ideal!!?

[A20A1]

No you're not over thinking... I was looking at a simmilar design.

2 possible spring placements ( in or out )... all you'd have to do is rig up the supports to hold the diaphram and mess with the spring tension.

The spring wont rest on internal moving parts nor interfere with them... this simply shows you the general location of the spring within the distributor if one will fit.

I can wled up a longer support rod... I've had to modify diaphragms before to work between hitatchi and Tec distributors.

[Civvy]

uve sussed it man! but if we used the inline air tap to adjust the pushing airflow to the diaphragm, it would save us worrying about spring tension?? what d'ya think?

[A20A1]

I was thinking if the shaft is long enough you can add on a Drill Stop that they use on drill bits as a way to make fine adjustments to the chosen spring rate... it's a lot easier then adding say a few washers... plus it can act as a stopper if the diaphragm used is one that has more travel then you actually need.

[A20A1]

air tap or do you mean restirctor? I dunno if you can give me an example that will be good.

[Civvy]

I like it! What about a knock sensor(as a/if ncc'ry safeguard?) do u know how they're wired? if we could install one and have a light/l.e.d come on ...maybe under the bonnet for tune up? ..The only thing i'm not sure about is when is it going to need that specific particular degree of timing...if u know what i mean? ...i.e. if boost opens the diaphragm fully to the max retarded position will it be too far to early or for that rpm? kind of thing? ...thats what made me think of the knock sensor. i know it wont fix it, but mite alarm us of danger!

[Ludi Mali]

you 2 is the craziest peoples. Actually this makes a lot of sense if you could have some kind of variable restrictor for more manageable control.

[Civvy]

Yes, a restrictor. Like a fuel tap! u can adjust the flow.

[2ndgenludedude1986]

ok you lost me, i was justing thinking aobut throing a turbo on the motor with custom piping and calling it a day!

[Civvy]

been doing some more thinking. Hopefully, what will happen is as boost increases, this will cause (via fine adjustment using the air tap/spring tension) more pressure to the diahragm thus, retarding the ignition according to boost pressure = plan worked!
Problem. what if we havent got enough boost pressure to feed the diaphram?
Answer. we can plum in another pipe using a larger diameter.
Conlsn. If the original plan worked with the first pipe using the air tap to adjust pressure on the diaphram/timing. We can learn from the amount of flow needed to make a excact size pipe to flow the correct pressure to the diaphram. ...Making the job look pro!
I guess the knock sensor isn't that important but, it would tell us if we were too advanced and then perhaps give us a starting point to setting the timing from...maybe usefull!! O.K. i'm on a fine line of confusing my own shit! i'm going to bed! I guess since uve all logged off now i'm talking to my self anyways!?? ....Hello?

[Ludi Mali]

yeah, but if there was some way to automatically adjust it based on rpm's, you could tune the amount of retard at a given point.

[Civvy]

I cannot believe uve kept up!!!
That would happen automatically! ..i think?

As stock, the vacume advance diaphram must operate in accordance to vacume pressure from the manifold (which i think? increases with rpm and load) to advance the timing for full power. More manifold vac = More adv. timing ..Definatly not sure about that one as vacum guages say poor when u got ure foot down?

So as we've now reversed that, i guess the Turbo will be generating full boost at higher rpm and load, and also because the throttle is opening further as the driver is compensating/feeling the load? ...full boost = max retarded timing

but, ive just had a thought! The engine can be reved up to high rpms without the use of the boost = meaning the ignition would not retard!!! but....it dosent need to retard then BECAUSE theres no boost to cause damage!

I'm working on a DIY ignition (c tech forum) which is Crank fired...maybe the answer? but its distributorless! up to now i havent seen how/if it can be retarded mechanically/at all, It mite be clever and be able to retard electronically. like our dizzy's! ...Think its time for more research!

[Ludi Mali]

one other thing i was thinking of for fuel enrichment, instead of putting an injector in the manifold. What if you put it in the uppipe somewhere. like right before the carb, almost in a position where you'd put water/methanol injection. Might be easier to fab it there.

[Civvy]

or u could use the needle drop type carb (i.e, S.U.). There's no change over point and u wouldn't need extra fuel systems, just correct jetting. The MG Maestro i mentioned earlier was also a 2.0L 16v so it gives us a good base to work from!

[A20A1]

well a knock sensor could open the restrictor and then that would overcome the srping more and increase boost retard... problem is finding an electric restrictor valve...

Would it need to bleed the excess boost back into the intake I'd guess thru a one way valve? I may be thinking of it wrong...



*****

I wanted to know the effects of running something simmilar to a wastegate off of vacuum, like a secondary one that would operate off of vacuum created when the throttle is closed... So you can dump as much gas as you could to prevent the trubo from building up vacuum and sucking up oil... even to go as to say have the pipe from that wastegate exit into the down pipe in a way that would slow the turbo turbine...

I'm only saying this as a measure to save the turbo... and this will only be activated with high vacuum... normal cruizing should not open the valve.

I'd just rather not rely soley on the carbon seal...


I was reading and I found out that I need a larger wastegate when going for low psi levles.

[A20A1]

Oh shizzle... what about a vacuum operated exhaust brake? Would that slow the turbo down without killing it... I just want to decrease the occurance of a high vaccum situation.

Have the brake come on and add resistance to the turbo... slowing it down but bleeding pressure thru some smaller exhaust port... this in turn would slow the turbo down and relieve lessen the vacuum pressure?

I wish we could just bleed the damn vacuum but that would be like opening up the throttle again but without any fuel to go with it.

I have 3 spicy chicken Taco Bell burritos in my lap waiting to be munched on... brb

[A20A1]

Methanol isn't as easy to come by as alcohol...


BTW I was reading "HOT VW's" Magazine and saw a few dune buggies with carbs and turbo... one was blow thru and one was draw thru... both had DCOEs I believe. I wish they'd offer up more in depth info.

[maka_RTH]

I have 3 spicy chicken Taco Bell burritos in my lap waiting to be munched on... brb

dude, why'd you say that? i just got a huge freaking craving for taco bell now, and it's 2:30 in the morning here! i need to go to bed, lol. anyways, you guys are crazy. if you're not too worried about budget, you could just always go with an aftermarket igntion that would automatically control everything. like retarding the timing and whatnot. possibly get the 4g dist. if you need to. otherwise, sounds like you guys are coming up with some awesome stuff. can't wait to see the finished setup. i suppose in a way we're going against the flow. turboed carbs for you guys, and N/A FI for me. lol, good luck!

[A20A1]

Well I'm not going turbo just yet... just getting the ideas on the table. Basicly though I want to be able to use existing parts and mods and run the setup with as little electronic controlls as possible to reduce the cost, but also have it duplicatable for others to make simmilar modifications.

LOL your sig says blown engine, I almost thought you were turbo but then I remembered the hole in the block thread.


Here is my thread on HT A20's Turbo Question to the HT Guru's

It will be interesting to see what kind of replies I get if any.


urr, is it a surge valve or isn't it... I hope that will limit the high vacuum or is the surge valve another name for blow-off valve.

[Ludi Mali]

i think surge valve is another name for blow-off valve, lets the extra pressure escape.
I was watching trucks today and they were upgrading the turbo on a what i think was a ford diesel. and it had this little vacuum actuated actuator that held the wastegate closed longer for more power. There has to be something you can do with that so it will work opposite.

[Civvy]

Going back to carbs, i was planning on using twin 45's but i've been heard rumours 40's might be better because of choke size! Was wondering if i could fit chokes similar to the 40's into my 45's?

[A20A1]

http://www.mooreparts.com/Merchant2/...ry_Code=WEBVEN

[Civvy]

Thats for IDF's? I'll be using DCOE's! guess i was asking if u'd heard/read of this in practice?

[A20A1]

OOp's I didn't read what they were for... sorry.

What do you think about my EGR idea in the other thread?

[Civvy]

I think I hope it works!
The draw-thru route is getting a little too complicated for me tbh!
I'll chip in my help as oftern as i can. but, i've never had any experience wit that setup!
It all sounds good tho i have to say, just copy from the oldskool finds out there!!
Good luck.