mi87lano

So I am new to the 5 cylinder 20v turbo engine and I had a question...bear with me here as I explain:

I have a 93 S4 that is chipped - the previous owner states the car has an MRC stage 1 chip with a 2.9 bar tranducer...When I bought the car he said its around 280hp with 330 torque. Car has stock turbo, stock EM, headers and exhaust. Engine is also stock. The car is boosting between 17 and 23psi (if weather is hot it boosts 23 if cold below 20psi) A friend of mine who owns an UrS6 told me I should put a 1.9 bar spring in the wastegate to make the car even faster....So I got one from 034 motorsports and installed it. The car was boosting 25 to 27psi... And I started thinking thats too much for a stock turbo and stock motor, so I ended up taking it off.

My question is on my current stock and chipped setup is there any danger of runing the 1.9bar spring in the wastegate and boosting so much???? I am planning to build the motor and virtually the whole car in the future but dont have the funds yet....so simply put...

Can this $45 1.9 bar spring eventually lead to bigger problems if used with current set up???

thanks
-Emil

UrS4boy

you had the 1.9 bar spring adjustment screwed down to far because the ECU should have be able continue to limit your boost to 23 psi as before. The benefit of the 1.9 bar spring is to get up to full boost faster, without any concerns about wastegate creep.

My car has most of the RS2 upgrades (MAF, turbo, injectors, FMIC, exhaust manifold, etc) and I have 1.9 bar WG spring. I keep the adjustment screw turned ALL the way UP.

If your WG cap is still a virgin (plug on top is still there), you might want to consider removing the plug and adjusting the spring perch UP a bit.

Also you might want to unplug your waste gate frequency valve for a boost test to see how much boost the spring is supplying alone.

Instructions to adjust the spring perch are in the link below:<ul><li><a href="https://forums.audiworld.com/s4s6/msgs/149838.phtml">Click HERE</a></li></ul>

kinderutz

I tried the 1.9 bar myself(still have it somewhere in the trunk), it's better off boost(somehow less lag)but bucks and jerks on WOT as it spikes over 25 then cuts off to 20 then 25 again and so on, fuel cuts off....not good
I'm running MTM 1+ 3bar V-Map and it spikes at 25PSI but holds 22PSI only(no needle fluctuation)
Make sure your boost gaude isn't some knock off misscalibrated gauge.
Do you have a FMIC? that might help however i don't think the stock fuel system can suply enough to feed the 27PSI of boost
my 2 cents

WVUrS6

There shouldn't be any threads showing on the cap. I have a MRC stage 2 chip. 3.0 Bar VMAP, and run the 1.9 Bar wastegate spring. At WOT it does boost too high IMO but I can modulate it with my foot and the benefit of earlier and better torque outweighs the disadvantages.

But it is absolutely necessary to have that wastegate screw backed all the way out. You can experiment with the last thread but any more than one thread and it does not behave well.

UR-maninblack

or at least it seemed it did. maybe I have a torn WG diaphragm?

UrS4boy

Not limp mode, just WasteGate mechanical boost, e.g. about 6 psi on stock spring.

UR-maninblack

ok... thats pretty much what I was seeing. I gues no CEL=no limp mode?

mi87lano

will do that tonight and give you all an update

-Emil

Sloooo4esT

I had 4 turns on the 1.9 spring with no hesitation

WVUrS6

It all depends on the tune, in my case Mihnea chips with stock K24.