3 Turbos

If I clamp off the hose from the intercooler pipe that goes into the throttle body and the input side of the diverter valve, I can get any boost I want. I wonder if reversing the valve would help? Evo recommends installing their valve in the stock orientation. Which is the way it is installed now.

I thought my stock diverter valve was bad, so I bought a EVO aluminum billet diverter valve. This valve didn't fix the problem. Do I need two diverter valves in tandom or is there something else wrong or leak somewhere.

Other than that the car runs perfect, no stumbles, flat spots or any other driveability problems, I just can't get boost unless I clamp off the hose as stated above.

One exception is, if I increase the throttle easly rather than "stomp" on it, the boost "can" go past 15lbs to 17lbs, 1lb less than what I'm trying to reach.

Other side note, it "use to go to the 18lbs boost" I am trying to reach with the stock diverter valve. Now it doesn't unless I squeeze off the hose. What went wrong?

FYI, what I have if this helps;

Guru chips
3.0" Test pipe
"O-ring" block
Widefire Ring Headgasket
SFR MAF Level 1 (with K&N filter)
Garret Turbo Level 1 (water/oil cooled)
Tial 46mm Wastegate
ARC2 - piggy back computer
ARM1 Split Second air/fuel indicator
Greddy Profec B adjustable boost controller
VDO Mechanical Boost gauge
Billet adjustable fuel pressure regulator
Stainless steel braided fuel lines
SFR 2.25" Intercooler Pipes

TIA! Steve

Danno

Hmmm, in the stock configuration, the spring AND boost is used in parallel with each other to hold the valve closed. If you reverse the connections, boost will fight the spring prematurely and you'll most likely will lose boost.

Sounds like your bypass valve is opening prematurely somehow. Is the control line hooked into a T that comes from the intake-manifold? This actually uses boost to hold the valve closed. If you have vacuum leaks, then you'll get atmospheric pressure in the diaphragm instead of boost; thus less pressure to hold the valve closed.

Very, very strange that low boost would be caused by a bypass-valve, which should ONLY operate under vacuum/closed-throttle conditions. Unless it's a stock one with a ripped diaphragm. Or unless you have it vented to atmosphere, in which case, you definitely want to install a stiffer spring. This will delay venting action and cause less-than-optimal venting, thus not preserving turbo-spooling as much, but you won't waste boost by having it open at partial-throttle conditions such as driving down the freeway.

What spring do you have in the Tial? You should have minimum 1-bar spring in there. Test that by plumbing the banjo-bolt line directly to the side-port on the Tial.

3 Turbos

Danno,

My Tial 46mm has a .8bar spring.

When I had my Autothority chips ver2.5 in - that was the only time I could hit 18lbs with a stock diverter valve - all else being the same. It did still fall off at redline though, but only by 1 or 2lbs max.

I think it was after installing your chips is when the problem happened. This was kind of a mixed blessing. Your chips makes my car feel less powerful seat of pants - probably because it is smoother and no lag, and the dyno shows more horsepower.

The Autothority chips felt faster, but had a some lag and a hiccup at around 4000rpm driveabilty problem, not bad, but not as smooth as yours and slighly less horsepower.

I also had you reburn some chips per my dyno sheets I sent you. I just rec'd them last Saturday. I sent you an email asking what I should reset my ARC2 at before I bring to dyno. Should it be set to all zeros? BTW, I have not installed them yet. I'm trying to get this boost thing fixed.

All my vacum hoses have been replaced. I barely put a 1000 miles on since all my modifications. Runs good but can't get boost, except via the "clamping" of the said hose.

I'm stumped! I didn't do the installs, my mechanic did. I basically watched what he did and he was VERY METHODICAL DURING THE INSTALL and I had everything that even looked old replaced. But we all make mistakes and IT IS a 17 year old car. But it is a VERY WELL taken care of car.

See: http://www.p-caronline.com/directory/3_turbos

Thanks! Steve

3 Turbos

BTW to answer your questions;

1) Is the control line hooked into a T that comes from the intake-manifold?
(I'll ask my mechanic tomorrow)

2) Unless it's a stock one with a ripped diaphragm
(it is a EVO billet aluminum valve - just installed - made no difference over the stock valve)

3) Or unless you have it vented to atmosphere
(no, it is installed exactly like the stock and in the stock orientation and not vented to the atmosphere)

3 Turbos

Just looked at my engine compartment in;
http://www.p-caronline.com/directory/3_turbos/

My picture of the engine compartment - I had the stock diverter valve reversed - that is not how it is installed.

I had not updated my pictures. Just in cased you noticed.