schnellfahrer

Here's the deal:

New turbo, new exhaust 3" w/o cat, MAF, all new vacuum lines, venturi delete, Guru modified wastegate, Accuboost, Lindsey CBV.
Starts to build boost slightly over 2000rpm but will not hit 15psi untill almost 5000rpm in 3rd gear.
Car boosted 18psi@3200rpm prior to turbo/exhaust install.

Vacuum at start up (cold 50°) ~8hg , after 2 minutes ~14hg, warm 18hg.


Where do I start?

mroberts

One thing to try is to drive for a little while at low throttle, make sure you never hit boost, and see if the wastegate dump pipe gets warm. If it does, it means your WG is opening too early.

testarossa_td

I am sure someone here has the answer.
Here is a temporary distraction.

I will delete these at the end of the day.

hosrom_951

Av GURU LOL



Eivind: Did you double check the vacuum lines/hoses? did you check the exhaust system for cracks when re-installing the x-over pipe? You definately "did something" upon installing the Vitesse Stage 2 (since it was doing fine before that). Follow "youre footsteps" on what did.

PS: 8hg on cold is very low, it should read anything from 13Hg-15Hg when cold (once started).........that could be a vacuum issue?

schnellfahrer

A mech did the install for me. I only visually inspected the exhaust when changing the starter a couple of weeks back, but everything looked OK.
If there's a intake leak it's got to be huge to cause such slow boost.

As for the low vacuum; this is only when it's cold outside (high 40's) and it only lasts a couple of minutes, but I agree it's low.

I guess I need to pressurize the intake and look for leaks. I guess the next step would be to pressurize the exhaust.
Any tips on how to?

Ian Carr

Sounds like a vacuum leak. Even on a cold day when my car idles rough i am getting 11hg of vacuum. Also i thought using the reliaboost with a dual port wastegate wouldn't work properly? That could be a problem.

schnellfahrer

I just replaced all the vacuum lines including removing the venturi system. I will go over all of them again.

The wg is singleport.

(Typo in original post. I'm using an Accuboost now).

Ian Carr

o opps sorry i thought it said reliaboost not accuboost. But still its only a single port so it doesnt matter.

The wastegate might be the problem though, i heard that the guru modified ones dont hold so great so that could be one reason.

schnellfahrer

I did say reliaboost but edited it.
The wastegate would hold 18psi easily with the old turbo.

schnellfahrer

I'm testing the intake for leaks right now. I've connected my tire compressor to the intercooler pipe right after the turbo.

Should I open the throttle?

I found a small leak right after the intercooler. Not nearly big enough to cause such slow boost.

Ian Carr

DUDE, Switch your by-pass valve. I had a problem holding boost before but i switched it back to the way the stock one was and its louder and holds boost much better. Let us know what happends after you do that

Black Arrow

Eivind, dont remember if you tried it or not, but you could plug it from the IC, and see if that helps on the spool up! I`ve already made a plugged hose you can plug it with! I tried to push down the sylinder in the "LR" bypassvalve, and it`s very easy to push down. Even with the shims.

schnellfahrer

Cured a small leak and vacuum is up from 8hg at cold idle to 14hg. Warm idle is up to almost 19hg.
There is a small leak from the throttlebody. It's coming from the right side of the TB, in vicinity of the spring. There is also a leak through the screw on the top of the TB. Comments?

Thomas; you mean run without the CBV? I'm afraid of damaging the turbo.

schnellfahrer

Well I'm boosting a bit quicker after fixing a couple of small vacuum leaks.
Still not very quick, though. I guess the next step is to try a different cbv.
Can I run without the CBV without damaging anything? Just for testing purposes.

Ian Carr

Eivind, im serious switch the two ports on your by-pass valve you and you see boost sooner and hold it longer