Boost Issues

[90S13dude]

Hi all,
Here's the deal. I have had my Redtop installed since February. It has been running fine until a few weeks ago when it decided to start being stupid. When I first got the car running we installed the HKS SSQV and a Hallman MBC and was boosting about 12 psi with no problems. But now when I am in first gear I can't get any boost, when I go to second I get about 5 psi, and then third through fifth I get 10 psi. I have tried everything and am now lost. I have taken the turbo off and had it checked, and replaced the Manifold Gasket with a copper one. Any help is greatly appreciated.
Chris

[s13gold]

stock turbo im assuming???

[90S13dude]

yes sir it is.

[G-spec]

could be a problem with that MBC but i doubt it....sounds to me like your turbos on its way out. (edit--missed the part about having the turbo checked)

[skylindrftr]

This may sound quite obvious, but have you had a boost leak check?

[90S13dude]

No, but I guess I need to. I have done what I can at home. I held the idle at a higher rev of about 3k the other day and noticed some leaks, but its kinda hard to do it that way. I will take it to the shop this weekend and have the test done.
Chris

[G-spec]

^turbos dont make boost free reving at a steady rpm....at least not that i've ever seen...anyone say yay or nay on this?!

Not a bad idea to make a boost leak checker to help diagnose future issues...they're not hard to make and come in really handy.

[90S13dude]

No, I realize that. but the pressure in the IC piping does build at higher rpm's. Anyone know of a DIY on this boost leak checker?
Chris

[mRclARK1]

^^^Valve stem, some ABS plastic plumbing parts from home depot, a rubber or silicone coupler and a couple hose clamps and you're good to go.

[benefitx]

yes

http://www.vfaq.com/mods/ICtester.html

damn no1 gives me props for all the searching i do

[i need tires]

what is your vaccum looking at?

should run between 17 and 20psi... if less check for boost leak

[mRclARK1]

what is your vaccum looking at?

should run between 17 and 20psi... if less check for boost leak

I think you mean 17-20 Hg? 17-20 PSI would be almost 40Hg... that's a high vacuum reading.

[skylindrftr]

you could also plug a tire valve into a vaccum line, put it at tdc, cap off inlet to turbo and put pressure into the system, that's how i found out my compressor housing was leaking =(

[90S13dude]

It is about 19 hg.

[i need tires]

It is about 19 hg.

sorry i did mean HG.. but yea 19 HG is perfect... Mmm weird.. sounds like turbo is going down hill man...

[90S13dude]

I had it checked out and was told that it was fine??? It has minimal shaft play. I also removed my MBC today to check if it was that. Running straight to the wastegate I was running less than 5 psi max and the car seemed like it was bogging down horribly and dying on me.
Chrs

[GSXRJJordan]

I agree that it sounds like your turbo or MBC is going south, but if you pulled the MBC and the turbo's fine, it's probably a leak. They'll make the car run like shit... that's for sure. Also, check your MAF/CAS/TPS plugs/wiring, just to be sure that it's all got a solid connection (if the ECU's gettin bad or intermittent signals, it'll mess up the timing, and that'll screw up your boost too).

[90S13dude]

Im going to try the boost leak thing, but why would it run worse when I unhooked the MBC?
Chris

[skylindrftr]

You should actually be running at about 7 psi....unless you switched the stock wastegate spring for some reason...

[DJ_Sunrise]

Buy 4 ply couplings and T-bolt clamps. Install them, and then check if you have the same problem. You should not run anything less. 4Ply and T-Bolt will really save you from a ton of hassle..

-Bart

[steve shadows]

Hi all,
Here's the deal. I have had my Redtop installed since February. It has been running fine until a few weeks ago when it decided to start being stupid. When I first got the car running we installed the HKS SSQV and a Hallman MBC and was boosting about 12 psi with no problems. But now when I am in first gear I can't get any boost, when I go to second I get about 5 psi, and then third through fifth I get 10 psi. I have tried everything and am now lost. I have taken the turbo off and had it checked, and replaced the Manifold Gasket with a copper one. Any help is greatly appreciated.
Chris

the problem is probably your shitty boost controller + old internal wg.

Get a fresh HKS style wg actuator with adjustable arm if you want to raise boost and have it consistant as possible, then later on if you want tog over 12 psi you can get an AVCR or other electronic unit.

[90S13dude]

Ok, so we unhooked the wastegate just to see how it boosts without a controller or wastegate and it boosted 10 pounds in first gear and then went up to 15 pounds. Does that sound right??? If so I guess it will be my wastegate???