matt566

have a 87 gxl with turbo 2 swap and runs awesome well went out racin one night (destroyd everyone with the fc) but now it wont hold boost and it jumps. before it would hit 7 and stay like a champ. now itll boot to 7 or just continually(10-11 lbs) boost and when i let off of it drop to like 25 or 30 vac when before itd just hit 20ish
i was thinkin boost/vaccum leak

but reading through the posts i see boost creep and want to know if that what it was and if i needed to just port my wastegate.

or if my turbos going out. when i grab the compressor wheel it does have play in/out left/right.

t2 swap from japan.
other than that car runs amazingly did switch to electric fan(16') and temp raises alittle (at 135-145mph) or if its really hot outside dont have shroud or cooling plate will those help?

phoenix7

boost creep is when your wastegate cannot expell the air fast enough and it builds up so you are boosting MORE that what the car is set for. On an open exhaust with a stock wastegate I saw my boost jump up to 15psi. instead of the 12 I had the boost controller set at. The problem with this is that your fuel is not set up for this boost and you could kill your motor.

The undebelly tray is a MUST.

If you continue doing what you're doing you're going to kill your car or yourself.

matt566

since the boost creep i havnt driven it much just trying to figure it out so all i need to do is

A.
make the wastegate hole bigger like in the diagrams ive seen
get a fuel mgt./piggy back system

B.
upgrade aftermarket turbo / add external wastegate
get a fuel mgt/piggy back system

matt566

oh and i do have the 3" complete racing beat exhaust (but it was on it the whole time and boost creep JUST started like 2 weeks ago been running the car for 4-5 months regularly) (dont get on it much)

CyberPitz

I don't know if you have cats, but...clogged?

phoenix7

port the wastegate OR check out the BNR turbos. You get tokeep your RB DP and it's got a ported WG.

matt566

i know i must sound like a dush and youve answered this question like 7 billion times but thanks i learn new things about that car every day

phoenix7

not really, It's not a stupid noobish question when you want to know WHAT it IS. I only get mad when they ask HOW to do something without actually ever searching.

You could have searched but i don't think the posts would have explained what boost creep IS, they would tell you what to do about it but you kinda need to know what it is before you can fix it.

RETed

http://fc3spro.com/TECH/FAQ/bcreep.html


-Ted

dial8

iTrader: (4)

^

phoenix7

this is one of the reasons FC3S pro is bookmarked. Thanks man.

CyberPitz

Ahh, that was a really good write up on Boost creep. I'm learning!

JyRO

iTrader: (3)

Just thought I'd throw in my $0.02 worth. Check out the signature.