boost creep issues

[red240ne]

Here is my setup...

T3/T04E 57 trimIAP manifoldTial 38mm WG(6 psi spring, open dump)I am getting my wastegate signal from about 8" away from the throttle body.

Ok, yesterday I was driving around and did a 3rd gear run. I hit 6psi around 2600rpms, and it was pretty solid, but then around 4000, the boost decided to creep up to around 11 psi. 11psi kind of scared me though, because I'm on stock fuel, besides the Walbro pump, LOL.

I am thinking that it may be my wastegate signal. It's probably too far away from the compressor. I just wanted some other input from you guys though..

curt

[ftrs13]

first of all, get some new fuel management ... that is really scary.

its probably that your wastegate signal is too far away.(I was thinking the opposite, spike and then drop, never mind me.)

[daniel240]

that shouldnt matter all. as long as there are no air leaks in the line, or where i connects on the ic pipe or wastegate. i have my wastegate signal from close to the TB. do you have a boost controller, or anything else running off your wastegate signal hose? check to make sure there are no leaks in the line.

[red240ne]

Yea, about the fuel management, LOL. I'm throwin a 10:1 FMU on there today or tomorrow. I don't really care about this engine anyways. I can get junkyard engines around here for 50 bucks..

No, I don't have the line T-ed off or anything. It's running by itself, and is a brand new vacuum line. I also know it's a 6psi spring because I put it in myself..

curt

[ftrs13]

its till a pain to swap.

[red240ne]

still creepin...

usually it holds boost strong at 6 psi.

But yesterday I hit 10 psi again in 3rd gear. I'm pretty much clueless now as to what it is.

curt

[C-Kwik]

what's the diameter of your dump tube? Is is straight or with any bends? If there are bends what are the radii of the bends?

If all else seems okay, it might be that you installed something in the wastegate wrong when you put the 6 psi spring in. Just throwin out possibilities.

[daniel240]

yea, any restrictions at all in the dump tube can cause boost creep. i had i small lawnmower muffler on mine, and it creeped up to 14psi. After i knocked out the inside of the muffer, so it was basically straight through flow, it still creeped up to about 8 or 9psi w/ my 5psi spring.

[red240ne]

I'm running open dump.

I guess I could take the wastegate apart again, and see if there are any problems..

curt

[C-Kwik]

You mean you are running no dump tube at all? Even if Divorced?

[red240ne]

You mean you are running no dump tube at all?

no, that's bad? does that valve need to seat?

[quote=" C-Kwik

Even if divorced?[/quote]what does that mean?

curt

[C-Kwik]

no, just trying to get a clear picture of your set-up. The valve seats against the body of the wastegate. Or at least it should.

Divorced is simply a term used to describe an open dump wastegate.

You have any photos?

[Ubernoober]

A post in this forum about getting a new IAP manifold mentions that there was a lot of weld material still in the wastegate port/runner. You may want to see if that is causing a restriction to wastegate flow.

Divorced: External wastegate with dump seperate from normal exaust piping.

Semi-divorced: External wastegate that eventually breathes through the normal exaust piping (either before or after the cat/muffler).

[red240ne]

Yea, maybe I should try the dremel to the wastegate runner idea..

curt

[:: orion ::]

Maybe it's just the design of the manifold...isn't this the second guy with boost creep issues with an IAP mani???

- Brian