Wargasm

Hey guys,

I've got a T04S single on my 93 with an HKS Racing model wastegate with a yellow spring which should be 10 PSI.

When I get on the gas, the boost gauge goes up to around 11 PSI or so and then when the porting on the motor gets in the sweet spot around 5K, it climbs another few pounds up to around 14-15 PSI. This is with a Profec B boost controller, but it does the same thing with the boost controller turned OFF or ON but turned all the way down.

What's up with that? I'm going to completely remove the boost controller to see if that fixes it, but any other ideas? I run an open exhaust and a wastegate vented to atmosphere with a dump pipe so backpressure on the wastegate is not the issue

Brian

twokrx7

iTrader: (1)

I'd suggest a few things.

Check for leaks.

Make sure your lines are short and pressure taps/hose are large enough to flow enough boost, your wg will leak internally and bleed off pressure.

Pull the dump tube off the wg and hook up a hand pump and press gage to the wg lower tap (if you use your existing lines you can pressure check them, if they are leaking you have just found your problem). Pressure test the wg and make sure it is going open around 6-7 psi and full open by 10-11 (typical for 10psi spring). If you pull the wg off the car you can manually compress the spring to get an idea of what full open is. This wg is huge so you should not be creeping that much.

Check your ignition, excess retard or misfire may run the boost up.

Good luck.

AJC13B

Check the WG dump pipes are big enough. I had the same problem and so did a mate, overboost. Re did the WG pipes and made them bigger and all was well

1FooknTiteFD

try looking at your wastegate hose for leaks. If your wastegate hose isn't silicone but rubber, it can harden and brittle (since it's near the manifold and turbo). If this hose breaks, or leaks, your boost is likely to creep

Wargasm

OK those are all good ideas and I'll be checking on them ASAP.

The only one that I'm pretty sure isn't the problem is the dump tube. It's about 1 3/4 inches or 2 inches in diameter and isn't long or crimped up.

One thing I'm interested in is the spring. That thing is DAMN hard to compress. When I installed the top of the wastegate, I could barely squash it down on there! I was pushing on it so hard that my body was actually sliding across the garage floor! I had to use two vice grips to hold it down while I put the screws in. Is that normal? Is it possible that I have the wrong spring?

Astro

Hmm..im pretty sure the yellow spring is a 0.7 bar one you think it is.
I just bought one for my HKS racing wastegate because it apparently came with one set for much higher with the t04r kit (like 1.3 i think?)
The spring i took out was blue and it was quite a bit tougher to compress than the yellow one (as well as the fact that it had twice as many coils (?) in the same legnth as the yellow.
I also had a hard time putting the spring in, but i think it definetely is a 0.7 bar one.
Check here: http://www.hksusa.com/products/?id=767

Its kinda weird that the blue spring i had in the wastegate initially is not listed on this page however...
Maybe they ran out of grey paint?..haha

1FastT2

iTrader: (1)

I would check the sharpness adjustment on the boost controller first. I had one hell of a time controlling boost before I had that adjustment set correctly. I have no prolbem any more with boost spikes at all. If that doesnt work then you definately have other prolbems.

Wargasm

Hello guys,

I took off my boost line and blew into it with my breath... guess what? I could detect that something was leaking. I could even hear a tiny hiss.

I took a GOOD hard look at every inch of the silicone line and found a section that seemed rigid and hard to the touch. I held that section in my hand and blew into the hose with my mouth... hissing air could be felt escaping around my hand area. A little slight prodding and it split right open all the way.

Of course, this was in the hardest possible place to see hahah.

I am in the process right now of replacing that section of hose with 1/4 inch copper tubing which should provide me with good protection against any more of this nonsense.

Thanks for the advice guys...

DIE SILICONE HOSE! It's great for the vacuum lines but not for a line crossing over a downpipe!

Brian

Wargasm

Ugh I spoke too soon.

The hose was indeed in terrible shape with multiple cracks in it, but replacing the part I could reach from the top of the engine didn't fix the problem... still overboosts.

I removed the boost controller from the picture entirely so it's not that. I guess my next action is to get down under the car and test the wastegate itself with just a short hose on it.

Luckily for me, I have maps and fuel injectors to keep me going up until 17 PSI where the stock MAP sensor will become useless so I'm not blowing up since I'm only overboosting to about 13-15 PSI.

I'll let you guys know when I finally iron this one out.

B

AJC13B

External diameter means very little, internal diameter is the key....