I just had my STS kit put on last weekend. Yesterday as I checked my methanol level I noticed a hose off the passenger side valve cover that goes to some STS solenoid looking doohickey was blown off and oil was all over my firewall and motor. Does anyone know what that part is and perhaps why it did that. Next is that I am getting boost creep. When I floor it from a stop boost builds to 5 at about 3000rpm then as I keep into it the boost creeps up to 7-8. When I activate my boost controller even with it backed all the way out it goes up to 8 then creeps up to 10-11. This is all from a stop. If I am moving down the road at say 50 mph and floor it, it drops to 2nd gear and jumps instantly to 7psi on the low setting and 9psi on the high setting. Suprisingly at the low setting I get no KR. On the high setting I also get no KR when fully floored. However in either setting at part throttle, less than 50% then I get KR of up to 5.5. My question is why is my boost not being held constant.

 

You need to reference the boost off the manifold and not the outlet of the compressor. That should take care of the boost creep issue.

Also the reason why that hose popped off was because it probably wasn't clamped. All those hoses need to be, as they see boost and vac now, not just vac.

 

So you ran a hose all the way back from the engine compartment to the wastegate? Yeah that hose wasn't clamped, I clamped it yesterday. But still that means I have positive pressure in my crankcase. Could that be from blowby?

 

the switch valve (solenoid dohickey) is there so when you get to 1psi of boost, it shuts the port to the throttle body off so you dont boost your crank case. The hose from your throttle body should go to the dual port side to the nipple closest to the metal body. Also make sure the valve is grouned properly.
If you have an intercooler, then you should absoulutely move the boost reference to the intake. If not, you can try moving the reference from the outlet of the compressor housing further up on the scroll of the housing. There is usually a plug there. Using the intake is usually the best source for boost reference though.

 

I had that same problem with mine. It would start at about 6 psi when I went WOT and then creep up to 9 psi and spike to over 9 psi at the shift. I tried moving the boost reference around the scroll to the plug as suggested by STS. Then it would boost to 4.5 psi - 5.5 psi when I went WOT and creep down to under 2 psi at the shift.

I decided to move the boost reference back to the original location and to take the 0.4 bar red spring out of the waste gate and put in a 0.3 bar yellow spring. STS sent me a spring to try and I am happy with it. It is a little weak on the boost but is very steady. I get around 5 psi and sometimes see 5.5 psi when I go WOT and it pretty much stays there till I get out of it. I use this for everyday driving without meth and it works great. The IATs don't seem to go up much on a 15 second WOT run and it is pretty easy on the drive train.

I use 10 psi right now on the high boost setting. When I go WOT it pretty much goes to 10 psi and stays there. It might vary a pound or so.

I am going to try the manifold for a boost reference and put the red spring back in the waste gate when I have a minute. If this works and gives consistent results I think it would be stronger than the yellow spring and a lot more fun to drive without having to resort to the high boost setting.

 

I am going back up to the shop that did the install tommorow. We will try a new wastegate spring first, then maybe move the boost reference to the manifold if that doesn't work. Thanks for the info guys.

 

Make sure and clean up ALL of that oil form the engine and especially the firewall. That's how my engine fire started

My advice is to carry a good fire extinguisher in your truck after you do any mods to it.

 

Well I got it all figured out. The kit STS sent me had the wastegate vented back into the exhaust and that was causing the wastegate to not open at 5 psi like its supposed to. Now that I vented it to atmosphere it works like a champ. Of course now I have to take it in to an exhaust shop and have that little piece cut off the exhaust pipe so I can bolt it back up to the wastegate then seal the hole in the exhaust that is going to cause. Hopefully STS will repay me for that exhaust work since it was their f-ed up kit that caused this. I guess all the new STS kits come with the wastegates vented to atmosphere. Does anyone know if they make mini mufflers to put on that wastegate pipe since it is now really stinkin loud vented to atmosphere?

 

Just had my STS kit installed with the wastegate bypassing the turbo like advertised, and it works great. Did you check the vacuum line that runs from the turbo to the waste gate, if that came loose the gate wouldn't know to open and you would overboost. Mine was just a little loose causing me to overboost.

 

I think all STS kits have the waste gate vented back into the exhaust after the turbo. I know my kit is done that way.