So I am getting my tune back together with the Z06 cam and I have a question. On high boost it shoots up to 8-9psi and holds strong until about 5k rpms and then it falls off to 7psi until redline. I want to run 10psi on high boost but I am afraid that it will spike to 11-12psi and then settle to 10psi in the upper rpms. What should I do? Should I turn it up to 11-12psi and let it settle to 10 or stick with 10psi through the mid range and let it fall to 8-9? I don't want to break anything but I want to get as much as I can safely.

 

Did you ever contact STS and see what they thought about this problem? Are you tuning it yourself? 2 bar?

 

I have not contacted STS about this problem but everyone seems to think it is pretty normal due to running a light spring for low boost. Parish thinks that it is back pressure pushing open my wastegate due to the weak spring and small turbo. I had the same problem with this wastegate when I tried to install a small side mount intercooler and the backpressure kept pushing open my wastegate. If I put a stronger spring in, it gets better but I don't know if want to run 7psi on low boost. I may try the 7psi spring this weekend and see if it helps.

I am tuning it myself and I am still 1 bar.

 

If you are tunning it yourself, I don't think it matters, just how long you want it to live, and how close you want to run on the edge... 10psi can be a safe for years. 5psi can kill an engine within minutes...

 

I am trying to keep my tune pretty safe. I have it tuned for 18 degrees of timing for low and high boost and have not seen any knock. I am running 11.8 AFR on low boost and 11.0-11.4 AFR on high boost with 50/50 meth/water.

 

id say your wastegate isnt holding well and backing up like Parish has previously said. also wondering if the turbo itself may be an issue as well.

 

According to Wild Racing the 60-1 should support 10psi pretty well. I think it is a problem with the wastegate since it does the same thing at 5.5psi. I did some research last night and a lot of the import guys have the same problem at high rpms but I couldn't find a good fix for it.

 

dont forget psi level is irrevliant {sp}. do you have a EBC or you using a manual one? i would look into the wastegate issue also see if you ahve anythign that could be choking the turbo. I think spoolin has issues of boost dropping off in higher rpms. his A/R is too small and choking the motor

 

I'm using the STS two stage boost controller.

 

the 60-1 I had a gt wheel and I cant remember the exhaust side....Still though I think it will support a 5.3 with a z06 cam, I think the exhaust side is too small.. How big is it anyhow?