CT15 Wastegate Settings Options

[HardHead93]

I just got my CT Sweet 16 turbo upgrade back from ATS racing. It is a CT15b turbo from the Gen 4 3sgte with an upgraded billet wheel.
CT SWEET 16-2
CT SWEET 16-3
CT SWEET 16-1
I got the billet wastegate upgrade and had them send me a few different size springs. I have the option of using a 7 psi, 10 psi, or 12 psi spring. The 7 psi one is definitely out because I am running close to 90% duty cycle on my boost controller with that size of spring to get close to my desired boost level of 17 psi. Also depending on my flex fuel tune I may be able to run a couple more psi on e85. Should I use the 10 psi or the 12 psi spring? Why?

This post has been edited by HardHead93: Dec 29, 2017 - 8:27 AM

[Smaay]

if you can run 17 safely, go with the 12lb spring. it will make the duty cycle on the boost controller lower and more reliable

[HardHead93]

if you can run 17 safely, go with the 12lb spring. it will make the duty cycle on the boost controller lower and more reliable

Thank you! You tipped the scales, my tuner agrees with you but other forums where saying it may cause wheel spin. 12 psi spring it is!

[HardHead93]

So I installed my CT SWEET 16 last night with the 12 psi wastegate spring and I think I preloaded the wastegate wrong because it is only running at 7 psi. DOH! I guess I will need to go back in there and add more preload to the wastegate.

[ILoveMySilly97]

Nice upgrade man. Good luck with it. Hope it treats you good.

[HardHead93]

I just finished getting my Sweet 16 upgrade all dialed in. The turbo spools quickly and the car takes off like a beast! I ended up putting in the 12 psi spring and with no duty cycle it runs 10-11 psi (I think that is due to the high elevation). I am running 15 psi on 91 octane and 17 psi on E85. That was with me doing a street tune on the car to get it up and running. Eventually I will take it back to the tuner because I believe I could run a little more boost and timing with this set up but I don't want to push it without a dyno.

[4-eyed-freek]

ct15b(sweet 16) in a ct26 housing? interesting...