Supra Forums banner

Boost falling off

735 Views 9 Replies 7 Participants Last post by  Spoolme
ok well i got my spec stage 3 broken in and so i cranked up the boost till fuel cut.
im one of the lucky few that can get 14psi! WOOT!!! well, after i punch it it goes to 14 and stays for a while and then falls off to 13,12,11 and stays.

what i was wondering, can i shim the wastegate and it will stay?
i got a mbc.
1 - 10 of 10 Posts
i'm pretty sure that's just normal for the CT-26, espescially with stock IC and pipes.
You can shim the wastegate and it will help, but you're not likely to get 14psi steady even with that.
anyone else know?
why would it fall off anyway? just wondering
The stock CT can't push 14psi with the amount of exhaust energy being produced by the motor at that RPM. It just can't keep up. Shim it all you want, but it's not going to make any difference. Be glad you can sustain 11psi.
Hmm... I haven't heard that before..

All I know is I'm running 17 psi all day on mine, and at about 4500 it drops to 15. That is on a cool night.

I hit and hold 15 all day long with 60-70º weather.

That is with stock CT/stock intercooler/MBC.
ok well...i shimmed my wastegate with washers from the stock head bolts. 1 on each side.
boost holds!

but im getting kinda scared to though cuz i havent seen fuel cut yet.
when i get it fixed i will take a pic of my boost. its like at 15 1/2 when i punch it and then it goes down to like 14 1/2 then 14.
it was about 75° last night.

last night i went out and boosted it and it pulled crazy and then i poped off my 3000 pipe to my throttle body and it was late and i coasted to my house for like a 1 mile!!
i havent fixed it yet.
You must either be really lucky or have an innaucurate boost gauge! That is alot of pressure for the stock turbo to pound out - sounds like you need to fab up some hardpipes. I hope you don't boost like that all the time.
I wouldn't run that much boost on a stock CT w/ stock IC pipes just not efficient and more importantly you run the risk of running lean with the stock fuel system! I run no more than 13psi with the stock fuel system, i.e. pump FPR and that restrictive J-tube. But thats my preference.
well i turned it down to 12 but will prolly turn it up for a race or something. i need to get rid of my intercooler pipes i know. when i get my SSQV im gonna try and make some.
1 - 10 of 10 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.