Derekismoney

Ok so I did a motor swap and trans conversion on my car (auto-manual) and i have been driving my car a lot getting a feel for it. I decided i want to crank the boost up a bit and go to the track. I just ordered a supra TT fuel pump. My wastegate is ported and im running only 8lbs right now with no boost controller. How much boost do you guys think the stock turbos can handle with stock injectors and rails? I have seen supras pushing 18lbs as daily drivers.

Thanks,

Derek

DaveW

IIRC, the stock twins can do ~15 lbs or so. The stock fuel system also maxes out around that figure. This is just an approximate figure from my (sometimes inaccurate) memory.

There may be a few threads in the archives about this subject.

4CN A1R

iTrader: (6)

check the faq.

and 10lbs of boost is all the stock ecu can handle, without some kind of replacement engine management and tune. you also need mods to support the increase in boost. you have alot to learn yet before you start messing with your boost.

DaveW

He has a PFC...

Derekismoney

ya i have the pfc and the supra tt fuel pump which is better than a walbro 255. I was just asking the threshold of the stock twins and stock injectors. I plan on keeping the boost at 8lbs for driving around town but i want to get it tuned by the local guru to push maybe 12-15 psi.

4CN A1R

iTrader: (6)

wow, didnt even see his sig

dgeesaman

iTrader: (7)

Some guys have gone to 14psi on stock injectors, but I'm not sure I would push that far unless I had a wideband to be sure. Most rotary tuners aren't big fans of tuning over 90% injector duty.

Dave

Derekismoney

i've got the aem uego waiting on installing it. Sounds like it couldnt hurt to just get bigger injectors. So it sounds like a safe assumption to say the threshold on stock twins is 14psi

NissanConvert

iTrader: (1)

'round about 14psi is when the stock turbos start to become inefficient as well. IMHO even when i have a ported wastegate and denso pump i'm not going over 12psi on the stock snails.

I don't know what the base map is good for as far as boost is concerned but if i were going to go over about 12psi i'd get a retune.

Remember the PFC cuts fuel about 3psi over the peak boost. Do you have a boost controller or the pfc boost control kit?

Derekismoney

ya i have the profec a which i have heard is inaccurate so i just put it up on ebay and im going to invest in the profec b spec II. Thanks for your help guys!