turbodremz

iTrader: (18)

getting ready to start the final touches on my friends 1JZ project, but he brought up a good question and had me scratching my head.

For a bpu 1jz @ 12psi, does the car NEED an safc? Or can the GTE ecu compensate? I have read a couple threads on SF.com of bpu 1j's simply using a larger map and larger injectors and doing fine, with no boost cut issues, but can it be done with the engine/injectors/map completely stock?

94_soarer

iTrader: (8)

Honestly with the stock 1JZ u can make more boost the 12psi when its bpu...my car is bpu ATM and i dont have my boost controller hooked up and jus with a 4" Fmic,3" Dp,3" full exhaust, & intake i make about 14-15psi...

i thought that was kinda high for a bpu 1JZ without turning up the boost so i checked for any boost or vacuum leaks and i have none..so if u do a exhaust, and fmic u should b good but once u do a custom or aftermarket dp then thats when u start pushing it and u will hit boost cut..

Boost cut is right at 13psi

turbodremz

iTrader: (18)

So it should be fine @12-14psi without an safc?

94_soarer

iTrader: (8)

Yea, i dont have a Safc on my car ATM, i did have one but i sold it before i did the 1JZ swap..smh that was a big no no cuz now it wouldnt hurt to have it so i can tune my car but oh well ima get another now...but to answer ur question no u dont need a safc..

then again, i dont have a wideband in my car either right now so idk where my air/fuel ratio is at when boosting etc...

But in order to boost more then 13psi, u will need a BCC,FCD, or a tuned Ecu

turbodremz

iTrader: (18)

Thanks Nate. I will more than likely just keep it @ 12psi then.

94_soarer

iTrader: (8)

Yea cuz the stock map sensor is not used to seeing more than 12psi that is why if u dont have a BCC,FCD or a tuned Ecu to bypass the boost cut then once ur car hits about 13psi then it will cut and go back down to about 10psi and u will get a CEL for a few seconds

blk&blu*j

iTrader: (1)

the car is going to hit the boost cut from the ecu in 3rd gear around 5800 rpms if it sees a glimpse of 12 lbs.
what ecu is in the car is it a auto or stick ecu?
You also still have to contend with the speed cut at around 120.
Keep in mind the boost cut will be more obvious as the weather cools down more and will become quite annoying.
Hope this helps

turbodremz

iTrader: (18)

Well if the car has to settle at 11psi for a while its no problem. Its a 5-speed ecu, and the speed cut isnt really an issue just yet, just concerned with boost/fuel cut. Eventually the car will be getting a FCD and a SCD, but for the time being, I just wanted to be sure the car can be run successfully without the need for an safc.

94_soarer

iTrader: (8)

Yea it can run jus fine without a safc...
But honestly when u start to mod it and want to get rid of the boost cut n speed cut i would go with the Greddy Boost Cut Controller & Speed Cut Controller, i wouldnt even bother with the HKS FCD & SCD

Greddy
HKS

blk&blu*j

iTrader: (1)

^^^ I agree

My 1j back in the day of twins I was running around 16# on aet of cams and a 440 injector
with no issues with a boost cut installed and a WB for safety, ran like THAT FOR ABOUT 3 YRS TILL THE TWINS GRENADED!

turbodremz

iTrader: (18)

Alrighty, thanks for the help guys. And just for a tease, this is what showed up today:








Thats 2-1JZ's with R154's, one with stock twins, the other has a single turbonetics turbo, Greedy WG, Greddy fmic with Greddy pipes (not pictured), Exedy (I think) twin-plate, and some other goodies.

No these are not for my SC, sorry CL.

t70 supra

iTrader: (-4)

Are u still doing the ls1

turbodremz

iTrader: (18)

Yes the ls1 is still going in my SC, and may come a bit earlier than planned, and may be boosted sooner than anticipated.

1 of the engine pictured is going into an s14, the other will be going into something a bit less common, and will possibly be widebody.