1jz boost leak

[91 mK3]

i have just done a 1jz swap into my mk3 and i cant even enjoy it because i have a boost leak somewhere (or atleast i think i do). I have a stock fmic with 2.5" aluminum piping with brand new not cheapo silicone couplers. i am at stock boost and the only mods that i think would have any affect on it would prob. be the 550 injectors with stock twins. I have also got a cap and put a valve stem and have put it on my piping to stimulate a turbo while blocking off the other side. i tried to listen for the leak but didnt hear anything so i took it off, took it for a drive and it felt horrible. It felt like having a 7m w/ a code 21 where it would hesitate around 2500-3500rpm and then just go. any ideas on some test or do i just need to get tuned?

 

[JASONA70]

i had someone rev the engine a little while i checked around for a large masses of air, which you will feel when someone revs the engine.

 

[The Reaper]

you running 550's with no fuel controller? SAFC, EMANAGE, AEM???

if so then thats prolly your problem. the 1JZ runs pig F'in rich stock

 

[Ric]

When I installed my 550's before I got to tune my SAFC2, it barely ran.. like.. not driveable.


You need to install some kind of fuel managment system and remove 33% fuel volume for it to run, or put your stock injectors back in til you install a bigger turbo and need the fuel.

There is no reason to install 550's on a stock twin car, the stock injectors can handle any boost the stock twins can do.

Next time you do a mod, do some research (search). This has been covered countless times.

 

[91 mK3]

i already have the safc 2 installed in my car. this 1jz actually came out of another supra. it was tuned for 14psi of boost. so what a good friend of mine told me was that every supra is different and its not going to run the same way or even better until i get tuned.

 

[91 mK3]

hopefully that is the situation. any other ideas for boost leak detection?

 

[Burntz]

yea u really need to tune it correctly. for boost leak um.. have a friend rev it while u stand thier, and if theirs a leak, at a certain rpm you should hear the pressure escape somewhere.

or thiers a method where you hook an air compressor up to something yada yada and it does the same thing. iv never done one lol

But with experience from friends cars, if you have a leak, you hear it.

 

[Ric]

i already have the safc 2 installed in my car. this 1jz actually came out of another supra. it was tuned for 14psi of boost. so what a good friend of mine told me was that every supra is different and its not going to run the same way or even better until i get tuned.

Actually, they do.

14psi on stock fuel is perfectly fine. You'll blow the turbo's before the stock injectors run out of fuel.

Set your SAFC2 to -33% across the board and enjoy a good running car again. Better yet, just borrow someone's wideband, you can probably go leaner.

 

[suprastanger507mgte]

Actually, they do.

14psi on stock fuel is perfectly fine. You'll blow the turbo's before the stock injectors run out of fuel.

Set your SAFC2 to -33% across the board and enjoy a good running car again. Better yet, just borrow someone's wideband, you can probably go leaner.

How can you determine he needs exactly 33% less fuel exactly>>>????

 

[Ric]

Because 550's are exactly 33% bigger then stock.

 

[Burntz]

Owned. Lol.


Crazy what a little bit of math does

 

[suprastanger507mgte]

Because 550's are exactly 33% bigger then stock.

And that is the only factor you take into consideration ?

 

[91 mK3]

so subtract 33% equals stock fuel which would equal no hesitation? what you think moe? lol

 

[suprastanger507mgte]

so subtract 33% equals stock fuel which would equal no hesitation? what you think moe? lol

Its your car...you can listen to anyone you want, or you can take it to a qualified tuner with the right knowledge and tools to get it right. If it was as simple as that, I would have done that myself and let you boost your heart out...till you blow up the engine or melt a piston...

 

[Van Diesel]

Its your car...you can listen to anyone you want, or you can take it to a qualified tuner with the right knowledge and tools to get it right. If it was as simple as that, I would have done that myself and let you boost your heart out...till you blow up the engine or melt a piston...

I have verified this with a wideband. Seriously. 33%. Honestly, I did it twice. Once with 440cc and once with USDM 550cc.

 

[91 mK3]

Its your car...you can listen to anyone you want, or you can take it to a qualified tuner with the right knowledge and tools to get it right. If it was as simple as that, I would have done that myself and let you boost your heart out...till you blow up the engine or melt a piston...

all imma say is that you need to hurry up man. lol. lets go our cars tuned. even better, lets organize a meet so whoever is not tuned can get tuned. maybe the guy will lower the price.

 

[suprastanger507mgte]

I have verified this with a wideband. Seriously. 33%. Honestly, I did it twice. Once with 440cc and once with USDM 550cc.

How can 440 cc injectors be the same as 550cc?

 

[Van Diesel]

they aren't. But when using 440cc injectors and you remove 16% fuel top end it tells me that the formula works.

When I went to 550cc and removed 33% with my SAFC and at WOT it put the A/F ratio almost exactly the same as the stock 370cc. IIRC it was actually sightly richer. I don't have 550cc's anymore though, and have since gone with the stinger4.

 

[Ric]

Whatever you do, do not install a 2JZGTE map sensor!

 

[The Reaper]

Ric is actually correct on this.....did i just say that? hahahaha

around 33% taken out it puts it damn close to stock. as long as your wiring is good it will be fine....but you'd be better off getting an AFPR. lower fuel pressure then minus out only 15-20%.

cause on piggy backs, you can only take out so much fuel before you start messing with timing too much....THEN you melt pistons