How much boost???

[87soup]

Just swapped the 1JZ into my supra and it's boosting at 8lbs...

I was wondering how high can i go without hurting the engine???

Mods:
Driftmotion IC, 2.5 Pipes, Walbro 255, HKS BOV, 3" Y& D pipe!

 

[OneJoeZee]

If you're only boosting 8psi, something is wrong. Check for boost leaks.

Stock boost should be around 10-11.

How high can you go without hurting the engine? Depends on what fuel you're running.

 

[87soup]

Depends on what fuel you're running.

Really???
My mechanic told me to only put 87 in the tank since its a low compression motor...

I believe OneJoeZee, over him just because i have seen your JZ's and know you know about em!!!

Any way my ultimate question is;
Should i install my boost controler? I just got the motor so im kinda scared of blowing it... I love my 1JZ:love:!

I would like to get optimal performance outa it with out hurting my baby...:biglaugh:

 

[OneJoeZee]

Really???
My mechanic told me to only put 87 in the tank since its a low compression motor...

Take whatever that guy says with a grain of salt. Maybe the whole bag. At 8psi, I guess 87 octane is ok... But when you're running the correct boost, 10-12, use 91...


I would figure out why you're only getting 8psi of boost before you install your boost controller.

 

[JonoTurbo]

Especially with a y-pipe on there you should be running more than 8psi. I'd say you should even be creeping over the stock 10-11. I pulled 11 on a stock y and downpipe.

Also, I was stupid and ran 87 for a tank and the car was definitely suffering. I run only 93 now, on any turbocharged application octane is key.

As for when you fix your leak and get the boost controller in, my opinion is 14psi max on stock injectors.

 

[annoyingrob]

my car pings on anything below 94.


my stock motor would ping on 91 sometimes too.

 

[honestabe]

I'm running a full 3" (downpipe back) free flowing exhaust and cold air intake and I'm boosting about 14 PSi on 91. Although I'll have my boost gauge reinstalled shortly, so I can tell y'all what I'm boosting using 92 octane Oregon gas (been stuck in Cali using their emission friendly 91).

Adam

 

[87soup]

The only thing i can think of differant from my car and the other 1JZ's is my
BOV... My mechanic put it on the hot side right before the turbo pipes!

:nono:

 

[87soup]

Does it matter what side the BOV is on???

 

[annoyingrob]

Does it matter what side the BOV is on???

Yes, but not with those turbos.

If you have something larger, then it starts mattering more. (ask me how I killed a GT40 )

 

[upgradedsupra]

Keeping raising boost until you go BOOM! then back up some. :sarcasm:

Like Joe had mentioned, your boost is too low as the stock is 10.8 IIRC. Make sure you have mods to support what you plan to do.

Duane

 

[87soup]

Oh!!! Kool... Well do you know how to install one of those twisty do boost controllers from ebay on to the one-j???

I know how ut im not sure what to do to get to the waste gate:aigo: , or where it is even???

 

[Slow_Sc3]

Yes, but not with those turbos.

If you have something larger, then it starts mattering more. (ask me how I killed a GT40 )

interested in what side you put the bov i was always told to put it close to the throttle body?

 

[87soup]

Keeping raising boost until you go BOOM! then back up some. :sarcasm:

Like Joe had mentioned, your boost is too low as the stock is 10.8 IIRC. Make sure you have mods to support what you plan to do.

Duane

What could be wrong???

Your right 8lbs is too lo for a set up like mine!!!

 

[87soup]

So... What should i do about the boost controller???:1zhelp:

 

[87soup]

Oh... Actually i just remembered i have a bad O2 sensor!
Can that be restricting my boost???

 

[Big Rob]

No.
I think you should go do some reading on basic turbocharger setups.

There is a pressure line that goes from the compressor housing to the waste gate. The waste gate is a device that bypasses exhaust gases around the turbine wheel in an effort to control boost pressure which is proportional to the stiffness of the spring in the waste gate.

As you can see the only way for pressure to be lower than the stock level would be for a leak, restriction or part failure, purely mechanical failure.

 

[Dylan JZ]

I'm running a full 3" (downpipe back) free flowing exhaust and cold air intake and I'm boosting about 14 PSi on 91. Although I'll have my boost gauge reinstalled shortly, so I can tell y'all what I'm boosting using 92 octane Oregon gas (been stuck in Cali using their emission friendly 91).

Adam

Is that with boost creep?.. I'm just curious as you didnt list that you had a boost controller.

 

[Prettyazznouka]

Use 91 or 93 like the other guys said. I was running 89 for about 2 weeks and I boosted around 8-9 now I put back 93 yesterday and Im back at fill 10. No mods still stock. Not even a boost controller.

 

[annoyingrob]

interested in what side you put the bov i was always told to put it close to the throttle body?

You should put it close to the throttle body. I have mine right off the turbo, as that was the only place with room for it. Needless to say, my car surges like a mofo, and ended up causing some serious shaft play in my turbo. Goes in next week to be moved. Now that I've eliminated my catch can, I have room beside the TB for it.

With a smaller turbo that moves less air, it's less important, but the larger the turbo, the more important placement becomes. Air doesn't like stopping and turning around to go out the BOV.


No room near the TB