No, I'm joking, it's not too small at all.

Garrett GT40-88 with a Precision Turbo .81 T4 hotside.





Here's the HKS 50mm wastegate, and equal length manifold going with it.



This thing is going to be FUN!

wow, the cold side alone is bigger then my whole turbo....lol What numbers are you expecting??

I'm hoping to put out mid 500s to the wheels on 94 with my 2.5L. I'm stroking it to 3L, and should be able to manage 600whp very nicely, provided my injectors (550cc) can handle it, which they probably won't.

550cc will not cut it at all.

600WHP on 550cc injectors?

so do u have a spare set of oem 1jz turbos?

looks awesome, you'll definatly need larger injectors. Wont that be pretty laggy, when are you expecting boost to kick in.

Originally posted by heavyD
600WHP on 550cc injectors?

You have to keep in mind that this is an I6, not an I4, there are 6 injectors.

I have 2 right now. The ones on my car, and a spare set. The spare set is going on another car, and the ones on my car right now are blown.

3L is 3L. 550's won't be enough fuel.

ya, time to start looking at 800's

keep in mind...this is using a 32x32 fuel map table so the precision is there, he doesn't want to drip fuel out his ass...

There isn't really a set formual for injector size -> hp range. You want to have the smallest injectors possible for the power you are making, will make more power being lean anyway.

If everyone is saying that 550cc isn't enough, wheres the proof?

Should make 20psi by about 4200 on the 2.5L bottom end. The motor revs to 7500 now, might rev it to 8000 if the power holds out. Even revving to 7500, the car shifts WELL within the power band.

As for the injectors, have you guys even seen a 1JZ motor? No offence, but I think you guy's are going a little overboard on what's required fuel wise to make power. I make about 350whp on 370cc injectors, with a base fuel pressure of 35psi, and an A/F ratio <12:1. These motors are quite efficient when it comes to fuel consumption. I'm not saying that 550cc isn't too small for 600whp, I'm saying it's not THAT small. The injectors will do mid 500whp. Off the top of my head, I can remember a guy in Toronto making 524(maybe more) on a twin K26 1JZ running 550cc injectors. Another guy made 500whp on 550s in BC with a good amount of fuel left, etc, etc.

600whp may be a stretch, it may not. We'll see. Like I said, first step is mid 500s on the 2.5L bottom end. If I don't like the duty cycle at that power, I can change them out, it's that simple. I think you guys are going a little overboard with the "OMG, STOP YOU'LL BLOW YOUR ENGINE!!!". you honestly think I'm just going to throw them in, crank it right up, and see what happens? . Baby steps here people.

HeavyD: 3L is not 3L. You have engine volumetric efficiency and brake specific fuel consumption to take into account. Plus we're talking forced induction here too, 3L can equal 6 or 7L of air. The comment is completely irrelivant anyways, as engine displacent has little to do with over all injector size.

Cant give you any proof as with 100% duty cycle, higher than normal fuel pressure, and dangerously lean tuning my guess is 600 at the wheels MIGHT be remotely possible... but to do it with any margin of safety or error wont happen

also the only real disadvantage to bigger injectors is getting them to work properly at low duty cycles... lots of big injectors wont work great at low loads like idle...

Which is where a precise fuel controller comes into play...means you can really crank them down low and have it stable. Rob says Reg is running 1000cc injectors...and he idles just fine.

thats a beast!!!

Toight like a toiger!

What Duty cycle will they be running? like near 100% @ 7500? Failure rate of those injectors? How old are they bro?
How lean are you thinking of tuning this?

I know you have proven yourself as a turbo god, so I trust your judgement, I just dont trust your injectors .


1jz correct? How big is the intercooler? V-mount it for shits and giggles!

Well, like I said, I was only aiming for around 500whp with this setup, but I have decided on tossing the 550s and going with 800cc injectors just to I know that the fuel system won't be the weak point.


Intercooler is still up in the air right now. I'm leaning towards an HKS type R core or something equivalent.

Edit: and yes, this is a 1JZ.

Small update: Intercooler has been chosen.

HKS R-Type JZA80 intercooler kit that I'm going to modify to fit my JZA70.