IndigoMKII;1823763 said:
Could I ask why people do the whole 1.5jz if the 2j head outflows the 1j head? What would be the whole purpose? I thought it was done because the 1jz head had a better flow.
Another good reason to do a 1.5jz is because you already have a good head, like mine. Ported VERY nicely, already have aftermarket cams... of course it's not *so* much work that I wouldn't consider a 2j if this thing blew up, but still... it's a really nice head. I am really looking forward to seeing how it behaves when it has a real turbo that isn't a choke point on it's potential.
rshn117;1823765 said:
piggyback tune on pump, i would guess around 500
If you're only going to be looking for 500whp (unless you're just talking crank here), and overall powerband/response is important to you, then a 67mm turbo is a HUGE waste of potential there. Little example for you here, once upon a time, two years ago, I raced Albert on here. He had a 67mm journal bearing turbo (running roughly 12psi) on his 1j, along with intake, exhaust, and little else. I had (still have) stock twins on 12psi, stock intake/intercooler, 3" exhaust, a nicely ported head, and BC264 cams. Out come of this race? I pulled ahead by about half a car length at the start... and held that same advantage the entire time, up to about 125 (kph, wink wink, we were in Canada) or so. Reason I beat him? My powerband/response was better overall. The turbo setup on my car was better suited for the application.
Now if he had been running that same turbo at it's 600ish whp potential, obviously I would have saw nothing but tail lights.
Another story, same setup on my end, racing Dustin (gurley0916 on here), along with a couple other guys. He also had a 67mm turbo at the time, on a 2j, I forget just how much boost he was running. Later that same day we both dyno'd, I laid down 320whp, Dustin 340whp. Same story though, I pulled away while he was waiting for that big turbo to come alive, and held that advantage until we stopped the pull.
The key to a good setup is how well you can flow air. If you deal with the basics (porting the head, intake, exhaust, cooling), and choose an APPROPRIATELY sized turbo for your desired power level, what do you end up with? A monster, plain and simple. I'm just saying you're wasting your time with a 67mm turbo these days if all you're hoping to break is the 500hp barrier. You'll get left in the dust by people with proper setups all day long because you're wasting potential with an oversized (and under utilized) turbo.
Boostage;1823888 said:
I had two dynos that Could show you the difference but i can only find one. this is my personal friends 1.5jz
Holy crap man, the numbers (and revving, wow) seem right for a 1j, but damn... did he dyno in 2nd gear?