Turbo combinations for my 1GZ

[Kagetsu]

I'm trying to consider what would be the best turbo for my applications.

Basically, on one hand, I don't know much about turbo's themselves (as in, what kind of performance a T04z has against say a GT35/40 etc) but I understand the way they work.

Firstly (for those who haven't heard of the 1GZ) the engine is a V12 with 5L capacity. The engine will be twin turbo (room will be an issue, so quad turbo isn't an option really).
I'd like it to have good response down low (ie, 2000rpm), but I'd also like the power/torque curve to be relatively smooth and controllable.

I figure something that works with a 308 may be workable in my situation, or comparitively something that works with a 1JZ...

Here's the kicker... I'd like to be able to get upto, on a Dyno run (not on street) 1000rwkw... (of course assuming everything else is done to the engine).

I'm sure many ideas will be had, but this is just to give me an 'idea' of what to aim for. I just have no idea.

Anything over 1Mw is probably overkill. I'm keen to have it, but I don't want a car that's going to be all or nothing power.
Incidentally, I may be overestimating at 1000kw's and smooth power curve even with a 5L engine, so feel free to say so. If you can suggest two combinations, and a relative idea of what response would be like for each, or give me something to work out response, I could get more of an idea. ^_^"

[Mr Ed]

1000rwkw is equivalant to getting 500rwkw out of a 1JZ. Sure its possible, but no way in hell are you gonna have decent power at 2000rpm.

Id go twin GT3040s and aim for a reasonably smooth and responsive 900rwhp.

If you want uber massive crazy power, go for twin T04z's with .82 AR and hope for 900rwkw. Should still get boost at a very useable rpm (3800???)

I expect 1000rwkw would be a bit of a dyno baby with that much power/lag giving you no real benefits for track use.

[RONA]

Any idea if the engine can be bored out a touch and use of bigger pistons for slightly larger capacity ie 12 cylinder even with a minimal change in bore is going to be a decent cc increase.

Most of the big power commodores run 355Ci or higher.

If you want 1000rwkw you aren't going to have a driveable car, as the saying goes you can't have your cake and eat it too.

[NeoNasty]

As if a 12Cylinder 5 liter twin turbo isnt impressive enough.

1MegaWatt! Oh my thats somewhat insane. Perhaps go with somthing that give you insane amounts of torque instead? I guess 1000Nm doesnt sounds as special

[MR 1JZ]

dude people have already said it...it wont happen with useable power

my vote goes for a Pair of 3037S pro's...very good turbos for RB25's and 1JZ's

id imagine two of them on a 1GZ would be spectacular

[Kagetsu]

Fair enough. Hopefully if the guys at the workshop have time this weekend, we may end up pulling the heads off and sump to have a look. Hopefully so I can take a set of pistons and con rods with me to Japland next week.

[Norbie]

I agree with the above - as impressive as "1000rwkw" sounds, it's completely impractical and there's no possible way you could actually make use of that sort of power. Even half of that is getting into silly/dangerous territory with a 2WD street car.

If it was me I'd be going a pair of GT3540's with a small shot of gas (say 50hp) to spool it up nice and quick. That will potentially get you up to 1000rwhp which believe me is more than enough. Have you ever been in a seriously quick Supra before? You might find that a "mere" 600rwhp makes you crap your pants.

[Kagetsu]

Might have to get a spin in one sometime soon I think. I've driven a Diablo before. That was interesting.

[Mr Ed]

Diablo has around 600hp and weighs over 1800kg. Pulls 11s.....so yeah, theyre fast but nothing like a 1000hp+ 1500kg 2WD!!!

Fastest Supra Ive been in has 480rwhp, and Im no high power car vetren but that is reasonably scarey fast in a straight line, let alone sliding sideways in the wet!!

[chris davey]

First of all, what a great topic

I would be bringing that power aim down a bit. If the car is still going to be used for street driving then I would be going twin GT3076R's. Jampac is making 5psi by 2900rpm with one on a 1jz and making 270rwkw@19psi. I think this turbo will make 300rwkw at its peak.

I don't know if the 1gz-fe heads and cams flow the same as a 1jz but it sounds like you are going to spend the money to make sure they flow well.

This would be an absolute torque monster from low rpm all the way to redline.

Otherwise, if the car is less street orientated then I like norbie's idea of twin GT3582R's with .8 turbine a/r and I would think a 75-100hp shot of n2o would be good. 1jz747 runs 40hp shot on the 1j with a much larger turbo that a GT35 and spools it up well.

I think this sort of combo could see 1000rwhp and still have torque down low but obviously you can't use nitrous on the street so less low down torque for street use.

[MR 1JZ]

but obviously you can't use nitrous on the street so less low down torque for street use.

dude he is in darwin...you could use cocaine powered monkeys to move your car and the RTA wouldnt care

[Draven]

First of all I'm with Chris - best topic ever.

As people have said - revise your aims. you can either have good power at 2000rpm OR ~1000rwhp/kw/ps

For low down, I'd agree with the 30/67R
For good top end and a reasonable curve, twin GT35rs would be awesome, with the medium exh housing (.86? .9something?)
but with a 5L engine sitting under the hood, who needs to hit boost for street use?

[jezza323]

i say keep it n/a, nothing better than the sound of v12 but if you are serious about the big numbers from the engine then perhaps you can go for a laggier turbo because you have 5L of engine to get you around until boost hits

i guess it will really depend what you primarily want to do with the car? drive it? dyno queen it? drag race it? take your pick and your choice of turbos with it.

[Mr Ed]

but with a 5L engine sitting under the hood, who needs to hit boost for street use?

This is a very good point

[chris davey]

But if the engine is built for boost it will have lower compression (and crappy fuel in Darwin I hear?) then you will have less off boost performance than stock so I think the GT3076's would be a pretty good compromise. 550rwkw or so and full boost by 3500rpm sounds good to me