Gt42r Approx Spool Rpm?

[groper]

lol bcl is here now, im sure he can let you know how much its going to cost to get it to rev to 7500 safely...

what kind of person buys such a turbo for a street driven car?

[groper]

how much $$$ you got to spend?

what are you trying to achieve here?

with turbos, you need to start with the end...

[bcl]

As a guide for you with a 1000hp turbo:

5lb by 3000

15lb by 3500 (not sure what you could stall to).

24lb by 4000 ... this is uncontrollable on the street (turn it down)

I have tested up to 32lb boost on race fuel; then backed off;

maximum torque at around 4800 revs

maximum power by 5200 revs. But with extractors and cams I have peak power at 6800 revs. Log style manifold may make less.

Engine has bad harmonics at high revs; will destroy oil pumps and harmonic balancer.

You need very strong internals and well chosen block.

If you don't increase the rev limit your power band is too small. Increase the rev limit and your costs will increase substantially.

I'd recommend a smaller turbo with better response and more useable power band.

It comes back to what you are trying to achieve and your budget.

Brian

[groper]

youve STARTed with 1000hp turbo.

unless your gonna END up with 1000hp, its gonna be a pig with no boost, then a narrow power band, then revlimit.

Is your engine with stock valve springs, crank, rods, pistons etc etc gonna hold whatever it makes in this narrow band? not likely....

so your gonna have to build a motor.... are you gonna build a motor than can rev more or just forged piston and rods and oil pump gears? whats the point if its gonna be a pig? so you wanna be able to rev more.... hope your rich mate, other wise your wasting you time....

[ltd351t]

lol bcl is here now, im sure he can let you know how much its going to cost to get it to rev to 7500 safely...

what kind of person buys such a turbo for a street driven car?

what kind of person makes judgements about other people who they know nothing about? you have absolutely no idea how this turbo came into my possesion or why.

Edited 12/02/08 04:58 AM by ltd351t

[senna_T]

groper may have been a little presumptious mate, but you have to agree that this turbo is a bit extreme for a street driven car, the turbo was designed for drag use...

[ltd351t]

how much $$$ you got to spend?

what are you trying to achieve here?

with turbos, you need to start with the end...

50$

185rwkw

so tailpipe first hey

lol just kidding mate, I'm not stupid so no need for basics.

As a guide for you with a 1000hp turbo:

5lb by 3000

15lb by 3500 (not sure what you could stall to).

24lb by 4000 ... this is uncontrollable on the street (turn it down)

I have tested up to 32lb boost on race fuel; then backed off;

maximum torque at around 4800 revs

maximum power by 5200 revs. But with extractors and cams I have peak power at 6800 revs. Log style manifold may make less.

Engine has bad harmonics at high revs; will destroy oil pumps and harmonic balancer.

You need very strong internals and well chosen block.

If you don't increase the rev limit your power band is too small. Increase the rev limit and your costs will increase substantially.

I'd recommend a smaller turbo with better response and more useable power band.

It comes back to what you are trying to achieve and your budget.

Brian

thankyou very very much.

Speaking with someone from nizpro they have said that without the VCT active the spool will be much slower, and that the only real way of running the system properly is with factory ecu, and a few other expensive goodies, which may put the whole deal off.

Would you say the harmonics are any worse than the Au engines?

I know the turbo is mismatched when used on a stock engine.

youve STARTed with 1000hp turbo.

unless your gonna END up with 1000hp, its gonna be a pig with no boost, then a narrow power band, then revlimit.

Is your engine with stock valve springs, crank, rods, pistons etc etc gonna hold whatever it makes in this narrow band? not likely....

so your gonna have to build a motor.... are you gonna build a motor than can rev more or just forged piston and rods and oil pump gears? whats the point if its gonna be a pig? so you wanna be able to rev more.... hope your rich mate, other wise your wasting you time....

I mean no offence but spare the basics please, I might have low post count but that doesn't make me ignorant.

groper may have been a little presumptious mate, but you have to agree that this turbo is a bit extreme for a street driven car, the turbo was designed for drag use...

diesels actually but yeah I understand.

So far we have a general consenusus of 3000-3500rpm brake stall speed required, assuming VCT is working. that's what I needed to know, thanks.

With no VCT I have been told this could raise to as high as 4500rpm, this came from people that know, so I'm going to take this as fact.

As has been stated these engines don't like to rev, if they are worse than the crossflow or similar engines then that sucks, but if they are the same as crossflow 6500rpm shouldn't be that hard, some degree of safety margin would be employed with the factory rev limit one would assume.

It costs me nothing to make this turbo work, so I will try it, it might suck but I won't have lost anything but my time, if it works ok then the system is just a built engine away from being a useable package. If its too laggy I can easily swap out for a smaller turbo.

Not to mention making the manifold and then selling it along with turbo I will make money, so its no biggie.

Appreciate the constructive input, thanks.

[senna_T]

my concern here is the level of boost you will be running, and in turn power.

The BA engines aren't really strong and 300rwkw is about the limit on stock engines with stock turbos, I'm afraid that with the way this turbo may hit, its gonna put a hole in the side of your block

Someone correct me if I'm being a bit too extreme here

[ltd351t]

I totally think your right, their is every chance that will happen, the cylinder press even when properly tuned might just mash the pistons to peices, they are 9.5 or something to 1 comp after all, I can reduce comp properly for cost of headgasket, providing crown has some meat, if not head will. This stuff is interesting to me, blowing up a few engines along the way is no big deal they are very very very cheap. I can buy new engine bare and make some money back on selling head and any leftovers.

I'm not familiar with the strengths and weaknesses inside these engines, apart from what has already been mentioned, rod strength who knows turbo is softer on rods and they generally fail in tension not compression, ie prepped crossy rods have taken over 400rwkw, rpm kills them. Some have killed stock engines at 300rwkw, but did they do that running pump fuel and standard comp ratio?

Without knowing anything about these rods I cant say, but with the cost of basic aftermarket stuff I wouldn't even bother touching them.

Do the stock rods/pistons have floating pins or press fit?

The simple things are not a worry for me, the harmonics issue is, as obviously it requires more in depth work, and cranks for this I assume are not cheap.

[bcl]

So how many engines are you prepared to smash before you strengthen one?

Believe me the torque will absolutely smash a stock engine.

Stock compression is 8.7:1.

Decompressing it to say 7:1 will make it doughey; that's like turning back the clock 25 years.

It's like cv's. After you smash a few it's time to do something about it.

Like me you may end up with lot's of spare parts (lol).

Brian