How Much Power Can A Standard Rb25Det Handle

[Fat_Tony]

boost = torque yes?

if your making 21 psi @ 3000 rpm then your peak torque is pretty low.. and therefore you'd be rapidly accelerating from that point onwards.

I guess I'm trying to say its good for a dyno test. But its not a real world situation. I can say I have full boost at 3000rpm, that only happens in a situation you would never use. 4th gear, 3000rpm is about 80km/h. I would be in 2nd or 3rd gear if I wanted to have some fun.

Hey, why not load it up in 5th gear going up a hill and see how quickly it builds boost.

Take it easy. Mad skids uleh.

[joeyjoejoejuniorshabadoo]

Exactly, hence compairing boost on a relatively standardised dyno run

[hypergear]

Well isn't "today's" turbo engineering is trying to get away from the tire frying behavior and concentrating on displacement? Power curve with sudden increase in power and torque are more likely to fry tires, while consistent increases are more likely to stick the car on road. Car that do stick on road during acceleration is lot faster then car that loses traction.

[R31Nismoid]

boost = torque yes?

if your making 21 psi @ 3000 rpm then your peak torque is pretty low.. and therefore you'd be rapidly accelerating from that point onwards.

Exactly!

You also don't need to wring the balls off the motor with boost coming in nice and early.

You just dont rev to 7500rpm - you shift sooner to stay back in the solid/meaty area of torque and surging forward.

It's like a win-win as less RPM the better for reliability.

[Lithium]

Except there is nothing beyond the claim that the GT2835 spools that fast, dyno plot makes it look like almost 500rpm laggier than the numbers referred to here

[high_hp]

I made 400hp on stock internals

Gt30/76r turbo

Haltec e11 ecu

3.5" exhaust

700cc high flow injectors

After market fuel pump

Running 18psi on pump fuel with a good tune from addrenline imports in mackay

[wolverine]

Except there is nothing beyond the claim that the GT2835 spools that fast, dyno plot makes it look like almost 500rpm laggier than the numbers referred to here

Lith, the HKS2835ProS on the stagea makes 16psi at 3300rpm (150rwkw at 3500rpm and 180rwkw at 4000rpm). I am not sure how much earlier power could be brought on with more time on the dyno but this where it ended up last time out.

The car was on the dyno on a bull$hit hot >40deg day and the skinny OEM radiator wasn't coping well with temps becoming uncontrollable . Additionally we hit a boost limit around here where it wouldn't make more power...I think I have sorted that issue out as I suspect the stock BOV was cracking open here. This needs to be dynoed at some point with the new radiator and BOV mods.

[joeyjoejoejuniorshabadoo]

Well isn't "today's" turbo engineering is trying to get away from the tire frying behavior and concentrating on displacement? Power curve with sudden increase in power and torque are more likely to fry tires, while consistent increases are more likely to stick the car on road. Car that do stick on road during acceleration is lot faster then car that loses traction.

Less lag and more tine under the curve is faster. You need to setup your suspension to put the power down

[Rolls]

tune is more important than power level, loads of cars driving around pinging their tits off, especially when people flog it in summer when it has been tuned in winter with no temperature correction set up.

quite easily blow it up with only 220kw if the tuner has been quick and nasty

[Tony de Wonderful]

Exactly!

You also don't need to wring the balls off the motor with boost coming in nice and early.

You just dont rev to 7500rpm - you shift sooner to stay back in the solid/meaty area of torque and surging forward.

It's like a win-win as less RPM the better for reliability.

Virtually any motor needs to shift at red-line to make the fastest 1/4's.

It's cos torque at the wheels = engine torque x gear ratio.

Just do the maths and see.

Unless your torque is dropping off massively at red-line then shifting to a longer gear (upshift) is invariably going to result in less torque at the wheels.

[Rolls]

Virtually any motor needs to shift at red-line to make the fastest 1/4's.

It's cos torque at the wheels = engine torque x gear ratio.

Just do the maths and see.

Unless your torque is dropping off massively at red-line then shifting to a longer gear (upshift) is invariably going to result in less torque at the wheels.

Yep, basically you need to shift to maximise power under the curve, this usually means shifting above peak power and well above peak torque. Torque can drop off quite massively towards redline yet it is still faster to shift up there.

With street gear ratios I'd say shifting on the limiter is going to be the fastest a lot of the time.

I think nismoid realises this though, he was just saying you don't need to rev it as much to get the same average power.