Tuning Advice (T45S Turbo???)

[Nocturnal]

Alright, I just made some research on my current project car, and manage to dig up the specs list of my car.

88mm Piston (2.7L)
HKS Step1 CAM (dur 272, 8.7mm lift)
T45S Turbo (To4R Exhaust Manifold)
External Wastegate, 700cc injectors, the rest of the engine is ready.

So what I have here is a DINO Fossil of a turbo, but it makes good power and the boost treashold isn't all that bad (1.2bar @ 4300ish)

According to the Dyno, the bhp peek at 510ish at hub around 7500rpm.

I am looking to make around 650bhp at flywheel (580hub) by running the boost up to 1.5bar from the 1.3bar right now.

The question here is, is there a way to make the power smoother instead of peeking at 7500rpm, can it peek around 7200 and trail its way down to around 8000rpm so I get some wider power band.

Is there a way to make the turbo boost faster (other than chucking it and getting a GT35R which I would love, but fund wouldn't allow)

I also happen to have a set of Tomei Pon CAM on order (260, 9.15mm), and I order it before I actually got the car, so too late for that already. Would that be a better choice than the HKS 272 Step1 CAM?

At least now I got an engine specs and I know what is in the car, so I can move on from this point. Oh yea, H shape con rod already in the car.

Thanks.

[Pikey]

Nitrous

[BBD]

more boost.

88mm pistons ?

[ahapartridge]

Are these dyno graphs from UK mapping or from history with the car?

If you haven't had the car re-mapped over here then maybe that can resolve some of yor issues.

I have the T51s which is very similar to yours so its good to get an idea of what power yours is kicking out for when mine is completed.

[Nocturnal]

The specs I got on the car I received from the Tuning company that done the car in Japan. However, this car has been in UK for about 2.5 years, and the details from the Tuning company said was about 5 years old. The sheet never said it had a Trust Deep Sump and H-Beam Con Rod install, and both of these has been confirm by Abbey that it existed. Therefore it could of been more work done to it. It also doesn't have HKS Cam pulley even though it say it have HKS Step1 CAM, but a set of HRD one so that is quite rare. But the Idle is a bit lumpy so I would expect it to be at least 270 cam anyways.

The power graph are from Abbey on a Dyna Pack. Not bad at all, just a bit rich in the mid section at 11.5 AFR. I hope to push more out of the car by runing it at 1.5BAR and an AFR of around 12.0 across the board.

Anyone know if I am being a bit too risky at a 12.0 AFR? Or is it better to stick with 11.5 and make sure no det will happen?

Also, search through some old cars. It seems the old R32 Demo car from SIGNAL also use a T45S. It made 710PS @ 7300RPM with 1.8 Bar!!! according to HyperRev. It was using Tomei PROCAM (280, 10.25mm)

[Nocturnal]

Originally Posted by BBD

more boost.

88mm pistons ?

Yea, 88mm bore. It is a bit big, so I hope the block isn't too weak. Anyone have any idea how you can check the stroke of the crank to see if a after market crank have been fitted without taking the engine apart?

The long as I keep the Det down I think I will be okay. I hope.

[Nocturnal]

actually, after some reading today, I realise that the map on the car is perfect. 11.5:1 AFR across the max torque of the car and lean out to 12:1 on max power range. This Mapping thing is interesting but sure hard to do.

[SteveN]

Cant say a map is good or bad purely on AFR number, safety will change wildly with the spec.

And regardless of safety, drivability and boost threshold is the thing ive seen skimped on the most in mapping.

Often seems a "its safe, and peak numbers are good, so job done" thing.

[Nocturnal]

I must of read something wrong, or eyes need checking.

boost 1.2bar @ 4700 rpm...

Old Truck Turbo

[R33_GTS-t]

Originally Posted by Nocturnal

actually, after some reading today, I realise that the map on the car is perfect. 11.5:1 AFR across the max torque of the car and lean out to 12:1 on max power range. This Mapping thing is interesting but sure hard to do.

I know sod all about mapping but was under the impression that you run aggressive timing and AFR (lean) in the mid-range to get the turbo spooled and then drop it back for safety at the top end.

Whether your setup is risky depends on AFR and timing. Many people at supraforums believe 11.5-11.6 is as high as you should go on the dyno as this equates to ~13.5 on the road. Again, other people's opinions. You're best off getting it to a recognised tuner if you're really concerned.

In theory, you should be able to knock the peak off the graph by richening the mix and/or retarding the timing in that area. Ultimately not worth doing just for the sake of it.