tkgb

Dynochart of my 3.0 8v engine.
M-tune and regular pump gas

V2Rocket

what turbo are you running? what cam?
seems to flatten off pretty early, but a nice torque line the whole way across.

is your kPa absolute?

tkgb

The red line is WHP so it holds power to redline.
Its the torque line that is dropping.

The turbo is a lindsey racing super 75 T4.
Cam is regrinded by a company in sweden,i dont have the spec on it.

Boost was 1.9 bar=27 psi.
Pretty high boost and it was not much gain in power from 23 psi.
It has a standard turbohead so thats one of many limits i guess

refresh951

I hope you are monitoring knock.

tkgb

I do have a knock monitor system installed and obviously knock can be a problem when you run on petrol at high boost.

But i have spend alot of time logging and tuning with the tunerpro software and got a pretty safe ignition map set so knock is not a big problem.

Thom

What is the level of overlap on the cam and what is the peak exhaust temp you are seeing?

333pg333

Interesting that you don't get the traditional 'fall-off' at about 6k. Especially with a stock turbo head?!!?
Weird.

Thom

Patrick, tkgb is running a self-made short runner intake, similar in shape to the one from the Estonian's 968.

tkgb

The info i found on the cam is duration 280 and lift 10.8 mm,dont know about the overlap.
Never monitored exhaust temp.

I did dyno this engine with stock intake and then the power started to drop at 5800 rpm,so the short runner intake really made a big difference

Im aware that the turbo head is a limit to more power and i have a 2.7 liter head that is going to be installed this vinter.

Thom

Would be interesting to know the exhaust temp to check if the cam profile is suitable. Is it a symmetrical profile?

Any progress with the new intake?

333pg333

Ahh, make more sense Thom but even so we have seen some motors that have fallen off with custom intake. Especially since he's running a supposedly safe map and on pump fuel. Cam and egts might be where some of us are missing?

tkgb

Its possible that my exhaust temp is sky high,but since i been pushing this engine hard for a couple of years now and nothing has melted i have not bother to monitor egt.

I will not use this cam on the 2.7 liter head, i have a new 8SR/8SR-14A1 camshaft from Jon Milledge that i will be using.
This camshaft is probably more race than street but it will be fun to try it.

Thom

Patrick, as far as I can see from the dyno sheet the torque loss is pretty steep past peak torque rpm. "Steep" in the sense that there is a loss of 100 N.m over just a 1500 rpm width.
I don't think it may be much noticeable from the driver's seat though, since engine acceleration may be quite fast past peak torque thanks to the short runner intake and the biiig turbo - 1.0 bar of boost is here reached are at a relatively "late" 4000 rpm. The LR75/T4 is I think a T66 (750hp turbo), not something you'd want to drop on your foot by accident.

I am sure the JME cam mentioned here will help flatten the torque curve, especially with 1° of advance, but had not heard of this 8SR/8SR combination before as this suggests a longer exhaust than intake duration? Unless the figures I have are incorrect.

tkgb

Yes the torque drops alot after it hits the peak number,but its not something that you feel when you drive the car.
The turbo is big and takes a little time to build pressure,but not to bad and i dont like turbos that cant hold boost at high rpm so better a little to big than to small.

The 8SR/8SR-14A1 camshaft is not listed on Jon Milledges website,its a combination that Jon suggested after he got the specs on the engine.

Thom

I just sent you an e-mail.