Tuning a 8TB manifold 383 with big cam

[Clubsport R8]

Dont worry about the numbers, its quite normal to have a small VE % at low RPMs due to the camshaft nature, hence the low vaccum, you will loose a certain amount of fuel in the event of camshaft overlap.....LSA the tighter it is the more you loose cammed cars smell fuely..... In regards to the IAC not working make sure its operating (IAC its self), or nothing in the way of its air path & check that there is vaccum there.

A good start would be around the high 30s or 40% on the assumption that the IFR table are right.

Hope this helps

Cheers

Tim

[oztracktuning]

No IAC motor at all.
But thanks for info on overlap and "real AFRs" what sort of real afr would you have if the car 02s want to trim -20%

Is it a good idea to let the car try to trim with stft or not?

What afr is a good target afr to measure with a plx wideband to cruise around on at low load etc. It doesnt sound like it has heaps of overlap it might be 110-112

[TAQuickness]

No IAC motor at all.
But thanks for info on overlap and "real AFRs" what sort of real afr would you have if the car 02s want to trim -20%

Is it a good idea to let the car try to trim with stft or not?

What afr is a good target afr to measure with a plx wideband to cruise around on at low load etc. It doesnt sound like it has heaps of overlap it might be 110-112

You would need the cam specs at .004, .050, and .200 to get a real idea of overlap. Lobe profile is everthing.

[ringram]

Keep us up to date dude. Id hate to think how you get that to idle from cold start with no adjustments. Carbs even have chokes!

[TNT76]

Any updates?

[oztracktuning]

It was made quite close pretty easily and the customer was happy. It is supposed to be coming back to get some more fine adjustments made as it had quite a conservative tune in it just so that it could be driven the next day.

[ringram]

How did you sort out idle with no IAC?

[TAQuickness]

I would imagine idle is quite a bit more stable without the traditional manifold. Spark may be enough to hold it.

[oztracktuning]

Its idle was good at 920rpm. The air was adjustable in each TB. No problems at all - it has in the high 20s timing at idle.

[ringram]

I guess you need a vacuum guage to get each tb set right? Like the old SU carb days