Tuning a 8TB manifold 383 with big cam

[oztracktuning]

I have just started tuning a car with 8 TB and 383 with a good sized cam. It can idle as low as 900rpm and 65Kpa MAP.

I have installed OS5 but havent started using the TP table yet. The car seems to be very rich everywhere when given the numbers i would expect it to need.

I am absolutely new to tuning car that doesnt have IAC etc and didnt know i would be tuning this car until this evening. So any advice would be greatly appreciated.

[TAQuickness]

Off topic, but can you post a pic of the set up? The 8 TB setup is sounding much better to me as I can't get my fast90 to seal up.

[Tordne]

Check this out - not sure it its the one your using Flyer...

Harrop 8TB

[ringram]

Sorry we cant make any helpful suggestions unless you get a good highres video of it running at full throttle with sound!

But anyway, why dont you use the IAT? Surely you can locate it somewhere, Id have thought it would be helpful.

If the cam is large with decent overlap I think your WB reading wont make much sence until the RPM gets up. You might be better off either making educated guesses or trying to set it up at low rpm with tps mode.

Perhaps its too rich down low. How about using bidi controls to lean it out till it stumbles when dial in a little fuel to even it out. Idle should be easy like that. That might give you a baseline, then the section between idle and midrange can be filled in by hand.

I made most of that up, but hey, it might be useful.

[joecar]

You need the IAT and MAP sensors since these are used (with the VE table) to compute the cylinder airmass, which is in turn used (with the IFR table) to compute the injector period; so those 2 sensors are essential.

If the manifold is the Harrop 8TB, then it looks very nice, too bad I wouldn't be able to sneak something like that past the visual inspection.

[Tordne]

It it the IAC (stepping motor) he doesn't have I think... That Harrop manifold is real nice but it is pricy!

[ringram]

Yeah I cant read.

[Tordne]

I can't spell

[joecar]

Yeah I cant read.

Oh, the IAC, I misread...

I can read but it all goes dislexic... or is that lisdecix... siclixed... xilsecid...

[oztracktuning]

Here is a pic. Its not a Harrop.
I dont know much about them but this one has a plenum.



It seems that idle air does nothing. The TBs can be adjusted individually for air at idle.
Its numbers in the VE table are small for what i would have expected at low throttle openings (and this is taking into account IFR). I havent started using the TP table in OS5 yet. But it is set to run in semi closed loop.