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 (http://www.harrop.com.au/root_folder/harrop_manifolds/amfd7022-00.html)

[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. :D

[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... :bash:

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

[oztracktuning]

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

http://i77.photobucket.com/albums/j45/oztrack/cars/8throttlebody.jpg

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.

[Tordne]

Damn pic is too small. Looks pretty nice though!!!

[oztracktuning]

I am going to do an auto VE on the Throttle % table - has anyone got some good starting values i can use.

My guess is it has about a 230 cam and its 383

[Tordne]

I can send ya a table from my stock cammed car? You'd probably want to add a percentage to it for the cam. But you may be able to fine tune with BEN factors.

Let me know and I'll send it to ya I an excel sheet.

[oztracktuning]

The 129005 file im using already has it populated is a GTS M6 one. Are these the same values.

[ringram]

Actually near idle you probably dont need to add anything. Stock is probably more efficient there.

How much costy that shinny octopus Sir? Where can we see pics and info!?

PS: Guys get Firefox 2 Beta 1 it has a built in spellcheck for forum posts. It checks each word as you type. Well cool! http://www.mozilla.org/projects/bonecho/all-beta.html

[Tordne]

The 129005 file im using already has it populated is a GTS M6 one. Are these the same values.

Not for the TPS VE Table as the X and Y axis are different.

[Tordne]

PS: Guys get Firefox 2 Beta 1 it has a built in spellcheck for forum posts. It checks each word as you type. Well cool! http://www.mozilla.org/projects/bonecho/all-beta.html

Mate, this is the answer to my dreams!!! Finally I don;t have to paste to Outlook, check and then paste back to forum :cheers:

[oztracktuning]

PM sent about the 8 TB

Are there two version of 129005?? Maybe just send me the excel file and i will compare.

[Tordne]

Nope, just the one version :) The TPS VE Table is located under the Custom OS section. It is RPM vs. TP% rather than RPM vs. MAP like standard VE Table.

[Tordne]

Fire me a PM as well with the TB info if you don't mind, and your email address.

[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

[TNT76]

Any follow up info on this Manifold setup OZTRACK?
How it tuned up in the end, did you get it back to fine tune it.
Any power, torque figures.
Would like to have an idea of how it would compare to a Harrop and the like.
I tried emailing the website you gave me a couple of times a few weeks ago and have had no response.
Do you know of anyone else using this setup?
Cheers
Trent.

[joecar]

TNT,

You may also want to send a PM to oztracktuning (http://forum.efilive.com/member.php?u=829) to be sure he sees your questions.

[TNT76]

Thanks joecar,
Oztrack has allready sent me a PM and filled me in.
May look into this manifold for myself.