Tuning Aftermarket ecu's with Alpha-N

[ChaosAD]

Does anyone have any good links to sites on tuning an aftermarket ecu with alpha-N (TPS) and Alpha-N/Speed density (TPS/MAP).
Cant use map due to big cams and Quads.

Thanks,

[RedMist]

Best site I've come across so far is the megasquirt sites. Nice detail and a set methodology for creating a map alpha N or speed density.
Are you running Link? If so then why not run both?

[Akane]

You could tune by TPS vs RPM I think?

[RedMist]

Thats exactly what hes talking about Alpha N is a map generated on a matirx of TPS and RPM points.
http://www.megasquirt.info/manual/mtune.htm#alphan

[10k 20v]

what size injectors are u running, i'm sure daniel or i could set u up with a decent base map

[ChaosAD]

Im about to install a megasquirt running megaSquirtnSpark.
Getting some gt starlet injectors off -Stu- that are about 290cc.
Going to get the engine running with standard cams and Megasquirt, tuned with the narrowband O2 sensor.

Then once im sure theres no problems ill drop the cams in and try to get it tuned with the narrowband o2 sensor again so that I can drive it to the dyno to get it tned properly.

I was thinking of just running 20 degrees static timing till its on the dyno.

The version of MegaSquirtnSpark im playing with now will only do Alpha-N OR speed density. But I think the later version will do blended.

The tricky part with tuning alpha-N is working out where the effective WOT is. It is a very non-linear relationship and depends critically on the sizing of the throttle body.

Whats the best way of tackling that problem? is it just trial and error till you get it right

[Drifter4ag]

eayh ? i would suggest running a different code then.
TPS / MAP is fine and relativley easy to tune for. Running signal dampener is the best thing to do when you are running quads/big cams

[1598cc]

i really doubt youll be able to tune on a narrowband aye. narrowbands are useless

[Stu-]

You can get a tune of sorts via a narrow band o2 sensor but a wideband is the way to go. Before I got my wideband I used a new NTK narrow band unit to set the masterfuel and strip some fuel out in my car without too many problems.

[ChaosAD]

eayh ?

??

Wideband would be preferrable but I cannot justify spending $700 on one when I can get the vehicle professionally tuned on a dyno for not much more.

I know that 'stoich' isnt preferrable for power etc, but doesnt the factory ecu sit on that ratio when the car is in closed loop? ie all the time except idle and WOT. its only till I get it on the dyno anyhow

[spencer]

I know that 'stoich' isnt preferrable for power etc, but doesnt the factory ecu sit on that ratio when the car is in closed loop? ie all the time except idle and WOT. its only till I get it on the dyno anyhow

For best economy it should run leaner when not under load.