Jeff Curtis

John McM, the AIM Solo showing small HP improvements is possible, but not likely.
It would likely show up as better lap times, but then we enter into a wildly objective situation there as tire condition, brakes, environmentals, etc. all make a difference.

Yes, I understand booking time on a "rolling road" or AWD type dyno can be a pain. I'm fortunate that the dyno is literally right around the corner from my home/shop and I'm on good terms with the owner.

EVERY change I make, whether it be exhaust, tune, etc. I go to the dyno and keep pretty good records/notes on the changes. I had two chips for my 964, a generic Autothority chip basically given to me by a friend to fix my idle issues due to a LWF, also offered a few HP advantage, and the custom chip by Steve W. that hit the nail on the head with one of his files, we did not have to fine tune that chip as our #s (air/fuel) looked great after several passes due to different exhaust systems over a race season.

John McM

[QUOTE="Jeff Curtis;11145964"]John McM, the AIM Solo showing small HP improvements is possible, but not likely. It would likely show up as better lap times, but then we enter into a wildly objective situation there as tire condition, brakes, environmentals, etc. all make a difference. Yes, I understand booking time on a "rolling road" or AWD type dyno can be a pain. I'm fortunate that the dyno is literally right around the corner from my home/shop and I'm on good terms with the owner. EVERY change I make, whether it be exhaust, tune, etc. I go to the dyno and keep pretty good records/notes on the changes. I had two chips for my 964, a generic Autothority chip basically given to me by a friend to fix my idle issues due to a LWF, also offered a few HP advantage, and the custom chip by Steve W. that hit the nail on the head with one of his files, we did not have to fine tune that chip as our #s (air/fuel) looked great after several passes due to different exhaust systems over a race season.[/QUOTE

Any idea what impact a non functioning WOT microswitch would have on power for a ROW car with no 02 sensor?

scarceller

Cold start idle hunt often is the result of rich mixture and/or to much ignition advance. Either of these 2 conditions increase flame front speeds and result in hunting cold start idle. In a stock 3.2L engine usually leaning out the base mixture a tad corrects the issue.

However, in 3.2L engines with modified cams, light flywheels, custom exhaust, ... you sometimes can't totally eliminate the idle hunt at cold start.

scarceller

With a WOT switch that does not close at WOT you will run in the PT Maps and these have lower ign advance than the WOT map so you will simply be down on power. The WOT switches often have corroded contacts since they are not a sealed switch like the idle switch. And the WOT switch is not often activated in a daily driver and this causes the contacts to corrode even quicker in humid environments. Good news is that the WOT switch is easy to take apart and clean the contacts.

Lorenfb

"With a WOT switch that does not close at WOT you will run in the PT Maps and these have lower ign advance than the WOT map"

Not necessarily!

scarceller

What exactly does Not necessarily mean?

Do you mean you don't run in the PT maps?

Or do you mean ignition won't be reduced?

For reference here's the WOT map from the 89 chip and the max load ign from the PT map, side by side

RPM - WOT IGN - PT IGN
2520 - 23deg - 20
4000 - 26 - 25
4520 - 24
5000 - 24 - 20
5200 - 23
5760 - 22
6000 - 24 - 20
6160 - 23
6400 - 23

Those are the values right out of the maps for the 89 chip.
I also have fully disassembled the DME program code and know for sure you won't ever enter WOT maps without the WOT switch closed.

So what do you mean by 'not necessarily'?

Lorenfb

"So what do you mean by 'not necessarily'?"

Without actually checking the so-called "tuner's" ignition maps from the so-called
"performance" chip, you really can't state with certainty which of the two maps sets,
PT or FT, has the greater timing advance.

scarceller

Loren, that's a good point, I was only referring to the stock chip.

John McM

I'm installing the Specialist Components engine management kit so I went for a dyno run to get baseline data.

With the help of a fellow Rennlister we used two ECU units, one standard and one with the Steve Wong Chip. The later unequivocally added 20kW at the rear wheels. We did two runs with each ECU and AFR were good with all, the Steve Wong chip running an AFR of ~ 11.3 from 4,800 rpm onwards.

For me personally the debate is over, the Steve Wong chip works in my car and is worth every cent.