2006 Rule Book Posted!!

[Crusin]

Why are we hung up on the type of sensor? If an ecu requires an oxygen sensor to perform a function, why does it have to be the stock sensor? I would argue that any sensor can be used as long as an equivalent sensor was part of the original stock ECU configuration. It would be illegal to use a crank trigger for the ignition if the stock ECU used a cam angle sensor for example.

So, I would propose and aftermarket ECU is allowed in ST as long as the sensors perform the same function and no additional or alternate function sensors are allowed.

Hope this makes sense. If not, blame Diego

[Grippy]

What started all this is the question: if you run an aftermarket ECU that replaces the stock AFM with a MAP sensor, is that legal.

I think they perform the same function so I don't see a problem here. But the way the rule is currently written you must have the stock AFM which means you cannot use an aftermarket ECU that uses a MAP.

[WillM]

And this is exactly the spirit of the rule we voted on, and I agree.

Hmmm...interesting. I'm glad to see we are mostly on the same page, although I did a poor job of describing my point of view earlier.

I would argue that sensors are NOT an integral part of the ECU. In
particular, a fancy ECU like the Motec should be able to interface with
the stock sensors. While I personally wasn't thinking Motec when we
wrote this rule change, I agree that they should be allowed, provided
they are used with no other changes to facilitate their use.

So this all goes back to the air flow sensor. I agree with the point that Lee is getting at above.

"Sensors which measure air flow or air pressure may be added or substituted."

[jrussell]

What started all this is the question: if you run an aftermarket ECU that replaces the stock AFM with a MAP sensor, is that legal.

I think they perform the same function so I don't see a problem here. But the way the rule is currently written you must have the stock AFM which means you cannot use an aftermarket ECU that uses a MAP.

They may perform the same basic function, but the MAF would potentially provide a restriction in the intake where the MAP sensor will not. In the case of my 2nd Gen RX7 turbo the stock MAF sensor is basically the bottleneck. I replaced my ECU and most everything under the hood with an ECU I co-designed, so the first goal was to eliminate the MAF sensor. My car is far beyond the ST rules, but this discussion seems to be centered around airflow and ECUs.

I don't know of an aftermarket ECU on the market that would work with the stock RX7 MAF sensor since it's non-linear, and I don't know of any people that would install an aftermarket ECU and keep a MAF sensor. Speed Density is much simpler unless you have something unique like far too oversized cams or individual throttle bodies, although that can be made to work with MAP also, or Alpha-N and MAP blending.

My first impression was the thought that a chipped ECU in ST seemed OK. A standalone ECU replacement seems to not fit into the spirit of ST.

[HerbD]

This is on the agenda for tonight's Board meeting...

[HerbD]

So this all goes back to the air flow sensor.

Not exactly.

Remember, the old rule allowed "chip" changes. This presumes you are
keeping all the stock engine management and just changing the program
in the EEPROM.

Then, we added "flash", since that was the same as chip changes for
those who can't physically change the EEPROM, which is most OBD2
cars.

Then, the folks who couldn't "chip" or "flash" wanted to change the whole
CPU.

The only way this whole thing fits the spirit of the old rule, is if the ONLY
thing you change is the programming, by whatever means necessary,
and none of the other electronics.

However, since we are allowing CPU change, I'm not opposed to allowing
in aftermarket CPUs, the issue that I want to see minimized is the
rules creep that occurs when we do a LOT more than level the playing
field by introducing a whole new category of modifications.

I hope that makes my position more clear.

[kfoote]

There are cars out there where the MAF meter/sensor is a combined piece, and is the most restrictive part of the intake.

A Motec can be set up to use the stock sensors. We have a couple of them here at work that run quite well. If you got creative enough, a Motec could be used legally in ST. I've seen what I would consider to be an ST legal Motec setup in an SCCA IT car.

[Stynger]

Then, we added "flash", since that was the same as chip changes for
those who can't physically change the EEPROM, which is most OBD2
cars.

Then, the folks who couldn't "chip" or "flash" wanted to change the whole
CPU.

Correct me if I'm wrong, didn't this all start because turbo guys were chipping their cars, we couldn't police it, made it legal, then said they have to run stock boost.

Let's go back to stock ECU's, put turbos in their own class and watch for the smoke.

[Crusin]

Restrictor Plates...I vote restrictor plates. Run 18 lbs of boost, 40 degrees of advanced timing, 104 octane and a 40mm restrictor plate.....

[WillM]

This is on the agenda for tonight's Board meeting...

Woo-hoo!