TRACTION CONTROL

[Steve]

Whoa!!!
Don't cut spark on a car with a converter.  You will melt it very quickly
(trust me I did it playing with an MSD two step).

Most OEM's use a combination of things to reduce torque output.  Secondary
throttle, brake application on spinning wheel, retarded timing and dropped
injector pulses (fuel cut).

Most OEM ecu's take the timing out very quickly, but are much slower to put
it back.  I don't think that retarding the timing would be enough to
eliminate traction problems on a high power vehicle.  On a low power
vehicle, it might do the trick.

There are several good SAE papers on traction control out there.  One
(942474) is on the BOSCH system for the Chrysler F1 engine.  They used a
rotating cylinder cut on fuel to control traction.  They were concerned with
wall wetting issues and crankshaft torsion vibrations so those were the 2
biggest concerns that led to fuel cut.  The ignition cut was ruled out
because of high EGT's with the fuel buring in the pipes and it wastes fuel.
Retarded timing was ruled out due to EGT being too high for the exhaust
valves.


Steve


>

>Bruce and Stuart  wrote:
>
>My "idea" was using a sudden change in VSS.  Ran some 555's for generating
>pulses on +and - transititions, to charge two caps.  Then a voltage divide
>by 10.  To drop the power I did stage one at losing every 7th ignition
>pulse. then very 5th, then 3rd.Problem with my design was totally dependent
>on temp to work.
>  Also tried using a MSD Multistep-Retard to back the timing up has three
>stages, and you can add them together.
>
>>
>>I am wanting to do a DIY traction control.
>>Does anyone know if OEM systems use ABS/apply brakes or >retard timing in
>the event of lost traction..
>>If it was retard timing maybe simulating a KNOCK would be a easy >way to
>reduce power and get traction back. The only problem i >would see here is
>how quickly doesn the ECU ( 808/165 ) give me >back full timing once a
knock
>has gone away.
>
>The decay rate is in the memcal, as well as the timing limits.
>
>Best idea I've seen is incorporating a front wheel speed sensor,
>and comparing it to the rears, or driveshaft.
>Bruce
>
>>Thanks in advance....
>>Best Regards,
>>STUART BUNNING
>>SALES ENGINEER
>>KENELEC PTY LTD
>>23-25 REDLAND DRIVE
>>MITCHAM VICTORIA 3132
>>AUSTRALIA
> stuart at kenelec.com.au
>>WEB:    http://www.kenelec.com.au/
>>
>
>