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drag car traction control

mitch1987

Apr 29, 2012
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Apr 29, 2012
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I am new to the electronics thing and really can admit I dont know what im talking about. I havnt ever taken on more than a few kits in my time so please bare with me. I am an auto electrician so have a basic knowledge of electrics and electronics. I am trying to make a traction control system to put in a drag car of mine. The theory is I have a speed sensor on the front and rear wheels and when the rear wheels increase over the front wheel speed I need to switch a positive, negative or relay and I can link this back into the engine computer and slightly cut power until wheel speeds become even. I think it should be a pretty simple task. The 2 speed sensors output sine waves. They are identical sensors however different pickup setups and front and rear tires are different diameters. So the inputs need to be adjustable or programmed some how. easiest way would be to drive along at 80 with meters connected to each and adjust a pot or something. The next adjustment I would like would be a way to adjust the sensitivity of the output trigger. basically what differences would be required to in the inputs before the output is triggered.

now the only way I can see to do it is to have a regulator for supply voltage and drop it down to 9vdc? then run 2 separate frequency to voltage convertors with output adjustments via a pot? then i need something to measure the difference in the voltages before triggering my output.
dont know if im anywhere near the rite track so im here for someone to let me know.

if someone could draw me a circuit or point me in the rite direction or any help would be great. Even if you could build it for me and we could sort something out for your time it would be much appreciated. thanks
 

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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Drag racing starts off with a high degree of wheel spin. The issue with traction control is that it might prevent wheel spin giving you a nice smooth (and slow) start.

(I don't know, I may be wrong)

I would look at the technology of MPPT tracking regulators. They calculate the power at a given instant, then make a small adjustment and see if the power goes up or down. If it goes up they keep making changes in that direction, if it goes down they start making them in the opposite direction.

It seems to me that you could do something similar with the G forces due to acceleration. apply a bit more throttle, if the acceleration improves, apply a little more, if it doesn't, apply a little less.

Such a system would have problems starting from zero because relatively large changes are initially required (presumably), and then fine control requires to keep in the region between that where too little power is being produces and where traction breaks down completely. Finally, once the speed of the vehicle is such that the wheels are no longer spinning, perhaps large changes in throttle are again possible.

All conjecture, since I have a car that couldn't spin its wheels on a skin-pan.
 

jackorocko

Apr 4, 2010
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Drag racing starts off with a high degree of wheel spin. The issue with traction control is that it might prevent wheel spin giving you a nice smooth (and slow) start.

(I don't know, I may be wrong)

Actually I was watching Paul Tracy the other day on tv test racing a ferrari. One of those test was a drag race against a porsche, tracy lost. His excuse, he forgot to turn off traction control. Then they showed a replay from inside his car during take off, it was nothing to pretty.

I think you might have a good point.
 

CocaCola

Apr 7, 2012
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It's my understanding that for drag racing you don't want any on board traction control, the slip and grip is better solved with a combination of proper tire and air pressure...

BTW car companies have invested HUGE amounts of money and time into these systems, they are huge undertakings if they are to work right... It's not something you are going to whip up overnight with a cheap design... My Vette is day and night with or without traction control, not good off the line when activated, but for every other instance it's a charm...
 
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mitch1987

Apr 29, 2012
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Apr 29, 2012
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alright guys thanks for your interest. This is correct when running big slick tires you need a certain amount of wheel-spin. The tires have to be turning the full length of the track to stop tire shake. and a small amount of wheel-spin off the line in most cases increases engine revs, getting up to the engines higher power/ torque area and making a faster run.
Traction control has been used in drag racing with much success in the past. The most common type is a tailshaft speed sensor and when the speed here increases over a preset amount the engine ignition timing is retarded and wheel-spin is gone.
This wont work for me as i drive the vehicle on the street and with differing ground conditions my actual acceleration rate changes. therefore i need something like what im trying to do to go faster.

Also in response to what you guys are saying hopefully i can change the amount of deference in needed between the front and rear wheels. so i can have a small amount of wheelspin.
thanks heaps guys
 
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