Hi People I am about to fit a wheel speed sensor to my quattro. I've read about the honeywell hall sensors that people use but my car already has a switch on the gearbox. The switch is a reed type with 2 wires and is switched 8 times (by magnets) for every revolution of the wheels.
As i understand the hall sensors are just transistors that switch 5 volt to the ecu so can i use my switch instead of a hall. 5 volts into the switch and the other wire going back to the undriven wheel speed pin (pin 2 on the sensor connector i think)?
Although after recently changing my ecu away from DTA...
Not sure if you would use ground or 5 on the reed switch.
I'm beginning to think the DTA had an internal pullup, and the GT101 actually switched to ground for the trigger. As opposed to no pullup, and switching high to 5v for the trigger.
I find it handy to wire 0v, 5v and signal to any sensor really...then it covers all options regardless of sensor type. Just use the pins you need, and it's future proof.
I would try Ground on one wire and the other to the input. It may have a 5V pullup already, as stated (I haven't checked) but you can add one with a 10k ohm or 1k and see what it does if it doesn't work without.
Thanks guys, I'll try switching the sensor ground to pin 2 first and see what happens.
Hi Stevie, I understand you switched to Syvecs, is that what you were using at TOTB? I'm liking your 183mph on the Kilo BTW . Grip must have been a big problem though.
Grip was a bit of a problem...but the fucked gearbox was more of an issue. Simply couldnt get gears and it hurt me badly, was down an easy 20mph on the 1/4 on that run.
Managed to go from 1st, to 2nd....back into 1st again LOL Didnt sound nice. Then took forever to get 3rd. Lost a good 100-150m of track because of it.
It would definitely have done 190 if I could have got a clean run.
And yes, on Syvecs now.
Strangely, first couple of runs I used my Hoosiers, circa 20psi. Had to back off at 165mph though, as every time I touched the throttle even then, it was just breaking traction. The 888's actually gripped better.
Hoosiers just seem to like very low pressures.
Had to try the runs as easy as possible to have a hope of getting the box into gear.
gnutz2 wrote:I've heard about wrinkle wall slicks doing strange things at speed before.
You've run the car into the high 9's before? any idea of the power output?
They were radials, not wrinkle walls ! and slippy at low and high speed lol.
It's ran 9's at Santa Pod some 6-7 years ago...havent actually been back since. Lost interest in drag racing after that, as had no real desire to break anything trying to go faster.
Havent a clue, needs more power though ! ( and needs even more grip lol ) just no easy way to add 4wd.
stevieturbo wrote:
They were radials, not wrinkle walls ! and slippy at low and high speed lol.
It's ran 9's at Santa Pod some 6-7 years ago...havent actually been back since. Lost interest in drag racing after that, as had no real desire to break anything trying to go faster.
Havent a clue, needs more power though ! ( and needs even more grip lol ) just no easy way to add 4wd.
I know what you mean about breaking things for the sake of half a second or so, drag racing is a slippery and expensive slope. I'm in a similar situation at the moment. My Quattro golf will run in the 10's, I'd like to get 9's but I can't commit time and money to justify a piece of paper saying 9.XXs. Track days seem to be the way forward for me to enjoy the car.
I still enjoy drag racing, but it's only been on airfields. Slower which is frustrating though, but almost no chance of breaking stuff ( almost )
I'd love to run a 10 in fully road legal format, tyres included, ie fully E marked etc. But best so far on 888's is around 11.3. I'm sure with enough practise and good launch I can do it though.
Weight and traction are heavily stacked against me though Also want a 150+ traps...which still elude me. Need more rpm's for that really.
Will investigate cam options over the winter.
Plus I'd like to do some 1/2 mile, 1km, or maybe mile runs again. Nowhere local does that sort of thing. I'd love to hit 200mph in 1km, but 190+ is more realistic
Been trying to do some hillclimbs locally, which although only done 3-4 so far, they're great fun.
Cant say today's was though as it bucketed down all day, I gave up at lunchtime and went to work instead.
Weather here sucks !
But they're a relatively cheap form of motorsport. Although need a racesuit, helmet etc. But if your car has original type of engine etc, entry is fairly straightforward.
I am about to fit a wheel speed sensor to my quattro. I've read about the honeywell hall sensors that people use but my car already has a switch on the gearbox. The switch is a reed type with 2 wires and is switched 8 times (by magnets) for every revolution of the wheels. 
. Grip must have been a big problem though.