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Discussion Starter · #1 ·
Anyone know what the various ESP sensors are and how the algorithm operates in general?

I've recently heavily modified the suspension and now I'm seeing ESP kicking in all the time. I've checked wire routing of the wheel speed sensors and nothing seems to be making contact. I'm wondering if this stiff setup - 900lb/1000lb F/R - is causing some wheel lift or if the algorithm is kicking in due to the lack of body roll.

TIA!,
Greg
 

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There are four sensors in the R32's ESP system. A brake pressure sensor, steering angle sensor, lateral acceleration sensor, and a longitudinal acceleration sensor.

ESP typically kicks in when the steering angle doesn't correspond with the reading from the lateral acceleration sensor, i.e. during a skid, and it will brake individual wheels to bring the car back to the ideal line. It would also kick in if the reading from the longitudinal acceleration sensor doesn't match what the wheel speed sensors are seeing, i.e. wheelspin.

I don't think your ESP is malfunctioning, there would be a fault code if it was. When exactly does it seem to kick in? During cornering or acceleration?
 

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Discussion Starter · #5 ·
There are four sensors in the R32's ESP system. A brake pressure sensor, steering angle sensor, lateral acceleration sensor, and a longitudinal acceleration sensor.

ESP typically kicks in when the steering angle doesn't correspond with the reading from the lateral acceleration sensor, i.e. during a skid, and it will brake individual wheels to bring the car back to the ideal line. It would also kick in if the reading from the longitudinal acceleration sensor doesn't match what the wheel speed sensors are seeing, i.e. wheelspin.

I don't think your ESP is malfunctioning, there would be a fault code if it was. When exactly does it seem to kick in? During cornering or acceleration?
Kicking in on acceleration is normal. ;-) Since the suspension changes it's kicking in on corners, but not overly hard. I turn ESP off and take the same corner at 80 that triggered ESP at 60.
 

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Discussion Starter · #10 ·
what was the deciding factor for those spring rates?
I guess you can all my R a DD, but I don't drive into an office. I'm either working from my home office or flying off to some remote circus. So over the past 2 years I've been slowly transforming the R into a track focused build.

Suspension work is being done mostly at AR:
http://www.arautoservice.com
(feels a bit like the ghetto car in the high roller bay..)

Local support is through Edge Motorsports:
https://www.facebook.com/pages/Edge-Motorsports-Repair/110752455654233
(GREAT local supporters of all things VW!!)

They use mostly all MCS dampers on all customer cars from Miatas to GT3s.
http://www.motioncontrolsuspension.com/mcs-custom-made-dampers.html

Working through them with MCS and GC we're starting with 900/1000 f/r

Right now the rears are actually mounted as coil-overs on the rear dampers due to GC sending the wrong adjustable spring mounts and AR improvising to get me back on the road. Right now I think the rears are a bit soft compared to the fronts. Hopefully next week the correct GC mounts will be in and AR will be installing 1000lb rears in the stock location.
 

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With rates like those, I'm going to assume you have double adjustable shocks. Try setting your rebound damping to full soft.

Thoroughly inspect the ABS sensor wiring again. Check with a voltmeter.
 

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Discussion Starter · #12 ·
With rates like those, I'm going to assume you have double adjustable shocks. Try setting your rebound damping to full soft.

Thoroughly inspect the ABS sensor wiring again. Check with a voltmeter.
Nope, I got a set of custom MCS singles valved for these spring rates. They're upgradable to 3-way with remotes, but I've other place on the R to put the $ right now.
 

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Discussion Starter · #14 ·
Try disconnecting one of the rear sway bar endlinks, then.

What kind of tires are you running and what's the temperature where you are?
I'll wait until the rears get sorted out next week. I have a Hotchkins RSB currently on the softest setting, I believe 20% over stock. I had it on full stiff w/ stock springs but wanted to easy my way into rotation with the new setup. Again, need to get the rear sorted first.

ESP has been kicking in from day-1 with this setup, ranging from 20deg to 60deg. 235/45-17 Yokohama YK580. BTW, these tires ROCKED in the snow and ice!!
 

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Discussion Starter · #15 ·
..I should add that I'm also suffering from another failed CAT that is partially blocking one down pipe. That gets sorted on Monday with a test pipe. 2 failed HF cats in 2 months. I'm done. I can then at least open it up again w/ the rear link disconnected on the current setup.
 

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The other issue to watch out for is the "rock hard brake pedal" when the ABS freezes up the brake pedal when you are trying to brake.

Seems to happen when ABS kicks in but one rear wheel is off the ground over a bump.

No one has mentioned that for a while.:p
 

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..I should add that I'm also suffering from another failed CAT that is partially blocking one down pipe. That gets sorted on Monday with a test pipe. 2 failed HF cats in 2 months. I'm done.


If you burned through 2 cats in 2 months- a test pipe is not a solution. Are you misfiring? Dumping fuel? Something has to be seriously out of wack to melt 2 cores. Who's tune is on the car? What other mods? The cause should be easy to figure out with vagcom.
 

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Discussion Starter · #18 · (Edited)
If you burned through 2 cats in 2 months- a test pipe is not a solution. Are you misfiring? Dumping fuel? Something has to be seriously out of wack to melt 2 cores. Who's tune is on the car? What other mods? The cause should be easy to figure out with vagcom.
Yes, yes.. Nothing too crazy - UM, NA, 264/268 cams, some head work. Ran this way with the stock cats for over a year, w/ several track days and AutoX with no issue. Then I dropped in TT's high-flow cats (not the race cats). First one failed within a month. Suspect is CATS from same bad batch. The failed CAT was cut out by TT and a new one welded in. Failed 2nd cat within two weeks. We see it has a different date code on it than the failed cat. Once we get it out we'll see if the other, older date code failed on a different DP, or the new one on the same DP. Then we can speculate on fueling, etc, or just happily rock the TP.
 

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Then I dropped in TT's high-flow cats (not the race cats). First one failed within a month.The failed CAT was cut out by TT and a new one welded in. Failed 2nd cat within two weeks.

Nothing changed other than the cats? Nothing taken apart in the engine bay? How many miles on the car? Could be a coil pack acting up. Do you have a vagcom?
 
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