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Have any of you track junkies had this problem with your ABS? At a test day at Thunderhill a "friend" (actually a very experienced race driver and a bit more agressive than me) spun on turn 8, did a 180, and coasted up the hill in reverse. He reported once the car was going backwards the ABS stopped functioning and he had no brakes!

Anyone heard of this one? Any fixes?
 

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I think if you search for 'ice mode' you'll find a lot. One theory was that after a sustained run of full throttle, a leaking valve in the brake booster meant loss of vacuum in that component and hence loss of brake assist, leading to a perception of loss of brakes when in reality the brake force was just greatly increased (edit - or rather, the pedal force to produce a given braking force increased).

There's a difference between 'ABS stopped functioning' and 'no brakes', hard to see those both happening at the same time....if ABS stops functioning, that usually means wheels will lock up.
 

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Thanks Matt,
Perhaps I should have been more clear. The driver reported that once the Exige was backwards the brakes were non-responsive. The wheels did not lock up. Did the ABS prevent the brakes from working?

BTW - I have an 06 Exige, track pack, Katana, Moroso oil pan, Accusump, 2Ubular 8' X 24' exaust, etc.
 

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Thanks Matt,
Perhaps I should have been more clear. The driver reported that once the Exige was backwards the brakes were non-responsive. The wheels did not lock up. Did the ABS prevent the brakes from working?

BTW - I have an 06 Exige, track pack, Katana, Moroso oil pan, Accusump, 2Ubular 8' X 24' exaust, etc.
Any news on this topic? I aggree, that the wheels are not locking by going backwards. So your ABS-Lotus gives you a hard time in this situation:). Braking with the handbrake could be on solution. The other one, would be to switch off ABS.
Are there any "nice" solutions available?
 

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I removed the ABS system completely and re-plummed the brake lines with a prop valve for short term solution. This has caused me to make some adjustment to how I brake, but for the most part I don't miss ABS at all, even when I was running in the Wet last Monday at Infineon.

Long term solutions is separate front and rear master cylinders and a brake balance bar ... I have the pedals already, just need to add masters and plum lines and add strength to footwell area to support brake foot pressures.

Only downside to no ABS is that if you have some very sticky rubber it will flat spot a tire quickly -- with the Lotus the fronts can lock up without providing much initial input that they are locked up -- it's been a learning curve for me, but I still prefer no ABS.

Many OEM street ABS systems aren't good to have active when on track - a friend of mine (in his Vette) hit the wall in T6 at Infineon because of a right front flat which caused his ABS system to basically disable all other braking ... not fun for him ... lots of damage that could have been avoided and/or minimized.

Rob.
 

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That's a common experience... the ABS seems to get confused when the car spins; even when you have both feet in the car will roll (especially backward).

To avoid this, release the brake and reapply.

As to removing/disabling the ABS: +1 to Rob's post. Lightweight slicks can lock up very easily and will be fatally flat-spotted in seconds.
 

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Don't get wrong about ABS or TC, they are great systems to have, but without the ability to control/tune both you are left with factory assumptions that don't translate well to track conditions and tire choices.

There are some really good aftermarket ABS and TC systems out there -- some race series permit their use, some don't. A good race worthy ABS system (with software) start around $12,000 (such as the one used in World Challenge GT on Vettes) -- the key is the software and tuning the system.

Rob
 

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Thanks for the quick response. Sorry, that I'm not knowing Infinion - it happend in Spa Francorchamps, while rain has started after weeks of sunshine.
I probably can't switch off ABS. ABS increases my safety while going forward, especially braking really hard at high speeds. I like, how this car brakes going forward :).
Andy: Release the brake just in a split of a second and brake again? Does this work reliable? So does ABS get's the information of going backwards? Why?
End of the story: I turned another 180°, came in wet grass and hit the wall after a while. At least, I touched very soft, but there still is a completly damaged front clam and something on the upper wishbone.
I'm pretty sure, the situation of turning would much easier to control without ABS. Exactly at the point of loosing the car at corner exits (oversteer, fully steered against). Hitting the bakes to 4 fully locked wheels slides you simply tangential - at best out to the straight :)! ABS works against this. It tries to follow the angle of the car. So there are often crashes towards inner sides of corner exits...
Or am I wrong with my theory?
 

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Sorry to hear about the damage. I still think you would be better/safer with OEM ABS turned off (remove the fuse or install a switch) on track. Some event organizers actually require you to turn ABS OFF.

I was very thankful I no longer had ABS last Monday when the car stepped around (throttle oversteer) on me ... I was able to manage a 360 degree rotation and grab the right gear (2nd) and carry on without going off into the grass ... happened so quickly the corner workers didn't even catch it -- had I been using the OEM ABS system I probably would have been in the grass and into the wall.

Wish I had my video camera running, but didn't want to get it wet (no windows and all) so wasn't mounted at the time.

Rob
 

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I'm tempted to install a switch that cuts out one of the wheel speed sensors (disconnecting a wheel speed sensor disables the ABS, but also causes the traction control to behave badly... I used to disable both).

Yes, if you release quickly and immediately brake again the ABS will allow braking again. I don't think the ABS can sense that the car is going backward... what's probably happening is that at some point in the spin one or more wheels are turning (or not turning) at a very different rate... that triggers the ABS to attempt to "release" pressure on the slow wheel(s). Since the wheels will really only turn when the car is pointing roughly forward or backward (while you're sideways in the spin the wheels don't turn much), the first "stable" configuration once a spin starts is likely to be while you're going backward... and if you're not braking hard when the car turns backward, it will suddenly get traction as the slip angle appoaches zero.
 

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It sounds attractive, driving without ABS, but I'm not knowing, in which situations it already helped me!?
I'm concerned that my rear brakes could be too strong for going without. This could easily cause a spin at the moment of hitting the brake very hard. My rear brakepads (and discs) are a little more worn than the front ones (regular brakes, not AP)? Could this be a correct balance? The car squiggles a little when ABS starts working. But up to the point ABS starts working, the brake feels really good.
LTC is another story. Mine seems not working well. What's the purpose of a TC, if you still spin while accelerating in corners??? Or is it just mine?
 

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It sounds attractive, driving without ABS, but I'm not knowing, in which situations it already helped me!?
I'm concerned that my rear brakes could be too strong for going without. This could easily cause a spin at the moment of hitting the brake very hard. My rear brakepads (and discs) are a little more worn than the front ones (regular brakes, not AP)? Could this be a correct balance? The car squiggles a little when ABS starts working. But up to the point ABS starts working, the brake feels really good.
The regular brakes are really quite well balanced... my front and rear brakes and rotors wear very evenly... of course the front pads start out thicker than the rear, but they seem to wear in the same ratio.


LTC is another story. Mine seems not working well. What's the purpose of a TC, if you still spin while accelerating in corners??? Or is it just mine?
You have variable TC, yes? You could always reduce the slip allowed by the TC (turn the dial counter-clockwise). Or you can use your right foot as traction control... ;)
 

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You have variable TC, yes? You could always reduce the slip allowed by the TC (turn the dial counter-clockwise). Or you can use your right foot as traction control... ;)[/QUOTE]


Yes, I have the variable TC. Isn't it set to "on / 0% slip" automatically after starting the engine?
I'm going to try hand throttle, my right food isn't sensitive obviously :)!
 

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apk919 said:
You have variable TC, yes? You could always reduce the slip allowed by the TC (turn the dial counter-clockwise). Or you can use your right foot as traction control... ;)

Yes, I have the variable TC. Isn't it set to "on / 0% slip" automatically after starting the engine?
I'm going to try hand throttle, my right food isn't sensitive obviously :)!
No, by default the TC is set to around 6% slip, I believe. You have to press and hold the TC button for around 5 seconds until the light comes on... only then does the TC knob actually set the level of TC.

Unfortunately you have to do this every time you start the car...
 

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No, by default the TC is set to around 6% slip, I believe. You have to press and hold the TC button for around 5 seconds until the light comes on... only then does the TC knob actually set the level of TC.

Unfortunately you have to do this every time you start the car...
I just checked my manual i got with the car 2009. It says to the Variable traction control: "Each time the ignition is on, normal full LTC is activated. To enable..."
Is there a easy way to test function of the LTC?
I tried different LTC settings on a safe but wet place back in 2009. I could spin arround in every setting - it didn't matter if it was set to 0% slip (on) or completely switched off. Sure you can't cheat physics, so there are cases it can't work. But accelerating with same steering angle or even with opening the steering while accelerating, it should defintively control. It only controls while accelerating when it's very slippery e.g. starting in wet gras:). Than the wheel speeds of front and rear are that much different, that it works there at least. There must be a wheelspin of min. 2% (owners manual). I would say, my car needs much more wheelspin or the system is just too slow...
Lotus said, that I would push the throttle to much (in corners)... Just wondering for what purpose it's invented, only for the starting process:shrug:?
 

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I just checked my manual i got with the car 2009. It says to the Variable traction control: "Each time the ignition is on, normal full LTC is activated. To enable..."
Is there a easy way to test function of the LTC?
I tried different LTC settings on a safe but wet place back in 2009. I could spin arround in every setting - it didn't matter if it was set to 0% slip (on) or completely switched off. Sure you can't cheat physics, so there are cases it can't work. But accelerating with same steering angle or even with opening the steering while accelerating, it should defintively control. It only controls while accelerating when it's very slippery e.g. starting in wet gras:). Than the wheel speeds of front and rear are that much different, that it works there at least. There must be a wheelspin of min. 2% (owners manual). I would say, my car needs much more wheelspin or the system is just too slow...
Lotus said, that I would push the throttle to much (in corners)... Just wondering for what purpose it's invented, only for the starting process:shrug:?
First, I think the TC is defeated at speeds below 6mph (10kmh), but I'm pretty sure you're talking about higher speeds. All the TC can do is cut the engine power when it senses the rear wheels spinning... when this happens you should definitely feel and hear the engine "misfiring", as if one or two cylinders are not firing. But if you've already started rotating at that point, it's not going to prevent you from spinning; it might actually make it worse. It's not nearly as sophisticated as a "stability control" system, which can also control the brakes independently.
 

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First, I think the TC is defeated at speeds below 6mph (10kmh), but I'm pretty sure you're talking about higher speeds. All the TC can do is cut the engine power when it senses the rear wheels spinning... when this happens you should definitely feel and hear the engine "misfiring", as if one or two cylinders are not firing. But if you've already started rotating at that point, it's not going to prevent you from spinning; it might actually make it worse. It's not nearly as sophisticated as a "stability control" system, which can also control the brakes independently.
If the LTC interupts when you are already turning, you get something like a "highsider". I would turn it off in my car, but I'm luckily that mine isn't working in this situation:). I think in wet conditions you can lift the gas pedal much more than in dry while drifting. So the LTC could work maybe better there - if it works in generall.
Other idea:
Could my strong plate type LSD, make the problems? At a open dif. you probably have much more wheelspin at the inner rear wheel. The outer rear wheel could still go with the same pace than the front wheels. The car haven't started turning, but the LTC already works. 2% spin could be detected much earlier. At my car both rear wheels need to spin, what probably causes turning already. This would explain, why I think my LTC is just to slow or very late.
Or am I wrong with my thinking?
 
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