Picked up a beat Lexus SC300 (three-pedal version) about a month ago to use in crapcan next season (hopefully). Got it running after cleaning out the fuel system and I'm getting ready to start stripping all the accessories. I've been debating whether to tear out the abs system and put in an adjustable prop valve, or to just keep the brakes as they are.
I'll probably have a definitive answer for myself after getting the car to the track and seeing just how much of a nanny the abs unit is, but I'm curious to hear what you guys think.
I like the simplicity and weight savings of removing the abs and I think it will make bleeding the system easier. I also like the idea of being able to dial in the optimal brake bias.
I don't like the idea of teammates flat-spotting tires if they're not used to the brakes/tires/car or the idea of them needing to adjust the bias if it rains, etc. Also, it is a $25 budget hit in Chumpcar.
Anyway, let me know what you guys think. Much appreciated.
Pics or it didn't happen, right? (Build thread to come when I have time to post more.)
BTW, I'm used to racing without ABS (and usually with R-comps) so I don't have an issue personally with tossing the ABS, though I could see it being nice to be able to just stomp on the brakes in an endurance race without worrying about keeping the tires right at the threshold of grip.
Also maybe useful info, the car will have pretty aggressive pads (something like the Hawk DTC-60s) and "street" (200 treadwear) tires.
I'd put an adjustable proportioning valve in along with a switch to defeat the ABS. The prop valve will help get the balance in the ballpark, which should delay the onset of ABS in the first place.
sort of like how Traction Control works wonderfully with an LSD. If you can delay the onset of the nannies, you can get more out of them when you really need them
Oh dear science! Glad you're gutting the interior and going racecar because that's one of the more disgusting interiors I've ever seen. I mean I've seen people driving around with trash piled everywhere in their car, but I can almost smell the interior of this car through the picture.
I'm with Keith on this one.
+1 for what Keith said. Plus it gets around the budget hit of removing ABS even if it turns out you never want to use it.
If the ABS isn't horrible and the brakes are that touchy (or the drivers are that noobish 
) it might be better to run with it even if it means extending your braking distance, it's an endurance race after all.
ABS is wonderful for new drivers and rain. Keep it keep it keep it.
Once you've run a race or two and are sure your team can threshold brake better than the ABS system, defeat it. But you shouldn't need to. Endurance racing is about enduring, and ABS should help you do that.
One word of warning about ABS and racing - I've seen some evidence that it increases brake pad wear dramatically. That can be a big deal in an enduro.
My Neon had ABS, which I would pull the fuse on, since its not legal in IT. With the front wheel drive weight bias, I had a "holy E36 M3" moment as I popped over the brow of a rise just before a left- the fast line is to brake as you hit the upslope, and trailbrake into the corner. When the left rear tire lifted off the ground, as it is likely to do in such a situation, the ABS pump kicked on and tried to shut that wheel off, and as is typical with most American applications, it turned off most of the brakes to all 4 wheels.
I pulled the system shortly after that.
Thanks for all the great advice guys - lots here to mull over.
I think for now (and maybe for the first few crapcan races next season) I'll keep the system installed and we can pull the fuse to try racing with and without it hooked up.
I have driven the following cars with ABS on track in anger and have never had any issues that ABS aggrivated and plenty of times where it saved tires at a minimum and a lot more in several cases. I like it so much I wouldn't have a dual purpose car without it and I don't want my wife to ever drive a car on the road without it. I also ran a Spec Neon w/o ABS so I can brake without the aid I just choose not to.
The cars I have tracked multiple times with ABS and without issue.
00 Focus (X2 disc/drum)
02 WRX
99 10AE Miata
02 Neon RT
01 S2000
05 Saab 92X
05 Focus ST (disc/disc)
06 STi
09 Civic Si
Saab 9-3
Opel Astra at The Ring
Dry or wet, bumps,curbs and even jumps (Grattan) I never felt the car had any issue anyway related to ABS. The only ABS related issue I have experienced was with the 02 WRX on the street on bumps when almost at a stop (~7-12MPH) where it would go into ice mode and greatly reduce brake force for a split second. No incident but less than comforting when it wasn't expected.
The safety, tire saving and ease of braking near the maximum for all skill level drivers would have me looking for how to best maximize the system and keep it, particularly in any endurance setting.
We had a situation in the 2011 Thunderhill where one of our drivers switched on the ABS. Pad use shot up, to the point where the car ate a set of pads far earlier than we expected and the driver had an exciting ride when the car ended up on the backing plates. We turned the ABS off, problem went away.
It's something I'd definitely check if I was going to be racing enduros, rate of pad use with and without ABS.
In reply to Keith Tanner:
Yeah, that's definitely a big deal. A successful crapcan team is doing an entire race on a single set of tires. If the car chews through brakes bad enough to need a change within 24 hrs, then that's a deal breaker. It would be really hard to place near the top with even one pit stop long enough to do fuel and brake pads.
We usually needed to do two pad changes in the 25 hour race, but this wasn't crapcan racing. We could do them pretty quickly.
In reply to Keith Tanner:
Yeah, I don't think it would take a ton of time, but the crapcar races are seeing pretty ridiculously close competition with several cars often finishing on the same lap at the end of the race.
ChumpCar gives you a 5 minute minimum pit stop to do fuel, and it usually takes about 3 minutes or so to do that. If you don't have the car rolling towards pit out at 4 1/2 minutes, you could have lost the lead. You also can't work on the car while fueling, so pad changes aren't going to happen in 5 minutes.
Add to that the fact that competitive teams are only making pit stops to do fuel and driver change at 2 hour intervals, which is the maximum allowed driver stint time, and it makes it hard to justify anything that would require more than a couple minutes for service.
