No ABS?

[jlevie]

I had always thought of threshold braking as being just to the point of ABS activation until I did a Skip Barber racing school in Formula cars. They have no ABS (or brake boost for that matter) and we spent a good part of one morning learning to threshold brake. True threshold braking is past the point that a street ABS system activates.

Threshold braking means enough brakes to keep the tires at the point where there's some slip. In this regime the car sort of squirms under braking with very small oscillations in yaw as one side of the car gains and losses grip. That's obviously past the point where ABS would activate. And once triggered the ABS will remain engaged to a point well below the trigger point (the logic has to have hysteresis). I suspect that the ABS system on an E30 probably can't maintain more than about 85% of what's possible and the system found on late model BMW's probably tops out around 90%. And I've heard numbers in that range from the instructors at Skip Barber racing schools. A multi-channel race ABS raises those numbers to the point where it is worthwhile to have.

[Hallen]

In my context, we've seen problems with an E30 going into a braking zone and when you go to the pedal, the pedal is rock hard and you have no braking at all. Not a good feeling when you are 10/10ths on track doing 120+ at the end of the straight. You have to get off the brakes for a slight moment, somehow they cycle, then you get back on the brakes and you have brakes. Problem is if you really leave your braking to the last bit, then to have to get off the brakes means there is no way you will make the turn. Thus the big off and possibly a wrecked car if there is not good runoff.

The ABS on an E30 is really rudimentary. We think it is more designed for the occasional use in the wet, but not in a high performance setting as a routine way to slow the car.

I've experienced it once while driving another PRO-3 car in an enduro, when we had 4 drivers doing stints in the car. Got the rock hard brake pedal going into T1 at Portland. It does not happen every lap, so you don't know when you'll get it, and when the brakes will be OK.

Thanks Lance, that's good to know. I will be doing the first track day for my E30 without the ABS. It is currently disabled. That wasn't by choice necessarily, I just didn't have time to fix it. I will just have to be careful on cold tires and work my way up to speed. I would do that anyway since it is a new to me car and I have done tons of work on it so I need to approach things methodically.

[Raxe]

For some reason unknown to me, my 1988 325 never had ABS installed from the factory.

[Lance Racing]

I have an '87 Canadian Eta car (4-door) that does not have ABS too. Also came with cloth seats, hand crank windows and steel wheels. Sort of a stripper model.

[george graves]

What is needed to delete the ABS unit? I wondering if there are factory bent(or at least flared) lines to do it.

[PiercedE30]

details(on the 4 channel ABS)?

I've got a pump from an E46 328 that am going to be working with. I need to get the harness out of it and go through it and see what can be removed and make sure it will work. The guys who made MegaSquirt are working on a project that SHOULD be coming out in late June/early July, at the latest end of the summer, that will be able to do traction control, ABS control, and tranny control (GPIO board). I will end up using that to control the ABS pump solenoids and take readings from all 4 wheel sensors. I will also have a knob in the passenger compartment that I will be able to use to adjust the amount of slip/traction control adjustment.
A LOT cheaper than a Bosch Motorsports ABS system.

[Jean]

I've got a pump from an E46 328 that am going to be working with. I need to get the harness out of it and go through it and see what can be removed and make sure it will work. The guys who made MegaSquirt are working on a project that SHOULD be coming out in late June/early July, at the latest end of the summer, that will be able to do traction control, ABS control, and tranny control (GPIO board). I will end up using that to control the ABS pump solenoids and take readings from all 4 wheel sensors. I will also have a knob in the passenger compartment that I will be able to use to adjust the amount of slip/traction control adjustment.
A LOT cheaper than a Bosch Motorsports ABS system.

That sounds pretty cool! Keep us updated with your progress :D

[nando]

"Dreaded ABS Lockout" is when the ABS system fails for one reason or another.

I will be excited to try out the 4 channel ABS that I will start working on later this summer.

anyone ever consider upgrading to the ix ABS? it has 5 sensors - not sure if it's 3 or 4 channel though. But threshold braking from 100mph+ I can just about lock them up without ABS activating.

[JGood]

Anyone unable to get wheel lockup or ABS while running r-comps? I'm running 205 V700's, Hawk HT-10's, and have the 25mm master cylinder. Proper bleed with Super Blue.

I can lock up street tires in a heart beat and get the ABS activation, but it seems on the track I can mash the pedal and it will be below the lock-up point (not sure how much, but the braking is still very strong, I just don't get lock up or ABS action). I don't know if the ABS is activating so smoothly that I don't notice it (doubtful) or the pads are just not enough to overpower the grip of the tires (also doubtful...)

[Massive Lee]

If ABS was engaging, you would feel it automatically. The brake pedal would kick back and grind. It makes also a very typical knocking sound.

[PiercedE30]

anyone ever consider upgrading to the ix ABS? it has 5 sensors - not sure if it's 3 or 4 channel though. But threshold braking from 100mph+ I can just about lock them up without ABS activating.

How many brake lines are coming out of the abs pump?

[SimonH]

What are your goals for driving?

Lance, I agree with a lot of your points. I just think alot of drivers are under the impression turning off the abs will be faster because that is what they have heard. I'm just saying they will probably be faster with it on, even if it is giving them some bad braking habits. They'll still have to figure out how to be fast in the first 3rd of the turn, with or without abs. Ultimately you are correct they will learn more without abs but I still don't recommend it for inexperienced drivers. And for the poster that couldn't feel the ABS on the track, sometimes it is working without that distinctive pulsing in the pedal. Take out the relay and report back to us, you're probably find out you're braking too hard still.

[JGood]

If ABS was engaging, you would feel it automatically. The brake pedal would kick back and grind. It makes also a very typical knocking sound.

Yeah, I know what it feels like. It engages fine with street tires. I just don't feel it on the track, whether it's engaging or not...

[Hick]

No ABS here. Works fine for the Autocross with big sticky tires and hawk pads. last event i locked them up a few times on the first run because it was cold, but after that they dont lock up unless im way out of shape or on the dirty stuff.

Autocross is nothing like track use. so for that im not sure.

[ethirtydavid]

ABS is your friend