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I got the car back in February and have had two track weekends to try and asses it. It's a 323is chassis with an S52 w M50 intake, 24lb injectors, MAF, tune. A dyno sheet from 2010 shows 260 rwhp. Weight is supposedly 2425 lbs.
Problem:
This is my first car without ABS and I can easily lock the rear brakes up under heavy braking. I'm sure I will adapt, but I am hoping there is a better solution.
Current braking setup:
Front: Brembo BBK with Girodisc two piece 332mm rotors, Hawk DTC-50
Rear: stock m3 calipers and rotors, Hawk DTC-50
The ABS pump is still in the car but the wiring harness seems to be deleted. I think that might be the only thing stopping it from being functional though.
There is a Tilton screw type brake proportioning valve on the dash, but the stainless lines are not connected to the master cylinder or the abs pump. I was going to plumb it back in, but the H (rear) port on the master cylinder is a larger diameter than the V (front) port, and the end fittings on the stainless lines are both the smaller size. My guess is the master cyl has been replaced and the Tilton valve was disconnected due to the fittings.
Current suspension setup:
Bilstein PSS9 (re-valved for heavier spring rates) with H&R 150-60-150 springs, not sure of the current damper settings. They are quite old but are not leaking.
Turner Motorsport sway bars front and rear
Turner Motorsport carbon fiber brake duct kit
Front Camber plates
Turner Motorsport rear lower camber arms
My M3ish
M3ish.jpg
Last edited by rs4eva; 05-09-2023 at 11:55 AM.
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These cars come with rear bias, and the ABS is then designed to manage that. WIthout the ABS, you'll absolutely need that proportioning valve installed. Buy/install whatever size line adapters are needed.
Long term, or short term if possible, get that ABS working. It saves tires, among other things.
Check if your ABS control module is still in the car (right footwell wall of front passenger).
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The brake bias in an E36 uses the ABS pump in the exact way you've described, where proportioning is rear-biased to a destabilizing, dangerous level when the ABS pump is no longer powered.
The natural hydraulic bias in an E36 is actually very reasonable, with rotor diameters of ~315mm F / 312mm R, and brake piston diameters of 60mm F / 40 mm R. This results in a ~67/33 front/rear bias, which should be more or less naturally stable at max deceleration.
If you want to completely delete ABS, go full measure. Remove all piping to the ABS pump and run new lines off the master cylinder. It should not be very difficult.
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I agree that 67/33 should be in the ballpark of ideal for most car/tires. But I've talked to quite a few who have lost ABS on the E36, and everyone says the bias is too far rear for non-ABS track driving. And it certainly was on my E36 M3.
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Agreed with the heavy rear bias without functioning ABS. Even using a manual bais valve it was difficult keeping the rear tire from locking up even after running an ABS free e36 for near a decade and was frustrating to say the least.
OP,
Dont mess around and just plumb in an MK60 ABS system. Yes, its another 500 or 600 dollars but it SOLVES the problems. If you want any e36 ABS equipment to swap in while diag or as spares or whatever let me know as my failed attempt to standalone e36 ABS was such a failure I went through with the MK60 and have all of those parts laying in the garage.
Member
Agreed with the heavy rear bias without functioning ABS. Even using a manual bais valve it was difficult keeping the rear tire from locking up even after running an ABS free e36 for near a decade and was frustrating to say the least.
OP,
Dont mess around and just plumb in an MK60 ABS system. Yes, its another 500 or 600 dollars but it SOLVES the problems. If you want any e36 ABS equipment to swap in while diag or as spares or whatever let me know as my failed attempt to standalone e36 ABS was such a failure I went through with the MK60 and have all of those parts laying in the garage.
Member
Thanks for the responses. I have some follow up questionsOriginally Posted by FredK
What is the rear bias without ABS?
Does the larger front brake setup improve the bias, but obviously not enough?
Would a more aggressive pad on the front or less on the rear help?
@olemiss540 I googled Mk60 ABS system, but it seems like they are closer to 2k. If there is somewhere they are available for 500-600 please let me know.
Last edited by rs4eva; 05-10-2023 at 08:36 AM.
Member
The bias is the same with or without the ABS pump installed or working. If the ABS is working, it simply prevents the rears from locking when at threashold, while the fronts might be at 70%.
Larger front brakes usually change bias, but it depends (mainly) on rotor size, piston diam, and # of pistons. It can move bias forward or backwards.
Yes, a more agressive pad in the front and less agressive in the rear can help. The challenge is when you move to different compounds f/r, they'll have different temperature ranges. It can work (I do it), but might take some experimentation.
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Rs4,
I found mine on a part out for sale section. Bought pump/yaw/sensors all for around 650 bucks. Then a cheap e36 z3 3.0 booster/master off ebay and a wire terminal kit.
Get abs working on your current car as priority #1.
Member
/off topic a bit
Me and a friend are thinking about buying one of the cheap MK60s (preferrably off a RWD like a Vovlo, but maybe even a VW or such), and popping the ABS computer on my car, and seeing how well it works. It could be a path to a cheap(er) solution.
/back to OP's problems
Member
/off topic a bit
Me and a friend are thinking about buying one of the cheap MK60s (preferrably off a RWD like a Vovlo, but maybe even a VW or such), and popping the ABS computer on my car, and seeing how well it works. It could be a path to a cheap(er) solution.
/back to OP's problems
Member
You could always just grab an MK60 setup off a regular e46 or z3 I would think for cheap and get 90% of the benefits. No point in going with a non-bmw option if the non-m versions are cheapish I would think.
Member
If cheap enough, yes! The ones on high volume cars can be had for under $100.
Member
Thanks.
The current setup is actually not unmanageable, but it does give me something else to think about when braking. I'll try the proportioning valve to start and see how hard it is to get the original ABS connected.
- - - Updated - - -
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I'm looking into the current 4 channel ABS setup and it doesn't appear to have the computer or any wiring going to it. I am also not running a stock gauge cluster if that matters at all.
Member
Update on my ABS.
I plumbed in the proportioning valve and at first had a little trouble getting it the driver rear to bleed using the Motive, very little fluid came out. I had my friend work the pedals and it bleed fine.
Now, the pedal is firm when the car is off, but when I turn it on, it is squishy after the first press. I have bled the system again using the motive and I didn't see any bubbles, but the squishy pedal is still present. I've only had driven the car a couple times and I honestly don't recall if this is how the pedal behaved before.
When I connected the stainless brake lines from the rear (H) MC out -> Tilton proportioning valve -> rear in (H) of the disabled ABS pump I did not purge the air from the lines before completing the circuit. I'm thinking that I pushed the air that was in the stainless lines into the ABS pump and now I won't be able to bleed it, as the pump wiring has been removed from the car.
I'm going to try another human bleed and see if that changes anything.
Member
Why are you leaving the ABS pump plumbed in? First step I would do is buy some unions and remove the ABS pump entirely until a later date (if you ever decide to add back in ABS). There is a bleed screw on the side of some ABS systems that you can use to bleed the pump but I almost think those were 3 channel units only.
Pull the pump so its out of the equation from a balance and bleeding perspective.
Member
If it's not wired, then any air that got in to the pump should come out on a normal bleed.
Should.
But I'm with olemiss, just get it out of there.
FYI, it's typical for a vacuum boosted system to feel very hard when the car is off and you've pushed the pedal a few times (you've lost all the vacuum so no boost is being applied), then softer when started (you get boost back).
Member
Two reasons. I did not have the proper fittings and hoses at the time and figured it wouldn't make a difference since the pump was not active. I wanted also to see if the brake proportioning valve actually worked. If it did I would remove the pump entirely, if not I would get the ABS working again.
and that is how it was hooked up in the past as far as I can tell.
Last edited by rs4eva; 06-12-2023 at 04:47 PM.
Member
Two options: bleed it a bunch and recirculate fluid through it (so you don't waste fluid) and then send it on a track day (bleed after or if the pedal gets soft)
Remove the ABS pump with some tee's and get rid of dead weight and rebleed.
Either will work fine but even with the prop valve fully retracted still had rear lockup in mine :-(
Member
That is kinda of what I am suspecting will be the result of this setup and I'll just figure out how to hook up the ABS again.
Going to the track this weekend and we'll see what happens. Fingers crossed it's not a total disaster.
Member
The test results are in.
I ended up doing more bleeding prior to the weekend and the pedal firmed up. As far as the proportioning valve, like @olemiss540, I had to pretty much have the valve at its lowest setting, otherwise it would lock up pretty readily.
So I will be adding back the ABS system in prep for the next event at Watkins Glen in July. Thanks for your inputs.
Here is my best lap from the weekend.
Member
Yep, those that have lived this know the rear bias on these cars seems worse than the math says it should be.
Glad you're getting it figured out.
Consider an MK60.
Member
I will look into the MK60, but I'm hoping to work with what I got for now.
I have:
ABS pump
Wheel speed sensors are still in the hubs
ABS module from another e36. I have to figure out if it's the right one for my car.
I'm missing:
the screw on connector from the engine wiring harness.
the wheel speed sensor wires going back to the harness/computer.
the ABS relay, or even the bracket in the fusebox.
What else do I need? Is there a good reference for the OEM system somewhere?
If I can't get it done in time for the next event, my contingency plan is to try a less aggressive pad in the rear or more aggressive pad up front. I'm currently DTC-50 all around.
Rear options: Ferodo DS2500, Hawk HT-10, Stop-tech sport (I used these on my first M3 for years and they were fine.)
Front options: Hawk DTC-70, 60
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Should have took me up in my offer for all those parts I had before they went to the dump :-(
I would find an e36 part out and just grab everything they have for cheap. A 3 channel system may be the route you want to go for ease of standalone wiring/setup...
Last warning, you will be spending a good amount of time trying to get an OLD system that worked intermittently back when it was new.....
Be ready to diag issues frequently until you give up and get a more modern setup.....
On the brake pads, I would get dtc-70 fronts and give that a try. If there is still too much torque in the rear go with a set of dtc 30 rear pads if they sell them in your pad size. Should have lower torque than the 50 or ht10.
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