This!
Or centric's etc from rockauto.com
Usually, if a pad is rubbing enough to cause rotor warpage, you'll definitely know it after pulling into pits. Smoke, smell, rotor hat turns a different color, rotor surface looks different than others, etc.
Have you measured the run-out of your 'warped' rotors. It's extremely rare to warp a rotor. Even a cheapo $30 E36 rotor.
Do you have these in your car? I do. From the Bimmerworld website. Not saying I am correct but hope you give Jame and the boys some slack for posting this on their site. Pay attention from 2:38 out. Notice when he has the clip installed the bushing literally slide when he turns the caliper sideways. A small bit of lube should be where the pad sit on the carrier. My car is on the lift and if I stick my finger up on the bushings they will move. I think the design on these is to spread the resistance out on as many surfaces as possible since the bushing does not sit tight laterally in the caliper. Why? (rhetorical) Hope this helps.
https://www.youtube.com/watch?time_c...&v=XFJ0Wog0Seo
ME:"I want to make my car faster and lighter"
THEM:" Get out and let someone else drive"
They don't smell or smoke afterwards and the hats don't turn a different color. The rotor surface does look marred with streaks of what looks like black pad deposits. So do you think with an OEM rotor I should be fine after changing out the calipers with rebuilt ones? or do you think I should see any difference with the DBA T3 4000 series rotors? Do you think it's worth it to spend $180 a rotor (even though I found a site that sells them for $135)? Or should I go with a stoptech slotted rotor (around $95 a rotor)?
If i'm not mistaken the run-out was .04"
+1 on post 26. That is why it would be nice to see heat numbers. Or if the bedding is off a bit or something. Just throwing crap at the wall to see what stick: If the pad is wrong what is the affect on not getting the temp range correct? I don't know anything on this but it might be an issue.
Also agree on the rebuild caliper as the money you save is usually non existent if you place any value on your time
ME:"I want to make my car faster and lighter"
THEM:" Get out and let someone else drive"
Agreed this is pretty weird. I've been running, bimmerworld brass guide bushings, any random/cheap rotor, and Hawk DTC60s forever and have never had pad deposit issues. (I had tons with Carbotech pads, fwiw). I have my heat shields removed, but no other ducting. I'm actually not great at caliper bushing maintenance either.. they've never given me trouble. I run fairly quick on R1-Ss, R7s, and NT01s.
I'd recommend rebuilding the stock/OEM calipers, though. Its dead simple with just a bike pump. I've heard aftermarket calipers aren't as good somehow. Who knows, but its at least cheaper and you know you're getting quality (ATE) seals/boots.
I'd investigate the path of overheating the brakes due to over braking or a mechanical issue. Maybe get some thermal paint for the rotors and calipers.
I just started a new thread to see if there is some input on rebuilt vs new calipers. I would not consider buying a rebuilt caliper if there is a concern with safety. I have talked to a few people already and some say buy new and some tell me they always just buy rebuilt ones and don't have any issues.
Come highly recommended by one of the forums mastertech and racer, bmwdirtracer
Read here:https://www.bimmerforums.com/forum/s...1#post29508051
Last edited by HalfFast1; 07-11-2018 at 10:15 AM.
The reasons are in the thread link above, if you read through it.
Last edited by MIKYZZ4; 07-12-2018 at 02:22 PM.
Last edited by bluptgm3; 07-11-2018 at 07:50 PM.
I know with the ECS bushing kit I have the bushings are ribbed and press-fit. They shouldn't move anywhere once installed. They are also a bit longer than the ones in that video, have a flat side on the flange end to clear the piston bore, and don't sit quite as flush (though that doesn't matter since there's always a gap between the caliper and the bracket, unless you have no pads). The length means that the pins sit entirely inside the bushings once tightened, allowing the plastic cap to fit neatly over the end.
I only had binding issues due to human error right after installation when I was using a stubby hex bit that was too short on the front brakes and slightly bent the end of one of the guide pins causing it to bind and drag the pad. After replacing that, all my pins slide smoothly and are easy to remove and reinstall.
Last edited by TostitoBandito; 07-11-2018 at 07:36 PM.
1999 M3/2/5 - Titanium Silver - Track/Weekend Toy
You do have your rotors correctly oriented right?
He said he had the centrics. Think they are straight but it is still a good point as I have see guys at the track with the rotors on the wrong side.
ME:"I want to make my car faster and lighter"
THEM:" Get out and let someone else drive"
Cars: '98 M3 Coupe - Daily Driver
'98 M3 sedan - Track car:
Well there's your problem,
deleting the cooling that was incorporated into the design.
Yeah, seriously. Granted I have two-piece front rotors, but just with the stock cooling and trimmed backing plates (no ducting) my front brakes are fine even on tracks with long straights where I'm braking from 135+. If anything, my rears can get hotter at times, though that's probably more due to me not braking as aggressively as I need to than anything.
1999 M3/2/5 - Titanium Silver - Track/Weekend Toy
Several track only M3’s I race against have blocked off the stock cooling tunnels and have no other cooling ducts and have less issues with brakes. Race only pads of course.
That may be the clue here.
He has replaced rotors multiple times&brands,
but never once mentions switching pads.
Right, AFAIK the people who block off the stock cooling ducts do it to maintain more ideal (higher) operating temperatures for whatever race pad compound they're using, so the brakes don't get too cool on straights. These guys are typically in full track/race cars which are quick enough to get enough air without any ducts/inlets, and are also usually lighter than street cars so the brakes don't have to deal with as much thermal energy.
I don't think heat/cooling is the issue here, unless the OP can provide brake temps from the track which indicate an issue. The OP said he was using pretty aggressive Hawk DTC-70 pads which are certainly a track compound which should love high temperatures. These pad compounds should supposedly work even to the point where the rotors would be visibly glowing (1500F or so). Seems like the possibilities are:
- Pads defective or poorly performing, leaving excess deposits, etc... (try different pads on fresh rotors)
- Pads/rotors not bedded properly
- Rotors defective (very unlikely)
- Driver-induced, meaning that the way the OP uses the brakes on the track is why this is occurring
Last edited by TostitoBandito; 07-15-2018 at 08:11 PM.
1999 M3/2/5 - Titanium Silver - Track/Weekend Toy
I do put put on the parking brake when I park the car.
I can’t believe nobody mentioned this, but using your parking brake when your rotors are hot is the best way to warp your rotors.
Another thing that would warp your rotors is over tightened wheels. What torque are you using on your lugs?
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