Race Tracking Your Supra - Information exchange

[tomfree]

Didn't realize 1 post and a couple replies on a subject warranted shitty remarks. I take everything you post as incredibly helpful, truely, you're a massive asset to what i do to track my car. This has been an incredibly frustrating portion to a newcomer such as me so hopefully others can save time instead of throwing away a couple track days as i have.

Your post was one of manyyyyyyyy.

I get where Bryan is coming from, as we've had a LOT of "no matter what I do to bed in the PMu pads, I still get shudder" commentary over the last few months, and Bryan has consistently said that if you think you've bedded them in properly...bed them in some more.

I think it's safe to say that the PMu's need more bedding than most other compounds, ESPECIALLY if you are using rotors that have been used with ANY other compound (street, race, etc.)

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[Rob_SER]

Might as well rename this thread to "let's talk about brake shudder and how I am not able to properly bed in my brakes"

well I guess we're all idiots for having the same issue even though it's been discussed manyyyyyyyy times.

 

[spaghettihoes]

engine air filter anually?

I use an AEM DryFlow as they seem to filter better than K&N and don't require any oiling.

 

[tomfree]

Oh...and another quick thought. I've learned this the hard way. Aside from turning a rotor on a lathe, not a whole lot else you can do at home (wire wheel, emery cloth, etc.) really cleans the surface of a used rotor sufficiently.

Sure, you can get rid of some surface rust and discoloration, but not a many things you'd do at home really have the ability to "prep" a used rotor.

 

[spaghettihoes]

Now I know why you guys just do new rotors with new pads. I wired wheeled the stock rotors and installed the club racer pads. Bedded the snot out of them a month back and 2 hot laps into the track day today and they were shuddering like crazy.

I had this issue along with everyone else. I took off the rotors and hit them with brake cleaner, scotch brite and flex hone with an electric drill. I also lightly sanded the pads down a bit before re-installing.

I went to the track again 2 days ago and still had some shudder issues although it was definitely improved from the first time. I'll try it again before my trackday on Friday but I have new rotors and pads on order as well.

 

[razorlab]

well I guess we're all idiots for having the same issue even though it's been discussed manyyyyyyyy times.

Where did I ever say or even elude to that?

Five people posting again that they had issues makes my snarky statement carry even more weight.

 

[Rob_SER]

what I'm trying to say is, your reply implies everybody but you is an idiot because we are not being able to bed in those pads properly. Because everybody seem to have brake shuddering issues with those brake pads, except yourself.

 

[spaghettihoes]

Where did I ever say or even elude to that?

Five people posting again that they had issues makes my snarky statement carry even more weight.

The discussion now being about these snarky comments (which seem to be an epidemic on this forum) is less constructive than the original discussion.

Given how often the PMU Club Racers are suggested as track pads, the only place I could find out that other people had the same problem was in this thread. Unless everyone is willing to add a disclaimer about bedding or new rotors every time that pad is suggested I think more exposure on the issue is warranted. It's not like other topics haven't been beat to death in this thread either.

 

[razorlab]

The discussion now being about these snarky comments (which seem to be an epidemic on this forum) is less constructive than the original discussion.

Given how often the PMU Club Racers are suggested as track pads, the only place I could find out that other people had the same problem was in this thread. Unless everyone is willing to add a disclaimer about bedding or new rotors every time that pad is suggested I think more exposure on the issue is warranted. It's not like other topics haven't been beat to death in this thread either.

Can we just change the subject to oil? What oil is everyone using?

 

[garudathree]

I’ve over 1300 laps/24 hours of track time this season on PMU fronts, no issues. When I first started tracking, poor braking techniques (on/off switch) and lack of proper cool down (on track and during bedding in) caused pad smear /brake shudder.

 

[razorlab]

I’ve over 1300 laps/24 hours of track time this season on PMU fronts, no issues. When I first started tracking, poor braking techniques (on/off switch) and lack of proper cool down (on track and during bedding in) caused pad smear /brake shudder.

So... you're calling everyone else an idiot, right?

 

[i3igpete]

TBH, his comment just confused me more. You/mark/bob mentioned to bed in them in hard/violently, which I interpret as slamming the brakes with little to no modulation repeatedly to threshold, from full cold to full hot. But Peter mentioned that treating the brake pedal like a fully on/off switch didn't work for him.

 

[garudathree]

i'm not a brake expert, but my poor technique seemed to have caused more chunking, leading to poor leading edge self cleaning behavior, and eventually glazing/smear that doesn't come off in a few braking events.

 

[razorlab]

TBH, his comment just confused me more. You/mark/bob mentioned to bed in them in hard/violently, which I interpret as slamming the brakes with little to no modulation repeatedly to threshold, from full cold to full hot. But Peter mentioned that treating the brake pedal like a fully on/off switch didn't work for him.

Perhaps the open interpretation of "brake pad bedding" is the real issue here.

The following is how I have done brake pad bedding for 20+ years. If I get any judder, I do the bed in process more. It has worked for me and I'm actually the biggest idiot I know.

I start off with some hard braking from about 50-60mph. Not slamming on the brakes but very firm threshold braking events. Threshold braking to me is not standing on the brake pedal and letting ABS figure things out. I have found that can lead to an uneven transfer layer. I do this from 50-60mph to about 5 mph or so about four times. The I start upping the speed to about 70-80 and do that about four more times. If I can't find space, I repeat the 50-60mph events four or five more times.

After this, you should 100% smell brakes. Like something smells broken. I do not stop the car and keep my foot on the brakes, I drive around for around twenty minutes or so. If you had to drive a good distance to find enough open road to do this, just driving home will give you this time. If you have to come to a complete stop, put the car in N and sit, or try and time your twenty minutes of driving to cool everything off so you don't have to stop at all. I find rural roads are great for this.

 

[tomfree]

I pretty much do the same thing. I have access to enough back roads with minimal stops that I can do the cool down almost entirely without touching the brakes for 15-20 min.

I did the 60-5 stops at least 20 times bedding in the RSL29s. It was night, so I couldn't see smoke, but I'm guessing they were smoking...and the friction compound smell was very strong.

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