N80

I recently put some good, but blank, OEM type rotors on my 07 non-Brembo Z for track use. Last weekend was just the fourth track day for these rotors and one of the front rotors is warped....or something....I do not see any cracks.....it just vibrates when braking. It did not happen until after the last session on Sunday.

It is still plenty thick so I'm wondering if a warped rotor can be cut and trued or is it toast? These rotors only cost about $55 each but a local shop will cut them for $15 each so it would save me a little bit. And every little bit helps because going to the track is getting pricey.

Brake pads alone are killing me. I just got Carbotech XP-10s front and XP-8s rear and even though they work fantastic and have never faded they are about gone after 4 days at the track. I might can get one more day out of them. That comes out to about $75 a track day on pads......but my local track is known for being hard on brakes.

terrasmak

iTrader: (8)

Yes, but it will warp again soon

b18ccivics

iTrader: (11)

yes there is a minimum thickness so they can be turned down to that, but the thinner they are the easier to warp.

N80

So worth it or not? I'd be fine if I could get one more track day out of these rotors but at the same time don't want to screw up a track day with a rotor that warps.

Maybe I should just get them cut, put them on and carry an extra set just in case. I'm to the point where I can change pads and rotors between sessions if I have to.

I'm just at the DE-2 level but I'm finally catching on and getting considerably faster (I really sucked when I was starting out) so now I'm carrying more speed into the corners and trying to compress braking zones so I'm getting harder on pads and rotors. I'm sure I could improve my technique to conserve brakes a little but I'm wondering how much pad/rotor you guys are going through in a typical track day/weekend?

terrasmak

iTrader: (8)

Cut it and bring an extra rotor or two with you to the track. Simple to swap between sessions

KNS Brakes

iTrader: (2)

Sometimes what you are experiencing isn't a warped rotor at all. Its whats called brake judder.

It happens from an uneven pad deposit onto the rotor and will cause a vibrating sensation through the steering wheel when braking. You can take it to a machine shop and have them take a thin layer off, or clean your rotors and sand down the deposits with same fine sand paper or emory cloth. Next time you go to put the rotors on be sure to bed them in properly.

-Nick

scotts300

iTrader: (46)

THIS ^^^ is most common over warped rotors on a Z, in my experience.

N80

That could be the issue. I felt it more in the steering than in the brake pedal. So maybe I will get them to cut a tiny amount and see how they do.

Two other issues now that I've had more time to inspect things a little better:

1) The wear on the pads (all 4 fronts) is uneven from top to bottom by about a mm or two. Not much but visible. Not sure why.

2) Close inspection of the rotors shows some tiny, short, mostly radial (extending out from the center) cracks. They look like short little spider webs. Does this kill the rotors?

terrasmak

iTrader: (8)

You may have bent a wheel

Outer part of the rotor is actually traveling at a higher speed than the inner part and will cause more wear on the outer section

No, it is normal on a tracked car. Till they can easily be caught by a fingernail or crack all the way thru, they are good.

Just give the rotors and easy pass. Since you are on stock rotors, just carry an extra set to the track, simple and cheap, takes about 20 minutes each to swap. Sucks my rings are $250 each, i want extras to carry at the track.

N80

Cracks are too small to hang on a fingernail, or any thing else. Will cut them and see how it goes. I've got an extra set to take to the track.

Wheels are brand new Enkei RPF-1s....hope they're not bent!

terrasmak

iTrader: (8)

Probably not, maybe a wheel weight got thrown. I actually use duct tape over my wheel weights like what is required in sportbike racing. I have thrown a couple weights on the track.

KNS Brakes

iTrader: (2)

The cracks you see in the rotor are just stress cracks, like terrasmak said unless you can hang a fingernail on them they are fine. What kind of pads are you using?

-Nick

N80

Carbotech xp-8 rear, xp-10 front.

Don't thinks its a wheel or wheel weight. Changing the rotor made vibration go away and it only happened with braking.

bestkiter

This is luck that I found this thread.
I hope I can get some advice on this.

I just found out that the rotors on my 2009 European 370Z are warped... The front ones were turned and are ok but the rear ones need done.

I would like to know what would be suggested to order for new rotors and brake pads. I saw some information on the DBA's but am not sure what is the best to get and also the model number if the USA models have the same as the European models... Also with the brake pads, which ones would be advisable??? I drive in Germany and sometimes get up to 180mph in which needs to be sure to stop good :-)
I will order from the USA and ship through my APO.

Thanks for your advice,
Carl

KNS Brakes

iTrader: (2)

DBA has great rotors, but unfortunately for you the 370Z owners they do not make a T2 version of the rotor, but the T3 is better heavier duty rotor.

Brake pads, If you worried about stopping from 180 I would more than likely suggest the HP+, but on the downside of that they have a tendency to be noisy, and dusty. But those are the prices you pay for having a brake pad with good bite.

Another pad is a Carbotech XP-10 or XP-8, but also they have a tendency to be noisey, but less dusty than the HP+.

-Nick

bestkiter

Thanks Nick,
A great help. So, I should get the DBA Rotors but there is a T3 and also XS...??? Would you also know if they surely will fit my European model?

Also, where is the best place to order them and the Carbotech pads??

Thanks for the help,
Carl

KNS Brakes

iTrader: (2)

I see that DBA has the Slotted in stock I do not see an XS, but the drilled is only for looks, it actually decreased the structural integrity of the rotor, I do not know 100% if the European model is the same as the one here in the states.

But I have the DBA rotors and also the Carbotechs, you can order those through me.

Shoot me a PM, we are new to the site so we are offering great new vendor promotions.

-Nick

Escobar

iTrader: (27)

It could also be the hubs. When I put my bbk on I had a pulse in my pedal when I braked. I tried everything, new pads rotors, everything and it turned out to be the hubs. $200 on rockauto and I was back to smooth braking.

N80

Not the hubs. Again, changed rotors and pads and vibration is gone. So it has to be either rotors or pads. Likely due to residue build up on rotors. Superb article here:

http://www.stoptech.com/technical-su...nd-other-myths

N80

I just read the whole article linked above and I think he got it exactly right; for my problem at least.

Here is what happened:

1. Mounted brand new blank rotors and Carbotech pads.
2. Followed bedding in procedure.
3. Went to track. Great brake performance.
4. Left rotors on a put oem street pads on.
5. Put maybe 500 miles of daily driving on car.
6. Pulled OEM pads off and put Carbotech pads back on.
7. Never really did a real bedding in process.
8. Went to track. Good but maybe not great brake performance (but I was much faster this time (awesome, insane instructor) so it may be that I was just harder on them.
9. Notice vibration, right front, when braking on way home from event.
10. Put street pads and old rotors back on. No vibration.
11. I can feel deposits on the rotors and the Carbotech pads are badly pitted.

The article was exactly right.

The moral of the story is that I did not bed the pads/rotors properly after driving with street pads on. But, even if I had, I might have still gotten the same result since Carbotech says very clearly that the bedding in process requires a new or newly cut rotor.

Moral of the story: 1) Always do proper bed in. 2) In my case, use one set of rotors for track and another for street. That way the rotors will always be bedded in for the Carbotech pads.