svp928

Hans, I'll wait to see what Mike wants to do- he may get some more people who want rotors, and we can do group buy then. If nobody signs up, I'll see what we can do.

hans14914

I talked to Mike about hats several times, and he has always been ready to go. I have just been on the slow side on ordering rotors. Was planning on getting StopTech rings and using Mike's hats. Still want to use Mikes hats, but cheaper rings from Coleman would be perfect for me, and hopefully help other people get the discount too.

Mike Simard

I'm just making a couple of sets. I have 1(count em, one) customer and am taking care of them.

Steve, it sounds like you have a good handle on rotors and could be the go-to guy for that. I could always make hats for whatever rotors appear if you don't want to do that.
The same question that this thread is for will come up though about rotor offset but it's no big deal to make hats for a batch of Colemans if they are different from the Brembo standard. It might be handy though to stick to a certain mounting bolt circle.

BC, these are full floating. That's the only way I would make them. I don't understand why anyone would not want that unless looks were the main goal.

svp928

Mike, I will look for specs on the Brembos and see what variations they come in. Most guys here seem to be using rotor that take either the "Big Red" size pad, or the std S-4 size pad. The S-4 is a very popular size, and fits a number of different brands of caliper. As for floating vs fixed, which hardware are you using? We need to get rotors spec'd for that particular setup. I agree its a better way to go for racing, a bit noisy for street.

Steve

Mike Simard

I'm using Brembo bobbins with my modified Coleman rotors. Since I had to machine them I went ahead and made the fit to the specific bobbins very close. I've never sensed any kind of vibration or noise from my brakes but it is a race only car. Maybe the tight fit helps? Now I'm curious if available rotors would be different with their slightly looser clearances to allow for normal variations.

This also brings up the age old question of what kind of performance car like behavior characteristics will be tolerated in a performance car by soft, consumer grade wimps. Heaven forbid your Porsche makes more brake noise than a Camry, oh the horrors!

If you can get rotors in a 355 x 32 with the 233 mount, it would be interchangeable. The question is whether Coleman can duplicate the offset or if they'll want to make them "flat".

BC

There are floating rotor hardware pieces that "reduce" the noise potential of the pins. I am sure that's enough.

Mike Simard

yes, the Brembo hardware has spring washer thingies on every other bobbin in an attempt to prevent vibration.

BC

I am sure that's enough in the name of using a rotor that does not become a bellville washer when heated.

mark kibort

The S4 pad is what is used on the ST40 Stoptech system, (uses a 13" rotor) popular with the WC touring racers and most of the BMW racers out there.

I have the 322mm rotor (GTS rotor) on my S4 calipers with the use of spacers and radiusing the calipers to fit the larger rotor. it works great. in fact, im generally using used GTS rotors now, and having them turned before I put them on my race car. (because I was going through a set of drilled rotors from the 965T every 3 weekends )

svp928

Mike, it sounds like the offset in the rotor bolt ring area you mention is something they do for the floating hardware- most are just flat. Mine are flat.. Coleman will cut them any way we want, with any hole pattern, so any info you have will help...

I am guessing that your hardware bolts solid to the hat and the rotor floats on the hardware- yes? This makes more sense in a "public" application, and the wave washers do kill the rattle.
The ones we made, the titanium bobbins bolted to the rotor and ran against a machined flat in the hat. Rattles at low speed, and make the hat a wear item. Throw-away every race! Not public friendly. Even racers whine about how much brakes cost- if only they knew how bad it could be..haha.

I do agree that the rattle is a minor detail- I was just too lazy to research the parts and machine everything to fit!

Mark, if Mike decides to run a few more hats and we decide on how to configure rotors, you may want to switch. I would choose to go with the S-4 pad size because of its common application, and the treated rotors seem to last a long time.

hacker-pschorr

I'm interested in a "package" to fill the gap of my 18" wheels. It's a street car so I'm well aware that my S brakes are sufficient. I just want really really big brakes on my 81.

With a pre-S4 suspension I have a feeling whatever setup is created will be for S4+ spindles though.

Lizard928

hey Hacker,

I have a complete S4 suspension FS.

svp928

Eric, I had a thread about big brakes on an pre-s4 on here somewhere....if could remember what it was called...

Lizard928

I managed to get my hands on a set of 380mm rotors the other day for trial fitment.
1x Brembo race, and 1x AP racing (for a titan). Along with an AP 6 piston caliper, and an F40 caliper

I tried them in my 18x11" kodiak rims,

I found that with the AP racing caliper that it was simply put WAY too tight to possibly be able to work without some work to the caliper, and even then airflow would be poor around the caliper.
However with the F40, which is pretty close to the S4 caliper, it clears with more than enough room.

now I just need to get the rings myself. and begin the modifications.

hacker-pschorr

Thanks, but I already have everything for a full conversion, just want to go bigger.