Having some difficulty getting my rear rotor kit sorted out, the company that supplies EBC pads/rotors here is insisting I've got the wrong kit selected, and there is conflicting information all over. I know (think?) they switched to outboard in the mid 90s?

Car is a 89' with inboard brakes.

Most websites show rear rotors at 10.4" and some at 11.6?

EBC 3GD Series Sport Slotted Rotors #GD239
Rear 10.4 in. Dia.

or

EBC 3GD Series Sport Slotted Rotors #GD550
Rear 11.6 in. Dia.


Can someone clarify which is right? I have until tonight to either confirm or cancel the order and then fight with them to get my money returned.

 

The inboard solid rotors are 10.4". The later outboard (again solid) rotors are 11.6" and the final outboard vented rotors are 12".

 

I'd imagine I would have to buy different calipers then OE to fit larger rotors? Mine are the original solid ones with a tone ring, moving to slotted vented ones so I never have to change them again.

 

Yes, I suspect different calipers. There isn't space in there for an adapter bracket.


Are the vented rotors thicker than the original? Even with the same diameter, you'd need a different caliper to accommodate a thicker rotor.

 

If anyone wants to use vented discs on the inboard axle, then you need callipers adjusted to take the wider vented disc. Kits are available with all the necessary parts from UK suppliers.
My concern would be the proximity of the exhaust pipe to a wider calliper. As it is, the best I can do is about 3/4 of an inch gap between the pipe and the calliper at the nearest point. If this mode were to be done, then routing the exhaust under the cage would be a very good idea.
FWIW, unless you are racing, this is a totally unnecessary mod, in my view. Decent solid discs and EBC Redstuff pads all round will stand up to very hard road use easily.

 

The caliper-to-pipe spacing has always worried me a bit. Even with original configuration I've oft thought of wrapping that area of the pipes to keep some of the heat away from the calipers.

I agree.

Cheers
DD

 

That is a good idea, Doug.

 

Thanks for the replies, I've ordered my 'overkill' brake kit, thankfully I don't have rear exhaust pipes to deal with. For people that do, or if you happen to be in a position to remove your entire system the cost for thermal coatings is relatively cheap, I'll be coating my new system before install, leaves a chrome like finish from manifold to tip. Wraps are nice but subject to damage and unraveling over time.

 

Vancouver, what I meant was that with wider callipers, installing the normal exhaust through-axle pipes might make them run extremely close to the callipers in use. I did not mean the installation of the callipers etc would be more difficult to do.
Did you mean your exhaust has been, or will be, re-routed and not go through the cage?

 

Side exit straight pipes on this car, stock pipes fell off awhile ago.