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Discussion Starter #1 (Edited)
Left Handed Brake Discs....L & R?!?!?

Looking over my second Elise up close recently I noticed that the handed brake rotors (curved vane design) appeared to be the same on both sides of the car. (Most rotors have straight vanes)

Usually curved vane rotors are handed as in a left hand and a right hand version. So far both of the Elises I've looked over have what seem to be LHS rotors on both sides of the car. When I saw the first one I noted it to myself and wondered if it was an oversight or if they all came like that. It could be two RHS discs. I wonder if this is a cost saving measure and if it has any effect on the cooling effect a vented disc enjoys as it centrifuges air from the center towards the outside diameter. This move would have cut tooling costs as only one style of casting form would be required, and twice as many of one kind can be made. From the Pics below you can see that with only one orientation, one side of the car would have to have the discs mounted backwards.

Here is a curved vane disc (nonLotus) with the innards exposed.



Typical installation orientation:

 

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Hmm..interesting issue>>>

the StopTech brakes I put on my TT had clearly marked L & R for the rotors for that reason of being unidirectional...but with that said I have little insight as to what issues exists when something that appears to be unidirectional becomes non directional. Good question...
 

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Discussion Starter #3 (Edited)
>>>the StopTech brakes I put on my TT had clearly marked L & R for the rotors for that reason of being unidirectional...but with that said I have little insight as to what issues exists when something that appears to be unidirectional becomes non directional. Good question...<<<

You are right about things getting tricky in terms of directionality. I have seen some curved vane rotors that flowed more air when rotated the opposite way than theory says is proper! I chucked them up on my old lathe and tried it out. That's why I'm not 100% sure if they are rights or lefts. They look like typical lefts though.

Spoon makes curved vane rotors for S2000s and they are also one handed CV discs. But in that case there is a slight cooling issue. Had a buddy check with a pyrometer. One whole side of the car runs cooler than the other side by over 100 F. He didn't notice any issues in spirited street driving though.

Stan
 

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Re: Left Handed Brake Discs....L & R?!?!?

Stan said:
Looking over my second Elise up close recently I noticed that the handed brake rotors (curved vane design) appeared to be the same on both sides of the car. (Most rotors have straight vanes)
Correct.

On the S2 and later Lotus uses only 1 disc all around on the car. Front/rear/left/right are all the same discs.

This means that 1 side turns the 'wrong way'. But Nick Adams explained (when people questioned this as the S2 was released) that they found no significant difference in brake disc cooling between either side that they did not want the additional cost of getting 2 different types of discs.

So yes.. It's cost-cutting, but also because it's not a requirement to run the discs in the other direction.

Bye, Arno.
 

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Discussion Starter #5
>>>This means that 1 side turns the 'wrong way'. But Nick Adams explained (when people questioned this as the S2 was released) that they found no significant difference in brake disc cooling between either side that they did not want the additional cost of getting 2 different types of discs. <<<

It would be interesting to use an infrared pyrometer ($50-100 for a cheapie) to get a sense of any side-to-side temp differences. Likely the front and rear RHS discs will run a bit hotter than the other side.

I think that the Exige has a different braking system - I'm pretty sure that machine has L & R discs.
 

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I'm going to have to check if the US version is "handed". They are cross drilled, and that is "handed", so why wouldn't the disk they make them from be "handed"?

Tim Mullen
 

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Re: Re: Left Handed Brake Discs....L & R?!?!?

Arno said:
But Nick Adams explained (when people questioned this as the S2 was released) that they found no significant difference in brake disc cooling between either side that they did not want the additional cost of getting 2 different types of discs.
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Reg Riemer (of RCTS/One Lap fame) tried reversing the direction of the front rotors on the MKIV Supra and found no noticeable difference in brake temps.

Jim
 
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