Question on the rotor...

[LastToy]

Does anyone know if the rotors have directional vanes? I thought the car I test drove had directional vane rotors but the vanes were the same direction for both left and right rotors (meaning one side is facing the wrong way). Was I mistaking?

[Stan]

This is correct....Lotus checked the difference in disc temps and found that while there was some, it was not significant or noticeable to the driver. Disc temps are much lower than in most cars.

[LastToy]

Thanks for the info. If that's correct, I'm a little disappointed. It's an engineering shortcut... soley to cut costs. I hope their definition of "significant" is pretty low. I've had too many brake issues on the track to put up with another one from a car that is supposed to be one of the best track cars straight out of the box. Will find out. What do I care... the second set of rotors will likely be after-market anyway.

[Stan]

It's not really a short cut in this case. I think they found about a 40F temp difference side to side. It was tested and evaluated and found not to be a problem, but it was a concern and this was not ignored. Bear in mind that most cars are much heavier, cannot enter turns as fast (requiring more braking) and mostly use the front brakes for stopping (rears do little).

The Elise uses all four corners heavily when slowing down so the heat is spread out. And for the weight of the car the rotors are huge.

Additonally the Lotus does not use splash shields, so even though the brakes are not ducted from the factory, more than usual cooling airflow is enjoyed from the get go. Removing those shields helps out a bit with normal cars when they are tracked.

You'll be fine.

[CJC]

I was also suprised to see two new cars at Park Place last week with the same brake rotors on each front corner. Many people believe that the proper rotor orientation is important:

http://www.baer.com/Support/TechTips.aspx?TechTipID=2

Chris

[Stan]

>>>I was also suprised to see two new cars at Park Place last week with the same brake rotors on each front corner. Many people believe that the proper rotor orientation is important:<<<

It is important. But in our case the amount of heat is very low compared to "normal" cars and it is spread out amongst the four corners instead of being heavily front oriented. To wind up with the sort of track temps the Elise experiences, many normal cars would need something like 14-15 inch rotors.

So the technically incorrect orientation (reduced cooling air flow on one side of the car) is offset by the inherently lower temps in the first place. Lotus could have used a straight vaned disc to get more even cooling. But that is a slightly weaker setup than curved vane discs. I think Lotus did a good job of balancing the priorities.