E30M3,

Thanks for sharing that information.

 

Great post, E30M3.

Even before I got to it, I was agreeing with the people who think direction matters. IMO this ices that argument (or, more accurately, fries the alternative argument).

This is exactly the kind of "minor" thing that will not make much difference in daily driving, but could have a huge impact (probably brake fade on whichever front wheel has the backward disk) on the track. Spoon really should know better, and probably does. Luis probably got a set of rotors that was packed wrong.

 

Well, not so fast...

Your experiment did not take into account the airflow through the rotors as the vehicle moves.

I don't know what percentage that represents of the overall cooling capabilities but I guess that quite a lot.

You have found a temperature difference of 16% when rotors were spun in opposite directions. If airflow as a result of car movement is responsible for 90% of total cooling, then that becomes 1.6%! If it is 99%, then .16%.

This has been my argument all along. Race cars have needs that are not applicable to street vehicles. Just look into a WRC and its street legal counterpart. One is purity of design the other is a heap of compromises.

To produce handed rotors costs more than non handed rotors. A manufacturer, when considering their options, have to balance costs, margins and benefits to their customers.

If producing handed rotors make negligeable contribution to performance FOR ITS INTENDED APPLICATION, then doing it is overengineering. Companies that do it, either are monopolies, stop doing it or go bankrupt.

If this is the case, and it may be a big IF, then disparaging Spoon for doing non-handed rotors, has the same relevance as disparaging Honda for not supplying forged wheels instead of piece-of-sh1t cast wheels! (sorry, got a bit carried away there...)

Now, some of you may be wondering that I'm trying to save face as a buyer of faulty goods. This is not the case. Couldn't care less, but there are indications that give credence to my suspicions.

These are that Spoon is an engenieering company with a racing tradition, and that
if they were looking to save costs regardless of functionality they would not have opted for cast drills which are more expensive that drilled holes.


Anyway, I am a bit tired of this argument, and its general tone. I really like and respect people that know, and are wise, and experienced, but I also think that style is important. And that, sometimes, has been lacking (see the way the "cracked cross drilled rotor" ended).

So with all due respect, me too, will drop out of this thread.

But before I do it, I promise to put the argument to rest. After all I'm the interested party (or the gullible sucker that got taken to the cleaners, depending on your POV ).

I'll gladly accept suggestions for a thermometer that can be used for the intended purpose, and that, hopefully, may later on be useful to cook the turkey.

So bear with me.

 

Sorry Luis, but I think the only person who's getting hot under the collar here is you.

I don't think that you can deny that the directional vanes make a difference, whether it's 16% or 1.6%, but after investing how many dollars in Spoon rotors you feel a need to justify your purchase and, as a result, Spoon's reputation.

No one is having a go at you. Fact is, good companies sometimes make bad products, and we all occasionally buy them.

I just hate to see a bad product get a positive endorsement based on the manufacturer's past reputation and your loyalty to your purchasing decision, and flying in the face of rationalism and scientific tests.

 

Luis, you are the one who is claiming that about 4-5 basic universally accepted braking system assumptions backed up by unending testing by folks all over the world and over decades of time is all wrong. With no back up and in a message board. Sorry but i simply disagree. I'm simply relaying the established facts combined with my own experience and testing.

I do know a fair amount about this stuff. You are conversing with someone who has years of experience with street and racing braking systems. I measure everything. I've designed many aftermarket brake upgrades for various aftermarket companies FWIW. Many street cars and many winning race cars have benefitted from my approach.

If you choose to shoot the messenger then so be it. If you are angry at anyone it shouldn't be me.

Discs such as your Spoons on your s2000 do not cool primarily via simple forward car motion. The centrifuge action is very important. It is much cheaper to make flat solid discs which the car companies would do if they could. Tests run on cars with same size and mass but vented and nonvented discs typically show around a 300-600 degee F temp drop with the vented discs under enthusiastic or panic stop driving conditions. Vents absolutely do work and are very, very worthwhile. It also makes a lot of sense to ensure that they work evenly on each side of the car.


Stan

 

I would recomend painting 3 to 4 temp paints on both rotors after 3 to 4 panic stops check color through wheels . When color leaves paint temperature has been reached.

brad
ps
I feel that Spoon has sent you 4 of the same rotors and they must make lefts and rights.

 

I guess I'm a bit surprised that Luis was offended by what seems to me to be a very high-quality, informative post with lots of people weighing in with thoughtful input. For any part I had in angering him, I apologize.

In any case, it would seem that one of the primary concerns could be easily settled by calling Spoon and finding out if they really make only one shape of what seems to be a directional rotor. As I said, I find it more likely that Luis got a mis-packed set.

 

I realise I'm flogging a very dead and recycled as glue old horse here but a recent incident in the Australian V8 Supercars Series reminded me of this discussion.

http://www.v8supercars.com.au/no-advantage...35/default.aspx

In summary, the Ford Performance Racing team was penalised for installing the rear rotors on their cars on the incorrect sides. According to the administers this allowed them to keep heat in their rotors on a track like Hamilton. According to FPR there was no advantage. They claim there was a disadvantage in that their rotors over heated.

Either way, it supports my argument that directional vanes in rotors promotes cooling when installed correctly and suppresses it when installed incorrectly.