14.12:7 "Brake rotors may be replaced with any rotor of equal or larger
diameter made from a ferrous or aluminum alloy"

EDIT: notice that's an STX rule which is inherited.

Shouldn't be a problem.

d

 

I guess your right but, if you look over the rules there is nothing in there to that effect although I guess that can't specifically state what is and is not allowed hence the reason they only note what isn't.

 

Question, is upgrading from an evo 8 stock diverter valve to an evo 9 valve legal. Mine sounds like it is releasing early( a noticable octave change in intake sound at 3 quaterss throttle) I think it is leaking under boost.

 

AFAIK, no. You have to retain everything stock and there is a mention that changing b/o valves or diverter valves in not permitted.

 

Nope. Anything that controls boost must remain stock. The only solution you have here is to replace it with another stock evo 8 valve.

d

 

The Evo 8 valves suck. I tested mine and it leaked at very low boost, like less than 10psi.

The Evo 9 valve did not leak until 23-25 psi.

 

Back for more 2pc rotor question:

Mike, my co-driver thinks I have a hole burned in my pocket and I need my head examined, but I just can't get the 2pc front rotors out of my mind.

Anyone here runs 2pc rotors? Baer front rotors are 14 lbs. lighter, do they offer any benefit in autox? Anybody experiencing any cracking of the drill/slot rotors in autox conditions?

I know DaveMac will just tell me to lose weight and I plan to after Christmas. But for now the car gets the diet first... Any comment is greatly appreciated. Thanks.

 

I've been wrestling with this question myself but what it comes down to is that rotors are rotors, all of them are a "wear item." With that being said, 10-14 lbs. of total unsprung weight is a benefit. Any time you can lose weight, it will help acceleration, braking and handling to some degree.

 

I saved 2-3lbs per corner going to a Performance Friction 2-piece rotor. The big reason I went for them is I wanted better heat dissipation for track driving. The weight savings is just a bonus to help justify buying them.

The rear rotors will be much harder to justify when the weight savings is less and there isn't a big need to better heat dissipation back there.

-Jon

 

Track driving conditions and auto-x conditions are VERY different. The amount of heat generated by the brakes during auto-x does not comes close to the amount that get generated while driving hard on the track. I seriously doubt you are going to crack either a slotted/cross-drilled rotor while doing Auto-x ...

 

I'd say save your money and concentrate on making yourself faster. Once you are on par with National guys then start looking into stuff like this.

That said 14 pounds of un-sprung wieght loss is a benefit but, how much is hard to say. I simply replaced my OEM rotors with Powerslots up front and will be doing the rears once JSC gets them back in stock.

 

I'm in the same boat as far as two-piece rotors. The only real benefit they are going to provide is weight savings. I'm seriously considering them for next season, but only after I've gotten the car down below 2950 lbs. Lb per dollar is not very good. If you're hung up on rotational mass, that money is probably better invested in wheels unless you have the absolute lightest ones available.

Come to think of it...Is there are reason why we can't run a composite wheel?

d

 

I think at my age there are only so many things I can improve physically. If I rely only on improve my driving to get faster, I think I will never make it to the Nationals. However, my co-driver is good enough to replace high nationally, and even though he wants me to save the money too, I still try to look through all areas of the car and improve it based on what's allow by the rulebook.

Other than saving weight with exhaust, stock seats, wheels, coilovers and adkins diet, I just can't think of any other legal method to shave decent weight other than Baer rotors. I just want to make sure I prepare the car the best I can, and only blame my driving skills if I perform poorly.

Anyone here runs Baer front rotors like to chime in? If not I will be the guinnea pig and report my findings after I install mine before the beginning of next season. Thanks for your input.

 

other then being specificly not allowed in the rules (other then in FSAE)....no reason.

3.3.3.B.9 "Other than standard parts as defined by these rules, non-metallic wheel construction is prohibited"

 

Jack Brennan ran them on his SM Evo in WDCR events with no problems.