Cal Club Autocross Forums

http://www.scca.com/documents/Fastrack/ ... g-solo.pdf

Finally back on pole position! Wakeup Marshall. You too Isley

Giovanni Jaramillo wrote:http://www.scca.com/documents/Fastrack/ ... g-solo.pdf

Finally back on pole position! Wakeup Marshall. You too Isley

Damn! I was going to post it and got distracted!

Bob Beamesderfer wrote:

Giovanni Jaramillo wrote:http://www.scca.com/documents/Fastrack/ ... g-solo.pdf

Finally back on pole position! Wakeup Marshall. You too Isley

Damn! I was going to post it and got distracted!

You snooze you lose!

Now...on to important things:

Separately from the above cleanup changes, the STAC has recommended that the following proposals be passed along to
the BOD:

o In Appendix A, Street Touring Class U, remove the line under “Excluded” which reads “BMW M3 (E46 ‘01+)” (ref.
07-001)

Now instead of bringing a knife (E36 M3) to a gun (Evo, STi) fight, this is more like bringing a gun (E46 M3) to a gun fight! Hallelujah!

o In 14.13, under STU, change second sentence to read: “…and the maximum tire width is increased to 285mm for
FWD or RWD vehicles…” (ref. 07-438)

I'm a big believer in WIDER is better!

STOCK
o Comment: AWD cars do not fit with the current class philosophy of GS.


Now if only they could apply this statement to STU, I'd be happy but beggars can't be choosers here! So far so good by SEB with these proposals.

Fastrack wrote:
STOCK
o Comment: AWD cars do not fit with the current class philosophy of GS.

how do the Mitsubishi Eclipse Turbo AWD/Eagle Talon Turbo AWD not fit in the GS class philosophy of "Get Spanked by a Mini Cooper S?"

If I could have run the shorter 285's on the SRT instead of the 275's, it obviously would have dominated STU.

E: STX and STU: Brake rotors may be replaced with any rotor of equal or larger diameter made from a
ferrous or aluminum alloy. Calipers are unrestricted, but must mount to the original attachment
points. Drum brakes may be replaced with disk brakes of a diameter equal to or greater than the
inside diameter of the standard drum part. Brake backing plates (dust shields) may be modified the
minimum amount necessary to accommodate allowed alternate rotors and calipers.

Interesting to note that smaller diameter discs aren't allowed. How do the sizes of rear drums vs. rear discs compare on the various generations of Civic, for instance?

Why Bob?

No comparisons are necessary. The allowance defines the min rotor size as the inside drum size. Which of course is smaller than any commercially available rear disc conversion.

Funny, there are already a few AWD Turbo cars in GS--

Mitsubishi Gallant VR4
Isuzu Impluse RS
Toyota Celica All-Trac

And the 2.5RS in G-Stock, 165hp and two LSD's.

I fail to see how the DSM cars would be any different? Why not just move them, they'll be lost in the shuffle anyway.

Steve Ekstrand wrote:Why Bob?

No comparisons are necessary. The allowance defines the min rotor size as the inside drum size. Which of course is smaller than any commercially available rear disc conversion.

Because even though the rear drums on Civics of your generation are small, the discs on the back of Civics aren't all that big. I wondered which was larger. I would expect an aftermarket kit to be bigger because most of the mouth-breather, street tuner Civic folks are lured by anything that says "bigger" "more" or is made of a billet when such engineering and machining is complete overkill.

So, what about the factory discs? They wouldn't need to be the same or larger diameter than the drums to provide more braking power; are they bigger or smaller?

STX and STU: Brake rotors may be replaced with any rotor of equal or larger diameter made from a
ferrous or aluminum alloy.

This is a joke or a mistake right? Aluminum alloy brake rotors (if there is such a thing for automobiles) are legal but smaller diameter steel rotors are not?

John Coffey wrote:

STX and STU: Brake rotors may be replaced with any rotor of equal or larger diameter made from a
ferrous or aluminum alloy.

This is a joke or a mistake right? Aluminum alloy brake rotors (if there is such a thing for automobiles) are legal but smaller diameter steel rotors are not?

Smart machinists everywhere are milling aluminum rear rotors for STS Civics, even as you read this...

New Product Announcement

BetaMotorsports, LLC, with some fear and trepidation, announces new 11", 12" and 13" diameter 2024 aluminum allow brake rotors. Rotor and hat machined as all one piece, total weights are 1 to 1.5 lbs. Guaranteed lighter then any other rotors on the market and SCCA ST legal. $500 each. Warning: not to be used with metallic brake pads or at speeds above 70 mph. These rotors are single use items and must be replaced after each brake application.

On the EF Honda's (4th gen):
Available rear drums were 7"
Available rear discs were 8.4"

Steve Ekstrand wrote:On the EF Honda's (4th gen):
Available rear drums were 7"
Available rear discs were 8.4"

COOL! Stock pads rear, something with more bite up front. Or maybe swap to induce trailing throttle oversteer?

What it means is that an Andy Hollis type can custom construct a super thin super light uberunobtaniumable for mere mortals 7" rear rotor.

John Coffey wrote:

STX and STU: Brake rotors may be replaced with any rotor of equal or larger diameter made from a
ferrous or aluminum alloy.

This is a joke or a mistake right? Aluminum alloy brake rotors (if there is such a thing for automobiles) are legal but smaller diameter steel rotors are not?

Stoptech used to make aluminum rotors... This isn't a new rule, al. rotors are legal in STX and STU.

John Coffey wrote:

STX and STU: Brake rotors may be replaced with any rotor of equal or larger diameter made from a
ferrous or aluminum alloy.

This is a joke or a mistake right? Aluminum alloy brake rotors (if there is such a thing for automobiles) are legal but smaller diameter steel rotors are not?

I think this is to allow you to run a 2 piece rotor with an aluminum hat.

Aaron Goldsmith wrote:

John Coffey wrote:

STX and STU: Brake rotors may be replaced with any rotor of equal or larger diameter made from a
ferrous or aluminum alloy.

This is a joke or a mistake right? Aluminum alloy brake rotors (if there is such a thing for automobiles) are legal but smaller diameter steel rotors are not?

I think this is to allow you to run a 2 piece rotor with an aluminum hat.

That's what I figured; it allows the very common two-piece rotors with Ai hats.

As for Ai rotors, I can see 70xx heat-treated rotors being useful in some racing applications.

Bob Beamesderfer wrote:
As for Ai rotors, I can see 70xx heat-treated rotors being useful in some racing applications.

If by "some" applications you mean those where no brake pad actually touches the aluminum rotor then I would agree with you. Otherwise aluminum is a terrible material for brake rotors.

Jason Uyeda wrote:Stoptech used to make aluminum rotors... This isn't a new rule, al. rotors are legal in STX and STU.

Marshall Grice wrote:If by "some" applications you mean those where no brake pad actually touches the aluminum rotor then I would agree with you. Otherwise aluminum is a terrible material for brake rotors.

So, you're saying that heat-treated, hard-alloy aluminum was mere folly on the part of one of the leading manufacturers of racing brake components?

Bob Beamesderfer wrote:

Jason Uyeda wrote:Stoptech used to make aluminum rotors... This isn't a new rule, al. rotors are legal in STX and STU.

Marshall Grice wrote:If by "some" applications you mean those where no brake pad actually touches the aluminum rotor then I would agree with you. Otherwise aluminum is a terrible material for brake rotors.

So, you're saying that heat-treated, hard-alloy aluminum was mere folly on the part of one of the leading manufacturers of racing brake components?

the heat treating is useless. a couple brake heat cycles and the metal would likely be annealed. and 'hard' alloy aluminum is still soft compared to iron/steel and wears significantly faster. Combined with the poor fatigue properties, rapid strength loss with increased temperature, and lower heat capacity compared to iron/steel make it a poor choice for rotors. that doesn't mean you can't sell them...in fact you'd probably end up selling a lot of them due to needing to replace them continously.

Marshall Grice wrote:

Bob Beamesderfer wrote:

Jason Uyeda wrote:Stoptech used to make aluminum rotors... This isn't a new rule, al. rotors are legal in STX and STU.

Marshall Grice wrote:If by "some" applications you mean those where no brake pad actually touches the aluminum rotor then I would agree with you. Otherwise aluminum is a terrible material for brake rotors.

So, you're saying that heat-treated, hard-alloy aluminum was mere folly on the part of one of the leading manufacturers of racing brake components?

the heat treating is useless. a couple brake heat cycles and the metal would likely be annealed. and 'hard' alloy aluminum is still soft compared to iron/steel and wears significantly faster. Combined with the poor fatigue properties, rapid strength loss with increased temperature, and lower heat capacity compared to iron/steel make it a poor choice for rotors. that doesn't mean you can't sell them...in fact you'd probably end up selling a lot of them due to needing to replace them continously.

Granted, but there are forms of motorsports in which the brakes are used very little. Take Speedway motorcycles, which don't even have a front brake. If you're looking to cut some weight from a portly H-D 750, then an aluminum rear brake that only has to last 20 laps of a quarter-mile oval is a good investment. However, I doubt Stoptech made product only for what is an anachronistic form of motorcycle racing.

Did I read correctly that the non-awd tire limit for STX increases to 265 and that the wheel width limit increases to 9"?

Bob Beamesderfer wrote:

Jason Uyeda wrote:Stoptech used to make aluminum rotors... This isn't a new rule, al. rotors are legal in STX and STU.

Marshall Grice wrote:If by "some" applications you mean those where no brake pad actually touches the aluminum rotor then I would agree with you. Otherwise aluminum is a terrible material for brake rotors.

So, you're saying that heat-treated, hard-alloy aluminum was mere folly on the part of one of the leading manufacturers of racing brake components?

Stoptech also stopped making them I don't think it's for the hats of 2pc rotors either, at least not specifically (it would be simple to write a rule for just the hats).

Honestly, I don't know why the rule wasn't changed a long time ago. But even more so now that they're trying to get the ST and SP brakes rules in-line. Then again, how come a car that comes only with a wing, can only run a wing; not a spoiler or no wing at all? Maybe I'll write another letter on that...

Aluminum rotors are used on Midget circle track cars, racing bicycles, some motorcycles (rear disk), and some go karts. In the context of the FastTrack proposal (ST class cars) its a really stupid idea. As Marshall said above, the basic material properties of aluminum make it a poor choice for brake rotors that see temperatures above 400F. Artificial aging of aluminum (to get to various levels of heat treat) is done at temps in the 400 degree range - that's why an inattentive powder coater can take an aluminum rim at T351 or T651 temper and drop it to T0 in 15 minutes.