Why not power-to-weight ratio??

I've been sitting on the sidelines and learning as much as I can about amateur road racing with the intent of jumping in soon. I've looked closely at NASA CMC and also IT in SCCA and spec Miata and RX7. I'm leaning towards IT because I'm not sure I want to race a big bore, heavy American car in CMC. However, the NASA CMC and AI format makes the most sense to me. My question is - why doesn't SCCA adopt this format? I'm talking about power-to-weight ratio.

The GCR goes in great detail about what mods can be made to what cars and so on. It seems to me it would be far easier to class cars based on power-to-weight ratio. It would basically say "we don't care what you run or what you do to your car, but you must maintain a XX:Y power-to-weight ratio." Why isn't this format used in IT?

It seems to me that trying to specify all parameters of all cars can't cover all scenarios and only opens up the door for cheating.

This is a FMI (For MY information) post only. No flames intended.

Seriously, why doesn't SCCA use this format?

Thanks,
Scott

Deep breath......

This is a major topic, and I don't have the time to do it justice...

But.......a few points.

NASA has a limited number of models that they run races for, and they aren't nationwide.

And a few questions... how does NASA determine P/W ratio? I have been told they actually bring a portable dyno to the track, but everyone must realize the complete loophole in this approach...

If the SCCA said you must maintain a XX:yy p/W ratio, how would they determine the effectiveness? How would it be enforced?

And, even if it could be determined without doubt that my RX-7 was making the same 15 lbs to 1 hp that the CRX was, the CRX would likely win on torque alone. And it has a better suspesion, and brakes well too.

And thats the point....the P/W ratio thing can work when the parameters are tightly controlled, but when the class includes cars of front wheel drive, rear wheel drive, front, mid and rear engine configurations, I4, V6 and rotary engine types, not to mention the huge differences in suspension design, things get thornier.

To be sure, specifying what can be done to the cars doesn't mean that cheaters won't cheat, but the rules try to draw distinct lines that can be ruled fairly. Is the compression as required? yes or no.

If the car is to produce a certain power, how can I tell that it does?? I won't say that such a scenario is unenforcable....but....

So, the main reason is the wide scope of cars doesn't lend itself to such a system, and it would be very difficult to enforce at the hundreds of regionals that the SCCA runs per year.




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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

The P/W thing is not actually a NASA rule. The rule was part of AI/AIX and NASA adopted the rule set that was brought to them. I don't think any other NASA class has a similar rule. Although NASA does have an engine claiming rule for some classes.

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Spec RX7 #11
Scottsdale AZ

Hi Scott...

This is a good question and I think to many, me included, from the outside looking in it might seem crazy not to do a power to weight ratio type thing. We see it in SCCA Pro Racing, Speed GT and Touring Car racing, why not Club Racing?

From my, now only less limited perspective, I've learned one thing about club racing and specific to IT, the SCCA can not guarantee the competitiveness of any make/model car.

... keep in mind the SCCA has recently made some headway in helping out a few cars... Sentra SE-R, NX2000 and the Dodge Neon.

I've also had the opportunity to borrow my brother-in-law's 1st gen RX-7 for my first school. I decided not to buy this car for a couple reasons, one of them being that the car isn't a front runner in it's class outside the Southeast where they have "IT-7"

I'm not sure what kind of past racing experience you may have, autocrossing perhaps?, if so then you know that there are cars that always seem to rise to the top no matter what the rules are. It's the same with Club Racing.

The best advice I can give you if you're seriously considering racing, is to keep asking the questions. Learn as much as you can. Come to some racing events, direct question to folks who don't look really flustered and are wrenching on their cars, and volunteer to help work a corner or timing/scoring. It's a great way to see how things work. There's more to this whole club racing thing then I imagined looking in from the outside. Now that I'm "in deep" http://ITForum.ImprovedTouring.com/wink.gif I realize that many folks give up their free time to simply come out and have fun... some of the fun is simply working and hanging out with friends, others race too.

The SCCA as a "club" tries to keep IT cheap, so it must have this type of mindset. Playing around with weight penalties for a type of car, etc. could become extremely burdensome for volunteers. And what of the "talent" difference? Eventhough I have a "front running" (possible) car, it's a far cry from being competitive. The greatest reason is the driver no matter what the Power to Weight ratio is. http://ITForum.ImprovedTouring.com/smile.gif

If there is anything (we) can do to help you feel free to ask!

Club racing is Fun first, competition second.

Just my opinion...

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-dave
nerdsracing.com
8)

***The greatest reason is the driver no matter what the Power to Weight ratio is.

Club racing is Fun first, competition second.***

I second that ^.

Have Fun http://ITForum.ImprovedTouring.com/wink.gif
David

ps: jake, good explanation from my perspective.

Scott,

To make a simple comment on your question and to summerize the other posts above, the main answer is that some makes/models that have similar P/W are simply faster than others in their original OEM design right out of the box. SCCA IT "tries" to balance it.

Because gear ratios, braking capability, wheelbase, track, drivetrain orientation, suspension and even aerodynamics can be very important.

Thanks for all of the replies and good info. After I posted I realized one of my statements may be misleading - "we don't care what you run or what you do to your car". It would probably make sense to still use the GCR as it is regarding suspension, safety, tire and wheel sizes (adjusted for power output), etc. Not make it a free-for-all like my original post may have sounded like. Basically, just remove the car classes and engine sections from the GCR and relpace those with a P/W ratio chart.

One of the reason I posted my question is that there seems to be a lot cars NOT listed in the GCR that would make decent racecars (for some people). Some of the most dominant cars in IT are 25+ years old (260Z, RX7's, etc..) and no turbo cars. I would think that the ability to run more cars (and turbo cars) would greatly increase the attractiveness of the class to new comers.

I read the monthly FastTRack and it's filled with rule revisions and such aimed at keeping a level playing field by micro management (BMW restrictors, compression ratios, weight penalties, ECU mods, etc..) Seems to me it would be far easier to class cars at the track with a scale and a dyno (measuring torque and HP) and not worry about what's been done to it as long as the rest of the car meets the basic GCR for suspension and safety.

Thanks again for the insightful input and being patient with me during my learning curve.

Scott

Quote:

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Originally posted by alexands:
... and also IT in SCCA and spec Miata and RX7. I'm leaning towards IT...
Scott

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Hey dude,

Depending on what you want to achieve, money you're willing to spend and where you live might determine the best of the two vehicles you mentioned.

There are still quite a few 1st Gen RX-7s in ITA, and of course the 2nd gens would be a bit more expensive to run in ITS simply because the speed increase = more frequent replacement of wear items (tires/brakes/etc.) You could pick up a 1st gen relatively cheap.

If I were entering in now, I might see if I could find a used spec Miata and run that in ITA as-is to start. Because they are a bit newer, it "should" also be easier to find parts and support for them. However it might also be more expensive upon start-up, but it has greater potential.

Just some thoughts. http://ITForum.ImprovedTouring.com/smile.gif

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-dave
nerdsracing.com
8)

[This message has been edited by emwavey (edited July 07, 2005).]

I chose my ITB car for 2 reasons. Lower initial buy in cost, and I know the 8V VW pretty well inside and out so DIY is not an issue.