Why is the 12a so heavy in STL??

[AS-RACER]

Just a couple of questions and thoughts. Why is the 12a approved at 2600 in STL. That seems way to heavy to me. Also, what do you guys think about allowing the 13B non ported into STL?

[Knestis]

Because they make infinity horsepowers. We learned that back in the '80s, beat Mazda to death with our knowledge, and suffered their "death of a million Miatas" as a result. History. Know it or repeat it.



K

[AS-RACER]

and zero torque.

[CRallo]

Because they make infinity horsepowers. We learned that back in the '80s, beat Mazda to death with our knowledge, and suffered their "death of a million Miatas" as a result. History. Know it or repeat it.



K

Quote of the Month, if not the year!

[Greg Amy]

Can't give you the "official" reason for that weight (I don't know it) but I can tell you that from personal experience rotaries really wake up with porting (I built a Racing Beat/Holley-equipped and -ported RX that would keep up with a Porsche Turbo in a straight line to 100 mph). So that wold be why no porting is allowed (if you want porting, STU beckons).

And I don't buy the "no torque" argument, especially since the masses seem to think that STL will be a "Honda class", a manufacturer not exactly known for its massive torque output (what was my old sig line? "My Nissan's lugnuts have more torque than your Honda engine"...?)

Let's also not forget that it's perfectly legal to toss that engine into a Miata chassis...

Finally, note the car is legal in STU in IT prep and weight (but I recognize that's not really what you want).

Given that ST is pretty much on a clean slate right now (moving away from World Challenge VTS sheets and towards its own set of standalone prep rules) I'm not surprised there's some confusion and dissatisfaction vis-a-vis the Mazda 12A rotary. After all, it's a legacy engine and not really used by a high volume of competitors right now, so I'm guessing it's a low priority. However, if you're interested in seeing less weight considered, I'd recommend you submit a request with a reasonable weight that you think the engine should get (keeping in mind that Miata thing; in my mind all specific engine allowances/deviations should be done with the optimal chassis it could go into) with your support for that number (why you think that way). I'm confident it will warrant at least a reasonable consideration.

GA

[dickita15]

2. The Mazda 12A is permitted at 2600 lbs; porting is not permitted.

2. All cars shall use the installed engine’s stock air metering device (e.g., throttle body) and intake manifold, unless noted otherwise.

What am I missing

[Greg Amy]

What am I missing

Was that directed at me, Dick? I'm not sure what your question is...?

To summarize:

- The 12A-equipped RX-7 is allowed in STU in ITA trim (no porting) at 2280# (since the chassis was built through 1985).
- The 12A engine is allowed in STU with "street porting" at 2350#
- The 12A engine is allowed in STL with no porting at 2535# (changed Dec Fastrack).

If anyone thinks these should be lower, please do submit a request for the weight you think it should be to the CRB at http://www.crbscca.com.

GA

[dickita15]

Was that directed at me, Dick? I'm not sure what your question is...?

To summarize:

- The 12A-equipped RX-7 is allowed in STU in ITA trim (no porting) at 2280# (since the chassis was built through 1985).
- The 12A engine is allowed in STU with "street porting" at 2350#
- The 12A engine is allowed in STL with no porting at 2535# (changed Dec Fastrack).

If anyone thinks these should be lower, please do submit a request for the weight you think it should be to the CRB at http://www.crbscca.com.

GA

Not directed at you specifically Greg , although I applaud you taking the role of publicly furthering these discussions. The original posters question was why the 12a was so heavy in STL. In that class I have not found any allowances for porting of a carb change. As far as I know there are no allowances that would let the car make any more power that it does in ITA/IT7. Given that like the original poster I am not sure why the cars was speced in STL at 255 pounds more than the IT car. Hence my question, what am I missing.

[CRallo]

Not directed at you specifically Greg , although I applaud you taking the role of publicly furthering these discussions. The original posters question was why the 12a was so heavy in STL. In that class I have not found any allowances for porting of a carb change. As far as I know there are no allowances that would let the car make any more power that it does in ITA/IT7. Given that like the original poster I am not sure why the cars was speced in STL at 255 pounds more than the IT car. Hence my question, what am I missing.

+1

[Rabbit07]

Just a couple of questions and thoughts. Why is the 12a approved at 2600 in STL. That seems way to heavy to me. Also, what do you guys think about allowing the 13B non ported into STL?

Short answer..... "We F'd Up!" Working at fixing it. Stay tuned!

[dickita15]

Short answer..... "We F'd Up!" Working at fixing it. Stay tuned!

Thank you Chris, that is the answer I was looking for, nothing else really made any sense.

I assume the fix would be to allow something for more power at the higher weight, some porting and or an alternate carb.

Anybody know what an unported 12a can make with a Holley and an Racing beat intake.

[Dano77]

According to tGA, a millon billon horsepower. I have no data to support my argument and Im wasting company time.

How about a 2bbl Holly 2300 carb and an adapter to a stockish intake,since we are asking.

Dan 77 IT7

[Greg Amy]

Dan, when I was messing with rotaries, there weren't any such thing as chassis dynos. Then I grew up, quit building model airplanes, and began messing with REAL car engines...



tGA