Build questions
#1
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Build questions
I have a 1980 RX7 that is now my race car project. I have built 2 Hondas for racing, but i really don't know alot about rotaries yet. I am shooting for a high hp n/a class. Here are my questions:
Do i need to swap to a 13b?
What rotors would be best and where do i get them?
Ceramic or steel apex seals?
2mm or 3mm apex seals?
I think I can handle the rest. Thanks
Do i need to swap to a 13b?
What rotors would be best and where do i get them?
Ceramic or steel apex seals?
2mm or 3mm apex seals?
I think I can handle the rest. Thanks
#2
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13b will make more power, but you can get 200 rwhp from a race ported 12a.
Most are using stock rotors, having the entire rotating assembleys balanced. Racing beat sells lightend rotors. Others sell them as well. Ceramic seals will make the most power and last forever. Someone else will need to chime in on the size of the seals.
Most are using stock rotors, having the entire rotating assembleys balanced. Racing beat sells lightend rotors. Others sell them as well. Ceramic seals will make the most power and last forever. Someone else will need to chime in on the size of the seals.
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I can only speak for SCCA and ICSCC here in the NW, but many classes do not allow engine changes between differing models. Or if they do, then you have to change everything that was different between the models.
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SCCA E-Production is what i am shooting for. From my research i need about 280 to be competitive.
Also what are some of your 1st gen suspension setups?
Also what are some of your 1st gen suspension setups?
Last edited by PierceSA22; 02-14-08 at 11:55 AM. Reason: more information
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#10
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I'm going to guess about what jgrewe said...220, maybe a little more with your max build motor. I've never heard of a 12a pulling more than 205 range. This assumes building to SCCA street port specs.
#13
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You can only update and backdate on cars that are listed on the same page. IIRC you are correct, only the early 13B can go in the FB.
Nobody will care until you beat them but why take the chance. I'm pretty sure all the fast guys with FB's are running 12A's.(I stopped keeping track when I switched to FC's, its hard enough to keep up to date on one chassis)
Nobody will care until you beat them but why take the chance. I'm pretty sure all the fast guys with FB's are running 12A's.(I stopped keeping track when I switched to FC's, its hard enough to keep up to date on one chassis)
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You can only update and backdate on cars that are listed on the same page. IIRC you are correct, only the early 13B can go in the FB.
Nobody will care until you beat them but why take the chance. I'm pretty sure all the fast guys with FB's are running 12A's.(I stopped keeping track when I switched to FC's, its hard enough to keep up to date on one chassis)
Nobody will care until you beat them but why take the chance. I'm pretty sure all the fast guys with FB's are running 12A's.(I stopped keeping track when I switched to FC's, its hard enough to keep up to date on one chassis)
I did quite a bit of research and asking around a few years back and decided to go 12a. One of the reasons was that the lower rotating mass of the 12a lets you spin the motor faster and rebuild less often than the 13b. You can get the car lighter, and for you really fast guys the tires have a better change lasting the entire race. A lot of the mid pack guys go 2-3 seasons on a 12a motor. No doubt the 13b will have more power. As a matter of fact the current EP champ experimented with the 13b during the season and went back to the 12a for the runoffs and won. He blew up several 13b motors during the season, for whatever reason he could never get them right.
#17
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Have to keep stock steering box.
The best tranny would be a dog ring box purpose built for racing. Figure on $5,000 for one of those. Spreading your gears from about 2:1 to 1:1 is a good start, its all track dependent. Second best would be a 6sp miata gear set in your tranny case but you only use 5 gears. A few hundred for a donor box and some machine work and you're all set for less than $600 if you do it yourself.
The best tranny would be a dog ring box purpose built for racing. Figure on $5,000 for one of those. Spreading your gears from about 2:1 to 1:1 is a good start, its all track dependent. Second best would be a 6sp miata gear set in your tranny case but you only use 5 gears. A few hundred for a donor box and some machine work and you're all set for less than $600 if you do it yourself.
#18
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best setup for the 12A? 1) Nikki Carb w/ primary choke bored to match secondary choke on a stock manifold or 2)Auto-type 2BBL w/ 38mm choke on a "dual y" manifold
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Pretty much everyone in EP with a 12a is running the Weber, as posted above. There is a guy in the first gen forum Carl PB&J racing that modifies the Nikki to flow enough to run in ep.
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Weight reduction: even with the gutting and replacing all needed glass with lexan the car is probably not going to be down to its minimum weight. What is the most cost effective way of shedding some more pounds?
#22
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You can get them down to minimum weight no problem. Just look at the car and take off everything that doesn't make it go, stop, or turn.
If you keep the car simple you can get it below 2000 lbs easy. Cut off every unused bracket, door bars, remove headlight assemblies, brake booster, the list goes on.
If you keep the car simple you can get it below 2000 lbs easy. Cut off every unused bracket, door bars, remove headlight assemblies, brake booster, the list goes on.
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I got it from a place called Airgas here locally. They supply to welding houses and the like. I've heard of grocery stores having it. I recall an entire thread in this section devoted to this issue. Search for dry ice and I'll bet you find it. The guy at the cage shop said mine was the cleanest car he'd seen that had not been dipped. I even got the stuff off the bottom of the car. I was going to seam weld it but there is so much seam sealer in these cars, that I figured it be fine. If I had a hook up I would have bead blasted it, but way to expensive. I was quoted over a grand.