I am currently in the process of getting my '83 Mazda RX7 ready for road racing. What books/sources, if any, do you all recommend for gathering knowledge? The main reason I am asking is that I might someday decide to do an engine swap on my rx7, or I may go down the path of a mid-engine rwd fully independent suspension car and both options have very different beginning weight percentages, and I have no idea what would be optimum. Any help is appreciated.
Everytime I think about the debate between front,mid or rear engine I look at how well heavily biased front weight or rear weight cars can do when designed and engineered well. Porsche 911,Audi Quattro's, and Dodge Viper come to mind.
Unless you are looking to be different for different sake why not focus on making the best of the platform as it was designed? It is cheaper and easier and often will result in more reliability, safety and likely performance.
Yeah, there are a lot more questions to be answered first, sounds like. IIRC, the stock weight distribution on a first-gen RX7 is fairly good. From there, set your ride heights to get the appropriate roll and rake settings, then get your cross weights happy. That's assuming you've got adjustable spring perches, which you should if you're asking these kinds of questions.
What class are you planning to race in? That's a big question
Since no one is pointing me in the direction of literature and there are questions being asked, I guess I'll just lay it all out there. I plan to initially run the rx7 in the NASA PT classes to start with, and the ultimate goal is to LS swap it and run ST classes with it. Yes I like to be different, and with that being said, I have been tossing around the idea of a Pontiac fiero with an engine swap. There are alot of variables and differences between these 2 vehicles, obviously. The differences that jump out at me initially are:
MacPherson strut versus double a-arm front suspension
IRS versus a straight rear axle
50/50 rx7 weight (52%fr/48%rear even after LS swap) versus fiero percentages in the neighborhood of 43%fr/57%rear
I understand there are still alot of differences and it's not really comparing apples to apples, but that's why I was asking if anyone knew of literature out there that I might be able to gain knowledge from. Anyways, I'm open to feedback. And please don't tell me about how much support for the rx7 there is and how little support there is for the fiero, as that will likely not factor into my decision
I'm not sure what you are asking. The rx7 will vary its weight and therfore balance based on how heavy the cage is, how much you strip out, etc...
They are technically mid engine vehicles (engine in between the axles).
Hope this helps.
I guess what I'm asking is could the fiero be as competitive as the rx7 or would I be wasting my time, money, and effort? I wasn't sure if a 50/50 weight distribution was ideal which the rx7 is closer to than the fiero. Of course this question comes with the notion that either car will probably end up with an LS powerplant eventually.
Calling 50/50 "ideal" is little more than a marketing gimmick. There is nothing magical, or even particularly special, about it. If given the option when building a racecar, I would pick the 43/57 over 52/48, or even 50/50. A rear weight bias tends to have the advantage in both acceleration and braking. And at higher power to weight ratios where staggered tires really become desirable, a rear weight bias also more naturally utilizes the available tire grip during cornering. A front, or even 50/50, weight bias has to make more compromises in order to balance everything out.
"Race Car Vehicle Dynamics" Milliken
"Advanced Race Car suspension development" Steve Smith
For a couple.
Fred Puhns and Staniforth are a little more applied than those two. Especially Staniforth.
Milliken is pretty hard core for working on a large sedan.
Most "ideal" clean-sheet race builds seem to claim something close to 45/55 F/R is "ideal". Emphasis on quotation marks since YMMV 
Until you're so far along you're weighing everything and designing the whole rig in CAD w/ mass calculations, shoot for 50/50 cross weights and let the F-R fall where it may unless you can move a lot of stuff.
My sports racer is about 40/60 FR w/ a little RH total weight bias because of where the seat is. I can get the cross weights within a couple percent, but try to keep the front wheels within a few pounds. For right-turn biased tracks like Summit Point I leave the right rear wheel a bit heavy.
Like others have said, weight distribution is an incomplete picture. A 50/50 car with a stiff chassis and well sorted lateral load transfer distribution will handle loads better than a 40/60 car with a soft chassis and improperly sized swaybars, etc.
Pick a platform and develop it as far as you can, bench racing with theoretically unlimited modifications and deciding which is faster won't get you anywhere worth going.
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