RX8 Beginning the Performance Process

Mazda RX7 and RX8 Suspension, Intakes, Headers, Exhaust, Shocks, Springs, Sway Bars, Brake Kits, Autocross and track mods.
dgeisler
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Joined: Sat Apr 04, 2009 7:18 am

RX8 Beginning the Performance Process

Post by dgeisler »

Brian: I have a stock 2006 RX8 and am about to start autocross and track days. I just bought some new Bridgestone RE01R's (245x40x18) for my stock wheels. But have also started to eye-ball what the next steps look like. I am looking at everything - Suspension, intake, exhaust, lighter fly wheel, etc. Nothing is off limits. I do wish to keep some semblence of drivability on the road since I take the family for rides on the weekends.

What I need to establish is a priority list of where I can make the changes to get my best increases (i.e. Bang for the buck) and (performance per change) to keep it fun in the twisties and on the track. Can you help me prioritize what to start looking at first, second, third? I know this is a personal preference too, but there is nothing that beats your experience.

Your advice would be greatly appreciated. Thanks. Doug
Brian
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Post by Brian »

Well, since you just bought tires, and power mods for the RX8 are very limited in terms of bang per buck, I would focus next on suspension. Your priority list will start with deciding what class you want to run in for autocross? If real serious about the autocross your choices are B stock and STX (the RX8 was previously in STU). I ran our RX8 in STU and it was tough....and I don't expect things will be any easier for the RX8 in STX. Thus, if autocross is a priority then stock class would certainly be the way to go....or at least a place to start. With that in mind the starting mods would be a front Racing Beat RX8 sway bar and koni shocks....followed by a cat back exhaust.

http://www.good-win-racing.com/Mazda-Pe ... -1050.html
http://www.good-win-racing.com/Mazda-Pe ... -1051.html
http://www.good-win-racing.com/Mazda-Pe ... 1006F.html
http://www.good-win-racing.com/Mazda-Pe ... -1100.html



On the other hand, if you are already planning to move beyond the mods that are allowed in stock class, and are accepting that you will be running in STX for autocross, then I would look seriously at our KW coilovers which I expect to be the hot ticket for STX RX8 drivers on "street" tires....and will certainly give you a lot more stable and fun machine for track days. Combine those with a set of the Racing Beat sways and your RX8 will be a fun GoKart-like machine.

http://www.good-win-racing.com/Mazda-Pe ... 01758.html

http://www.good-win-racing.com/Mazda-Pe ... -1006.html
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
dgeisler
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Joined: Sat Apr 04, 2009 7:18 am

Post by dgeisler »

Thanks so much for your council. I should have been clear. I am far more concerned with having a car I love to drive and have fun with, than which class I could compete in for autocross. I will do autocross to hone the skills for the track (and fun), not do autocross as the end game. I love my RX8, I just want it to be more capable.

The debate on suspension I am having is Springs & Shocks vs. Coil-overs. I like the idea of adjustability a lot. I can stiffen some things up on the track days, and have it softer for the "every day". But it is quite a bit more expensive. What I want to really avoid is do the cheaper spring route this year, and then regret not doing coil-overs a year later.

Any advice on this debate?

Regarding the lighter flywheel and lighter pulleys. Do they produce a noticable response change?

Last, is brakes. I want to change pads and my car has 38K miles. Should I just do rotors at the same time as well? Can you make some recommendations on this topic?

Thanks so much for your advice. I (and hopefully others) really appreciate it.
dgeisler
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Joined: Sat Apr 04, 2009 7:18 am

Post by dgeisler »

I noticed you also opened the topic of exhaust. I have looked at the Racing Beat Exhaust, and like the looks of it very much. I like a throaty tone to a car, but am concerned it may be a bit loud for around the neighborhood. is their a performance value to putting it high on the priority list?
Brian
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Post by Brian »

dgeisler wrote:Thanks so much for your council. I should have been clear. I am far more concerned with having a car I love to drive and have fun with, than which class I could compete in for autocross. I will do autocross to hone the skills for the track (and fun), not do autocross as the end game. I love my RX8, I just want it to be more capable.

The debate on suspension I am having is Springs & Shocks vs. Coil-overs. I like the idea of adjustability a lot. I can stiffen some things up on the track days, and have it softer for the "every day". But it is quite a bit more expensive. What I want to really avoid is do the cheaper spring route this year, and then regret not doing coil-overs a year later.

Any advice on this debate?

Regarding the lighter flywheel and lighter pulleys. Do they produce a noticable response change?

Last, is brakes. I want to change pads and my car has 38K miles. Should I just do rotors at the same time as well? Can you make some recommendations on this topic?

Thanks so much for your advice. I (and hopefully others) really appreciate it.
No need to do rotors unless they are in need of change. On pads, every choice is a compromise. Hawk HPS for mostly street. Hawk HP PLUS for a dual purpose pad you can drive on the track. If the track days become more frequent then I like Porterfield R4 as a track day carbon kevlar pad that can still be driven on the street (barely---gotta be careful at that first stop sign in the morning).

If you want just springs and shocks then our Tokicos, the adjustment cables, and the Racing Beat suspension package. As for advice on going full coilover now...no way for me to answer that for you, certainly a full coilover kit will give you more for the track days.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
Brian
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Post by Brian »

dgeisler wrote:I noticed you also opened the topic of exhaust. I have looked at the Racing Beat Exhaust, and like the looks of it very much. I like a throaty tone to a car, but am concerned it may be a bit loud for around the neighborhood. is their a performance value to putting it high on the priority list?
The Racing Beat dual exhaust is a conservative choice....maybe 10 or 15% more sound than stock. Still well below the sound of many stock exhausts and not going to cause any issues around the neighborhood.

As to the performance question, in general the performance gain from exhausts, headers, intakes, etc., is small on the RX8. These items help a little but the suspension is a much higher priority.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
dgeisler
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Joined: Sat Apr 04, 2009 7:18 am

Post by dgeisler »

Brian:

Do you happen to know the Motion Ratio of the RX8?? I am trying to do some number crunching and thought you might have this and be willing to share. I am told it is pretty high. Is this correct?

Thanks
Brian
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Post by Brian »

Unfortunately, I am not always as organized as I could be.

But, my friend Shaik at Fat Cat MotorSports is really good about keeping this data...and posting it. See this link for all RX8 suspension data you could ever want:

http://www.fatcatmotorsports.com/FRC_RX ... DS_RX8.htm
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
dgeisler
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Joined: Sat Apr 04, 2009 7:18 am

Post by dgeisler »

Thanks much. This is a weslth of data.
tuberotor
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Joined: Fri Sep 07, 2007 5:56 pm

Post by tuberotor »

Brian wrote:
dgeisler wrote:I noticed you also opened the topic of exhaust. I have looked at the Racing Beat Exhaust, and like the looks of it very much. I like a throaty tone to a car, but am concerned it may be a bit loud for around the neighborhood. is their a performance value to putting it high on the priority list?
The Racing Beat dual exhaust is a conservative choice....maybe 10 or 15% more sound than stock. Still well below the sound of many stock exhausts and not going to cause any issues around the neighborhood.

As to the performance question, in general the performance gain from exhausts, headers, intakes, etc., is small on the RX8. These items help a little but the suspension is a much higher priority.
If you are still reading this thread (probably you purchased already), the RB Exhaust has a gorgeous, deep, throaty tone that reminds me of my old 1960s Austin-Healy 100/6 (ah, if only...). I never would have thought it possible, as I think the stock RX-8 tone is, uh, anemic. I do think it's louder than Brian hears it, but not too much. Know, however, that it is apparently no weight savings. I have seen in print at "RX-8 Club.com" that it is as heavy or heavier than the stock system. If this is true, I don't see the point in a performance mod that adds little power and saves no weight (or worse). I tried to get them to sell me their "Racing" exhaust, but they refused (they did the install), as it is not CARB approved/street legal. It is only a couple dB louder, I am told, and about 30% lighter. Oh, well, at least you know they are honorable people.
04 Titanium RX-8 6-speed
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