Rx8 series 2 suspension query

Mazda RX7 and RX8 Suspension, Intakes, Headers, Exhaust, Shocks, Springs, Sway Bars, Brake Kits, Autocross and track mods.
lucifuge
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Joined: Sat Mar 14, 2009 9:50 pm

Rx8 series 2 suspension query

Post by lucifuge »

I'm looking to drop my series 2 Rx8 very marginally to minimise the wheel gap. I don't want to go too low and feel the Tein H.tech springs are exactly what I'm looking for. I would like to change stock shocks at the same time and also feel the Bilstein B6 (alternatively known as HD's) would be a great combo.

Anyway, I'm having a lot of trouble sourcing B6's. I'm in Australia and can't see them anywhere (so far). Even SHOX.COM in the US has them for only series 1 Rx8. Are the B6 even available for the series 2 Rx8?? Failing this, what other shock absorber would complement the Tein h.tech which offer only a very subtle drop?
Brian
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Re: Rx8 series 2 suspension query

Post by Brian »

Every shock that fits series 1 RX8....also fits series 2. But, the lengths are slightly different and that means different heights. Thus, you can use the Bilstein in your series 2....but the result would be that the springs don't lower you as much as you expect. A very mild lowering spring such as our Racing Beat springs, intended to lower about half an inch, would not lower a series 2 at all. On the other hand, if you pick a spring that lowers a series 1 by one inch....you would get about half that on the series 2.

If you really want to be in charge of height....then pick a coilover.
Brian Goodwin
Good-Win Racing
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lucifuge
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Joined: Sat Mar 14, 2009 9:50 pm

Re: Rx8 series 2 suspension query

Post by lucifuge »

Brian, with the PSS9 for the Rx8, are you able to answer the following for me.

1. What is the range afforded by the coilovers height-wise, or rather what is the minimal and maximal drops they offer?

2. Are both the fronts and rears easily accessible for adjustments in both height and dampening? (I read the Tokico's for example are very difficult without the cables)

p.s. the quoted springs rates are frightening!? or, are these somehow scalable due to the application and not as extreme in reality?

cheers
brett
Brian
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Re: Rx8 series 2 suspension query

Post by Brian »

In practice we find that the mix of rates on the Bilstein PSS9 kit works out very well. If lowering your RX8 significantly then you will likely want to upgrade the front sway bar to the big Racing Beat or Progressive tubular front bars.....and leave the rear bar alone. However, if you stay close to stock height then the balance works out nicely even if you upgrade both front and rear sways. The key, as this suggests, is how much you lower the RX8. You can lower it just about half an inch or so.....or you can go about 2 inches lower. The manual with the kit suggests a very mild lowering and if you follow that suggestion then the balance works perfect. The lower you go, the more oversteer you will get and more likely you will want to upgrade the front sway, and not the rear. Yes, adjustment is pretty easy.
Brian Goodwin
Good-Win Racing
www.good-win-racing.com
lucifuge
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Joined: Sat Mar 14, 2009 9:50 pm

Re: Rx8 series 2 suspension query

Post by lucifuge »

Thanks Brian.

When you refer to height adjustment of 0.5" t0 2", is this something that is decided at installation time and its set. Or, can i change it myself after a while easily at home?
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Re: Rx8 series 2 suspension query

Post by Brian »

That's the beauty of any of the threaded body coilovers.....you can change your mind about heights whenever you want. If you go crazy with the lowering and decide you went too low....you jack up a side, pull the wheels and spin the spring perches to change heights. You repeat the same procedure on the other side. The racers will do this repeatedly to 'corner balance' the car with their weight in the driver's seat and the car parked on four scales. For those not racing it is nice not to be stuck with the height that you get with regular spring and shock sets.....you can change your mind and raise or lower whenever you want, you can get just the amount of front to back rake you want, etc.
Brian Goodwin
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lucifuge
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Joined: Sat Mar 14, 2009 9:50 pm

Re: Rx8 series 2 suspension query

Post by lucifuge »

0.5" to 2" (from stock) height adjust-ability is great for me. I noticed many other PSS9 applications on other cars going from 1.2" to 2"...but 1" maybe already more than my steep driveway can handle. It was sort of why I was leaning towards the RB springs, but by time I add shocks, the PSS9's are surprisingly good value by way of comparison! Strangely cheap for Rx8s!?
lucifuge
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Re: Rx8 series 2 suspension query

Post by lucifuge »

Brian, only in terms of daily driving comfortability; how would you compare the PSS9's to the TEIN Comfort sports?
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Re: Rx8 series 2 suspension query

Post by Brian »

That's a BIG difference in comfort because that's a big difference in spring rates.

The Bilstein RX-8 PSS9 rates are 370+145lb/in helper spring front and 375-445lb/in progressive rear.

The Tein Comfort Sport Coilovers FRONT SPRINGS 5 Kg/ 280 lb, REAR SPRINGS 3 Kg/ 168 lb.

Thus, if looking for full height control...WITH max comfort, then the TEIN is your better choice.
Brian Goodwin
Good-Win Racing
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lucifuge
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Re: Rx8 series 2 suspension query

Post by lucifuge »

many thanks.
Brian wrote:That's a BIG difference in comfort because that's a big difference in spring rates.

The Bilstein RX-8 PSS9 rates are 370+145lb/in helper spring front and 375-445lb/in progressive rear.

The Tein Comfort Sport Coilovers FRONT SPRINGS 5 Kg/ 280 lb, REAR SPRINGS 3 Kg/ 168 lb.

Thus, if looking for full height control...WITH max comfort, then the TEIN is your better choice.
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