altiain

iTrader: (3)

You’re welcome. As to the spring rates, I’m not sure. I know that Thomas is running 503 lb/in (9 kg/mm) front springs on his MX-5, while I still have the stock 447 lb/in (8 kg/mm) front spring on mine. I am thinking of ordering a set of the 503 lb/in front springs to test on my car as well. I think the damping will definitely handle an increase of 1 kg/mm without trouble, but I can’t speculate beyond that. I’m not sure you would want to run much stiffer springs on an STX car.

chiketkd

iTrader: (5)

Agreed. I'm going with Swift springs which will allow me to get a pair of 9K & 8K springs for the front, and 5K & 5.5K springs for the back (might even get a third pair of 6K rear springs).

The good thing about the rear coilovers on the RX-8, is that the entire shock and spring can be removed w/o undoing your alignment. My co-driver found an older post of Isley's when he described how to do this, and we were able to get it done when replacing my blown rear koni after Nats.

Miatamoto

Same disclosure as Iain. I'm testing a set of Endura Tech coilovers on my MX-5. I've come to a lot of the same conclusions as Iain on the performance and street driveability of the coilovers. I actually just got back from a 600 mile road trip in the car with my wife and there were no complaints from her.

I've driven with these coilovers on the 8kg/5kg spring rates at Eagles Canyon and a couple of autocrosses and Hallett and one more autocross on the 9kg/5kg spring rate. The stock RX-8 rates had too much oversteer (even with a Whiteline RX-8 front bar and no rear bar) on the shorter wheelbase MX-5. The 9kg front springs have helped some, but I've also been suffering from massive inside wheel spin while autocrossing (open diff and less droop travel compared to the Koni/Mazdaspeed spring setup). I installed a Mazdaspeed clutch diff this past weekend so hopefully I'll be out autocrossing some more after it breaks in.

The car was great at Hallett and seems to handle mid-corner bumps and curbs very well.

wankelbolt

iTrader: (21)

Thread resurrection for a good price on these. Endura-Tech is apparently having a "SEMA special sale" on these for $865 plus ship. That's a steep discount off the $1450 regular price. I found out when I asked about rebuilding some used ones somebody listed in the FS section.

I have no connection to Endura-Tech and get nothing for passing this information on: