Since different people lurke in different sections of the forum I will post this here as well:


I have decided to get Koni dampers. I already have RB sways on the car and now thinking about what springs to will work best the RB Koni combo.

The car is a daily driver, which I am hoping is going to do about 12-15 track events per season. Lapping, driving schools and possibly solosprint. All this is done with the objective to become a better driver and having fun, I am not competing.

In the future I will probably add a set of 17" RA1 for the track.

I am currently deciding between Swift and H&R. Their rates seem well suited to work with the RB sways (not overly firm, whatever that means).

I know that rates don't tell the whole story but don't have much more then this and people's inputs to rely on.

Here are a few points I have been thinking about.

H&R seems to have a decent reputation where as Swift is somewhat of a dark horse.

Swift has comparatively low rate for the rear spring but I am not sure what to make of this, on one hand this means more grip for the rear or understeer which might be good considering the aggressive nature of the RB sways and me starting up. On the other hand I don’t get this.


H&R drop is lower 1.25 to 0.8, which is probably better for the track.

Any other springs which would work well with the RB sway and Koni dampers?

Another related point;

Will I have to set up the Koni's differently based on the springs I go with?

Completely new to suspension set up,
All positive input is appreciated...

Spring Info:

stock sport
Front drop 0"
Front rate 156 lb
Rear Drop 0"
Rear rate 113 lb

Swift:
drop: -0.8 inch front and rear
front spring rate: 3.7 Kg/mm 207 lbs/inch
rear spring rate: 1.6-2.3 Kg/mm 90-129 lbs/inch

H&R Sport
Front drop 1.25"
Front rate 195 lb Progressive
Rear Drop 1.25"
Rear rate 141 lb Progressive


stock sport I verified these spring rates on post number 97 of this thred
Front drop 0"
Front rate 156 lb
Rear Drop 0"
Rear rate 113 lb


Sway info:
Off the RB site:
The diameter of the front tubular bar is 1.25” (32mm) x .1875” wall thickness, as compared to the stock 1.05” (27mm) x .134” wall thickness front bar.

The diameter of the rear tubular bar is .75” (19mm) x .125” wall thickness, as compared to the stock .632” (16mm) x .097” wall thickness rear bar.

It depends on your track versus street priority.

If you favor ultimate performance for track - the mazdaspeed springs would be my choice as they are the stiffest, but ride will suffer.

If you want the best compromise, several could work (Tanabe, Tein, Swift, H&R) and would all be pretty good, but I would likely go with the RB Springs as well since you have the sways. The RB total package with Koni's is a very good handling setup that is livable on the street.

My 2 cents.

Why don't you just go with the Racing Beat springs? Koni's w/ RB springs and sways make a good setup. Racing Beat did design the springs and sways to go together and using their matched setup will most likely provide a more balanced and predictible setup. Otherwise you're just doing you're own testing and tuning.

+1 on Racingbeat springs. Another Alternative is the Espelir springs. They are about a 30% increase in stiffness and a 1" drop all around compared to Racingbeat with a 0.5" drop and 20% increase in stiffness.

I have the Espelirs with stock shocks and think they're great. I am getting ready to swap out the shocks for Konis and then add Racing Beat swaybars. It's all in the mail as we speak.:)

AutoRnD sells the Espelir springs on this forum and they are cheaper than the H&R and Racing Beat.

please pay particular attention to the last line

http://www.rx8club.com/showpost.php?p=2080931&postcount=2

I say go with RB