jaimesix

Hi.

Time to upgrade the suspension. Began listening to some clunking noise. Seems the front L strut is getting old. Stock suspension.

What do you guys recommend. Thinking about coil overs Another option would be springs and struts on stock perches. But I think with a little more a decent coil over set up could be found.

There are several brands now. Remember when KONI was the top brand. Now I see several and I do not know most of them.

Already have Racing Beat Sway bars. Excellent deal. Sway bars add a lot, despite having only stock suspension.

Daily driver. Sport rider, enjoy spirited driving and enjoy occasional club driving. Been to Willow Springs.

dannobre

iTrader: (3)

Good pricing on Ohlins right now.......For 2K they are a great setup

jaimesix

Any Thanks Giving nice sale prices any knows about ? We are only a few days away !

dannobre

iTrader: (3)

SakeBomb and Goodwin Racing are worth a check for Black Friday Sales 😎

jaimesix

Ohlins Road & Track DFV Coilovers (RX-8) - SakeBomb Garage LLC

Ohlins DFV RX8 Coilovers OUR BEST RX8 COILOVERS- New Road and Track Version for RX8

Bilstein PSS9-Complete RX8 Coilover Kit for RX8 2004-2011

Tein Monoflex Suspension Kit (RX-8) - SakeBomb Garage LLC

http://www.sakebombgarage.com/tein-s...sion-kit-rx-8/

dannobre

iTrader: (3)

http://www.good-win-racing.com/Mazda-Performance-Part/61-0015-RX8-DFV.html

jaimesix

Thanks. Seen them Posted links above. Both SakeBomb and Goodwin Racing have it for 2K

Hope it goes down during Thanks Giving. On Monday will call them both.

jaimesix

See brands as Ohlin, Bilstein, Tein, (do not see any Koni coil over kits)

Ohlin I know from my motorcycle world knowledge, did not know they went into automobiles.

Bilstein is German quality as far as I know.

Tein I do not know. Seen their adds but never learnt anything about it.

Koni is the legendary japanese brand, but see no major suspension kits by them for our cars.

Got to study this situation and take advantage of this oncoming Thanksgiving day

jaimesix

Any more comments appreciated. Anybody used the Bilstein kit ? Tein kit ? Koni components ?

jaimesix

Well Guess nobody is fixing up their RX8s any more.

I will find out myself.

later

NotAPreppie

I just bought a lightly used set of KW Variant 3 for $1500 and I'm very happy with them.

That said, if the Öhlins sale had showed up before I bought the KW's, I would have paid the extra $500 for a new set of those instead.

If you aren't competing, almost any coilover kit from a good brand will probably be fine (Bilstein, Eibach, KW, Öhlins, etc).

jaimesix

Thanks NotAPreppie.

Made my own investigation online. Not much found except for Ohlin and Bilstein.

Called Sakebomb and made my move. Took advantage of Thanksgiving sales and asked for additional discount.

Paid today Wating for my RX8's Xmas present !!!

40w8

I have a 2007 GT and put on the Bilstein B12 kit from AJUSA.com.

It got rid of the sagging rear; even when new fronts were about 14.25, and rears about 13.5.

NOw it drives smooth, but firm, and no clunk, and i think height will settle out to 14 inches all around.

It didn't even seem to mess up alignment, but will watch older Handkook V12's to see.

AJUSA even has them on sale for about $701. now.

jaimesix

Hi 40W8.

Any photo of your RX to see its stance ?

Bilstein is great brand. For sure an upgrade. Never drove my RX with anything else but stock suspension. The sway bars (Racing Beat) added a lot better ability to corner.

I bet your car performed like night and day after the improvement

40w8

Sorry, no, but the suspension specs say 13.5 to 15.5 from center wheel cap to fender.

Level and 14 is as low as I'd want to go.

I never care about stance, just a firm suspension.

Everyone and their dog has been looking for lowering springs for years, but I knew when I got the right suspension it would raise.

The rears are gas pressured, and factory is crap just like Mazda Ignitions and fuel pumps.

I fixed those years ago, too.

jaimesix

Good to know it is working as planned.

About. Ignitions and fuel pumps....never had an issue with any in my "8".

Had a Mazda 808, RX3, 1st gen RX7, , 94 RX7 FD and this RX8. Never had an issue with ignitions nor fuel pumps. I may be lucky.

About stance, I just wanted to see how an RX looks with your suspension.

I am not looking to lower the car. I do not think the RX8 looks any better lowered. It is one of those cars that does not look better lowered

Not opposed to lowering either, had plenty cars I have modified, the RX8 is a car I am not actively trying to lower it. With adjustability I can tune its height That capability is welcomed

I am looking for a reliable and performance capable suspension. That is why I investigate. I have burnt myself with products and learnt my lesson.

Value is another consideration. Like to save intelligently. Value to me is durability and reliability plus performance. Price is irrelevant when within my range.

Lastly. Fun factor. We will not live forever. Want to enjoy while I can.

����

40w8

Being a little OCD, I don't like infinite adjustability, but everyone has different ideas.

I had a 73 RX3, and the same things were wrong with that car: bad synchros (especially 2nd), bad fuel pump, but I never found any that worked very well as mod.

Ignition had some flaw, but I just ran a hot wire to coil, and got a antitheft device at same time.

I'll see about a pic, but it's not driven much and dirty.

At 33k miles it's in mostly perfect shape, and I even got 26mpg the other day at 65-75mph.

jaimesix

Yes.

Mileage can be great at cruising speeds. On long trips I have been able to see the mileage odometer (always reset the odometer to 0 upon filling up) pass the 300 mark. Gotten up to 23-24 miles per gallon.

High speed and mileage are ok. The occasional pedal to metal stints bring it down. That is unavoidable. ��

I am sure driving easy on pedal at steady speed could get more.

On adjustability, in regard to the RX8 not that crazy about it. (My Datsun 610 model needed lowering down. Those old classics do look good low and can take all that lowering. I think my Datsun lost 5 inches from stock. Doubt a RX 8 could. Would not look happy)...There is not much room for that on this car. But there are times that a small tunning helps. Not crazy about super detailed adjustments but not fan of frozen set ups as well. Middle ground.

30K. That is great. It is a young kid that RX !

40w8

Ok, here's stance pics.

Tires are 25 inch diameter so wheel gap is around 1.5 to 1.75 inches.

lOOkatme

I have ohlins DFV on my rx7 FD and they ride very well. they came stock with 11/11 spring rates but I went down to 8/6 and it rides much better. My car is a street car only and one of the reasons I dropped the rates.


On the rx8 I think the stock tokico shocks are valved pretty good. car rides nice stock, This car is going to be tracked and I just want a little lower ride height and a little more spring rate. I purchased swift lowering springs. I run swift springs on my rx7 with ohlins. I think with the moderate drop in ride height and the spring quality and rates should do well all around. If the shock goes out I will replace with stock ones again. we'll see how it goes.

jaimesix

Cool.

Waiting for my set to arrive. Hope I will get it soon. I think Ohlin headquarters is located in Indiana.

Hope to get it by the weekend. Will add my comments once I get them installed.

My stock suspension was good. Wish it was a little firmer on corners. But the front struts began to clunk (lasted a long time) and an upgrade was in order.

Yes, firmness comes at a price, like softness does. But so far everything I hear about Ohlins is good.

Can't wait !!!

NotAPreppie

If the Ohlins are anywhere near as well-engineered as the KW (and I have no doubt that they are), then the difference will probably not be that noticeable.

When I first installed my KWs, I hadn't paid attention to the settings and it was UNBEARABLE. The guy I bought them from evidently had everything on full stiff. After setting the adjusters to the recommended starting point, it is only barely distinguishable from the OTS Koni Sport shocks with stock springs.

For ride height, most guys that autocross RX-8s in STX agree that 13.5" from wheel arch to middle of centercap is ideal for competition. Lower than that and you'll negatively impact handling due to suspension geometry. Higher than that and you aren't taking full advantage of extra camber and lowered CG. For the street, I'd say that 14" is probably a good starting place. It'll give you a little extra room for bumps and driveway skirts.

lOOkatme

So here is the skinny on all this suspension stuff.


If you get down to it there are a couple of things that effect ride quality and even handling.


The spring rate. Springs oscillate at certain frequencies given the sprung mass of the car. The stock rx8 is in the 1.3X to 1.4X frequency which is not all that soft for comfort, but stiff enough for fun. I set up my rx7 to ride in the 1.5-1.6Hz range which is slightly more aggressive than that of a stock rx8 or stock rx7.


The frequency at which the car oscillates matters to ride comfort.





here is a chart with random people rating the comfort vrs. ride frequency.


most race cars are in the 2.0hz + frequency.


ride comfort also is effected by flat ride. this means the front has a 10% or so lower ride frequency than the rear. the rear needs to catch up to the front so the car rides more "flat" otherwise you get a pitching motion which just flat out sucks. some aftermarket companies don't take this into consideration.


damping is the last and also very important. it seems that low speed velocities you want some support on both damping and compression forces, at high speed you want them to blow off. lots of damping doesn't blow off at the higher velocities so it seems like you are jumping over bumps at high speeds, the wheel needs to get back to the ground as quickly as possible. so you need a relief hole/valve to move shock fluid quickly at high velocities, hence the fatcat KBO, or Ohlins DFV technology. and it does work well. Also the Critical damping ratio matters very much to ride quality. low is .3 or so, and high is .8 to 1.0.


Mechanical grip is maximized with having the lowest frequency spring rates with the most independent suspension (no sway bars). this doesn't mean its the fastest, just most grip. so in my opinion I like lower spring rates cause they ride better and grip more and small sway bars. a balance needs to be made. if transition speed is wanted you either up bar rate or spring rate or both for things like autoX and wheel to wheel racing.


Furthermore, if you want an all out grip car, wide wheels, as wide as you can fit and softer rate springs are the key, stiffen only as much as you need.

NotAPreppie

Here is the spreadsheet that FatCat Motorsports uses to do rough calculations for the RX-8.
FCM_MSDS_RX8.xls

jaimesix

Studying both diagrams.

Interesting information. In most my modified cars, and I have more experience modifying classics rather than newer cars (Datsun 710, 610, Mazda 808/RX3, Plymouth Belvedere...etc) I always compensated larger sway bars with more rubber.

Wider wheels and wider tires. Wide tires and not less than 50 aspect ratio. That means not going overboard in wheel diameter which constraints rubber.

Big mistake, and I think it is done for looks, is to stiffen a suspension and increase diameter of wheels with very low aspect ratio tires.

Aside from adding more grip, more aspect ratio adds cushioning needed. Or else car rides like a chariot and slides like a moose on a frozen lake.

Formula One cars are stiff, but those cars do not have large diameter wheels and tires with little aspect ratio. No skateboard tires.

Nascar also uses more aspect ratio. A Nascar or Formula 1 car on 30 aspect ratio tires and big showy wheels would end up wrapped around a lamp post.

I saw a Datsun 510 with an SR20 DET motor, stiff suspension, and something like 20 in wheels and what must have been 30 aspect ratio tires cork screw and hit a water main causing a big embarrassing scene. The guy flored the pedal and it just flipped like a race boat catching in on a draft.

I have contemplated adding more rubber to my RX8. But this car has no real area. The flares that come from factory are just for looks.