Highway8

iTrader: (11)

This thread is being started because not only have I not found a good source of information about revalving coilovers on this forum, but there is very little information I was able to find on the internet in General.

Topics I am looking for:

- Shops that will revalve. We know the Manufacturer will revalve to stock specs and most will revalve or higher spring rates, but what about independant performance shops that may do a better job or that dont have the same agenda as a manufacturer who wants to just sell products.

- Opinions on before and after revalving. This is mostly for people who had their valving changed to accomidate higher spring rates.

- Choice of spring rates: Every car is different and if your serious about racing, you will probably have multible setups and you have tried even more, but in genreal what works well for one car/driver should work for another with curb weight, tires, sway bars and alignment. If you have a street car vs a race car vs a dual purpose car your best setup up criteria will be vastly different.

- Why would you want to or not want to revalve: Self explanitory, give your opinion on the subject.

I am going to get us started here. Background. 07 rx8 started out as a street car, went to one track day with tokico springs/struts and I have been hooked ever since. he car is weighing in at around 2900lbs wet plus driver and has a big splitter and an apr gtc-200 rear wing. For now it looks like a street car on the inside but thats going to change over the next year or 2.

Setup: I went from stock sway bars to racing beat bars to progress tech bars and Stock KW V3 coilovers and 275/35 r-comps on rpf1's. I have it lowered about .5" and run -2.5/1.8 camber with a little frot toe out and a little rear toe in and a 50% cross weight.

This set up has given me a very neutral feeling car and despite the loose nut behind the wheel I have done pretty well at both my home track and I ran decent times on my first track day at Buttonwillow in both directions. This setup is also very streetable. The coilovers are not too stiff and it makes for a firm but comfortable ride.

Custom Spring rates and valving: I have heard the KW spring rates are around 455/285 (or 8k/5k) with the rear being progressive. The opinions I hear is that the progressive rear springs are inferior to linear springs because linear will provide a more consistant feel and reduce excessive weight transfer. I have already put higher spring rates and subsequent revalving on my list of things to do. The only choice now is where to have it done and what rates to go with.

Spring rate of choice: From what I gather, 10/7 is popular but I have heard of full race coilovers going as high as 13/8 or 13/9. I am thinking I will stay in the 10/7- 11/8 range. Maybe even get a few sets of springs to try different rates out.

Where to have it done: Kster ( an s2 r3 nor cal owner) had a set of street/track ohlins installed by PSI of Infineon Raceway which is 20 minutes from my house. They are also an authorized service facility for KW and all the top racing brands. Seeing as how they are so close, experianced and recommended, I will probably have them do the work unless someone know a better place for a better price (not really the issue but... )

Other future mods. Mazdaspeed upper and Offset lower bushings in the front along with Megan racing rear control arm links with Heim Joints. OS Gilkin LSD and 4.77 gears.





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Highway8

iTrader: (11)

I take that back, there was another thread started 2-3 months ago in the s2 section but it went nowhere. https://www.rx8club.com/series-ii-wheels-tires-brakes-suspension-165/revalving-coilovers-223629/

Digger1911

Give these guys a call, they are good people..
http://www.kingshocks.com/home/about/

Highway8

iTrader: (11)

Found out nobody wants/can revalve the KW V3 coilovers. The shops I talk to say that parts are hard to get from KW and KW does it for $120 per strut in the California facility. Called KW and they said they wont revalve, only rebuild. Asked about using higher rate springs and they said you can go up 250LBS. Stock is 455/280 (progressive rear) or 8k/5k. So I could go up to 705/530 or 13/9. I am thinking 11/7 to be on the safe side and I might get a 12/8 set too so I can trade out the springs and try different combinations.

Getting coils. I didn't even bother asking KW if they sell higher rate springs, because I want to use standard race spring sizes. Swift springs to be exact. Swift tends to be a little more expensive but they are a little lighter and have a little more useable stroke.

The front springs are 8" tall by (61MM) 2.25" ID. Rears are progressive, so the tops are large like stock and the bottom is 2.25" also 8" tall. Both front and rear already have helper springs which I will continue to use. The KW V3 uses 20/60/80 helper springs, or 20 N/MM (114 FT LBS) 60 MM (2.25” ID) and 80MM long (3.15”) When fully compressed the helper is about 1.25”.

Front coils. I went with swift 8” coils. 2.25” ID, 11K (616 FT/LBS) I wanted to get 7” coils but swift was out.

Rear. As mentioned above, the KW rear uses a progressive main spring. Stock perch on top and 2.25” at the bottom. I bought Delrin adaptors from Goodwin racing that allows me to use a 65MM or 70MM spring with the stock perch and another adaptor to go from the 2.25” helper spring to the 65mm (2.5”) main spring. Final selection was an 8k 7” spring.

While I was spending money, I picked up a set of Thrust Sheets.
"Thrust sheets provide a variety of benefits to coilover systems. As a spring becomes compressed the coils attempt to distribute the energy by unwinding. This is called twisted force. The unwinding makes the spring rate irregular. By allowing the spring to smoothly rotate around the perch during compression, the spring rate will return to normal. Thrust sheets also help dampening and rebound of struts too. Thrust sheet’s bearing action allowing the rotation of a spring allow the load on the spring to be more evenly Distributed which reduces lateral shock shaft load. Increased lateral load on shock shafts cause a reduction in the struts ability to rely on valves for dampening force.

Thrust sheets works with all brand of coilover system & springs as long as inside diameter matches. Each kit comes with 4 composite rings and 4 stainless steel sheets that will cover 2 coilover springs."

r0tor

iTrader: (1)

Consult fatcatmotorsports

Highway8

iTrader: (11)

From what I can tell, fatcat only does Bilstein shocks. The problem with revalving KW v'2 is getting the parts.

BRODA

iTrader: (7)

Make sure you use a spacer and longer bolt for the rear lower shock mount, or the shock body may (will) rub the delrin upper spring mount. I'd suggest installing the shocks without the springs and moving the suspension through its range of motion to make sure there are no clearance issues before tightening everything up.

If you do decide to get revalved Ohlins, I have a set of Road & Track which were revalved by PSI. PM me if you want to discuss.

fuztupnz

iTrader: (4)

Personally, I'd sell the KW's and buy some ohlins, or AST's. AST makes the 5200 or 5300 series for our car which is double adjustable if I recall, and made to order with choice of springs. Last I looked they came in around $2900.

Found the infomation i was looking for. 5100 series, but 5200 or 5300 available.

http://www.vorshlag.com/product_info...roducts_id=467

Edit 2. They start at $3k + springs

Highway8

iTrader: (11)

I thought about getting the Ohlins from goodwin racing with the 13k/8K, Fatcat or AST coilovers, but I already have the KW's so I wanted to give them a try with new spring rates. Its no money really lost, I can use the springs in other coilovers if I go that route or I can sell them for 60 cents on the dollar.

This way if I switch latter, I can know if I wasted my money on a more expensive coilover or have the satisifaction of knowing they were worth it.

fuztupnz

iTrader: (4)

Eh. That makes sense. Good luck. I'm interested in your findings as I'm thinking of going one of these routes eventually myself.