Steve Dallas

Last weekend, I installed a set of Eibach Pro-Kit springs, a set of Bilstein Sport shocks, and a set of FCM bump stops. During installation, I preloaded the suspension by leaving the upper A arm bolts and lower shock nut loose in the front and jacking up the hub until the jack stand on that side just became loose. Then I torqued the bolts to spec. This seemed to work, as the ride height dropped 1.5", which is 0.25" more than I expected, but close enough. The advertised drop for this combination is 1.125 - 1.25".

I repeated the same procedure in the rear with the end links and lower shock bolt. The rear did not behave in the same manner. The left side dropped 1.625", and the right side dropped 1".

All measurements were taken at the frame. It rode this way for a week just fine, but I wanted to fix the rear this weekend.

I did some searching here and found the car actually needs to be on its wheels and preloaded with bounce before tightening the bolts. So, I put it back on stands today, loosened the bolts, and preloaded the suspension with the weight of the car on its wheels this time--both front and rear (although it should not be needed on the front's double wishbone setup). That solved the rear problem perfectly, but introduced a new and quite unexpected problem in the front.

The front dropped another 0.75" for a total of 2.25" on both sides. I did not notice it at first until I scraped bottom on a bump near my house that should not have caused me to hit bottom. To attempt to fix it, I put the car back on stands, loosened the bolts with the suspension under droop, jacked the hub up to proper ride height, and torqued the bolts. This had no effect. The ride height is still 0.75" too low in the front.

What have I done to my front suspension, and how do I fix it?

Here is a photo of one of the installed strut assemblies.



I used a combination of the shop manual, Racing Beat's instructions, and Bilstein's instructions during installation.

J8635621

iTrader: (10)

Profile shot of the car to show the ride height?

Steve Dallas

I can take a photo tonight, but suffice it to say the nose is quite noticeably down.

In other news, I triple checked everything there is to check again, and cannot find any reason for this to have happened. I am now beginning to wonder if I got springs from a bad lot in the front?

9krpmrx8

iTrader: (46)

Are you sure you did get the wrong springs? Maybe four front springs?

Steve Dallas

Springs and mounting locations were verified by both part numbers and dimensions prior to installation. I am very **** about such things.

9krpmrx8

iTrader: (46)

Oh wait, **** I just realized you have a 2011 (sorry did not realize this was in the SII subforum). These shocks and springs are only available for the the 2004-2008 I believe, the 09-11 RX-8 rear spring perch is different.

Steve Dallas

Yeah. I am aware of the difference in rear spring perches. I called both Eibach and Bilstein to confirm fitment, and they both told me their setup works in both cars. Knowing this, I am choosing to ignore the rear height for now. I think it would be fine if the front was correct. The front dropped a total of 2.75", when it was supposed to only drop about 1.25". If the front was sitting at 1.25 - 1.5", the frame would be virtually level front to back. Right now, it is very low in the front.

9krpmrx8

iTrader: (46)

Can you post pics, I have a hard time believing the front is almost three inches lower than stock. And if it is then you have a bad shock (rare if new) or sagging springs (even more rare). But both the shocks and the springs play a role in ride height.

Steve Dallas

I would love to post a pic, but...

I reasoned that either both shocks or both springs must be bad, which is an unlikely scenario. Therefore, using Occam's Razor, I determined the problem must be with the installation or the preloading. So, I decided to return the car to stock to see if the latter possibilities could be eliminated. With the stock springs and shocks, and preloading using the floor jack, the car is back to its original ride height. I'm going to drive it that way for a week and watch it while I decide what to do next. Fortunately, the vendor from which I purchased the parts is willing to work with me on replacements of some sort should I decide to go that route.

I am truly stumped.

9krpmrx8

iTrader: (46)

The issue is actually fairly common, I have seen it happen a few times with the Tokico D specs and the Koni yellow/Tein combo.. But never with Bilsteins/eibach springs combo. If you can get a refund I highly suggest saving the $1500.00 and getting the Bilstein PSS9's. Maybe Eibach will test the springs for you, I had a similar issue and I was able to rule out the springs as the problem because I sent them to Tein and they tested them free of charge and sent them back to me.

Steve Dallas

I almost sprung for the PSS9 coilover set, but I really wanted a set it and forget it suspension.

I plan to call Eibach and Bilstein tech support this afternoon to see what they have to say.

I do have some before and after pics of the wheel wells. They do not show the full extent of the drop, but they do give some idea of how things looked. I don't base any decisions on wheel well measurements, but they play well with some crowds. Anyway, here they are:


Front before and after. The after pic was taken before the extra 0.75" of drop happened.

27.5"


25.5"


Rear before and after. Exactly the amount of drop I was looking for.

27"


25.75"


Looks like the oil pan shield took the brunt of the damage, although my cat resonator is now of the new and improved flat bottom design.

9krpmrx8

iTrader: (46)

Yeah, that is definitely not right. Coilovers are set it and forget it, I have not adjusted mine in a long time.

Steve Dallas

I spoke to the tech department at Eibach today, and they asked for part numbers, lot numbers, and installation pictures. They offered to bring the springs in for testing. I may take them up on that.

I also spoke with Bilstein. They again asserted these parts should work together. The tech also commented that I could install the spring perches upside-down to gain an inch of lift in the front if I want to go that route, but they otherwise recommend taking it to a qualified mechanic. The spring perches do not appear to be designed to be installed upside-down. He also told me the spring perches are at the same location between the HD and Sport shocks.

I have an appointment with Cobb for a performance alignment tomorrow that I was planning to cancel. Maybe I should take the car and the parts and just let them sort it out?

9krpmrx8

iTrader: (46)

Are you in Austin?

Steve Dallas

Dallas.

9krpmrx8

iTrader: (46)

Ah, so you are going to Cobb Plano. I would send the springs back to you have something to show Bilstien or the vendor as they will likely deny it is the shocks if the springs test okay.

Steve Dallas

I called Cobb (Plano) and asked if they have spring and shock dynos. They said they can test them, so we are going to do that instead of an alignment. We discussed some possibilities like adjustable spring perches, which would be cheaper than paying a lot of shipping on my parts. I am still stumped, but at least I am in good hands.

9krpmrx8

iTrader: (46)

If they don't work as designed I would not try a work around. But if they have a shock dyno that is cool and should tell you if there is a problem. Won't be cheap though....

Steve Dallas

After spending some time with Cobb, we have determined the shocks and springs are fine, my installation was fine, and that the parts simply do not work with the Series 2 car. Surprisingly, Cobb did not charge me anything for looking at everything with me. I gave them a handshake and a promise to bring the car back when sorted out for corner balancing and alignment. Nice folks over there who really know their stuff.

One option is to order a set of Ground Control / Fat Cat sleeves and use these parts. Pros are salvaging the $$ I have spent thus far and ending up with a set of custom coilovers that can be changed in the future (different springs, revalved shocks, etc.).

Option two is to go with the aforementioned PSS9 coilovers. I don't know much about them, so I will start researching them. TireRack has them on sale, and can deliver them next day for free.

Option three is to research good coilovers in the $2K range and maybe give Fat Cat a call to see what they can do for me.

9krpmrx8

iTrader: (46)

Yeah you can definitely make coilovers out of them. But the fronts and the rears of the S1 and S2 are the same so I don't see why you would have issues in the front.

If you need help with that, send a PM to Houstonrx8er, he makes these for us.

Steve Dallas

Are the fronts and rears confirmed to be the same? I searched on that question here for hours before purchasing anything, and could not find any consensus other than there are a lot of different suspension part numbers between the S1 and S2 cars. Koni and some other manufacturers seem to think they are different enough to make different rear shocks at least.

In other news, Eibach tried very had to be helpful, and emailed back and forth with me several times. They looked at my installation photos, part numbers, and lot numbers, and told me the part numbers are correct, the lots are known to be good (no complaints in their database), etc. They again offered to test them with the caveat that there is only a 1 in a million chance they are bad.

Bilstein was much less helpful. The message was along the lines of, "Our catalog says they fit, so they fit. There is no chance they are defective--they never are. Have a qualified mechanic check your work. Goodbye."

I still don't know for sure why this did not work, and the perfectionist in me really hates that.

Thanks for the tip on HoustonRX8er. I may very well contact him.

Steve Dallas

A redeeming update for Bilstein customer service. I got through to another technician there, who, to paraphrase, said the following:

I will be working with my vendor for an exchange to the PSS9 product next week.

9krpmrx8

iTrader: (46)

Nice, Bilstein is awesome.

Steve Dallas

Time for an update.

My retailer flaked out on me a little bit on the exchange, so I had to buy a PSS9 set for the car and put the B12 parts on eBay to liquidate them. Fortunately, TireRack had the coilovers on special for $1400 with free shipping and no sales tax. I installed them a few days ago after setting the spring perches to the maximum position as indicated in the instructions. The ride height is almost exactly where I want it (-1.125" front and -1.0" rear) and almost level front to back (1/4" rake) on the first try. I will let things settle for a month, then take it back to Cobb for corner balancing and alignment.

Initial thoughts on the PSS9s are very positive and fall in line with those expressed in the massive PSS9 thread.

This was a potentially expensive mistake on my part. I'm sure the B12 setup is great for Series 1 cars, but not so good for Series 2 cars unless you are looking to slam and possibly rake it.

PSS9 **** for your viewing pleasure:





We are under threat of severe thunderstorms and hail here, so I have not taken the car out of the garage since late last night, therefore no good pics of the stance yet. Perhaps Friday.

9krpmrx8

iTrader: (46)

Nice man, this ordeal was a blessing in disguise.