I'm doing a suspension refresh on a 1995 M3 I just bought that I intend to do a fair amount of DE in as well as daily drive 100 miles a day. The car already has the H&R coil over set up installed which I feel walks a nice line between comfort and sport.

I have been told by the shop that did the PPI that the car needs new RTABs. I also want to undertake a few other suspension changes along the way. I have been recommended the full Powerflex set up (RTABs and offset LCABs), the Ground Control "Hybrid" Camber plates, and either the Turner or UUC Swaybarbarian sway bars.

I would appreciate input as to the noise/ride issues with the Powerflex and whether I would be better suited using an softer alternative (either 96+ e36 m3 or e46 bushings with the Ground Control) in the rear in the name of streetability without sacraficing too much at the tracks or, alternatively, if I could go a monoball bearing in an aluminum race (Ground Control or TC Kline) in the rear. Some reports say that rear monoballs are not streetable while others (like the guy who did the European Car M3 build up and a few on this board) say that they produce no ill effects.

I formerly daily drove a stiff older Carrera which I DE'd with Porsche Club so while I don't want to take it to that level, I don't mind firming it up so that the car will be more track worthy. That being said, I appreciate the comfort of the car and don't want a overly clunking and/or creaking suspension.

Thoughts on the RTABs? Any experience with the Powerflex front suspension bushings?

Thanks in advance,

David

I'm doing a suspension refresh on a 1995 M3 I just bought that I intend to do a fair amount of DE in as well as daily drive 100 miles a day. The car already has the H&R coil over set up installed which I feel walks a nice line between comfort and sport. The car currently runs 17x7.5 10 spokes with 235 RA1s on all corners at the track. I plan on running these rims until the tires die and then going to 17x8.5 down the road for track use.

I have been told by the shop that did the PPI that the car needs new RTABs. I also want to undertake a few other suspension changes along the way. I have been recommended the full Powerflex set up (RTABs and offset LCABs), the Ground Control "Hybrid" Camber plates, and either the Turner or UUC Swaybarbarian sway bars.

I would appreciate input as to the noise/ride issues with the Powerflex and whether I would be better suited using an softer alternative (either 96+ e36 m3 or e46 bushings with the Ground Control) in the rear in the name of streetability without sacraficing too much at the tracks or, alternatively, if I could go a monoball bearing in an aluminum race (Ground Control or TC Kline) in the rear. Some reports say that rear monoballs are not streetable while others (like the guy who did the European Car M3 build up and a few on this board) say that they produce no ill effects.

I formerly daily drove a stiff older Carrera which I DE'd with Porsche Club so while I don't want to take it to that level, I don't mind firming it up so that the car will be more track worthy. That being said, I appreciate the comfort of the car and don't want a overly clunking and/or creaking suspension.

Thoughts on the RTABs? Any experience with the Powerflex front suspension bushings?

Thanks in advance,

David

Im running the TC Kline delrin rtabs on my tracked 332i. The rear end deffinitely stays planted better during corners, but jeez they are noisy. I am very happy with them so far.

I also run the UUC sways, and have no complaints in the performance dept. Body roll is much reduced, and more outright grip. With those and the camber plates I installed, the car drives like a lazer. Goes exactly where I point it every time. It is very hard to find the limits on the street, unless you are a mad man. I took a 20mph on-ramp at 50, then put the hammer down at apex and had an exit speed of well over 70mph. Its completely nuts.

The PF (or IE) poly RTABs are just fine. You'll just have to lube them up occasionally if squeeks bother you. The spherical stuff is best left for track only cars due to the nature of the brearing ... they don't like dirt!

Cool,
Thanks for the reply.
My buddy who is a crew chief on a Speed e46 Touring Car is trying to encourage me to go with the aluminum race RTABs saying that it is still streetable, but I think he is coming from more of a "race car you can still drive on the street" rather than "highly capable street car on the track" perspective.

Thoughts on Turner vs. UUC bars?
Powerflex Offset LCABs -Are these a killer to change out? Are there other Powerflex bushings that I should be looking to do as well.

Thanks

db (first BMW obviously)

Cool,
Thanks for the reply.
My buddy who is a crew chief on a Speed e46 Touring Car is trying to encourage me to go with the aluminum race RTABs saying that it is still streetable, but I think he is coming from more of a "race car you can still drive on the street" rather than "highly capable street car on the track" perspective. Are the TC Kline Delrin the same as the Powerflex bushings?

Powerflex Offset LCABs -Are these a killer to change out? Are there other Powerflex bushings that I should be looking to do as well.

Thanks

db

Can't comment on the sways or camber plates (wish I could), but I can comment on RTABs and LCABs, but I have a 98 so I'm using centered LCABs. I installed Pflex bushings a little over a week ago, replacing the old ones that had 120,000 miles on them. The best way I can describe the change is secure, as in the car simply feels more secure under cornering, and more predictable. I didn't feel it was night and day like some people claim. Ride quality DID diminish some on poor streets which are plenty in my area. You get a little more jolted through pot holes and a little more vibration is transmitted in rough patches. But, it's definitely tolerable for me and on smooth surfaces (i.e. highway) I don't really notice a difference. Just in the city. No squeaking either.

Oh, btw, I replaced first RTABs then LCABs a few days later. RTABs made the rear feel more planted under hard cornering and more predictable like I said earlier. Once I installed the LCABs it felt like I could maintain the line I wanted better with less "skittishness".

Cool,
Thanks for the reply.
My buddy who is a crew chief on a Speed e46 Touring Car is trying to encourage me to go with the aluminum race RTABs saying that it is still streetable, but I think he is coming from more of a "race car you can still drive on the street" rather than "highly capable street car on the track" perspective. Are the TC Kline Delrin the same as the Powerflex bushings?

Powerflex Offset LCABs -Are these a killer to change out? Are there other Powerflex bushings that I should be looking to do as well.

Thanks

db
PFlex are polyurethane, definitely a lower durometer than delrin (delrin is much harder).

LCABs are not as easy as some make it out to be. Here it is in very basic steps:
1. Unbolt LCAB bracket (lollipop)
2. Use 3-arm puller to pull bushing off c-arm
3. Take to shop to press out old bushings from bracket (could DIY, but it will be a big pain)
4. Use large vise or press to press in Pflex outer "donut"
5. Lube up inner donut and slide onto c-arm with dish soap
6. Press bracket w/outer donut onto inner donut already on c-arm
7. Attempt to bolt bracket back to body and discover it's impossible (this is the step they don't mention)
8. Break out floor jack with wooden block
9. Force wooden block against bolt hole area of bracket and jack bracket onto centering posts
10. Finally can bolt up bracket and do other side

You could also use a large screwdriver potentially to force the bracket into place.

Search for more threads like this about sways: http://forums.bimmerforums.com/forum/showthread.php?t=512982&highlight=sway.

The general concensus on this forum is to avoid the UUC bars.

I'm running the solid AA RTABs. It is a sealed design, so worries about dirt.

I put them in when I was hitting the track on a frequent basis and they worked great. Completely eliminates the 'rear wheel steering' effect you get with stock RTAB's (especially worn ones). On the street, they were fine since the car had race shells, roll bar, stiff springs, etc. Essentially fit right in with everything else. You notice them on certain bumps, with a loud "thump" which resonates through the chassis.

For various reasons, I've cut way back on track events, and the car is going almost all the way back to stock, and the RTAB's now stick out a bit more in terms of NVH. With that said, i've got a set of OEM RTAB's with shims I'm going to have put in since comfort is more of a prioritiy than getting that slight gain in performance.

In conclusion, i would recommend them if your car is more a track toy than commuter, but if its the other way around, I would probabily stay away from them.....

Another thing to remember with solid RTABs is the risk of tearing the mounting points in the chassis. Big buck repair if you need to rebuild the area to OEM specs....

Your thread from E36M3 has been merged with this one. Cross posting is not allowed.

Jay

I'm running the solid AA RTABs. It is a sealed design, so worries about dirt.

I put them in when I was hitting the track on a frequent basis and they worked great. Completely eliminates the 'rear wheel steering' effect you get with stock RTAB's (especially worn ones). On the street, they were fine since the car had race shells, roll bar, stiff springs, etc. Essentially fit right in with everything else. You notice them on certain bumps, with a loud "thump" which resonates through the chassis.

For various reasons, I've cut way back on track events, and the car is going almost all the way back to stock, and the RTAB's now stick out a bit more in terms of NVH. With that said, i've got a set of OEM RTAB's with shims I'm going to have put in since comfort is more of a prioritiy than getting that slight gain in performance.

In conclusion, i would recommend them if your car is more a track toy than commuter, but if its the other way around, I would probabily stay away from them.....

Another thing to remember with solid RTABs is the risk of tearing the mounting points in the chassis. Big buck repair if you need to rebuild the area to OEM specs....

Does AA still make these RTABs? I don't seem them on their site...

I just had the Turner Motorsport RTAB's installed. The only noise I noticed is tire noise. Not anything that really disturbs me. There is a lot more "feel" in the rear now, compared to my tore up stock 60k mile RTAB's.

Search for more threads like this about sways: http://forums.bimmerforums.com/forum/showthread.php?t=512982&highlight=sway.

The general concensus on this forum is to avoid the UUC bars.
interesting read.....

i have UUC bars and have them at full soft front/full stiff rear. i will adjust them the opposite way before VIR.

i have also noticed the understeer on corner entry, then oversteer on corner exit.....

even though the front bar is a bit small compared to other brands, i still like my UUC bars. but i haven't crossed out the option of changing to Eibach or Turner bars.

OE bushings plus delrin shims, no doubt about it.

They have all the stiffness you need (the shims really help) and they'll last another 75kmiles maintenance, squeak, and NVH free.