RSS solid right? I think I'm going to go semisolid on mine to try and reduce NVH and possibly even use a Porsche part - not decided. I didmtake a long ride Ina friend's car with solid mounts and noticed NVH but his exhaust was loud enough to cover most of it. When my car gets home I expect to be making a few suspension changes so thank you for the input!

 

Great advise John,

I currently have these non adjustable in the rear.

Thrust Arm Bushing Kit (ea), all 996/997/986/987/981/991






I'm about to order 2 of these for the rear, is there anything else I need changing out? My car has traveled 83k miles. What about up front, should I change anything there as well? TIA Jim

Monoball Bearing (ea), Lower Control Arm, 996/997/986/987/981/991

 

Those parts are fine Jim. If you track your car a lot, which I don't think you do, I'd replace the rear LCAs at some point as I've seem the outer ball joint fail on high mileage track cars. On the street it's not really a factor. When you have everything apart in the rear, check on the rear thrust arms as they will develop some play with age. Just give them a good tug and feel if there is any clicking or play. Thrust arms are about $100 each and real simple to replace.

Nothing you really need to do on the front unless you are looking for more aggressive cambers settings in which case the split GT3 arms are the way to go.

cheers...

 

Thank you John

 

Took the car out for a quick jaunt last night through some turns and my god how the backend of this thing feels solid and planted like never before. First time I actually was getting the same type of confidence the GTR gave me in the twisties.

 

Just an FYI. I seriously doubt the trans or motor mounts have anything to do with this issue. The suspension all mounts directly to the subframe and chassis and is completely isolated from the drivetrain mounts.

Later, Steve

 

Great to hear, I can't wait to get my car back on the road.

Later, Steve

 

Okay, I installed rear lower control arms with monoballs and solid thrust arm bushings and I'm happy to say that I haven't had an issue with the "tank slapper" motion.

I've done approximately 4 pulls to redline in 3rd and more in second without any issue. I would still like the car to feel a little more planted, but I think the issue is more the soft PSS10 springs and potentially the stock rubber rear bushings in the rear toe links. I will probably upgrade the rear to links with monoball cartridges, but it's nice the "tank slapper" is gone.

Thanks pwdrhound.

Later, Steve

 

I've now had the car back on the road for a little while so can respond to this. The latest project included the rear LCA monoballs, Rennline rear toe arms, Tarett front and rear monoball top mounts, and 600/800lb springs on my coilovers.

I already had solid thrust arm bushings.

I have not noticed even the slightest increase in NVH.

I can't say if my "tank slapper" issue is resolved yet because my car would not do it every time. It could go weeks between it occurring.

 

Now that I have about 500 miles on the car I have to say I think the NVH has decreased. Or it's just in my head and i'm used to it now. But honestly the rattles I was hearing from vibrations aren't there anymore. Not sure if the engine mounts kind of settle in and loosen up a bit after some heat and use.

I don't think the NVH now is any worse/different than it was before.

 

Just had these parts installed, front and back along with a proper wheel alignment. I must say this has really transformed my car, car really feels planted and not easily unsettled at any speed, yet seems more complaint over most bumps in the road that used to jar and unsettle the car. I highly recommend these to anyone that's on the fence. Many thanks to John Pwdrhound for all his time and help.

 

Just got my engine back in from having the coolant pipes pinned/clutch replaced and 3rd gear WOT and i'm back to HUGE side to side "tank slapper"/movement I was fighting before....

I don't get it. We matched the alignment specs I had when i dropped the car off. Car was shockingly unstable and on the verge of having the backend break lose and come around on me.

Not really sure where to go from here. So much money spent on this car and now i'm left not wanting to even drive it as something is clearly wrong.

 

Have your alignment shop check your eccentric bolt make sure not bent I had similar feeling years ago when I had an alignment done they bent it when got car back felt like front end wanted to switch with rear. Took 3 alignment for them to figure out was a $3 bolt.

 

I know this is an old thread and it's been awhile since I updated it. I did a lot of things to eliminate this issue and everyone made it better, but it always felt like it was wanted to do it again, it just wasn't as severe. It also tended to be worse some times than others. Not one pull to the next, but 6 months later. I have finally found the issue.

I was running a 245/35R19 front and 295/30R19 rear. The front 25.8" tall and rear 26.0" tall. This is close to stock, but the rear is definitely taller than the front. Of course the stock size is 225/40R18 (25.1" tall) and 295/30R18 (25.0" tall). The rear is shorter than the front. My theory is the rear tires were "pushing" the front tires due to the incorrect size differential.

I have now changed to a 235/40R19 (26.4" tall) and 305/30R19 (26.2" tall). My actual Michelin Pilot Sport 4s tires are 26.4" front and 26.3" rear. Changing to this setup, where the front tires are again taller than the rear has eliminated my issue completely. I curious if others with this problem may have been running a similar tire differential.

Of course the much taller tires i'm running do require some slight modifications to clear.

Later, Steve

 

Interesting thread. My car exhibits a feeling as if the front tires are lifting off the pavement, typically under hard acceleration going up hill. So much so that Im uncomfortable and ease off the throttle, as the steering gets light. Mods in signature. Was curious if any of you had experienced anything like that?