Opinions on Poly VS OEM and check my suspension refresh list please

[Karl Lazlo]

Did the poly diff bushings tighten up the drive line slop you get when shifting hard?

Oh my, yes. Check your giubo and CSB coupled with diff and subframe mounts - It really is smooth as glass.

[Karl Lazlo]

Seems pretty close to what I have planned. When you say "harsh" what are you describing?

You end up feeling everything. Tighter and tauter. Maybe BP can compare, as he drove the car..

I'm not a racer, and doubt I will ever track my car, I just want the best handling I can get without having to kill the ride quality. (I lifted my 4runner and although it looks bad ass and can climb over anything, the on road ride quality is no where near the stock ride. I wouldn't change it because it's my hunting/winter truck, but for my car, I'm hoping to have a nice quality ride.)

The good news is... Most of the ride stiffness is from the dampers and not the bushings, so I think you will be fine. The 95A bushings should feel right at home, without the NVH typical with hard poly bushings.

Do you get any rubbing with your tires? That is actually about the same square set up with PSS's I was thinking of switching to later this year. I like the wider look of tires.

I loooooove my square set up. I get some rubbing in the rear when hitting decent sized undulations on the road and if I have heavy things in the trunk - tools, water, ammo, dead hookers, etc. Much more to do with the offset (ET35) than the width, as 255 is stock. On stockers or ET38, not so much.

Gratuitous photo:

[KevinC]

That's interesting to hear, I haven't experienced anything similar. Just out of curiosity, did he show you the alignment sheet afterwards?

No, though he did align it. Allegedly. I need to get off my ass and go talk to him about it - not at all pleased with how it drives. If it's as simple as a botched (or forgotten) alignment, I want it fixed ASAP.

[Vas]

I have some experience with poly bushings since I had the same mindset of using them for the same reasons as you which were longevity and an upgrade over the stock rubber bits.

My advice is ignore the poly and go for rubber bits from the M3/z4m. Use the z4m fcab, m3 engine mounts and trans mounts and z4m rtab ( or splurge for the bimmerworld rtab kit)

I ditched the poly in the fcab since they squeaked and I had to grease them to keep the noise down. Poly in the trans mounts was a nightmare on a street car with the noise from the gearbox.

If you don't plan to track the car and just want to upgrade while keeping the OE feel, go with rubber.

Also the poly and the z4m fcab feel exactly the same.

[BMWCurves]

I haven't driven anyone's car with poly bushings, so I can't speak about how the NVH, ride quality, or performance is with those. I can say I really like where my car is, suspension-wise using rubber bushings. I refreshed my suspension with the goal of getting a factory/OEM+ feeling i.e. still relatively comfortable with improved handling. To do so I used Koni Yellow shocks, kept the stock springs (necessary for where I live), Z4M RTABs with poly Vorshlag limiters, and Z4M FCABs. The Z4M rubber is solid rather than fluid filled like the stock ZHP bushings so they'll last longer and are a little stiffer. The Z4M FCABs increase the caster which I quite like how it feels on turn in. Additionally, I switched to from the heavy 135s (~50 lbs with the tire!) to a square setup using APEX ARC8s 17x8.5" ET40 shod in 245/40R17 Continental ExtremeContact DW tires. I shed some more unsprung weight with the BMW Performance brake rotors which shed about 3 lbs on each corner in the front and another pound or so on each rear.

The change was pretty significant. The car rides much better than before and is much more planted while providing even better steering feel that before. Bumps on one of my favorite roads used to upset and unbalance my car, but now they swallow the bumps and beg the car to be driven harder. I really like it and I could tell the difference in the reduced unsprung weight since I did the suspension refresh first followed by the wheels about six months later. The wheels are what really made my car feel like I can steer it with the throttle when I have traction control turned off. Poly might still be the way to go, but know if you take the more factory route, it's still a great setup.

Some helpful threads from when I did my refresh and was considering APEX wheel sizes:

• Suspension thread: http://www.zhpmafia.com/forums/showt...miles-10-years
• APEX thread: http://www.zhpmafia.com/forums/showt...Size-Questions

[Kimber]

I have some experience with poly bushings since I had the same mindset of using them for the same reasons as you which were longevity and an upgrade over the stock rubber bits.

My advice is ignore the poly and go for rubber bits from the M3/z4m. Use the z4m fcab, m3 engine mounts and trans mounts and z4m rtab ( or splurge for the bimmerworld rtab kit)

I ditched the poly in the fcab since they squeaked and I had to grease them to keep the noise down. Poly in the trans mounts was a nightmare on a street car with the noise from the gearbox.

If you don't plan to track the car and just want to upgrade while keeping the OE feel, go with rubber.

Also the poly and the z4m fcab feel exactly the same.

Thanks Vas, I plan on doing the OEM Z4M FCAB bushings and just use my old carrier's and press the new ones in. OEM M3 rubber stuff for the other things you said as well and have decided to splurge a little on the Bimmerworld RTAB for sure.

Your not saying to use factory rubber on the sway bar bushings as well are you?

More of my questions/concerns were on the poly differential mounts and subframe mount "inserts". I put 2 poly options for both locations linked in my first post. I was hoping to hear people's experiences with those area's.

Thanks!

[Kimber]

I haven't driven anyone's car with poly bushings, so I can't speak about how the NVH, ride quality, or performance is with those. I can say I really like where my car is, suspension-wise using rubber bushings. I refreshed my suspension with the goal of getting a factory/OEM+ feeling i.e. still relatively comfortable with improved handling. To do so I used Koni Yellow shocks, kept the stock springs (necessary for where I live), Z4M RTABs with poly Vorshlag limiters, and Z4M FCABs. The Z4M rubber is solid rather than fluid filled like the stock ZHP bushings so they'll last longer and are a little stiffer. The Z4M FCABs increase the caster which I quite like how it feels on turn in. Additionally, I switched to from the heavy 135s (~50 lbs with the tire!) to a square setup using APEX ARC8s 17x8.5" ET40 shod in 245/40R17 Continental ExtremeContact DW tires. I shed some more unsprung weight with the BMW Performance brake rotors which shed about 3 lbs on each corner in the front and another pound or so on each rear.

The change was pretty significant. The car rides much better than before and is much more planted while providing even better steering feel that before. Bumps on one of my favorite roads used to upset and unbalance my car, but now they swallow the bumps and beg the car to be driven harder. I really like it and I could tell the difference in the reduced unsprung weight since I did the suspension refresh first followed by the wheels about six months later. The wheels are what really made my car feel like I can steer it with the throttle when I have traction control turned off. Poly might still be the way to go, but know if you take the more factory route, it's still a great setup.

Some helpful threads from when I did my refresh and was considering APEX wheel sizes:

• Suspension thread: http://www.zhpmafia.com/forums/showt...miles-10-years
• APEX thread: http://www.zhpmafia.com/forums/showt...Size-Questions

Thanks for the thoughts! I actually used your thread as a starting point along with some awesome incite from Slater! I'm probably dumb for throwing this all on at the same time, and would be better served the forum if I did one thing at a time and then responded with how it changed the car, but to be honest, I don't have that kind of time at the garage. My mechanic buddy owes me a big favor, and is doing this whole install for me (with my help) to square us up basically. (well he said he will help me install the cooling system refresh in the spring when I get that stuff ready...next project...LOL)

[slater]

I have some experience with poly bushings since I had the same mindset of using them for the same reasons as you which were longevity and an upgrade over the stock rubber bits.

My advice is ignore the poly and go for rubber bits from the M3/z4m. Use the z4m fcab, m3 engine mounts and trans mounts and z4m rtab ( or splurge for the bimmerworld rtab kit)

I ditched the poly in the fcab since they squeaked and I had to grease them to keep the noise down. Poly in the trans mounts was a nightmare on a street car with the noise from the gearbox.

If you don't plan to track the car and just want to upgrade while keeping the OE feel, go with rubber.

Also the poly and the z4m fcab feel exactly the same.

vas, did you even read his post? he's already planning on using everything you stated. the only place poly is going is the swaybar bushings, and rear subframe mounts and diff mounts - where it belongs.

not sure how your poly FCABs squeaked, what kind of lube were you using? i've installed about 6 sets of poly FCABs on various E46's and have never had any squeaking. i use a small amount of PFTE lube to guide the busing into the carrier and then the bushing onto the control arm. that's it.

[ryankokesh]

I've never had any squeaking either... Only lubed when installed, too.

[Vas]

vas, did you even read his post? he's already planning on using everything you stated. the only place poly is going is the swaybar bushings, and rear subframe mounts and diff mounts - where it belongs.

not sure how your poly FCABs squeaked, what kind of lube were you using? i've installed about 6 sets of poly FCABs on various E46's and have never had any squeaking. i use a small amount of PFTE lube to guide the busing into the carrier and then the bushing onto the control arm. that's it.

Nope. I just saw the title and shared my experience.

As far as the noise, I had contacted AKG when I had the first set. The customer service was great and they had informed me to clean and lube them again. Then after a certain period of time, the noise came back and they sent out another set of the fcab. I installed those based on their advice and lubed them with the supplied lube. The issue returned shortly so I ditched them and went with the Z4M fcab.

The issue from what I could tell was the inserts that go into the outer portion of the bushing and slide on the end of the control arm have excessive play and this resulted in the bushing having movement forward and back.