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-   -   Poly RTABS or Rubber OEM RTABS Lemforder (http://forum.e46fanatics.com/showthread.php?t=985132)

Razmataz77 05-02-2013 02:17 AM

Poly RTABS or Rubber OEM RTABS Lemforder
 
Guys I have researched and gotten mixed reviews. I definitely prefer ride comfort over extreme stiffness.

I am getting the H & R Touring Cup Suspension Kit so that should def stiffen the handling but I am not sure if I should add the Poly RTABS.... Overkill?
Also heard the Poly's squeak even with the grease after a few months and it seems that people prefer the OEM Rubber Lemforder.

Any help and guidance as always will be most appreciated.

*If Poly, than best brand, best website to purchase?

*If OEM rubber, than best brand, Lemforder or Mele and best website to purchase?

:thumbsup:

Mango 05-02-2013 02:24 AM

In my humble opinion, poly is junk for high-demand, high-activity bushings. Go OE/OEM design such as Meyle HD for both FCABs and RTABs. You can also do Lemforder RTABs. Easy in easy out with correct tools. No maintenance needed and you don't have to be under your car looking for creaks and squeaks. The bones in your wrist also won't rattle out.

Try oembimmerparts or bmaparts.

GL

Drew@Swift Motorworks 05-02-2013 02:30 AM

I would stay with OEM for street driving and just add limiters.

djantlive 05-02-2013 07:41 PM

i used oem rtab with limiter as well. take it to an indy bmw shop that does this all day long. couple hundred bucks and you won't have to worry about getting the tool etc. too much trouble diy imo after doing it myself with the rtab tool.

get an alignment after!

illestminimike 05-02-2013 07:43 PM

Poly RTABS or Rubber OEM RTABS Lemforder
 
I had powerflex in my vert and I didn't notice the ride changing at all. My RTAB's weren't shot to begin with and the only difference I felt was more grip in the rear end. It sorta felt like I added more weight to keep the rear end stable. For $80 and a $80 install I was very satisfied.

E46Snowball 05-02-2013 07:45 PM

I had a hell of a time trying to fit the oem lemforder m3 rtabs into my housings for some reason, one just did not want to go in. Had the tool and everything, ended up bending the rod of the tool. So I gave up and ordered powerflex. Decently priced... same price or cheaper than oem+limiters, and honestly not harsh at all really. Rear end feels more planted, just make sure you grease em up alot. No squeaking or anything so far...

Grande D 05-02-2013 08:07 PM

For people who like the feel of rubber, the RTABs are the one place where it is acceptable to go poly. The NVH difference (RTABs only) is so small that if you didn't drive your car for a week in between you would not notice a difference.

Powerflex or AKG. AKG makes a part that is slightly softer than Powerflex and apparently cannot be distinguished from stock rubber. Stock rubber with limiters is more of a PITA than it's worth. Yes, I've tried that solution also.

Mango 05-02-2013 08:33 PM

Quote:

Originally Posted by Grande D (Post 15392952)
For people who like the feel of rubber, the RTABs are the one place where it is acceptable to go poly. The NVH difference (RTABs only) is so small that if you didn't drive your car for a week in between you would not notice a difference.

Powerflex or AKG. AKG makes a part that is slightly softer than Powerflex and apparently cannot be distinguished from stock rubber. Stock rubber with limiters is more of a PITA than it's worth. Yes, I've tried that solution also.

Poly can be unpredictable in the RTAB location due to binding. Yes, this is according to Vorshlag. But if you understand how the BMW rear suspension is designed, there has to be play in that location. It's designed that way on purpose for street cars. BMW calls it elasto-kinematics (12th time I am mentioning this very word/term on these forums here @ e46fanatics.com) and is a huge part of the success story of world-renowned BMW 3-Series handling and stability.

Plus.. I wouldn't want to deal with the noise. I just think poly is often installed because it is "easier" to deal with than bushings. But in my opinion, they aren't.

I doubt the BMW M3 CSL is buzzing around the Nurburgring with poly RTABs. In fact, I know they're not. They use standard M3 part# 33326770817. It's preference, of course, but I'm saying don't think that it automatically will make your car grip harder or drive faster cause it won't.

Just don't get the obsession with poly when BMW designed the entire suspension to be elastic, including the hardcore M3 CSL. I just think that money is better spent elsewhere like on the CSL-specific rear lower control arm that uses a spherical bearing on its inner pivot rather than a bushing. The same can be had with aftermarket control arms that have a bearing like TMS. Now that I'm sure would give you some "feel" :evil:

Grande D 05-02-2013 08:43 PM

Quote:

Originally Posted by Mango (Post 15393008)
Poly can be unpredictable in the RTAB location due to binding. Yes, this is according to Vorshlag. But if you understand how the BMW rear suspension is designed, there has to be play in that location. It's designed that way on purpose for street cars. BMW calls it elasto-kinematics (12th time I am mentioning this very word/term on these forums here @ e46fanatics.com) and is a huge part of the success story of world-renowned BMW 3-Series handling and stability.

Plus.. I wouldn't want to deal with the noise. I just think poly is often installed because it is "easier" to deal with than bushings. But in my opinion, they aren't.

I doubt the BMW M3 CSL is buzzing around the Nurburgring with poly RTABs. In fact, I know they're not. They use standard M3 part# 33326770817. It's preference, of course, but I'm saying don't think that it automatically will make your car grip harder or drive faster cause it won't.

Just don't get the obsession with poly when BMW designed the entire suspension to be elastic, including the hardcore M3 CSL. I just think that money is better spent elsewhere like on the CSL-specific rear lower control arm that uses a spherical bearing on its inner pivot rather than a bushing. The same can be had with aftermarket control arms that have a bearing like TMS. Now that I'm sure would give you some "feel" :evil:

Never said it made the car faster. But I do think you're over-thinking it. Plenty of respected people who've made track cars out of their M3s use poly, so they must see some advantage or they would not do it. Neither is wrong, but I do not think stock or limited stock RTABs are worth the effort at all. Two people I know who did stock RTABs with limiters agree with me.

Properly greasing them is key, you can't use the supplied grease. You have to use copper anti-sieze.

Having said that, I've never heard a single noise from either car with the PF RTABs. If you want softer, buy the AKG Poly RTABs which have roughly the same deflection characteristics as the OEM RTABs (based on eyeballing them both).

Furthermore, the CSL is still a compromise. It's not a race car no matter how great it may be.

nyredeye21 05-02-2013 09:21 PM

Poly RTABS or Rubber OEM RTABS Lemforder
 
I have powerflew rtabs in my 03 m3 ad I haven't had a problem since I installed them two years ago. You won't notice too much difference between the stock and poly unless ur really pushing it. That said poly will last longer than rubber which is a big reason why I bought them.

I also bought PF FCABs and so far they have been a disappointment. The passenger side has been riding up the control arm. I have to reseat it and see if it works.


Sent from BimmerApp mobile app

Alex323Ci 05-03-2013 05:34 AM

i think because you don't have a high HP car and also your weather is the type that your cars will see snow. i would go with rubber bushings, but upgrade to the M3 ones and maybe limiters.

i have the poly ones and have no issues or squeaks. love them. but in climates that see varying weather with salt and water i might be worried about it's effect on the bushing and grease. then you might introduce possibility for squeaks. which means you have to lube them again compared to maintenance-free oem style rubber bushings.

LittleBear 05-03-2013 09:09 AM

Hello BMW Experts!
Add one more vote for Poly RTABs. I had M3+limiters, which lasted ~ 40k, and were quite beat by then.
UUC has what might be the softest Poly RTABs, which is what I recommend. They also have very nice grease grooves, which should help keep them lubricated & silent.

Murf :woot:

Mango 05-03-2013 10:53 AM

Quote:

Originally Posted by Grande D (Post 15393032)
Never said it made the car faster. But I do think you're over-thinking it. Plenty of respected people who've made track cars out of their M3s use poly, so they must see some advantage or they would not do it. Neither is wrong, but I do not think stock or limited stock RTABs are worth the effort at all. Two people I know who did stock RTABs with limiters agree with me.

Properly greasing them is key, you can't use the supplied grease. You have to use copper anti-sieze.

Having said that, I've never heard a single noise from either car with the PF RTABs. If you want softer, buy the AKG Poly RTABs which have roughly the same deflection characteristics as the OEM RTABs (based on eyeballing them both).

Furthermore, the CSL is still a compromise. It's not a race car no matter how great it may be.

Again, why did you do it? If the rubber bushings could be installed just as easy, would you?

What method did you use to remove your stock RTABs?

I'm sure you didn't do it because you think it would make your car faster--I have more faith in you than that. But you've got to admit there's probably plenty of people out there blindly thinking that "stiffer is better" on everything suspension related. Or just because they want to be "modded."

I'm also well aware of the grease thing. Lots of "track guys" have also are of the consensus that rubber/limiters is superior to poly. I'm sure you're aware of that too.

Again, I know it's preference but if anything, I'd rather use poly in the FCABs or subframe bushings if at all where tiny bushings don't have to take rapid or drastic load changes in multiple directions. But never at the RTAB location. my personal take on it.

I think it just gives the car consistency in the way it's tuned from bumper to bumper. What would stop you from going poly engine/trans/fcabs/steering guibo/drive shaft coupler/diff mounts/brass caliper bushings, poly everything? just a thought.

These bolded parts really hits home from Vorshlag: Yeah I know :blah:

Many racers just blindly install polyurethane into this and all bushing locations as a "fix" for a worn OEM rubber RTAB bushing. Polyurethane is a bad choice for a bushing material if it has to deflect - such as in a multi-axis suspension bushing location like the RTAB. Rubber bushings + limiters or a complete replacement with a custom steel spherical bearing are the only two textbook choices for this location. We cannot count the number of times we have seen RTAB or front LCA failures on BMWs that were using poly in these areas - an expensive repair and dangerous racing situation. At the very least poly will add bind during significant suspension movement, and this can make the handling feel odd (unexplained oversteer) as well as add significant stress to the suspension-to-chassis mounts (which is how they can fail over time).

That said, some folks with fully track prepared race BMWs have had OK results with polyurethane RTABs. This is due to the much higher spring rates and smoothness of tracks they tend to run with - higher spring rates and smooth tracks limit suspension travel, and thus limits the potential for bind from a polyurethane bushing at this bushing location. So even though you may hear good results from one racer, it doesn't necessarily mean that poly RTABs are the right choice for you. If you have a street car or dual purpose BMW you should always stick with OEM bushings and RTAB limiters, and even many race prepped BMWs use this setup with excellent results.


OK I guess all of it hit home. :lmao: You don't want to damage those RTAB pockets or subframe mounts. Careful.

Mango 05-03-2013 11:00 AM

Oh I'll just leave these here. You might know who these guys are, D:

http://forums.bimmerforums.com/forum...0#post26088940

http://forums.bimmerforums.com/forum...8#post26088968

http://forums.bimmerforums.com/forum...2#post26089072

LittleBear 05-03-2013 12:30 PM

Quote:

Originally Posted by Mango (Post 15394243)
These bolded parts really hits home from Vorshlag: Yeah I know :blah:
[/B] [/I]

OK I guess all of it hit home. :lmao: You don't want to damage those RTAB pockets or subframe mounts. Careful.

...Although Vorshlag sell a whole page of poly bushings.

http://www.vorshlag.com/product_info...roducts_id=470
http://www.vorshlag.com/index.php?cPath=1_8_29

And your links (2?) were to an E36 M3 forum, the BMW which is most prone to tearing rear end stuff off. And the major warning that I saw was to not let your RTABs get too worn, which the BMW ones do very rapidly.

And BMW don't make or install limiters on the RTABs either, so...?

Murf

Mango 05-03-2013 12:31 PM

Quote:

Originally Posted by LittleBear (Post 15394501)
...Although Vorshlag sell a whole page of poly bushings.

http://www.vorshlag.com/product_info...roducts_id=470
http://www.vorshlag.com/index.php?cPath=1_8_29

And your links (2?) were to an E36 M3 forum, the BMW which is most prone to tearing rear end stuff off. And the major warning that I saw was to not let your RTABs get too worn, which the BMW ones do very rapidly.

And BMW don't make or install limiters on the RTABs either, so...?

Murf

yeah, but not for the rtab location.

use rubber rtabs and replace them often.

Grande D 05-03-2013 02:05 PM

Quote:

Originally Posted by Mango (Post 15394510)
yeah, but not for the rtab location.

use rubber rtabs and replace them often.

They were easier to install- and with poly you do not have to "replace often" as you say to do with rubber RTABs.

Alex, where I lived with my last ZHP (in PA) there is plenty of salt and snow. There is no problem with them from a grease/noise perspective in poor weather.

I wouldn't use poly anywhere else because other locations have a more dramatic impact on NVH. Although I have considered coupling poly FCABs with FSD shocks- but I don't think it's worth the effort to try it as it probably wouldn't work out that well.

My car with poly RTABs actually feels more stable in the back than an E36 M3 I drive regularly with more things replaced in the back and M3 RTABs with Limiters- though the difference is slight.

I used some washer/puller contraption to remove the old RTABs.

I do know jvit, and when I had my E36 M3 I respected his opinion quite a lot, but neither I nor a few other E46 M3 owners I hang out with have had any issues with poly RTABs. Also- E36 RTAB pockets are weak and I don't think correlation=causation from that standpoint.

I actually had the stock M3 bushings with limiters ready to install (again) on my last ZHP, and I got lazy and decided to give the Powerflex a shot. I don't regret it at all. When it came time to do RTABs on this one- the decision was Powerflex without question.

Have you really felt twitchy at the limit behavior from a car with poly RTABs? I doubt it.

I don't mean to call out Vorshlag- but binding sounds like improper/insufficient use of the copper anti-sieze, which is crucial with any poly bushing.

Mango 05-03-2013 02:14 PM

Quote:

Originally Posted by Grande D (Post 15394793)
They were easier to install- and with poly you do not have to "replace often" as you say to do with rubber RTABs.

Alex, where I lived with my last ZHP (in PA) there is plenty of salt and snow. There is no problem with them from a grease/noise perspective in poor weather.

I wouldn't use poly anywhere else because other locations have a more dramatic impact on NVH. Although I have considered coupling poly FCABs with FSD shocks- but I don't think it's worth the effort to try it as it probably wouldn't work out that well.

My car with poly RTABs actually feels more stable in the back than an E36 M3 I drive regularly with more things replaced in the back and M3 RTABs with Limiters- though the difference is slight.

I used some washer/puller contraption to remove the old RTABs.

I do know jvit, and when I had my E36 M3 I respected his opinion quite a lot, but neither I nor a few other E46 M3 owners I hang out with have had any issues with poly RTABs. Also- E36 RTAB pockets are weak and I don't think correlation=causation from that standpoint.

I actually had the stock M3 bushings with limiters ready to install (again) on my last ZHP, and I got lazy and decided to give the Powerflex a shot. I don't regret it at all. When it came time to do RTABs on this one- the decision was Powerflex without question.

Have you really felt twitchy at the limit behavior from a car with poly RTABs? I doubt it.

I don't mean to call out Vorshlag- but binding sounds like improper/insufficient use of the copper anti-sieze, which is crucial with any poly bushing.

That E36 is a generation older. The rear end has a massive amount of balljoints and bushings in back. your newer ZHP likely has everything back there in way better condition. particularly the rear upper and lower inner control arm bushings. make sure you take that into account.

Doing the RTABs with the wrong tool is definitely a turn off to using rubber bushings. I was considering powerflex as well due to that reason alone. But with the right tool, the job is a dream and so are the results of using a rubber bushing.

Grande D 05-03-2013 02:17 PM

Quote:

Originally Posted by Mango (Post 15394813)
That E36 is a generation older. The rear end has a massive amount of balljoints and bushings in back. your newer ZHP likely has everything back there in way better condition. particularly the rear upper and lower inner control arm bushings. make sure you take that into account.

Doing the RTABs with the wrong tool is definitely a turn off to using rubber bushings. I was considering powerflex as well due to that reason alone. But with the right tool, the job is a dream and so are the results of using a rubber bushing.

Idk if the results of any RTAB job are a dream... let's not be so dramatic. :rofl:

What I was saying (admittedly in an unclear fashion) is that the E36 M3 in question actually has all of those inner and outer balljoints replaced; mine is on the original bushing style parts.

Mango 05-03-2013 02:18 PM

Quote:

Originally Posted by Grande D (Post 15394820)
Idk if the results of any RTAB job are a dream... let's not be so dramatic. :rofl:

What I was saying (admittedly in an unclear fashion) is that the E36 M3 in question actually has all of those inner and outer balljoints replaced; mine is on the original bushing style parts.

there's no inner balljoints on the E36/E46 chassis. we talking about the same thing here?

My infographic:

http://forum.e46fanatics.com/attachm...1&d=1365562562


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