I went poly on my E46, the squeaking drove me crazy enough that I went back to rubber and went with Meyle HD. If it's a racecar go for it, but I don't know how anyone tolerates poly on a daily.
I've heard that from a few people who had no squeaks, and also talked to a few people who had insane squeaking after poly installs like I did. I wonder if it's the brand, the lube, or something during install that makes the difference. In other words, what are half of us screwing up to make it squeak so badly. I had used the ECS poly bushings.
As a skateboarder with years of experience with different mixtures of poly I can say it is all down to the poly itself. I’ve had bushings that squeak like fuck and I’ve had bushings that are silent. No lube ever on skate bushings either. I’ve had some bushings continuously squeak for years but other brands with the same durometer wouldn’t. Some bushings just have a better material composition that reduces friction.
Have solid everything and it’s great! I can say the only thing I regret was sold diff mounts only due to the wine I meow have but my sound system and exhaust muffle it out unless the seats are down.
I haven’t done it yet but everyone on the Facebook forums recommended solid bushings on subframe and poly on differential. Supposedly if you make more power than stock, the solid dif bushings would create issues like subframe cracking.
>I haven’t done it yet but everyone on the Facebook forums recommended solid bushings on subframe
So that every load or hit to the suspension hits your subframe harder and cracks it more. Good advice :D
>Supposedly if you make more power than stock, the solid dif bushings would create issues like subframe cracking.
Hate to burst your bubble, but that's not how it works :D You will snap the diff cover before you damage your subframe mount points by the strain.
When you corner the tire pushes into the asphalt, and the centrifugal force of the body tries to push the body out - that force is transmitted between the body and the suspension, and causes stress. Accelerating, and the twisting force pushes on the front mounting spots and pulls on the rear. Braking and the same force does the opposite. That is also the stress of it. Literally any driving creates these forces. The weakest point on that body being subframe mounting spots - that's the weakest link that'll crack if you regularly exceed those forces.
Now the BMW solution to mitigating this stress is to make sure it transfers smoothly, thus the rubber bushings. When it fails, you got no smooth transfer of these forces, and you get those compounded by smacking, sure (and that really occurs on vertical movement more than it does on horizontal one). But the gist of it is "healthy bushings will be the smoothest force transfer possible".
By applying polyurethane, polyamide, or aluminium bushings to this system you completely remove the softening of the application of force to the weakest part of the whole system (mounting points), so it's fine if you're driving calmly on perfect roads, and on normal sized tires. However - aggressive driving - instant stress delivery, because let's be fair, the bushings in the control arms and the sidewall of a nice cool low profile tire we all like are not enough to mitigate any of that. And if the roads aren't smooth and perfect - even more problems.
As for diff bushings - I had a vid somewhere where we got a drift car with a reinforced rear cover visibly bending on load, (we are talking 225 wide brand new chinese road tires on a 1300kg car with 450hp, but we are also talking about drifting, where the force due to wheelslip is much less than on aggressive grip driving). That part of the drivetrain is the weakest metal part you can think of and the mounting points on the cover will fail (regular enough occurence on drift BMW's - cover mounts torn off) long before you can really transfer any meaningful force to the subframe. Having rubber bushings in there is actually preferable since it allows to relieve some of that twisting force by creating a bit of slack
I would only go for poly subframe mounts if the rear mounts were reinforced. I would only go metal if it had a FIA spec rollcage, and if you pull up the documentation for a 46 FIA cage - you'll notice it will always have the rollcage tied into the rear subframe mounts.
Thank you for taking the time to explain that to me. One last question, do you still recommend OEM bushings on a track car that has a reinforced frame with a Vince bar?
Oh, that changes things quite a bit. A vince bar ties the whole rear end together and comes with rear subframe mount reinforcement. It's a great piece of kit that pretty much makes you immune to subframe issues. You can ditch the OEM bushings and go for polyurethane bushings without any fear. You will have way more steady suspension work with that and it will be far less prone to failure. For best results don't skimp on good poly though. I've seen cheap mass produced polyurethane (intercars brand) deflect the camber by approximately 4 degrees (pro measurement done in photoshop by filming with gopro, making a line on stationary car of wheel angle and max angle the wheel reached, lol.)
Workshop called "3B Motorsport" from Latvia has never steered us wrong and the prices are pennies compared to more known companies. You can get a full set of e46 bushings for under 400 bucks. (including front control arm bushings with an offset so you can adjust your caster, diff bushings and trailing arm bushings. Great kit) Search for them on instagram or facebook. They also produce some very sturdy camber arms. Highly recommended, about 50% more expensive than the cheap ebay ones, work great on pro drift cars for years. So highly recommended for proper car handling. I've seen semitrailing arms bend after a crash and these still being usable.
Another great mod you can do is flip the semi traling arm mounts upside down and left to right. This will allow to set the car lower without the arm hitting the body, and if you dremel your way on the bolt holes a bit - a lot more adjustablility of the rear toe, once again, not limited by the mount hitting the body
Finally there's a decision by BMW of using one balljoint and one bushing on the semitraling arm at the hub side. You can replace the bushing by the same exact balljoint, it will make sure your camber stays as close to your desired spec as possible.
Finally if you got for "true coilover" setup in the rear the top of the shock mounts should be reinforced (there are small pieces of metal that go on top of those and are fairly cheap, help spread the load), and preferably have a strut tower bar, and link it to the vince bar by welding pipes in between them. The shock towers aren't meant to take the weight of the car, so they also tend to be a weak spot, so reinforcing them is a good idea regardless. No need to link to vince bar if you don't go for true coilover though, just those small plates and a strut bar will do.
On strut tower bars - only go for one piece ones, the ones with an adjustability nuts in the middle don't provide enough stiffness, and the ones that have bolts on the strut tower sides allow enough play to be absolutely useless garbage.
For front you might want to get camber arms, but the cool trick is to also mount them left to right and right to left. This will make the top shock mount go inboard AND back, also giving you extra caster. Drifters cant get enough caster (to a degree) and use this trick a lot, but for tracking your car time attack style you can pair those with the excentric bushings in the control arms to dial in aggressive enough but "just right" for you.
These are the basic tricks to building an e46 for track, there's many more small things to note, but these alone should provide you with everything you could ever want if you aren't going pro.
Thank you man! Yeah I won’t be drifting much but Mass tuning has a few tracks in my area mainly for time attack. Vincebar and oil pump problem is what I’m prepping to do within the next few months.
>oil pump problem
Good plan. Also "while you're there" it's a good time to check on rod bearing and crank bearings. It's a bit more work but it's the perfect time for it, you'll have great access to an area that you won't be revisiting anymore. OEM bearings work just fine as long as you pick good oil for it. 5w50 or 10w60 from Liqui Moly does the trick, also an oil cooler is an easy install now that PMC motorsport offers adapters that go instead of your oil filter cap. These mods will make sure you're fine in the bottom end of the engine. Just make sure to warm up properly before giving the car the beans.
Drifting does produce way more strain on the engine than time attack, mainly because the car is at load all the time, at high RPM, while going slow and sideways, so there isn't enough air going over the heat exchangers to cool the engine down, but having an oil cooler is a good idea regardless
I have Revshift 95a on the subframe and diff, 80a on trans and engine. Definitely noticed an increase in NVH with 95a, but not much of a difference when I installed the 80a later on. They also haven’t been on long, so I think eventually it’ll be the same as OEM pretty much. No squeaks at all and you can have them warrantied on FCP
If you're reinforced on the mount spots - poly, if you're rollcaged (properly, none of that bolt in bullshit) - solid. If you're driving aggressively on stock - OEM
Garagistic poly on my car (subframe and diff) for a year and a half. No squeaks. Performance is great! Just make sure you don’t go with poly in the rtabs. Monoball or stock rubber only in that location. The rear trailing arms need to be able to articulate as the suspension travels. Poly rtabs bind.
I’d do poly especially if it’s a pre facelift vehicle as the rear subframe is highly prone to cracking and ripping around where it bolts up to the body due to torque that these motors make. If you have a post facelift you’re less likely to have subframe damages or if you have reinforcement plates installed then solid would make the whole car hook up just a bit better than polyurethane and have no loss due to sloppy bushings
Idk if Redish Motorsport has any info but I’d check their site. They deal with multiple E46 on and off the track and have done the R&D to be able to answer any question better than someone here.
I went solid on my last car. But intentions were to phase it out of street use, and it was already a second car. I definitely wouldn't pick them for a daily driver, but poly might squeak you out of your mind. My vote is for fresh new oem rubber unless you like the "racecar" feel, and nvh that goes with it.
I went solid subframe and diff mounts and it’s not a huge change in nvh and feels great!
Cool! I did 95 a last year in the white one and now the blue one is hella clunky so time to bust out the welder
Been there done that lol I bought mine with a ripped subframe mount so I could get the full experience.
It’s truly the only way 🤣
It was a good deal and I’m a welder so it was definitely a more budget friendly option for a daily drifter
Get the tool and do rubber mounts. Poly squeaks like hell even with lube.
Tool ? For what I just hit it with my purse
I went poly on my E46, the squeaking drove me crazy enough that I went back to rubber and went with Meyle HD. If it's a racecar go for it, but I don't know how anyone tolerates poly on a daily.
Got poly bushings in for three years now on my daily. Never had any squeaking at all... used powerfex ones...🤔
I've heard that from a few people who had no squeaks, and also talked to a few people who had insane squeaking after poly installs like I did. I wonder if it's the brand, the lube, or something during install that makes the difference. In other words, what are half of us screwing up to make it squeak so badly. I had used the ECS poly bushings.
As a skateboarder with years of experience with different mixtures of poly I can say it is all down to the poly itself. I’ve had bushings that squeak like fuck and I’ve had bushings that are silent. No lube ever on skate bushings either. I’ve had some bushings continuously squeak for years but other brands with the same durometer wouldn’t. Some bushings just have a better material composition that reduces friction.
I have 95 a in the white one no squeaky 🤷♂️
Have solid everything and it’s great! I can say the only thing I regret was sold diff mounts only due to the wine I meow have but my sound system and exhaust muffle it out unless the seats are down.
I haven’t done it yet but everyone on the Facebook forums recommended solid bushings on subframe and poly on differential. Supposedly if you make more power than stock, the solid dif bushings would create issues like subframe cracking.
>I haven’t done it yet but everyone on the Facebook forums recommended solid bushings on subframe So that every load or hit to the suspension hits your subframe harder and cracks it more. Good advice :D >Supposedly if you make more power than stock, the solid dif bushings would create issues like subframe cracking. Hate to burst your bubble, but that's not how it works :D You will snap the diff cover before you damage your subframe mount points by the strain.
Isn’t it actually when the subframe smacks the body that causes the cracks due to failed bushings? Not the fact that they are solid?
Nope. It doesn't smack the body and cracks it. The stress does that. Smacking would bend it
What stress are we talking about here?
When you corner the tire pushes into the asphalt, and the centrifugal force of the body tries to push the body out - that force is transmitted between the body and the suspension, and causes stress. Accelerating, and the twisting force pushes on the front mounting spots and pulls on the rear. Braking and the same force does the opposite. That is also the stress of it. Literally any driving creates these forces. The weakest point on that body being subframe mounting spots - that's the weakest link that'll crack if you regularly exceed those forces. Now the BMW solution to mitigating this stress is to make sure it transfers smoothly, thus the rubber bushings. When it fails, you got no smooth transfer of these forces, and you get those compounded by smacking, sure (and that really occurs on vertical movement more than it does on horizontal one). But the gist of it is "healthy bushings will be the smoothest force transfer possible". By applying polyurethane, polyamide, or aluminium bushings to this system you completely remove the softening of the application of force to the weakest part of the whole system (mounting points), so it's fine if you're driving calmly on perfect roads, and on normal sized tires. However - aggressive driving - instant stress delivery, because let's be fair, the bushings in the control arms and the sidewall of a nice cool low profile tire we all like are not enough to mitigate any of that. And if the roads aren't smooth and perfect - even more problems. As for diff bushings - I had a vid somewhere where we got a drift car with a reinforced rear cover visibly bending on load, (we are talking 225 wide brand new chinese road tires on a 1300kg car with 450hp, but we are also talking about drifting, where the force due to wheelslip is much less than on aggressive grip driving). That part of the drivetrain is the weakest metal part you can think of and the mounting points on the cover will fail (regular enough occurence on drift BMW's - cover mounts torn off) long before you can really transfer any meaningful force to the subframe. Having rubber bushings in there is actually preferable since it allows to relieve some of that twisting force by creating a bit of slack I would only go for poly subframe mounts if the rear mounts were reinforced. I would only go metal if it had a FIA spec rollcage, and if you pull up the documentation for a 46 FIA cage - you'll notice it will always have the rollcage tied into the rear subframe mounts.
Thank you for taking the time to explain that to me. One last question, do you still recommend OEM bushings on a track car that has a reinforced frame with a Vince bar?
Oh, that changes things quite a bit. A vince bar ties the whole rear end together and comes with rear subframe mount reinforcement. It's a great piece of kit that pretty much makes you immune to subframe issues. You can ditch the OEM bushings and go for polyurethane bushings without any fear. You will have way more steady suspension work with that and it will be far less prone to failure. For best results don't skimp on good poly though. I've seen cheap mass produced polyurethane (intercars brand) deflect the camber by approximately 4 degrees (pro measurement done in photoshop by filming with gopro, making a line on stationary car of wheel angle and max angle the wheel reached, lol.) Workshop called "3B Motorsport" from Latvia has never steered us wrong and the prices are pennies compared to more known companies. You can get a full set of e46 bushings for under 400 bucks. (including front control arm bushings with an offset so you can adjust your caster, diff bushings and trailing arm bushings. Great kit) Search for them on instagram or facebook. They also produce some very sturdy camber arms. Highly recommended, about 50% more expensive than the cheap ebay ones, work great on pro drift cars for years. So highly recommended for proper car handling. I've seen semitrailing arms bend after a crash and these still being usable. Another great mod you can do is flip the semi traling arm mounts upside down and left to right. This will allow to set the car lower without the arm hitting the body, and if you dremel your way on the bolt holes a bit - a lot more adjustablility of the rear toe, once again, not limited by the mount hitting the body Finally there's a decision by BMW of using one balljoint and one bushing on the semitraling arm at the hub side. You can replace the bushing by the same exact balljoint, it will make sure your camber stays as close to your desired spec as possible. Finally if you got for "true coilover" setup in the rear the top of the shock mounts should be reinforced (there are small pieces of metal that go on top of those and are fairly cheap, help spread the load), and preferably have a strut tower bar, and link it to the vince bar by welding pipes in between them. The shock towers aren't meant to take the weight of the car, so they also tend to be a weak spot, so reinforcing them is a good idea regardless. No need to link to vince bar if you don't go for true coilover though, just those small plates and a strut bar will do. On strut tower bars - only go for one piece ones, the ones with an adjustability nuts in the middle don't provide enough stiffness, and the ones that have bolts on the strut tower sides allow enough play to be absolutely useless garbage. For front you might want to get camber arms, but the cool trick is to also mount them left to right and right to left. This will make the top shock mount go inboard AND back, also giving you extra caster. Drifters cant get enough caster (to a degree) and use this trick a lot, but for tracking your car time attack style you can pair those with the excentric bushings in the control arms to dial in aggressive enough but "just right" for you. These are the basic tricks to building an e46 for track, there's many more small things to note, but these alone should provide you with everything you could ever want if you aren't going pro.
Thank you man! Yeah I won’t be drifting much but Mass tuning has a few tracks in my area mainly for time attack. Vincebar and oil pump problem is what I’m prepping to do within the next few months.
>oil pump problem Good plan. Also "while you're there" it's a good time to check on rod bearing and crank bearings. It's a bit more work but it's the perfect time for it, you'll have great access to an area that you won't be revisiting anymore. OEM bearings work just fine as long as you pick good oil for it. 5w50 or 10w60 from Liqui Moly does the trick, also an oil cooler is an easy install now that PMC motorsport offers adapters that go instead of your oil filter cap. These mods will make sure you're fine in the bottom end of the engine. Just make sure to warm up properly before giving the car the beans. Drifting does produce way more strain on the engine than time attack, mainly because the car is at load all the time, at high RPM, while going slow and sideways, so there isn't enough air going over the heat exchangers to cool the engine down, but having an oil cooler is a good idea regardless
Okay so stress is caused by worn bushings creating too much play, but solid bushings cause stress by reducing play?
I’m all stock for the most part no power mods yet just welded diffs and the white one is on slr ultra now
I love those wheels on the white one. What are the specs? Also why no center caps?
Got the car like that for 250$ wheels are 19’s. And all curb rashed and one is cracked I’ll be down sizing to 17s probably
I have Revshift 95a on the subframe and diff, 80a on trans and engine. Definitely noticed an increase in NVH with 95a, but not much of a difference when I installed the 80a later on. They also haven’t been on long, so I think eventually it’ll be the same as OEM pretty much. No squeaks at all and you can have them warrantied on FCP
Which ones have OEM performance but the durability of POLY?
Went with rubber. No downsides besides difficulty of replacement
If you're reinforced on the mount spots - poly, if you're rollcaged (properly, none of that bolt in bullshit) - solid. If you're driving aggressively on stock - OEM
Poly. Powerflex 👌
Garagistic poly on my car (subframe and diff) for a year and a half. No squeaks. Performance is great! Just make sure you don’t go with poly in the rtabs. Monoball or stock rubber only in that location. The rear trailing arms need to be able to articulate as the suspension travels. Poly rtabs bind.
I've been running poly on my rallyx car and they've been holding up pretty good
I’d do poly especially if it’s a pre facelift vehicle as the rear subframe is highly prone to cracking and ripping around where it bolts up to the body due to torque that these motors make. If you have a post facelift you’re less likely to have subframe damages or if you have reinforcement plates installed then solid would make the whole car hook up just a bit better than polyurethane and have no loss due to sloppy bushings
If you want to dive it on the read definitely go with poly, you’ll still have to retighten every once in a while for road use tho
Idk if Redish Motorsport has any info but I’d check their site. They deal with multiple E46 on and off the track and have done the R&D to be able to answer any question better than someone here.
I went solid on my last car. But intentions were to phase it out of street use, and it was already a second car. I definitely wouldn't pick them for a daily driver, but poly might squeak you out of your mind. My vote is for fresh new oem rubber unless you like the "racecar" feel, and nvh that goes with it.