Polybushing/Solid mounting
Discussion
Why don't you just resurrect your previous thread?
https://www.pistonheads.com/gassing/topic.asp?h=0&...
The answer is yes, many folks have, but you need to understand what you're trying to achieve, and how it'll compromise the car in NVH during its use.
https://www.pistonheads.com/gassing/topic.asp?h=0&...
The answer is yes, many folks have, but you need to understand what you're trying to achieve, and how it'll compromise the car in NVH during its use.
Made my 1973 911 very crashy and squeaky. Not helpful in that case at all.
ETA that was my first air cooled 911 and I have subsequently driven some superbly set up early 911s that handle brilliantly and communicate well and none have had polybushes.
Obviously not the same car, but I'm not convinced about them at all. (and rosejoints on a road car even less so).
ETA that was my first air cooled 911 and I have subsequently driven some superbly set up early 911s that handle brilliantly and communicate well and none have had polybushes.
Obviously not the same car, but I'm not convinced about them at all. (and rosejoints on a road car even less so).
Edited by BertBert on Wednesday 4th January 12:27
It's probably the last thing on the list of to-dos once all your other suspension mods have been done, your suspension travel and body roll is now virtually zero, your car is practically undrivable on day to day roads, and you drive the car with enough track mileage and experience to be able to notice the difference.
inline6bmwfan said:
Hi, has anyone experience with fitting polybushes or solid mounts to a car?
Mainly interested in if it helped increase feedback/stability and predictability of the cars chassis?
Only do it to a dedicated race or track car. It will make a car appalling to drive on a standard road.Mainly interested in if it helped increase feedback/stability and predictability of the cars chassis?
For everyone saying it will undriveable on the road, modern M cars all have their subframe directly bolted to the chassis without rubber bushes, they also quite often have uniball bushes in the lower control arm aswell and they are perfectly driveable day to day......
Thats why i was hoping for some direct experience with them, not hearsay.
Thats why i was hoping for some direct experience with them, not hearsay.
inline6bmwfan said:
For everyone saying it will undriveable on the road, modern M cars all have their subframe directly bolted to the chassis without rubber bushes, they also quite often have uniball bushes in the lower control arm aswell and they are perfectly driveable day to day......
Thats why i was hoping for some direct experience with them, not hearsay.
Erm, so why ask if you have so much experience?Thats why i was hoping for some direct experience with them, not hearsay.
I’ve got a couple of race cars with full on bushes/suspension, and I can assure you they are undriveable on the road (or at the very least, extremely unpleasant to drive on the road).
Don’t pose a question when you think you already know the answer.
inline6bmwfan said:
For everyone saying it will undriveable on the road, modern M cars all have their subframe directly bolted to the chassis without rubber bushes, they also quite often have uniball bushes in the lower control arm aswell and they are perfectly driveable day to day......
Thats why i was hoping for some direct experience with them, not hearsay.
Modern m's are pretty crashy and bouncy on a good b road too imoThats why i was hoping for some direct experience with them, not hearsay.
inline6bmwfan said:
For everyone saying it will undriveable on the road
Who said anything would be undriveable ? That's just bulls
t.And you do not specify which bushes or mounts, what vehicle, what usage etc etc.
All cars are different, peoples needs are different etc etc.
So what problem are you trying to fix, or what are you trying to gain from whatever it is you're thinking about changing ?
I have them on my Porsche (suspension arms and gearbox mounts) and they are absolutely fine. Whilst they don't squeak and the ride isn't crashy, they do transmit more vibrations which will rattle any loose trim.
The ones on my racecar do occasionally squeak but a squirt of PTFE lubricant tends to quieten them down... At least below the cacophony of other noises.
Worth adding that I only used polybushes on the Porsche due to convenience (as a home mechanic) and because it allowed me to get more camber on the front (adjustable bushes) for when I was using it on track. From a handling perspective, I don't think I could pin point any difference they may have made
The ones on my racecar do occasionally squeak but a squirt of PTFE lubricant tends to quieten them down... At least below the cacophony of other noises.
Worth adding that I only used polybushes on the Porsche due to convenience (as a home mechanic) and because it allowed me to get more camber on the front (adjustable bushes) for when I was using it on track. From a handling perspective, I don't think I could pin point any difference they may have made
Edited by LennyM1984 on Wednesday 4th January 20:31
Krikkit said:
stevieturbo said:
So what problem are you trying to fix, or what are you trying to gain from whatever it is you're thinking about changing ?
This is the key which the OP is ignoringI've replaced quite a few bushes on my VX Monaro with PU. Granted, its not a sophisticated car, but I'd say they've tightened things up a bit, hardly surprising though given the car is 19 this year.
In terms of NVH, maybe this has increased just a fraction, but they have certainly not ruined the ride of the car.
In terms of NVH, maybe this has increased just a fraction, but they have certainly not ruined the ride of the car.
LennyM1984 said:
From a handling perspective, I don't think I could pin point any difference they may have made
Well, this is because the Polybushes do the identical same job as OEM rubber bushes.Edited by LennyM1984 on Wednesday 4th January 20:31
Exactly. The. Same. Just... more.
Polybushes, hard mounting and rose joints are used in race cars because, primarily, reliability in adjustment. And additional feedback from the controls.
A soft spongy rubber won't exactly hold angle or position like a harder mounting option (like Polybushes or rose joints).
The stiffer methods make adjustments more precise, and smaller adjustments possible (as you're not just flexing rubber bushes for 0.1° adjustments to acquire marginal gains on race tracks.
My mum doesn't need a harsh crashy NVH high car, because, unfortunately, she's not really into smashing up B-roads and setting the best times around big Tesco.
If you've a race car, precision is likely highly desirable, as is adjustability and reliability / repeatability of adjustments. Similar for a B-road weekend toy; you can handle the additional NVH, because it's a fun car. Nobody buys an Atom or Caterham for smooth, quiet comfort...
A final bonus for Polybushes is ease of install / replacement. They often easily push in without need for hydraulic presses, and often come in 2 halves. Arguably easier for the home-gamer.
inline6bmwfan said:
Lack of feel, the front end feels completely numb to the point im not sure what the front wheels are doing, i also can never feel when the rear is at the limits of traction before it breaks loose, i just want more feel through the chassis, and stability.
And are the tyres, bushes, suspension, components on the car all cheap worn out ste ? are they brand new OEM ? Is the car renowned for feeling so bad ?Really, it's just a few bushes. Is it a full on drama just to change them ?
The car won't explode or anything
There are different grades of polybush's, including one that is a OE replacement, they aren't all just rock hard, except obviously soild mount.
Most manufacturers that do poly kits for cars, use different grades in the same kit, depending on what they think is best suited to the car.
Most manufacturers that do poly kits for cars, use different grades in the same kit, depending on what they think is best suited to the car.
stevieturbo said:
inline6bmwfan said:
Lack of feel, the front end feels completely numb to the point im not sure what the front wheels are doing, i also can never feel when the rear is at the limits of traction before it breaks loose, i just want more feel through the chassis, and stability.
And are the tyres, bushes, suspension, components on the car all cheap worn out ste ? are they brand new OEM ? Is the car renowned for feeling so bad ?Really, it's just a few bushes. Is it a full on drama just to change them ?
The car won't explode or anything
The car only has 15,000 miles on it.
inline6bmwfan said:
Lack of feel, the front end feels completely numb to the point im not sure what the front wheels are doing, i also can never feel when the rear is at the limits of traction before it breaks loose, i just want more feel through the chassis, and stability.
I don't think polybushes will solve this problem. As others have said, they might tighten things up a bit but they are not a game changer for handling. Have you had the alignment set properly for what you want? Also, are the BMW M135/140s not renowned for having fairly crap steering feel?LennyM1984 said:
inline6bmwfan said:
Lack of feel, the front end feels completely numb to the point im not sure what the front wheels are doing, i also can never feel when the rear is at the limits of traction before it breaks loose, i just want more feel through the chassis, and stability.
I don't think polybushes will solve this problem. As others have said, they might tighten things up a bit but they are not a game changer for handling. Have you had the alignment set properly for what you want? Also, are the BMW M135/140s not renowned for having fairly crap steering feel?If they want more progressive feel, narrow skinny tyres and less grip will help. But is unlikely to be what the op really wants.
Not sure if they ever answered previously, if this is for road driving or track use....
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