Bushing Upgrades

[Lucan 196]

Looking for people's experiences with differing brands of polyurethane bushings and experience in grades they've used.  I'm planning on upgrading all suspension bushings while my E30 is stripped down.

Have looked at a couple of suppliers in the US offering what I'm after:

Condor motorsport

Garagistic

Revshift

I've come to the conclusion that 80A is similar to OEM but slightly "harder"

95A more suited to a street/track car.

75D or solid Ali for dedicated track cars.

FYI I'm building a weekend street & occasional tracker. Definately won't be driven daily.

Keen to hear educated or experienced opinions.

Cheers,

Edited September 8, 2016 by Lucan

[zero 1162]

Powerflex is excellent.

[APT 195]

Lucan, I ran AKG 75D in my E30 (all bushes and mounts), BC Gold Suspension - Quality and feel were excellent but drivetrain/road vibrations is what killed it for me even with just weekend driving.

I ditched the 75D Engine and Gearbox mounts/BC Golds and went back to OEM mounts, and Bilsteins struts and now feels awesome. If i were to do it again for a street/weekend car I would prob run AKG 95A all around. 

[_ethrty-Andy_ 2132]

+1 power flex

I dont see any advantage to non oem engine and gearbox bushes. diff needs one tho as its an important connection point for the rear suspension.

Dont forget your sway bar bushings as well!

[RedRocketTi 131]

2 hours ago, _ethrty-Andy_ said:

+1 power flex

I dont see any advantage to non oem engine and gearbox bushes. diff needs one tho as its an important connection point for the rear suspension.

Dont forget your sway bar bushings as well!

Does a stiffer diff bushing help prevent diff hop? I notice in the Ti under power I can get some crazy diff hop when launching and that below 100kph.

[Olaf 3317]

I've stuck with OEM (mostly Lemforder or Rein), or uprated (Meyle HD) where available, for general drivability. 

I recently read a discussion from a bunch of friends who went through uni together, and are all development engineers for car manufacturers or race teams in Europe.  Their specific chat about OEM/Rubber vs Poly bushes was that when they poly'd anything, although it was stiffer and initially handled better, they usually turned to mush under a good development test pilot within an hour; whereas although rubber wasn't quite as stiff to start with and did deteriorate, it was still doing what it should do in the same hours hammering on the circuit.  Conclusion - Rubber is still used for a reason.  These guys all scoffed at the idea of putting poly bushes in their own rides, BMWs, Audis, classic Porsches.   

Your mileage may vary.

[_ethrty-Andy_ 2132]

46 minutes ago, RedRocketTi said:

Does a stiffer diff bushing help prevent diff hop? I notice in the Ti under power I can get some crazy diff hop when launching and that below 100kph.

the diff in my compact used to bang around under power but then went to poly and completely ruled out. im assuming you have also modified the floor a little bit for clearance as is required when fitting a medium case into a Ti

[BatMansWilly 74]

Powerflex all the way! I have redone every single bushing in my car with powerflex and love it. They also give you a little guild on how to put the bushings in along with a pack of grease for every bush! 

[E30 325i Rag-Top 2956]

9 hours ago, _ethrty-Andy_ said:

I dont see any advantage to non oem engine and gearbox bushes.

Have seen issues with how much the engine and box move around in a race car running standard mounts. Not sure it would be worthwhile in a road car though?

[zero 1162]

7 hours ago, Olaf said:

I've stuck with OEM (mostly Lemforder or Rein), or uprated (Meyle HD) where available, for general drivability. 

I recently read a discussion from a bunch of friends who went through uni together, and are all development engineers for car manufacturers or race teams in Europe.  Their specific chat about OEM/Rubber vs Poly bushes was that when they poly'd anything, although it was stiffer and initially handled better, they usually turned to mush under a good development test pilot within an hour; whereas although rubber wasn't quite as stiff to start with and did deteriorate, it was still doing what it should do in the same hours hammering on the circuit.  Conclusion - Rubber is still used for a reason.  These guys all scoffed at the idea of putting poly bushes in their own rides, BMWs, Audis, classic Porsches.   

Your mileage may vary.

Powerflex has a lifetime warranty.

[_BRS_ 209]

Have put Revshift 95A into my Tourings rear end, (subframe, trailing arms with a delrin diff bush) also have gone for the same up front with the engine and gearbox mounts. Hasn't been driven yet, but look like a good quality product and easy to install. My 2c

[RedRocketTi 131]

On 9/9/2016 at 2:44 PM, _ethrty-Andy_ said:

the diff in my compact used to bang around under power but then went to poly and completely ruled out. im assuming you have also modified the floor a little bit for clearance as is required when fitting a medium case into a Ti

Not yet got a medium case diff yet... still running the 4.44 auto small case haha. I have heard I can run a medium case E30 diff with the Ti output flanges and axles?

 

[_ethrty-Andy_ 2132]

On 11 September 2016 at 10:53 PM, RedRocketTi said:

Not yet got a medium case diff yet... still running the 4.44 auto small case haha. I have heard I can run a medium case E30 diff with the Ti output flanges and axles?

 

not sure if you need to change over output shafts, my diff was from a Z3, and i haven't checked the compatibility between the two. i drove mine with the 4.45 in it for a little bit, 1st and 2nd all but useless and 3000rpm in 5th at 50kph wow. i don't know how you can deal with it. i guess just use it like a 2 speed start off in 3rd and go straight to 5th.

[RedRocketTi 131]

10 minutes ago, _ethrty-Andy_ said:

not sure if you need to change over output shafts, my diff was from a Z3, and i haven't checked the compatibility between the two. i drove mine with the 4.45 in it for a little bit, 1st and 2nd all but useless and 3000rpm in 5th at 50kph wow. i don't know how you can deal with it. i guess just use it like a 2 speed start off in 3rd and go straight to 5th.

3750rpm in 5th at 100kph and yeah I dont use 1st gear lol, alltho its bloody quick 0-100 and passing at 100kph you dont need to change down! Alltho with the pickup you are in loss of licence territory very very quickly. I top it out at 7k rpm at 175kph down the straight at ruapuna and that was just after the start finish line. I was coming out of the final corner at 65-70kph on screwed goodrides compared to people on semis coming out at 100kph + so with the correct ratio diff it will be interesting to see if I can easily crack 200 down the straight!

[_ethrty-Andy_ 2132]

probably won't gain much speed top speed changing ratio as will take you longer to get there?

 

ill have a 3.6 open available soon if that is of interest. will have E30/E28 output shafts if they do prove to be different to compact.

[RedRocketTi 131]

3 minutes ago, _ethrty-Andy_ said:

probably won't gain much speed top speed changing ratio as will take you longer to get there?

 

ill have a 3.6 open available soon if that is of interest. will have E30/E28 output shafts if they do prove to be different to compact.

Could be keen, and yeah I still have a lot of straight left considering I break at about 100m out from corner 1! And oh yeah could potentially be keen, really was after a 3.46 but if its the right price and medium case