Product Review: Powerflex Control Arm Bushings
#1
Drifting
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Product Review: Powerflex Control Arm Bushings
These are relatively unheard of in the Porsche world, but EXTREMELY popular in the BMW world and other makes.
Had a friend's '83 944 that needed new control arm bushings - the factory rubber was beat on so hard, the whole arm was shifted forward on the front (of front) control arms (see first picture). Being a chassis engineer I myself am not a fan of rubber suspension bushings - gives too vague a chassis feel and poor geometry control. Not ideal for a sports car.
The Powerflex bushings are very reasonably priced, due to the fact that they are actually VW parts! (Because the arm is a VW part)
The rear bushing will give you all or more of the performance benefit of the 968 castor blocks, at half the price! $55 + shipping for each pair of bushings - that means $110 total for the whole front of the car (sway bar bushings excluded).
Since new control arms are cheap, and they do not come with front bushings installed, it was better/easier to just buy new arms and slide the Powerflex bushings in. Installation is a breeze. Best of all is the lifetime warranty on the bushings, and the fact that they won't tear if oil gets leaked on them (like the factory rubber would).
The performance difference is instantely noticeable - more direct steering feel and response, more stability under hard braking. Makes a 944 feel more like it should (since most of these cars are now "tired" after all these years). There are also Aluminum arm versions that I will be installing on my own car. Available from www.powerflexusa.com - which is actually Bimmerworld.
Had a friend's '83 944 that needed new control arm bushings - the factory rubber was beat on so hard, the whole arm was shifted forward on the front (of front) control arms (see first picture). Being a chassis engineer I myself am not a fan of rubber suspension bushings - gives too vague a chassis feel and poor geometry control. Not ideal for a sports car.
The Powerflex bushings are very reasonably priced, due to the fact that they are actually VW parts! (Because the arm is a VW part)
The rear bushing will give you all or more of the performance benefit of the 968 castor blocks, at half the price! $55 + shipping for each pair of bushings - that means $110 total for the whole front of the car (sway bar bushings excluded).
Since new control arms are cheap, and they do not come with front bushings installed, it was better/easier to just buy new arms and slide the Powerflex bushings in. Installation is a breeze. Best of all is the lifetime warranty on the bushings, and the fact that they won't tear if oil gets leaked on them (like the factory rubber would).
The performance difference is instantely noticeable - more direct steering feel and response, more stability under hard braking. Makes a 944 feel more like it should (since most of these cars are now "tired" after all these years). There are also Aluminum arm versions that I will be installing on my own car. Available from www.powerflexusa.com - which is actually Bimmerworld.
#2
Three Wheelin'
Keep a close eye on the bushings in the "barrel." Welt makes poly bushings in that location and a few 944-SPEC guys advised against them because the don't seem hold up in that location. They advised Delrin, which I used there and have never had a problem.
I hope they work well for you though.
I hope they work well for you though.
#3
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I think I would choose delrin too if I were using the steel arms on my race car, but for a street car you can't beat these - price/warranty/performance difference, add to the fact that you don't have to spend $170 on 968 caster blocks.
#4
Race Director
I use steel arms on my 944 race car.
Here is what happened after a couple weekends on track.
That was in 2003. I after that expereince and tearing up two sets in spring season I was able to get the very first delrin set made up. I am still using those as they actually outlast the control arms.
I use red welts in the rear. I just replacing the set now due to some wear, but these are 8-9 years old. I can't complain about that.
What kills the bushings is loading under brakings. It forces the thing sheet metal of the barrell into the flange on the bushing. This sort of cuts the bushing.
Here is what happened after a couple weekends on track.
That was in 2003. I after that expereince and tearing up two sets in spring season I was able to get the very first delrin set made up. I am still using those as they actually outlast the control arms.
I use red welts in the rear. I just replacing the set now due to some wear, but these are 8-9 years old. I can't complain about that.
What kills the bushings is loading under brakings. It forces the thing sheet metal of the barrell into the flange on the bushing. This sort of cuts the bushing.
#6
Race Director
They just look alot like the red welts that have been around for 10 years. Not sure how they might be different from them.
Before I used the red welts I used black welts. I had one of those break at the caster block on the track. Seems like they were stiffer than the red welts. That caused the failure. However I never trashed the back welts at the crossmember like the reds. Seems like when they went slightly softer for the reds they went too soft. I never really worried much after the delrin however since those work at the cross member and the red welts seem to work at the cross member.
As for stock rubber... Took me all of 1 day to push bushing out at an autocross. On street tires no less. I had control rubbing the crossmember. I figure the red welts are probalbly fine for cars on street tires. Racing brake pads and R-compond tires will expose their weakness.
Before I used the red welts I used black welts. I had one of those break at the caster block on the track. Seems like they were stiffer than the red welts. That caused the failure. However I never trashed the back welts at the crossmember like the reds. Seems like when they went slightly softer for the reds they went too soft. I never really worried much after the delrin however since those work at the cross member and the red welts seem to work at the cross member.
As for stock rubber... Took me all of 1 day to push bushing out at an autocross. On street tires no less. I had control rubbing the crossmember. I figure the red welts are probalbly fine for cars on street tires. Racing brake pads and R-compond tires will expose their weakness.
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I'm sure these would suffer the same fate as the welts on a track car, but this thread was not intended for track cars - except for the rear castor block busing which would perform fine under track conditions.
Powerflex also make a black "Race" spec urethane, harder durometer than the purple, but not available at this time for these particular part #'s
Powerflex also make a black "Race" spec urethane, harder durometer than the purple, but not available at this time for these particular part #'s
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#8
Race Car
try the Energy Suspension kit mor a MK1 volkswagen. Entire kit is like $40 and includes the front and rear bushings. The nice part is the front is of the same design as the original...not the hokey two-piece like the welts.
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the guys from Whiteline Suspension Engineering came to my work to give us the pitch and explanation of what makes their product better in terms of engineering/long life...they did not have good things to say about Energy's Urethane/manufacturing methods....they did have good things to say about Powerflex, mainly that they use the same quality urethane and manufacture the same way
#10
Race Car
Perhaps. I know that for $31 I do like the original design over the 2-piece thats so much more expensive. Energy's fr. bushing is a single piece that looks identical to the 3" long OEM part, but is made from black graphite impregnated poly. I have Powerflex front swaybar (outer) bushings that didn't fit the alloy brakets well at all. I do have 951 bars with the larger ends, but the PF bushings wouldn't fit into the bracket long before I shoved the sway bar into the braket. I had to "shape" them a little bit. They have been in there for a couple of years now with no problems. Same for the Energy bushings on the control arms...not a single issue. I have delrin inner fr. SB bushings from racers edge.
Energy Suspension kit #15.3115 is what I have. Got it from Summit racing.
Energy Suspension kit #15.3115 is what I have. Got it from Summit racing.