New Performance Suspension Bushings
#31
Three Wheelin'
Fred, this may give you a better idea of the operate and i can tell you they operate brilliantly. The way the car drives is night and day. The suspension feels far more compliant over bumps yet has more steering feel and sits flatter through hard turns. You have to try before it you can say whether you like it. It is no more noisy than the standard bushes. In fact I think the bushes actually let the suspension do what it's supposed to do.
#32
Rennlist Member
I hope the new ones work great, but I would keep an eye on them. I bought poly when 928 Specialist sold them years ago and put them in my 84. I noticed a couple years later that my steering felt really sloppy. The reason was the bushings were disintegrating. These new poly ones are probably much better material and design - but I would take a look at them now-and-then.
#33
Rennlist Member
The Weissach bush is available from Porsche - £571 each including VAT...
Alex
#34
Rennlist Member
Your mechanic may have a good CV and he is most welcome to his opinion but that does not mean he is exempt from making "rubbish" comments.
Lest anyone should happen to forget, Porsche have a pretty impressive track record, the 928 suspension design to some extent is at the heart of most cars they have designed and built in the last 40 years and whereas the original suspension is most probably "tired" by now they have served their owners very well. Whether or not the 928 suspension is good enough for race car applications is a different discussion. We know it was never designed as a race car but those who have raced it have not done too shabbily at all and if the suspension design was "rubbish" why would anyone bother racing them?
#35
Three Wheelin'
Scott,
Your mechanic may have a good CV and he is most welcome to his opinion but that does not mean he is exempt from making "rubbish" comments.
Lest anyone should happen to forget, Porsche have a pretty impressive track record, the 928 suspension design to some extent is at the heart of most cars they have designed and built in the last 40 years and whereas the original suspension is most probably "tired" by now they have served their owners very well. Whether or not the 928 suspension is good enough for race car applications is a different discussion. We know it was never designed as a race car but those who have raced it have not done too shabbily at all and if the suspension design was "rubbish" why would anyone bother racing them?
Your mechanic may have a good CV and he is most welcome to his opinion but that does not mean he is exempt from making "rubbish" comments.
Lest anyone should happen to forget, Porsche have a pretty impressive track record, the 928 suspension design to some extent is at the heart of most cars they have designed and built in the last 40 years and whereas the original suspension is most probably "tired" by now they have served their owners very well. Whether or not the 928 suspension is good enough for race car applications is a different discussion. We know it was never designed as a race car but those who have raced it have not done too shabbily at all and if the suspension design was "rubbish" why would anyone bother racing them?
#36
Rennlist Member
#38
You guys are missing some details here. Even if it was great in 1977, it is probably not that great, in a relative manner, TODAY, and could use improvement with current technology. Also, after 40 years - with many arms NOT rebuilt, this is a no-brainer improvement (alongside getting the originals rebuilt - properly).
#39
Rennlist Member
You guys are missing some details here. Even if it was great in 1977, it is probably not that great, in a relative manner, TODAY, and could use improvement with current technology. Also, after 40 years - with many arms NOT rebuilt, this is a no-brainer improvement (alongside getting the originals rebuilt - properly).
If I had a bush fail, I would replace it with OEM, and hey...im good for another 30-40yrs.
My POV is...if something is an improvement, I wanna see lap times, but that's just me...my philosophy is that 99% of vehicle improvement, is behind the wheel.
#40
Drifting
As another data point I also replaced the front and rear bushes with poly about ten years ago. They all collapsed at once on the near side during a track day two years ago.
#41
Addict
Rennlist Member
Rennlist Member
Thread Starter
Hi Nick,
What type of design were they? Were they running on the casting? Were they flexing like the factory bushings or did they slide like the Powerflex?
What type of design were they? Were they running on the casting? Were they flexing like the factory bushings or did they slide like the Powerflex?
#42
I don't think we're missing much...as "improvement" is only relative to what you choose to focus on being a perceived weak point, or failure.
If I had a bush fail, I would replace it with OEM, and hey...im good for another 30-40yrs.
My POV is...if something is an improvement, I wanna see lap times, but that's just me...my philosophy is that 99% of vehicle improvement, is behind the wheel.
If I had a bush fail, I would replace it with OEM, and hey...im good for another 30-40yrs.
My POV is...if something is an improvement, I wanna see lap times, but that's just me...my philosophy is that 99% of vehicle improvement, is behind the wheel.
The difference between a C7 Stingray Z51 and a C7 Grandsport (wider tires - really thats about it) - at a particular track is 4 seconds, which is essentially an eternity. Changes, when made at important pivots, make vast improvements.
But I can put those same wider tires on another similar car weight and distribution - and the lap times would not be the same. Because the rest of the system is different.
Having dealt with almost 20 928s since 2000, I will tell you that any improvement in almost any part of the car using new materials or design processes from the last -15 years - will improve the car either subjectively or objectively - or both.
Too much time has passed. And my further point that you were responding to was that the aged, cracked, overly stiff or overly loose bushings on the front of the car can be a major point of improvement when a change is made.
#43
Rennlist Member
I have read your posts. Healthy debate. My thoughts:
The difference between a C7 Stingray Z51 and a C7 Grandsport (wider tires - really thats about it) - at a particular track is 4 seconds, which is essentially an eternity. Changes, when made at important pivots, make vast improvements.
But I can put those same wider tires on another similar car weight and distribution - and the lap times would not be the same. Because the rest of the system is different.
Having dealt with almost 20 928s since 2000, I will tell you that any improvement in almost any part of the car using new materials or design processes from the last -15 years - will improve the car either subjectively or objectively - or both.
Too much time has passed. And my further point that you were responding to was that the aged, cracked, overly stiff or overly loose bushings on the front of the car can be a major point of improvement when a change is made.
The difference between a C7 Stingray Z51 and a C7 Grandsport (wider tires - really thats about it) - at a particular track is 4 seconds, which is essentially an eternity. Changes, when made at important pivots, make vast improvements.
But I can put those same wider tires on another similar car weight and distribution - and the lap times would not be the same. Because the rest of the system is different.
Having dealt with almost 20 928s since 2000, I will tell you that any improvement in almost any part of the car using new materials or design processes from the last -15 years - will improve the car either subjectively or objectively - or both.
Too much time has passed. And my further point that you were responding to was that the aged, cracked, overly stiff or overly loose bushings on the front of the car can be a major point of improvement when a change is made.
Agreed, but imagine 10-15sec a lap difference in just developing as a driver for $0, and zero risk on the longevity of "better".
I dont think the average Joe newbie would see 0sec between the two Corvettes, where your likely comparing a developed driver...I get that, I completely do.
I can put a highly competent driver is the worst ****box of a car, and within some reasonable comparison (and sometimes not) they would out-drive a spec race prepared car with an average good driver. The best example of that Ive seen is someone pilot a street/daily driven RX8 mid-pack in a Spec Mustang/Camaro Challenge pack..on street tires. Granted the driver was Dr McDreamy...hes hot, and can drive. Everyone at the track has something to smile about when he shows up.
I hope these work well long term for the people that have invested in them, and I will admit that I changed sway bars, because the stock roll rate was just insufferable, but I have some new noises up front that came with that..that will always be part of that too. (Heim joints)
Even with "weaknesses" a platform is only limited by the driver, i'm just a 'drive it' thinker. I also find this works better with drivers under 18, or even _16_ a lot better at the track, than ones over 30.
#44
Drifting
I’ve changed phones and can’t seem to add pics from this one at present. I’ll see if I can dig out a picture or two from my desktop when I’m next there. They came from Oz, really improved the driving experience for a while but began to fail progressively with elongation of the central holes and then crumbling. I’ve gone back to stock and have the same philosophy as speed toys on this one.
#45
Three Wheelin'
I think that was the point my mechanic was making. The a arms are a pivot point and should be able to move fairly freely, letting the springs, dampers and sway bar to do the work. I think he refereed to it as a flex point for lack of better words, as the bushing is just flexing, not really pivoting. I'm not all that bothered what people say to be honest. I have experienced the difference modern poly bushes make first hand, and it's a marked difference.