Roll Center Questions
Posted: Mon May 21, 2007 9:14 am
Hey everyone,
First post here on alfagtv6.com, but half of you have probably seen me learning about Alfa's over on the BB.
Well, I've been reading quite a bit about suspension setups and trying to figure out what approach I want to take when I begin modifying my car. It seems that the GTV6 has quite a lot of potential but the subject of this tread is the main thing I'm having trouble resolving.
It seems fairly obvious that the front of the GTV6 has some roll center issues as it goes quite subterranean when the nose is lowered, and in response it seems there are two main ways of attempt to maximize GTV6 suspension performance:
1.) Stiffen the front spring rates and anti-roll bars until the car has virtually no roll anyway, thus eliminating the issue via brute force.
2.) Using a crafty trick ('drop spindle', knuckle raiser', 'inverted ball joints') to lessen the inherent limitations of the geometry.
I somehow feel like option 2 is a bit more....'holistic' an approach, if that makes any sense. But I don't really know if such an approach is needed on a car that is basically not going to be a full fledged racing car, but will be used as a fun autox toy. I feel like if I'm going to keep the front of the car as low as it is (4.5 inches of ground clearance), that it's the right thing to do but, should I bother? And if I should, what method is best employed to correct the geometry?
I get the general impression that by 'fixing' the RC, by raising it after the car is lowered, that the same performance can be generated while utilizing lower spring rates and thinner anti-roll bars, but I've yet to see hard numbers concerning this thought.
So what are the thoughts? Are these modifications a good 'first step' in getting a lowered GTV6 to handle? Are products available and documented? Who can provide insight from personal experience?
Thanks!
First post here on alfagtv6.com, but half of you have probably seen me learning about Alfa's over on the BB.
Well, I've been reading quite a bit about suspension setups and trying to figure out what approach I want to take when I begin modifying my car. It seems that the GTV6 has quite a lot of potential but the subject of this tread is the main thing I'm having trouble resolving.
It seems fairly obvious that the front of the GTV6 has some roll center issues as it goes quite subterranean when the nose is lowered, and in response it seems there are two main ways of attempt to maximize GTV6 suspension performance:
1.) Stiffen the front spring rates and anti-roll bars until the car has virtually no roll anyway, thus eliminating the issue via brute force.
2.) Using a crafty trick ('drop spindle', knuckle raiser', 'inverted ball joints') to lessen the inherent limitations of the geometry.
I somehow feel like option 2 is a bit more....'holistic' an approach, if that makes any sense. But I don't really know if such an approach is needed on a car that is basically not going to be a full fledged racing car, but will be used as a fun autox toy. I feel like if I'm going to keep the front of the car as low as it is (4.5 inches of ground clearance), that it's the right thing to do but, should I bother? And if I should, what method is best employed to correct the geometry?
I get the general impression that by 'fixing' the RC, by raising it after the car is lowered, that the same performance can be generated while utilizing lower spring rates and thinner anti-roll bars, but I've yet to see hard numbers concerning this thought.
So what are the thoughts? Are these modifications a good 'first step' in getting a lowered GTV6 to handle? Are products available and documented? Who can provide insight from personal experience?
Thanks!