6
Ultimate Suspension Thread!
- Thread starter nearsite00
- Start date
the bruce
Go Kart Champion
First I'd like to say when it comes to handling of any car the TIRES are the most important.
The goal of proper handling is:
- fit the best tires (for the apllication) you can get
- choose a suspension that helps the tires to do their job properly
So when it comes to suspension the point is that it's job is providing:
- the best possible basis for the tires
- reasonable ride comfort
Ride comfort is a very individual thing. Feel free to decide on your own and don't get
persuaded into something you don't like. There is NO need to run uncomfortable suspension.
The 2nd point is what we're talking about at this place, but I want to emphasize that every-
thing the suspension does (regarding handling) is to help the tires doing their very best.
The keyword here is "contact patch". There's no grip without it.
True. That's why bigger bars at rear only don't work on a GTI. They aren't able to control
body roll and camber on front.
This causes positive front camber (positive values - NOT want you want) and understeer.
On a side note: If a rear bar is stiff enough to lift one wheel when cornering hard it doesn't
make any difference if it is lifted by half an inch or one inch. That's why I believe it also
doesn't make a real difference on dry tarmac if the rear bar is 24 mm or 28 mm when it's
stiff enough to lift the inner rear wheel. It does make a difference on wet surfaces though
where the 28 mm rear bar even at lower cornering speeds forces the inner wheel to lift and
makes driving in the wet much more dangerous.
Even more, most people who fit a bigger rear bar only don't know what they're are missing.
A bigger front bar also gives improved steering feel and turn in.
Keep in mind a bigger rear bar will have much less effect on roll compared to a bigger front
bar (or uprated bars both front and rear). The stock GTI rear bar is already similar stiff as
the (stock) front bar (see data on the stick official sway bar thread) and most roll 'happens'
where most weight is - on front.
The point is to keep some near stock balance to make the car handle better and not worse.
Good point. There's MUCH misleading and even wrong information particularly from the sellers
of lowering springs. Most lowering springs don't reduce roll, they increase roll.
The goal of proper handling is:
- fit the best tires (for the apllication) you can get
- choose a suspension that helps the tires to do their job properly
So when it comes to suspension the point is that it's job is providing:
- the best possible basis for the tires
- reasonable ride comfort
Ride comfort is a very individual thing. Feel free to decide on your own and don't get
persuaded into something you don't like. There is NO need to run uncomfortable suspension.
The 2nd point is what we're talking about at this place, but I want to emphasize that every-
thing the suspension does (regarding handling) is to help the tires doing their very best.
The keyword here is "contact patch". There's no grip without it.
True. That's why bigger bars at rear only don't work on a GTI. They aren't able to control
body roll and camber on front.
This causes positive front camber (positive values - NOT want you want) and understeer.
On a side note: If a rear bar is stiff enough to lift one wheel when cornering hard it doesn't
make any difference if it is lifted by half an inch or one inch. That's why I believe it also
doesn't make a real difference on dry tarmac if the rear bar is 24 mm or 28 mm when it's
stiff enough to lift the inner rear wheel. It does make a difference on wet surfaces though
where the 28 mm rear bar even at lower cornering speeds forces the inner wheel to lift and
makes driving in the wet much more dangerous.
Even more, most people who fit a bigger rear bar only don't know what they're are missing.
A bigger front bar also gives improved steering feel and turn in.
Keep in mind a bigger rear bar will have much less effect on roll compared to a bigger front
bar (or uprated bars both front and rear). The stock GTI rear bar is already similar stiff as
the (stock) front bar (see data on the stick official sway bar thread) and most roll 'happens'
where most weight is - on front.
The point is to keep some near stock balance to make the car handle better and not worse.
Good point. There's MUCH misleading and even wrong information particularly from the sellers
of lowering springs. Most lowering springs don't reduce roll, they increase roll.
nearsite00
Ready to race!
UNFOGIVABLE
Go Kart Champion
Where's "driving a fast car SLOW?"
Great writeup op and others who added some knowledge. Been following most of the steps described here and it's spot on. For instance after coilovers install, I've set ride height 26 up front (300lb springs) and 25 3/4 in the back(325lb) that gave my car look that most guys here hate. Car handles most neutral this way in everyday situation at least for me. Understeer is reduced (not drastically but to the point when I have more confidence in pushing it harder) compare to having front at 25.5 just half an inch made difference for me and I could feel how car respond under hard cornering going up or down and flat road turns.
Setting rear sway bar on hard and front on soft made car twitchy (maybe good for autocross guys) but high speed turns became very dangerous, when as I felt rear was about to catapult from the car in circular motion. Haven't tried Front on stiff and soft in rear yet, wondering what results would that setup deliver. Still on factory Pirelli tires and will switch to michelin PSS come next spring which I'm sure will force me to adjust both of the dampening settings again. Very interesting and informative write up guys.
:thumbsup:
Setting rear sway bar on hard and front on soft made car twitchy (maybe good for autocross guys) but high speed turns became very dangerous, when as I felt rear was about to catapult from the car in circular motion. Haven't tried Front on stiff and soft in rear yet, wondering what results would that setup deliver. Still on factory Pirelli tires and will switch to michelin PSS come next spring which I'm sure will force me to adjust both of the dampening settings again. Very interesting and informative write up guys.
:thumbsup:
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