excessive body roll after alignment?

[85carrera]

hey...i recently had an alignment/corner balance by TRE. however, now it feels like it has more body roll than it did before. the front wheels are easier to turn, but it doesn't feel like it cuts into the corners as well as it did before. granted heavy cornering is little more controlled now due to the corner balancing, but I would have thought it would cut into the turns a little sharper. Is there an alignment setting that effects body roll? maybe the alignment settings were set a little too conservative?

i have bilsteins sports and turbo tie rods both of which were installed before the alignment.

[IROC]

Originally posted by 85carrera
Is there an alignment setting that effects body roll?

The short answer is no. Alignment cannot have an effect on body roll. Body roll is a function of "roll stiffness" primarily, which is determined by spring rates and sway bar (or anti-roll bar) rates.

Ride height could have an affect, but I would think that you would need to make fairly drastic ride height changes to notice changes in the amount of body roll.

My 2 pfennigs...

Mike

[85carrera]

bump

[boba]

a better setup will yeild higher cornering loads which will in turn show the next point of weakness. = time for more upgrades.

[stlrj]

Too much toe will give you more roll.

[85carrera]

hey yah...i was actually thinking about the toe. so when you say "too much toe will cause body roll", does that mean too much toe-out??? (ie the front of the wheels point out). i have a feeling this may be the issue since they did tell me the toe was set conservatively to save tire wear. Also, after i had replaced the turbo tie rods my friend and i set the toe to toe-in at least 1/4 inch. it handled great then!!!

[stlrj]

Usually too much toe-in makes the body roll more. Best to experiment to see what works for you.

[Miguel Antonett]

The body roll is not affected by alignment as said above; however, it makes you feel like it does, the car gets light and nimble on the font = need toe out. AND don't worry about tire wear, enjoy the car as it should.

[RaceProEngineer]

Originally posted by stlrj
Too much toe will give you more roll.

Let me write that down - We are always learning . . . . .

Ed LoPresti

[RaceProEngineer]

85carrera,

First of all, TRE know exactly what they are doing, and I am certain, will be pleased to alter your handling any way you wish.

It is not unusual to find the car handling differently after a proper alignment, especially when accompanied by corner balance. Frequently, the car's capability has just taken a step forward, and you need to adjust your driving to take advantage of that.

You bring up 2 distinct differences since this work was performed: Excessive roll, and speed of turn in. We would think of these separately.

As IROC points out, body roll is regulated by spring rate and stabilizer bars (and ride height, and to a small extent, shock valving). If you have adjustable stabilizer bars, TRE undoubtedly disconnected them for the scales. When reconnected, they would have removed any preload. They may also have changed the indexing of your torsion bars (springs), and certainly adjusted ride height. The roll will FEEL different, especially if you are, as you say, cornering faster.

Speed of turn in is most effected (after tires) by toe, front camber, front stabilizer, and shock valving. You mention that you were careful to ensure a good amount of toe IN after the upgrates you did. Oddly, that degree of toe IN would have the effect of a very slow turn in, UNLESS the rear of the car had some toe OUT! This may have been corrected with the alignment. Also, if you are cornering faster now, NATURALLY the turn in will seem slower, and it is best to keep it that way for street driving!

I hope this helps at least explain what is probably going on.
Ed LoPresti

[atlporsche]

unless someone disconnected a sway bar and forgot to hook it back up...

gotta do the corner balance with them disconnected, you know.

sjd

[masraum]

Holy Shmoly, 1/4" of toe in. That's horrible. In the front I'd be looking for 1/32 toe in or even 0 toe. 1/16 if you want to be really conservative, or if you want to be a little more aggressive 1/32 toe out. I'd never use 1/4" of toe in unless you want to buy lots of tires.

Also, assuming your car is handling better now than it did before, you should have more grip, if you have more grip you'll have higher cornering loads, higher cornering loads mean that the car will roll more.

If your car rolls more than it did before TRE got to it then they either made it corner harder and you need to upgrade or they forgot to reconnect the sway bars.

I'd be surprised if it didn't handle or turn as well as before. Probably just an illusion and your perception.

[Huh]

If the alignment was dialed in by TRE to be a bit aggressive wouldn't you also feel the sidewalls of the tire more which also gives a feeling of more body roll?