ALFAGTV6.COM

grant · Post by **grant** » Sun Apr 15, 2007 12:41 pm

Hello. My car understeers too much, what can I do about it?

I have a Milano Verde (3.0 America I guess?) with:

27mm Torsion bars and about ~160 lb/in springs (they're the Shankle SS jobbies).

The shocks are Koni Yellows (don't like them too much)

RSR 28mm front and 26mm adjustable rear RSR sway bars.

The car has full poly in the rear and stock stuff up front for now (the rubber is OK..the car has 110K miles).

The car is also very low in the front and back...I think too low in the front. I came to the conclusion that I'm probably reducing my camber as the car tries to roll, rather than increasing it.

I'll attach a picture of the car, but unfortunately my car is so ugly that I've never taken a good side shot.

My caster is about 3 degrees up front, and I can't really touch that because I'm just barely clearing my 205/50/16 tires (they're a bit too large in diameter for this car) and my camber is -1 degree only. I don't think this is quite enough.

I have the rear sway bar set on the 2nd to stiffest setting, which is just enough to keep the front end from plowing off the road. I don't think this should be, because I already have the larger rear sway bar from Ron Simons that is supposed to be matched with his 30mm front sway bar, not the 28mm. I chose the 28mm because I am really afraid of tearing out my front sway bar mounts, even with a reinforcement plate welded in.

I think I'm losing speed by having to have the rear sway bar set so stiff. I thin I'm having to reduce the rear end traction of the car too much to compensate for the understeer I'm having. So, my question is, how much front camber should I have to help alleviate the problem. I really can't have too much camber as I commute this car and drive it on a daily basis.

Thanks in advance.

Micke · Post by **Micke** » Sun Apr 15, 2007 1:46 pm

I'd start by trying -2.5 deg camber. One degree is for sure not enough.

grant · Post by **grant** » Sun Apr 15, 2007 2:51 pm

Not too extreme for the street? I will onyl be doing about 2-3 track events a year.

Micke · Post by **Micke** » Sun Apr 15, 2007 9:58 pm

It will be OK on the streets too. The tires will wear slightly faster but it shouldn't be too bad. If the insides wear enough you can rotate the tires front to back.

Mats · Post by **Mats** » Sun Apr 15, 2007 10:10 pm

Slightly is the word here, camber does not (contrary to popular belief) make the tires wear faster, toe however will. Which leads us to the next question; what is your toe set to?

grant · Post by **grant** » Sun Apr 15, 2007 10:21 pm

It's 0 right now, but I read that I should have slight toe-out to combat camber thrust. I'm not so sure about this one...

Mats · Post by **Mats** » Mon Apr 16, 2007 3:04 am

Pardon my ignorance; camber thrust? Is that equal to roll-steer?

In what situations is the car understeered? Always? turn-in, steady state, exiting under power?

I would start by dialing in at least 2.5* neg. camber and 2mm of toe out, throw the Konis in a deep pond far-far into the woods then drink loads of whiskey (or possibly Vodka) so you forget what you did to them. Replace with other shocks, Bilstein B46-1175RS / B46-1176RS is a good replacement, shorter then the std Bilsteins.

rz · Post by rz » Mon Apr 16, 2007 8:45 am

i thought that rwd cars always have toe in?

Mats · Post by **Mats** » Mon Apr 16, 2007 9:12 am

Popular myth that one.

grant · Post by **grant** » Mon Apr 16, 2007 10:26 am

Camber thrust as in, an angled wheel wants to turn in the direction it is leaning in...like how a bicycle will make a smaller radius turn if it is leaning into the turn versus just turning the front wheel and guiding the bicycle around the turn (hard to explain, but I think you might figure out what it is I'm trying to say). What is the end result of two cambered wheels pushing against each other? I have no idea..

Good question. The car understeers right after turn in, all the way to just about after the apex. Once The car is fully rotated, I can get on the throttle, which takes care of the remaining understeer. It does seem as if the tail will come out too quickly under throttle...I think I could be gaining more speed out of turns by increasing the front end grip and reducing the rear roll stiffness. I realize trail braking could alleviate this, but my stock Verde brake bias is so much towards the front that it seems as if it would be better to get my braking done mostly before the turn, otherwise the nose wants to push more.

These are just some observations of an amateur driver. I'm sure with some more skill, I would know other methods of overcoming this situation.

I agree with you on the konis, but haven't tried out the Bilsteins yet.

Why do E30 BMW's seem to be so much more nimble!??

Thanks for the help so far.

PS, I thought we just came to the conclusion that having 2.5 degrees of camber and toe-out would be a bad idea as far as tire consumption?

grant · Post by **grant** » Wed Apr 18, 2007 8:45 pm

So Matts, how about an opinion on my car's transient handling?

MR2 Zig · Post by **MR2 Zig** » Wed Apr 18, 2007 9:03 pm

I found out the stock settings for a US spec car are; camber -1deg+-30"., caster 3deg+-30"., toe out 1mm+-1mm.

I just finnished doing my front rebuild and alignment. My sources are the CarDisc for 83 GTV6 and the alignment computer at the tire shop.

HTH,
Scott

grant · Post by **grant** » Wed Apr 18, 2007 9:49 pm

Yeah, we've got a shop manual for GTV-6 and Milanos too. I'm a little surprosed tha -1 degree is allowed as a stock setting. Maybe I really should be up in the -2.5 area...

grant · Post by **grant** » Wed Apr 18, 2007 9:49 pm

Yeah, we've got a shop manual for GTV-6 and Milanos too. I'm a little surprised that -1 degree is allowed as a stock setting. Maybe I really should be up in the -2.5 area...

Mats · Post by **Mats** » Wed Apr 18, 2007 10:58 pm

grant wrote:Camber thrust as in, an angled wheel wants to turn in the direction it is leaning in...like how a bicycle will make a smaller radius turn if it is leaning into the turn versus just turning the front wheel and guiding the bicycle around the turn (hard to explain, but I think you might figure out what it is I'm trying to say). What is the end result of two cambered wheels pushing against each other? I have no idea..

Good question. The car understeers right after turn in, all the way to just about after the apex. Once The car is fully rotated, I can get on the throttle, which takes care of the remaining understeer. It does seem as if the tail will come out too quickly under throttle...I think I could be gaining more speed out of turns by increasing the front end grip and reducing the rear roll stiffness. I realize trail braking could alleviate this, but my stock Verde brake bias is so much towards the front that it seems as if it would be better to get my braking done mostly before the turn, otherwise the nose wants to push more.

These are just some observations of an amateur driver. I'm sure with some more skill, I would know other methods of overcoming this situation.

I agree with you on the konis, but haven't tried out the Bilsteins yet.

Why do E30 BMW's seem to be so much more nimble!??

Thanks for the help so far.

PS, I thought we just came to the conclusion that having 2.5 degrees of camber and toe-out would be a bad idea as far as tire consumption?

Very interesting indeed, it's all pointing in one shining gold lined path= lose weight.

kidding, kidding, put the gun down...

The camber thrust you're talking about seem to come from the fact that you lean the steering axle the wheel rotates about, not the wheel itself. Try leaning a bike over while keeping the handlebars straight, I'll guarantee you can lean it until the pedal hits the asphalt without even a hint of steering.

You need camber, and as much as you can get without doing some major surgery, 2.5 at least up front to start with. add a touch of toe out (1-2mm on 15") and you'll have a nice baseline. Set camber first as this will screw up the toe setting. If you feel like you wanna do more you should add ~2 degrees of negative camber at the rear too, that's surgery though but if you cut the de-Dion tube next to the propeller and press it down to get camber you will also lower the rear roll center.
Try to get as much caster as possible too, this will give you more camber on the ooutside wheel in the turn and lean the inside wheel inwards, two birds with one stone...

Or you just drive too fast into the corner/have really crappy tires.

"Why do E30 BMW's seem to be so much more nimble!??"
Look under the hood, 4-cyl...

Street/Track alignment spec.