Any suspension experts know the exact relation between camber/toe?

[Porschefile]

I have my car set at -1.5 front and -2.0 rear camber, stock rear toe and ~.05-.06 front toe (told them to zero it but they apparently didn't heed my request). I am thinking about putting on the dinan plates to bump camber to 2.2 or so in the front and can do the install myself but I'd rather not pay a shop $150 to do a tiny tweak afterward and tell me they aligned it.

Of course the rear is going to stay exactly the same, and the front camber is going to go up ~.7 in camber, but what would happen to toe? I know it would go in some, but if it would be close to zero I could probably just let it stay.

Anybody know how much .7 increase negative camber in the front would affect toe?

[tibra1]

Dont you actually have to put the car on the alignment rack to see what changes when an adjustment is made?

Every car's (even identical models) have slightly different suspension geometries

[Porschefile]

Well to be "exact" I guess, but I just wonder how much that amount of camber change will affect toe. There has to be some known relationship between the two beyond "change camber and it affects toe".

And the camber will be right around 2.2 because in my case I'll just be putting the top of the strut as far inboard as it will possibly go, no adjustment really.

I mean it's a pretty well established fact that lowering springs give you like .3 negative camber added by dropping the car with no strut changes. It may be .2 or may be .4, but it's right around there. So if there is a similar known figure for how much toe goes in per degree of camber that would be awesome to know.

[Malek@MRF]

To help you out, yes adding another -0.7* of camber up front will change your toe settings. It will throw the toe outward, enough to require toe adjustments.

Have tested this numerous times on my own car and other guys that run camber plates. Drastically changing camber up front will in fact affect toe.

Vehicle alignment is one of the most important parameters in making sure your car performs properly, so I would not recommend skimping out on this. Go to someone that knows what they are doing when it comes to chassis and suspension setup as it could really ruin the driving experience.

When lowering the car, an alignment is necessary, many things change.

Malek

[Porschefile]

I realize changing camber will change toe, that's why I posted the OP, I just wonder how much. I know some guys with E46 M3's that would have two setting marked on their adjustable camber plates so at the track they could add a lot of negative camber. As a consequence of this the toe would change as well, and they take that into account so the street setting has proper toe and then when they change the camber it automatically changes the toe to a better track setting as well.

[Malek@MRF]

Originally Posted by Porschefile

I realize changing camber will change toe, that's why I posted the OP, I just wonder how much. I know some guys with E46 M3's that would have two setting marked on their adjustable camber plates so at the track they could add a lot of negative camber. As a consequence of this the toe would change as well, and they take that into account so the street setting has proper toe and then when they change the camber it automatically changes the toe to a better track setting as well.

Adding -0.7* - -1.0*of camber up front will approximately change toe by 1/16th" to 3/64" outward.

With that being said, even if you did toe in the front wheels enough to compensate for the toe going outward at the track, the wheels would be toe-in a good amount.

I personally run -2.2* camber for street and track with 275-30-19 PS2's up front and ZERO toe. Ideally, the car would drive a bit smoother with 1/32" toe in per side, however, I like the crisp turn in and grip.

[Porschefile]

Originally Posted by Malekreza11

Adding -0.7* - -1.0*of camber up front will approximately change toe by 1/16th" to 3/64" outward.

With that being said, even if you did toe in the front wheels enough to compensate for the toe going outward at the track, the wheels would be toe-in a good amount.

I personally run -2.2* camber for street and track with 275-30-19 PS2's up front and ZERO toe. Ideally, the car would drive a bit smoother with 1/32" toe in per side, however, I like the crisp turn in and grip.

Thanks, exactly the info I was looking for. 1/16 might be okay but 3/64 is pretty significant, maybe I can get a shop to do an alignment just on the front since the rear is set and pay half.

[Sleeper519]

Originally Posted by Porschefile

Thanks, exactly the info I was looking for. 1/16 might be okay but 3/64 is pretty significant, maybe I can get a shop to do an alignment just on the front since the rear is set and pay half.

Actually the difference btw/ 3/64 and 4/64 is insignificant.

When I had my GC camber plates put on, going from -1.6 to -3.0 camber the toe went from 1/16" in to 1/3" out...on each side, which is unacceptable. To adjust the toe along with the camber at the track involves making adjustments to the tie rods along withe the plates, adding complexity.

Others have posted different results and numbers. JM3, who I think works for Ground Control, found that toe change through the entire 26mm camber sweep (~3 degrees?) was 5/16", or 7mm total. I only moved mine through maybe half that arc and got a hair OVER 5/16". So, it seems to vary from car to car and doesn't seem to adhere to a set formula.

I agree with getting a pro to get it right and feel good about it regardless of the settings you choose to run.

Good luck. I have struggled with this same issue too!

[Porschefile]

Wow, thanks for the info. 1/3 is a ton.

[Car54]

Hate to dig this up again, so it sounds like it would be better to set you a 1/16" toe in at a moderate camber at say -2.0°. Then if you need more camber at the track, push the plates in, then you're only left with a very mild toe-out.

Church?

[Porschefile]

I found too that the adjustment of camber heavily impacted toe, to the point that I just set it at a level I can live with and zero out the toe. -2.7 has worn the insides a little more than I like, but it feels great at the track. May try -2.0 from here.

[Car54]

I watched the guy doing my alignment and when he went from 2.0 to 3.0 camber in the front it went from +.10° to -.50° which is 3/8" toe out I believe.

My Mcoupe with E36 front end used to go perfectly from 1/16" in to 1/16" out with an addition of about a degree of negative camber. I'll take all the good in the E9X over that little advantage any day I suppose.

Actually...I recall reading the E9X doesn't need the -3-4° like the E36 chassis anyway.

[RickyBobby]

Adjusting toe is easy and repeatble on our cars. I marked my tie rods with street and track settings so I have the best of both worlds. It takes about 1/2 turn of the tie rods to account for the camber sweep. No compromises!

[bigjae1976]

Originally Posted by Car54

Actually...I recall reading the E9X doesn't need the -3-4° like the E36 chassis anyway.

I think that's true. I run -3.0 on my E46 and E90. My E46 will still wear the outside of the tire a bit. My E90 still has all of the arrow markers on the outside of the tire.

A buddy just went with -2.5 camber up front at a pretty fast track that is notorious for cording/wearing the L/F tire on the outside shoulder. We chalked the tire, ran a PSS 265/35R18 at about 40psi and got very little wear on the outside.

I run RS3s which do have a little more grip but my conclusion is that the E9X chassis needs less static negative camber up front.

Originally Posted by RickyBobby

Adjusting toe is easy and repeatble on our cars. I marked my tie rods with street and track settings so I have the best of both worlds. It takes about 1/2 turn of the tie rods to account for the camber sweep. No compromises!

Great info!

[Porschefile]

How much camber and toe do you guys run without bad wear?

I've been running -2.7 and some toe out (between 1/32 and 1/16) and my AD08 are 3/32 insides and 6/32 the rest of the tire after a few thousand miles and 6-8 track days.

[Car54]

I'm running 2.2 up front and 1.8 in the rear. I just ran Daytona and with 275/35 x4 NT01's, I had even wear all around. Daytona is a goofy track and not a typical road course...you can't run a lot of camber on the banking. I'm driving Sebring in a couple weeks and will take note of the wear and post back.