BMW M5 Forum and M6 Forums banner

1 - 12 of 12 Posts

·
Registered
Joined
·
252 Posts
Discussion Starter #1
I have the Dinan front camber plates and rear sway set to the tightest setting. These two items have dramatically improved the “at the edge” handling for the track and canyons, cleaning up almost all the built-in understeer tendencies. :thumbsup:

Problem is, even with the camber plates, it looks like im still wearing the outsides of the front tires first. I asked Eric at Dinan if they make anything that can give me more front camber. As I predicted, his first thought was to sell me the stage 3 kit which would lower the car and stiffen up the ride a bit. Dinan will not be making a “more aggressive” camber plate, which I suppose is understandable from a business perspective. While lowering the car would give a slight bit more negative front camber, im not really looking to do that or to stiffen up the ride. Im very happy with what I have for what I do with it (I have a separate dedicated race car for the track so im not looking to turn the M5 into anything resembling a race car)…I like the ride I have now, and just want to dial in some more front camber to improve front tire wear based on my driving style. :wroom:

So, is this possible? I have heard bad things about the quality of the K-Mac plates, and good things about the ground control plates. However, I cant find much in the way of detail about the GC plates. I understand that they are adjustable. Can you get more negative camber out of them then the Dinan plates? Does anyone have any experience with these or other products that might work out for this application? :2:
 

·
Registered
Joined
·
463 Posts
Dinan Stage 3/lowering: I had the chance to remeasure my ride heights over the TD holiday. I had Stage with JRZs installed about 2 months ago. It's a bit lower now (left/right): front is 14 1/8 and 14 3/8, rear is 14 3/8 and 14 1/8 (#s not transposed, that's actually how it is). Alignment was also recently rechecked: I'm at -1.5 negative. The tech who worked on my car said he might be able to achieve more negative camber by modifying the strut mounts, but I didn't pursue it any further with him and don't know what that might entail. I think some board members have reported getting slightly more than -1.5 with Dinan Stage III, but not much more.

GC: When I inquired about 2-3 months ago, adjustable camber plates were not yet available for the M5. They might be now.

Have you considered a different tire? I think the SO3s have relatively stiff sidewalls and might be less prone to rolling over. Running 275s on front, with 9.5" wheels, might also help.
 

·
Registered
Joined
·
252 Posts
Discussion Starter #3 (Edited)
Hey EdP-

The front tires were rolling over bigtime at the track first time I took her out bone stock. Those tires were totally trashed after the second track event with the camber plates and Dinan swaybar. I bought Auchtung's original stock wheels and tires and am seeing the same wear pattern on the outside edges of those fronts now, even with no track events on these particular tires. It looks like a gradual increase in wear toward the outside edges, and not from tire rolling, which I would be very surprised to be happening during street and canyon driving. On the race car (full-cage Mazda RX7), we actually use GC plates, and can get some totally wild negative camber if we want (way too much even for most tracks around here), but im not sure if the stock geometry of the M5 chassis and shock towers will allow for anything much more radical than what Dinan has designed into their fixed plates.
 

·
Registered
Joined
·
7,535 Posts
The GC plates only work with their coilovers from what I understand. Redshift has the full GC setup, and I think he can get about -2.5 degrees camber when maxed out at his track setting. You may want to double-check your toe-in setting to make sure you don't have too much toe-in. I agree with you though -- for all out driving, at least 2.5 or so negative is needed up front. This much negative camber would not be practical for everyday street driving such highway driving as the insides would heat up and wear rapidly. It will also result in more tramlining.
 

·
Registered
Joined
·
2,773 Posts
I have the full GC setup (there is another thread with pictures and specs on this board). I run -1.4 degrees for the street and -2.2 degrees for the track, and my tires wear perfectly evenly at all times. I sometimes leave the -2.2 degrees in place if I am only a couple of weeks in-between track events and am not planning any long road trips, and I still get good tire wear.
 

·
Registered
Joined
·
4,515 Posts
The Dinan setup uses the large factory perches, upper mount & bearing turntable. The Dinan springs are large in diameter which limits lateral movement of the upper strut mount in the modestly-sized E39 strut tower.

The GC coil-over upper strut mounts offer lots of adjustment because they are designed for springs around 3" diameter, instead of 6". This allows a whopping 1-1/2" more strut mount movement in any direction compared to OEM-ish Dinan or K-MAC, before the strut tower is contacted. Considering the conical shape of the GC upper perch, it may even allow more movement than that.

The GC adjustable plates absolutely do not work with factory-type perches and springs (like Dinan uses) & there's no hope in modifying them to fit. It's an entirely different setup and philosophy. The factory-size springs limit camber and caster flexibility for high performance handling applications.
 

·
Registered
Joined
·
12,866 Posts
03E39M5 said:
Hey EdP-

The front tires were rolling over bigtime at the track first time I took her out bone stock. Those tires were totally trashed after the second track event with the camber plates and Dinan swaybar. I bought Auchtung's original stock wheels and tires and am seeing the same wear pattern on the outside edges of those fronts now, even with no track events on these particular tires. It looks like a gradual increase in wear toward the outside edges, and not from tire rolling, which I would be very surprised to be happening during street and canyon driving. On the race car (full-cage Mazda RX7), we actually use GC plates, and can get some totally wild negative camber if we want (way too much even for most tracks around here), but im not sure if the stock geometry of the M5 chassis and shock towers will allow for anything much more radical than what Dinan has designed into their fixed plates.
With 1.5 neg on the front, I would expect the INSIDE edges of the tires to be wearing out first. What tires are you running and what pressures? Assuming the rest of the alignment is set up correctly, you must be pretty aggressive on the street to get that kind of wear. Check castor, get as much as possible to help cornering. More castor allows a little extra neg camber when the wheels turn.
Consider 9.5 inch wide rears on the fronts to help? My Dinan Stage 3 has 1.5 neg on the fronts and on some "test ramps" I have a hard time getting the car to even understeer. Very balanced, rear bar is outermost holes IIRC. Tires are stock size Goodyear F1's, front 38 cold, rear 36 cold.
Regards,
Jerry
 

·
Registered
Joined
·
159 Posts
Lscman said:
The Dinan setup uses the large factory perches, upper mount & bearing turntable. The Dinan springs are large in diameter which limits lateral movement of the upper strut mount in the modestly-sized E39 strut tower.

The GC coil-over upper strut mounts offer lots of adjustment because they are designed for springs around 3" diameter, instead of 6". This allows a whopping 1-1/2" more strut mount movement in any direction compared to OEM-ish Dinan or K-MAC, before the strut tower is contacted. Considering the conical shape of the GC upper perch, it may even allow more movement than that.

Gc makes plates that do fit the stock diameter springs like the H&Rs. Ive got the plates. There being installed as we speak. I do have a problem though, I run the rear oem wheels up front. We just now are putting them on and they hit the coilover. We've gone to 15mm spacers its pretty close but the tire sticks out past the fender not much but its noticible. I guess I might have to put the stock fronts back on. I will know more a little later. I wonder does anyone have the H&Rs installed with the rears on.
Boz
 

·
Registered
Joined
·
4,515 Posts
My co firewall is burning me......

Are these H&R springs for stock perches or H&R coil-overs? I'm cornfused.

It is impossible for a rear wheel-tire combo to hit a factory-type spring or perch unless you're running taller SUV tires (lol). With proper diameter tires, the factory spring perch is always above the tire tread by a 1/2" or so.
 

·
Registered
Joined
·
159 Posts
Lscman said:
My co firewall is burning me......

Are these H&R springs for stock perches or H&R coil-overs? I'm cornfused.

It is impossible for a rear wheel-tire combo to hit a factory-type spring or perch unless you're running taller SUV tires (lol). With proper diameter tires, the factory spring perch is always above the tire tread by a 1/2" or so.
H&R coilovers
 

·
Registered
Joined
·
4,515 Posts
Boz M5 said:
H&R coilovers
Well that explains it! Thanks for info, Boz!

The H&R coil-over springs are smaller diameter than OEM & the perches are non-OEM.

Although you seem to be still in the experimental phase, it's good to hear you got the Ground Control Camber plates to mate with a non-GC coil-over setup. This is the first post about somebody trying it & it may mean they work with Eibach and other coil over kits.

The H&R coil-over springs often interfere with tire sidewalls, so I don't think it has anything to do with the GC plate. Folks with 540i cars tried the H&R coil-overs and found they needed to run 10mm spacers with 8-1/2" wide parallel reproduction aftermarket wheels with 20mm offset, if they wanted the car to sit lower than stock (14" from fender lip to roundel center). This is with stock upper strut mounts, by the way. It's my understanding that the 540i and M5 coil over kit by H&R is virtually identical.
 

·
Registered
Joined
·
1,345 Posts
My camber is running at -2.05 degrees F and -2.3 rear and inside wear vs outside wear is not significant, over 2k miles there is no discernable issue


This is using Dinan -ve camber plates
 
1 - 12 of 12 Posts
Top