Blocktrader

Anyone know if AMG makes the twin spokes in a 9.5 for the rear with the same (or within 1/8 inch) backspacing. I would like to move the rear wheels and tires to the front and then put 275's in back to help correct the understeer. I need to get the rear to stick out a little more to match the look at the front and dont want to use a spacer. The big 55's use a 9.5 I believe. Anyone know if the offsets are similar? Ideally, an 18x9.5 in the rear with the same backspacing as the stock wheel would bring the outside of the wheel out a half inch and match the front nicely.

Dr Chill

Unfortunately the styling IV comes in 9" as the widest in the 18" diameter. On the S and the CL, the offset is 44mm. They do come in 19" x 10" for the SL with 28mm offset. Did you already try the rears on the front yet? If so, did they rub?

Dr Chill

Oh, by the way, not to be too picky but adding a 1/2" wider rim with the same offset will cause the rim to only stick out 1/4" further and clear the inner well by 1/4" less.

By my calculation, if you move the rear wheel to the front, the clearance from stut housing to the inside of the wheel will be 22mm LESS and the outside edge of the wheel will EXTEND an extra 4mm.

Blocktrader

Yes, I put the rears on the front and there were no problems. I didn't get to test them in a bottoming situation, but if they hit, it would just relate to whether the fender had to be rolled and not be a big deal. I do not see anywhere they would hit on the inside. The rears stick out further. I would say the offset on the rears is closer to be equal to the fronts than the specs you were talking about would suggest. The rears have more brake clearance as well. (not that that matters as I cant see putting bigger calipers on the car.) Having both tires off the car at the same time it is readily apparent that the rear contact patch is quite larger than the front. The rears also have a more appropriate load rating for the weight. I think getting rears on the front is the simple answer for solving this cars track problem.

Blocktrader

Part 2. We are both correct. What you said is right, but adding a half inch and maintaining the same backspacing will move the outer edge of the wheel outboard by a half an inch and leave the same inside clearance. I shouldn't have used the word offset in my question about the other AMG cars. It made it more confusing, but I figured it was more likely for someone to know the offset than the backspacing.

The problem I am running into is that If I put another set of back wheels on the front, they fill the wheel well nicely and then the backs look tucked in. Worst case I am going to do this for the track and then just put the fronts back on for the street(for looks). Do you have the specs for all these wheels? I thought I ramember you were going to try an SL55 wheel on your car. That wheel is 9.5 wide I believe.

eclou

If you are only worried about appearance on the back you could simply use H&R wheel spacers to shim out the rear track until it looked perfect. Much cheaper to do than to change the wheels and then you could also rotate the tires and stock one size of track tire.

Blocktrader

I would like to avoid spacers. The s class cars have a little more lip on the rear as well. If the wheels from say a CL55 would work, that would be the ideal for me. If not, I may end up getting a set of HRE's made or something. I would like a setup where I will not have to make any changes to go to the track. I would never run spacers at the track.

eclou

Running spacers is not a problem until you go over 25mm. I run 18mm spacers front, 5 mm rear on my track car. The only limiting factor is the strength of the wheel studs or lug bolts. You need to have at least 3-5 threads of engagement.

The old problems with wheel "balance" has been eliminated with modern hubcentric spacers. Hubcentric spacers are just an easy way to change your backspacing without having to go thru the vigors of calculating the effects of different outer & inner rim halves and centers.

scorchie

AMG fit 9.5" SL wheels on the E55, no problems. I have been at Affalterbach and seen an E55 delivered (last April) with R230 SL wheels installed.

I believe the 9.5" wheels are ET33, so the outside lip would be .25" + 5mm = 11mm farther out than the stock rims. The backspacing should remain almost the same, as the 5mm less offset will cancel out the <6mm greater width.

I have a set of SL wheels but unfortunately the tires are not set up for the E55. I am looking for another set to use as daily drivers on the E55.

-s-

scorchie

Are you using the spacers solely to increase the track width, or to correct improper offset on wheels to come into spec?

If you're changing the intended offset of the car, have you considered the effect the increased track will have on the steering geometry, more specifically the change required for the Ackerman Principal to be handled correctly?

Just curious if people actually figure this out, or if they don't mind that their inside front tires are just scrubbing in the turns (which obviously limits ultimate adhesion).

-s-

eclou

Front spacers are being used to clear my Porsche 993TT brake kit. Changing rim halves will not solve the clearance issue since the shape of the centers (Kinesis K20's) take up alot of space. There is no discernable degradation of steering in the car. The steering has been more affected by by camber (-3.5) and toe (+.125) settings.

The rears are just for increase in track width.

Dr Chill

I decided to go with OZ Superleggeras when they arrive in this country in hyper silver. They weigh 18 lbs for the front 18 x 8 and coime with 35mm offset for about $320 each. That's about 10-11 lbs lighter than the stock wheel.

Dr Chill

Hey Mike, did you drive the car any distance with the tires reversed? I'm just curious if there was any rubbing when turning the steering wheel lock to lock when actually moving. If not, I'm changing my wheel order to 4-18 x 9's with offset 35mm and running 265's all around. Then I'd also be able to get a little more tire life also.

Blocktrader

Yes, I did drive the car and test steering lock on both sides with no problems. I did it with no radio or ac and the windows down. I heard no rubbing and found no evidence on the tire afterward. In your case I would definitely go with the rear size all the way around. You are only using those on the track so you wont care about the looks. On that subject. There is not a real appreciable difference in looks. The average person would likely not notice. I just want it perfect.

Dr Chill

With the setup I mentioned, the fronts would extend 4mm farther than the rear. Should be unnoticeable.

Blocktrader

You're right. What is compounding the problem is that I can't be sure what the specs are. Continental shows a few 265 tires. The one that is listed as MB OEM says it has a 10.4 inch section width. The others show a 11.1 inch section width. The front is either 9.6 or 9.8 inch depending on which version of that size we have. If we have the former, then there is only 1mm difference between mounted fronts and rears from hub to fender if you are trying to maintain the stock balance. If the tires are the latter size, then there is actually 7.25mm between the front and rear hub to fender differences. This probably makes more sense in my mind than on this page. What I'm trying to say, is if the rear tire has a section width that is 1.3 inches wider than the front, and that is what looks right, then the effective difference is really 7.25 mm after you account for the 9mm offset difference. I would like to hope that it is really the smaller sizes and the .8 inch difference. My experience doesn't make this look promising though. I am going to have to take the wheels off and do some more specific measuring.

Regarding your setup, I understand the stock rears are ET39. If you are getting ET35, then you are going to have 4mm more backspace. Any variationin section width will affect this as well. How long untill you order them. My car will be in service all week, but if you are not ordering for a couple weeks, I will let you know how much extra room there is.

Dr Chill

The hyper silver wheels I want won't be in the US until January. By the way, why is your car in service?

stephens

I'm not sure , but I beleive the maximum width you can fit on the front is a 255 and that is pushing it. I think you may find rubbing on the inside with the 265 and a 35mm offset. This is what I was told when my rims were fitted and checked for clearance with 255 and 285 tyres.
Brabus runs a 29mm offset on the front with 8,5" rims, changing to a 9" rim should not be a problem, but the tyre size would have to be a 235 or 245, otherwise you would have clearance problems with the lip of the guards. The 19" SL wheel has a 25mm offset which would limit you to a 245 tyre. The offset on the standard 18" rim is 30mm.

My car runs a 19X9.5 et35mm rear and fits 285's with a few mm to spare. With a 275 tyre you would be able to run a 30mm offset (or put in a 5mm spacer), but not alot less. From memory the standard offset on the factory 18" rear is 39mm. The SL offset is 29mm, which would be pretty tight with a 275 rear, but is pretty much the limit of offset that can be used unless you use a smaller tyre width.

stephens

Blocktrader
The best way to test, so that you know there will be no problems on full suspension compression, is to do this at your dealer and have them lower the front of the car via the service computer, to see if it rubs anywhere. I'd be interested to know the results.

Blocktrader

One of the Ventilated seat fans needs to be replaced. The tire monitor is broke again. The brakes are squealing slightly. I want to at least report the S/C chirping problem. Also, my accessory belt is squeeking a bit at idle. I am also getting a scratch fixed on a trim piece and a dent removed. Should have the car back early next week. Once I do I will spend some real time checking the wheel clearances.

Dr Chill

The different section widths are not related to differences in the tires, but rather the different width rims the tires are mounted on. The standard width rim that section width is determined for a 265 tire is 9.5" and the E55 rear is 9" resulting in a decreased section width.

I just purchased a pair of BFG G-Force R1 race compound tires and switched to the matt silver superleggera since the hyper silver will not be availablefor at least 2 more months. I ordered 2 18 x 9 wheels with 35mm offset and will mount them in front for a few days to see how they do.

I also ordered stainless steel brake lines ($135) and am getting closer to getting a race pad for the car. I'm optimistic I'll be ready for Jan 31.