smgC32

How many of you have needed to roll/modify your front fenders to accomodate a larger wheel/tire combo and/or lowered ride height? How much did you roll and at what angle/section of the fender? What front wheel width/offset do you have and what tire size/manufacturer are you running? Thanks.

Zeppelin

No Rolling for me. And no rub on fender or strut.

Stock AMG rear 17x8.5 rim on front

245/40/17 Toyo, Goodyear GS-D3, and Pilot Sport all fit, so would any tire with 9.8 section width or narrower.

Ride height is about 1 finger width between fender and tire.

Stock AMG strut with H&R springs.

Wiedermann

Mr. smgC32:

I am positive you are aware of fact this subject (Rubbing, rolling fenders and related issues) has been extensively covered, discussed, etc, etc on this forum , however, for the sake of the posting and MORE research I did, just to "make sure" that there wasn't anything I missed, I have checked, re-checked with many people that have any combination of (or all of them) lowering suspension(s), larger wheels/tires. So far:

With the stock C32 wheels and tires: As Mr Zeppelin mentioned, you can get some advantage to lower the car with the available suspension kits that are out there and mostly you won't have any problem with rubbing (comment based on "acceptable" size of tires)

I already have a set of 19' rims on my C32. Originally the wrong set of tires were installed with those rims (front: 19x8.5 245/35/19, Rear: 19x9.5 275/30/19). On both, front and rear there was some horrible, horrible rubbing, on the front the tire rubbed against the shock/strut mount base, not to count it rubbed against the fender's interior plastic molding when you turned, and in the back, the tire simply didn't fit at all (my car has the AMG Euro suspension set, that is aprox 1.5 inches lower than the US edition suspension package).

I know the "rubbing" subject is probably one of the oldest items of discussion in the forum, about offsets, etc, etc.. the only tire size that run fine on my wheels are Tires: Front: 235/35 Z R19 Rear: 265/30 Z R19... that is counting that the rear fenders HAD to be rolled.

Even after the rolling of my rear fenders was completed, when I have more than a total of 2 occupants on the vehicle (including the driver), say anyone on the rear seats, say one or more in the rear, when I go over a hump on the freeway at freeway speeds, the rear tires will rub; and to that, there is no escape. There are other people on this forum that I have been fortunate to meet in person and have seen that they (for those that have mods in suspension and/or wheels with or without tires) also have the same problem… reagardless how well their wheels’ offsets are, regardless how well their fenders are rolled, the cars still rub. That is now to count that in some cases... if the famous wheel's offsets are wrong, then regardless of how well the fenders are rolled the car will rub... one "solution" that is "offered" and it has to come to your personal choice is to choose a wheel offset that is lower than what is needed for the wheel of your choice. This will cause the wheel to "sit in" more inside the fender, which will allow your wheel and tire to travel more up and down inside your fender and possibly (and hopefully) help you avoid any rubbing... the downside to this... and those with engineering majors can probably explain it better than I will ever do, is the wheel simply sits more inside the fender and not flush with the fender as it is designed... not to count that you can opt to have negative camber on your wheels, but then other problems will arise.. again, all a matter of personal choice. Those that have visited the plant in Germany probably have seen the demo little cars they have where you can change the camber adjustment on the wheels and see how those cars freely run.... (negative camber will cause the vehicle to offer resistance on the road... therefore the car does not travel "freely" on the surface --won't "free fall" downhill per say-- however as result the car will have better grip on the road... and to compensate for that negative camber that basically grips the car on the road and doesn't allow it to "freely" go on the road??? whelp???.. basically you have the engine having to use its force to really "push" that car against the ressistance offered by the negative camber as well as the rest of the mass, blah, blah... again... someone with good physics, or engineer can show the mathematical reason of what I said .

Having bigger wheels and tires... The grip is great!!... however, rubbing is a problem when I have more than 2 people in the car... to eliminate that problem???>.. whelp???... the solutions have been posted:
-Roll fenders
-Take out the interior fender padding (though the tire then will rub against the fender.. so still rolling fender is the solution)
-Put 255/35 R19 on the rear (narrower tires) ... which actually eliminated completely the rubing on my car... however, I opted to keep the 265's on the rear, I don't have often people in my car except my wife... if I have more, then I take other vehicles that I have.

Wiedermann

AMG BRED

after a few months of hell with my 19s and H&R Cup Kit, Harris suggested a simple solution - to get rid of the cup kits, and go back to stock shocks, and renntech springs... I have never rubbed since, even with 3 adults in the rear and 1 passenger in the front. knock on wood.

smgC32

Sorry. I should have specified Front in the first sentence. I am aware of many rear fitment issues that some have not resolved and live with. Interestingly, I have never had a problem on the rear of my car and have not needed to roll the rear fenders, remove the plastic liner, relocate the attachment screw, or grind down the metal tab that sticks out and attaches the fender to the bumper. Even with a fully loaded trunk and three passengers in the rear of the car, my 18x9.5 ET36 wheels with 265 35 18 tires (both T1-S's and GS-D3's) have worked flawlessly. And at one point I was running a ride height of 12.5". It is the front of the car that concerns me. Some have noted that S03's with their larger tread width have caused problems in 235 sizes.

I tested the fitment of the stock 8.5x17 ET37 rear wheel on the front with 245 Rosso's and they fit and did not rub at the stock ride height. I never ran them with a 2" reduction in front ride height, and the Pirelli's are inherently narrow. It just seems impossible unless there is a huge tollerence in body panel fitment, that 245's would work without rubbing problems. Anything below a 30mm offset will interfere with the fender, anything above a 32mm offset will interfere with the strut tube given a 8.5" width and 245's. 30mm offset with fender rolling seems the only way to fit the 245's and still clear the strut tube especially if you run coilovers with their increased diameter housing. Has anyone cut their sidewalls of the tire due to rubbing?

I am confused by your comment:

"...if the famous wheel's offsets are wrong, then regardless of how well the fenders are rolled the car will rub... one "solution" that is "offered" and it has to come to your personal choice is to choose a wheel offset that is lower than what is needed for the wheel of your choice. This will cause the wheel to "sit in" more inside the fender, which will allow your wheel and tire to travel more up and down inside your fender and possibly (and hopefully) help you avoid any rubbing... the downside to this... and those with engineering majors can probably explain it better than I will ever do, is the wheel simply sits more inside the fender and not flush with the fender as it is designed..."

Rather, it is that the lower the offset number, the more the wheel will sit towards the outside fender. The higher the offset number, the more the wheel will sit towards the inside, closer to the strut.

The biggest hurdle to overcome is finding a way to increase the negative camber in this car to a minimum of 2 degrees negative. The strut tower housing and bearing design is the biggest problem. Maybe EvoSport can find a way to make some camber plates for this car!

Wiedermann

Your comment is correct. I have the tendency --as every reader has already see; right Vomit? -- to tell things backwards (ie. "increase the A/C": Is that adjusting the temperature thermostat going "up" or "down"? )

Cheers!

Wiedermann

Zeppelin

I thought Renntech made bushings to give -2 or more degrees of camber?

smgC32

RENNtech still offers its rear subframe modification but their front offset bushings have such little interest, that it is not economical to continue to offer them.

Prasith32

can somebody explain to me what a fender roll does? What exactly does it roll? How does it help in accomodating wider tires?


I am currently facing problems with my Kumho VictoRacers. I am running 245/45/17 on the front as per somebody's suggestion.

However the problem does not seem to be the fender. When I took off the wheel I saw that there were rub marks on the strut tube.

I take it that a fender roll will not help in my case? It does not happen often but it is noticeable on the track. When I just turn the wheel full lock there is a little amount of clearance there. However when the car is loaded and the body is rolling as much as it does in this car it rubs and people at the track commented that they see some smoke coming from my wheel well. I smell burning rubber too. This only happens on a left hand turn that is basically like a bowl. you go down a hill into the turn and up the hill out of it.

Now this is on the stock wheel so what offset is that? How does reducing the offset mean it will give more strut clearance?

Also in terms of more negative camber will that tilt the wheel more towards the strut and thus cause rubbing against the strut tube. Is that what you mean smg? What if you just put some spacers and then did a fender roll?

I don't know much about wheels and fitting etc so everything above is conjecture and questions. Now that I am experienceing rubbing I am suddenly interested in knowing all about wheels and the wheel whell and struts etc. Any and all information is appreciated.

Thanks.

Prasith

smgC32

Prasith, sorry to hear of your problem. Ask Norm and some of the others within this forum who are running 245's and/or 255's up front. They may have some good answers. Some are running a different wheel.

When ever you put on a larger width tire on the same size rim, the tire will shift more beyond the lip of the wheel since the side wall of the tire is not supported as much. Sometimes this is referred to as sidewall rollover. The wider the wheel with the same size tire, the less sidewall rollover or flex as the wheel lip pushes out the tires rim bead farther increasing sidewall integrity and increasing the tire's contact patch. Some will argue that a 235 tire on a 8.5" wheel will handle better than a 245 on an 8.0.

The W203's fenders are inexpensively made. There is no factory "U" channel bent into them, thus making a weaker fender. You can easily pull the body panel out with one hand. As with any metal, a "U" bend is stronger than an "L" bend which is what the W203 has. This "L" is only about 10mm long and is very sharp. When a wheel/tire combo that is too large comes in contact with this "edge", the tire is cut along its sidewall, sometimes to the extreme of needing to replace the tire due to exposed steel belts through the cut. It is more difficult to roll the W203 fenders since there is little material to deal with. The old method of using a baseball bat between the tire and fender and driving the car forward or backwards will not work with this car and ruin your fenders. The mechanical fender rolling armature that attaches to the hub and roll the fender edge or lip we are speaking of, does an OK job but will not roll the lip tight against itself. The only way to accomplish a proper and tight roll is to do it the old fashioned way; with a body shop hammer and block. This will provide the maximum clearance and require the repainting of the entire fender.

Evidently, the Kumho's tire width on your car is too wide for the steering angles your are reaching on the track. Do they rub on the street? The solution is to provide a spacer for the wheel which will push the entire wheel/tire to the outside. Depending on the size spacer, you may have fender clearance issues. Try the 10mm DR series H&R spacer. Many track cars run spacers for an increase in front track which helps the car's handling. Don't be concerned with needed to use a spacer. Porsche's use them all the time, and you must use them with any Brabus wheel, as well as others. Just make sure you use a quality spacer like from H&R and remember to buy new lug bolts that are longer by the same number of mm that the spacer is thick.

Rubbing the inside strut tube can be OK if it is only mild contact and occational. It sounds like you are grinding the rubber off! Take the wheel off and inspect the inside tire at the point of contact. Is the rim bead of the tire worn off? Is the strut tube missing the black paint at the point of contact at the tube's indent?

With camber plates, the entire wheel/strut assembly will move together. With the factory bolts, I am not sure, but they are at the bottom and may cause the top of the tire to be closer to the strut when turned for maximum camber.

Prasith32

smg,

That is an interesting point that you brought up regarding wheel width and tire width.

Where do I have a bigger contact patch and better traction. A 245 tire on a 7" (is that what our front wheel is?) or a 225 tire on the same wheel. The 245 feels better to me but I am really comparing apples and oranges here because the 245 is the Victoracer compared to my 225 which was Michelin Pilot Sport.

If this is the case then is there a point to upsizing tire without upsizing the wheel? It seems like unless the tire is not enough for the wheel then it would help to upsize but upsizing when it is at the optimum point seems to be pointless. Is this what you mean or am I not understanding you.

Also as for the spacer I am a little reluctant to go that route because the clearance seem tight with the fender as well and I am not sure if I would have moved my problem from the strut tube to the fender.

I am going to take my wheels off today and see what the wear is like and I will report back on the extent of the rubbing.

It does not rub on the street except on really tight full lock turns and that is only if i try to accelerate. If I take it slow it doesn't. My guess is that it clears but the body roll is the problem and is what causes the rubbing.

Who has camber plates for the c32? How much negative camber can you get with them?

Prasith

smgC32

Your comparison is not quite the same principle. Every tire size has a preferred wheel width range. 7" wheel with 245's is not a recommended fitment. Even a 225 on a 7" is a bit small. There are some who run 225's on a 8.5" rim, 8" being standard aftermarket for most tires of this size. A 245 should be running on a 8-9" rim. You should really know what the factory specs are on your car by now. The front wheel is 7.5" as printed in your manual and within the threads contained herein. The 245 on the 7.5 will have a bigger contact patch than the 225, but will roll over more. I would run a 235 as a happy inbetween.

There is nothing wrong with spacers if they are hubcentric and of quality design and manufacturing. You have nothing to loose by trying them if they will allow you to run a wider tire and be able to install your BBK. You can always roll the fenders!!

Where exactly does it rub? Inner fender or is the fender lip cutting the tire? On the manuver you mentioned, does the tire rub against the strut tube? What noise do you hear? What size tire are you running?

No one has camber plates because they would cost a fortune to make the prototype and you could only sell a few. The factory camber bolts have provided me with a maximum of 1.1 degrees negative which is not enough.