LaserSVT

So looking for suggestions on just a rear set of wheels and tires, drag radials for my 2012 CL65 that are as close to the stock diameter rears that will give me the widest patch and tallest sidewall. I dont wanna roll the fenders and I want stock diameter (275/35/20) so I can keep the ESP on without it freaking out. Not really dig racing but will be roll racing at TX2K17 next month and since the stock Contis go up in smoke at 120 MPH at half throttle I need some grip. I also want the ESP to stay enabled because I wont have a lot of wheel time in the car and dont wish to wreck it after all the money I just spent. So what suggestions?
For tires I really like the MTs because they always have hooked the best for me in my Cobras and Vettes but dont know if they have the right size so Nitto NT05s are fine or 555 DRs are good too. But I dont know if I can get a 17" wheel to clear the stock brakes. I would also love it if the wheels looked kinda like the stock wheels but thats the least of my worries.

Here is the stock wheels:



Thanks for the help gents!

Dr Matt

I run a M/T 285/40-18 at the track. I had to buy 18x8" wheels and have them widened because I wanted matching wheels too. The M/T's are listed as 26.9" tall with a circumference of 84.5". They work fine with T/C on my W215, but I don't know the exact diameter of your tires vs mine, however I think yours are actually closer to 26" based on looking at specs on tire rack. They hook well at the track with a big burnout, but wear very quickly. On the street they pick up so much fine gravel due to the soft compound that they need a burnout to hook, even on a roll. I have had better luck with the M&H drag radials on the street, they hook better than the M/T's on the street with no burn out, and last much longer. However, their shortest in a 18" is 28" talk with an 88" circumference. It's been my experience with them that they run a little small, but I doubt small enough for me to run my car in anything but dyno mode. If you get a 17" wheel, they have some 26" sizes though which should work perfect for you, you just need to find that 17" wheel. Here's a link to the M&H website. http://www.mandhtires.com/M-H-Drag-Radials#.WKCVLHjpqrX

LaserSVT

I believe my stocks are 26.7" in the rear and 26" in the front.

LaserSVT

Wonder if a 305/40/18 can fit? Thats the same diameter as the stock tire.

Dr Matt

Not sure, but if you have a 26/26.7 stagger you should be able to run the 285/40-18's for sure. Seriously though, for street vs. track use I would seriously consider the M&H's. M/T's for best possible hook on prepped tracks for sure.

LaserSVT

But I think the cars computer will still be looking for that size difference. The 285/40/18 is 26" not 26.7" and it may see that as slippage even though the rears will spin at the same RPM as the fronts then.
Since I have the suspension module installed I can command the rear up so the 305 does not rub the fender but I wonder if that wide of a tire would rub the inner well?
I guess I am just gonna have to wait ofr the car to get back and go to that custom shop in Dallas and have them put that rim tool on it with the 305/40/18 and see if it fits.

Dr Matt

When you first bolt them on, if you hammer the throttle you may get a warning that stability control is unavailable, but within a few miles of driving the computer learns the ratio of front to rear circumference and bases it's traction control on the current tires, as long as it is within about 3% if I remember right. My 285/40-18 M/T's are actually slightly taller than my 285/35-19's. I swap back and forth at least 3 times per year. I also swap on/off my snow tires every year. When I was buying those, no one had what I wanted in the factory sizes so I bought stock size Michelin Ice-X's for the front, and Blizzaks for the rear. The tread pattern looks so similar you would never know they are not the same make/model. However, now I know the Blizzaks run really small. They look ridiculously shorter than the fronts. It was so bad, I almost didn't even bolt them on the car once they were mounted up. But even with obviously shorter rears, they work fine and within a couple miles of bolting them on the car traction/stability control works perfect again. I think if you are within 3% of revs/mile either way you are fine.

RaceHorse

I think its hard to find the exact answer you are looking for since you are going into uncharted territories with the W216. However, I think I can offer some solid advice. For starters, I would play around with tire sizes on any tire calculator. Links below:

http://www.1010tires.com/Tools/Tire-Size-Calculator

http://www.discounttiredirect.com/di...nfoTireMath.do

Another thing that you need to take a look at closely is the offset of the wheel of choice. Take one of the rear wheels off and lower the car on a block of wood so the weight of the car compresses the suspension. This will allow you to measure how much room you have in and out to determine the max width and proper offset. You may have to mess around with spacers if you are cutting it very close. You can probably find stock replicas in 18" but may have to widen accordingly.


When it comes to running at the track you are going to want to put the car in dyno mode for the ease of burnouts. This disables your ABS and traction control. At this point there is no concern with different size front and rears. I run my car at the track that way, but everyone is different. Either way, its not a bad idea to get the tires very close. Consider changing your front tires too if it helps keeping heights close with the limited drag radial sizes available.

I realize you have a built tranny, but that just means clutch packs. If the hard parts are still stock, they along with the rear, will be pushed to their limits. A LSD, sticky tires and alot more power is a bad combo, but you don't have much choice with all the wheel spin. Sometimes you have to drive fast and take chances. Good luck, I look forward to seeing the car make a pass.

LaserSVT

Yeah I use the miata net calculator for size calculations. Been using it for years. I know with my Vettes they didnt care at all as long as the rear tire was taller than the fronts. Nice and simple. The AMG is much more particular. I also hate wheel spacers of any kind so would have custom wheels made before I added spacers.
I am also not concerned with the track, this is for roll racing at TX2K17 and I want to leave the ESP on just due to the cars power level (if its anywhere near what SpeeDriven claims it will be) and would prefer to have a little traction assist for the high speed runs. I just want to give the car as much ability as I can for it to put the power down.
I also do not want to run in dyno mode (I can get a good spin with the ESP off already) as I dont want the ABS system shut down, again since its roll racing i want to do and want that ABS for 180+ MPH slow downs.

Also, and I may be wrong here, but I am 90% sure that the trans gears were sent out for cryogen treatment. Now while I do plan on making a few track 1/4 passes just to get some numbers the car will really never do 1/4 mile track runs simply for the fear of snapping the rear end or axles.

Dr Matt

Another thing you can try to do to see just how much fender clearance you have with your existing tire & wheel combo that works for the W215 so should work for you W216 is:

Jack up the car by the rear differential. Start the car, and put it in drive, let go of the brakes so the rear tires spin for a minute or so. Use the brakes to stop the rear tires. Put it in park & shut off the car. Then lower the jack.

When you run the car jacked up this way, the ABC system reads the rear too high based on strut travel and ride height sensors and tries to lower it by dropping all of the pressure out of the rear suspension. When you lower the jack, the rear suspension will compress MOST of the way. You can then easily see how much tire clearance you then have at nearly full compression. When you start the car, you will get a "Suspension too low, visit workshop" message. Don't worry, just hit the ride height button and it will hop back up to the correct height. The warning will go away when you shut off and restart the car.

I found this really helpful when trying to determine the ideal rear wheel offset & width.

AMG-Driver

Laser, do you want to participate at the Texas Mile 2017 in march or is it another event you speak of, because you speak of roll races and texas mile is from a standstill I think?

I have no experience with drag radials, I always thought they are for 1/4 mile racing.

Are they also made for high speed driving in a 2 tons car with more than 180MPH?

LaserSVT

I plan on doing the Texas Mile as well but hat will be on normal street tires as I plan on a top speed run. I want the drag radials for the 60-160 roll races during the TX2K17 event.

AMG-Driver

Ah, O.K.

Good Luck and be safe!

RaceHorse

I remember reading they do not let you run MT drag radials for the Texas mile after some failures. I realize you mentioned running street tires, but another good in between tire would be the R888s. Besides looking for stickiness, you will want to make sure they have the correct load rating too. I would play around with size and spacers until you can determine the proper offset and tire fitment, before investing in custom wheels. If they are off a little and rub, you'll end up selling for a lot less than the original cost.

LaserSVT

Yes, I am aware. Thank you.

shardul

iTrader: (1)

I think we have a set. I will have exotic-metal PM you with details

LaserSVT

Okay

LaserSVT

I am now thinking the MT 305/35/20 will be the way to go. They are less than an inch taller and I THINK the compute can compensate for that if the W215 system can. They are also 1" wider which I do have room for. Even in lower mode with the module dropping snother 1.5"

I am just worried that the W216 computer wont compensate like the W215 can for the taller tire.

BlownV8

Wait until you get the car running right before investing more in the car. You may have hit a wall that can't be overcome without another huge infusion of cash, time, and some serious know how. Based on everything I hear, you wil need some type of stand alone ECU. I sincerely hope we are wrong.

LaserSVT

Well for those that want to know the W216 CL65 can hold a 305/35/20 drag radial without rubbing and with no effect on the ESP. Car dead hooks now! Yay!