jangy

As many of you know, I have been playing with the wheel / tire setup on this beast to see what exact specs I want for my final. Here are all of the combinations I tried and the results:

Stock:
Initial feel on both '05 and '06 cars was MASSIVE push. I drive this car very differently than I did my M3. On the M3, I literally matched the acceleration to my steering input to balance the car. In other words, the accelerator was used to steer the car while in the turn. For those that don't understand rear drives, just look up "lift throttle oversteer" for an example. Anyhow, the E55 has been a hard one for me to do these seat of the pants type moves with, so now I have learned to do as much of my braking as possible BEFORE the turn in. Then, I use the added power to catch back up on the exit and straight. The old days of me slipping inside of people on turns are over. The E is just not nimble enough to do that without going two to three wide in the turns. Last note, I had MASSIVE wheel spin when on it!!

Front (stock), Rear (275/35 PS2s):
Pushed even more (duh). However, the rear settled down a bit. I do not know if the PS2s last, but they seem like DRs compared to the Contis. The car launched MUCH better, but that is it.

Front (265/35), Rear (275/35): all 4 tires on 18X9 et39 wheels.
In this case, the fronts had 265/35 Contis and the rears had 275/35 PS2s. I was going for the balanced feel and was wondering if the rear setup even fits the front. It does. Very nicely, in fact. The steering got MUCH tighter and the push was minimized. This was the first time that i noticed any front body roll, so i must be getting stronger Gs. The rear was the same as before. Just OK.

Front (275/35), Rear (265/35): all 4 tires on 18X9 et39 wheels.
I focused on the front and tried to see if the 275 PS2s would fit. They did. No rubbing and an EXCELLENT fit all around. The rear rims on these cars go very nicely on the front. the et makes for a nicely tucked tire. The 275/35 PS2s are very nice up front. the feel is much sportier. The only option would be to get a fatter rim to stretch the tire walls a bit more for lateral G. Other than that, it is awesome. I stayed with this setup on the front.

Rear (295/30 PZero on 18X9.5 et29):
I got a pair of the CLS Style IV rims and tried the 295/30s. I figured go for the gusto!! This size is ALMOST perfect!! I wish it had a slightly larger et. Maybe a 35 vs the 29 it has. There is plenty of room on the inner side and up top. But, as the suspension compresses, there is only about a 1 credit card gap between the well and the tire. I was scared of body damage, so I took it slow. The tire does not come anywhere near the metal / plastic gap of the fender, so that is good. The only part that did "rub" were the rubber needles that stick out of the tires. I wore them off on the first hard drive. I heard nothing from the cabin, but the needles were gone after the ride and I had a gooey film on the fender lip. Since then, no problems. GREAT launches compared to the 265/35.

Summary: in the end, I think I will try to get the following setup:

I will stay with 18s, as I am into improving the lateral and not the straightline stability. I would prefer to go wider than taller. I will get PS2s all around plus I will get a pair of rears w/ DRs for drag fun.

Front:
275/35 on 18X9.5, et 40

Rear:
295/30 on 18X10, et35 for road rides
295/35 on 18X10, et35 for dragging


Next, I will look into larger sway bars and strut supports. I loved how the car stayed level on the stock Contis. i hope I can get it back to that with the added rubber.

jangy

All these hits and not one of you has feedback on this setup? Nobody ever tried? Nobody wants to hate?

FlyByNight

The 295s on my 19's caused the fishtailing, aka "wiggle" that I grew to really dislike... 285s are the sweet spot I think, as they never rub during compression...



Loren

pas

No but thanks for the info! I ran 20's 245/35 and 285/30 and just went back to stock wheels with new PS2's in stock sizes.

I loved the look of the 20's but got tired of the ride and the 285/30's caused the wiggle.

I have to agree the PS2's are impressive had I seen your results a couple of weeks ago I might have gotten different size rubber, maybe for the next set!

So basically rear wheels fit the front and you went as big as 275/35 on the front with no problems at all.

I also have 275/35 BFG DR's for the rears and they are amazing even with brake torquing they do not spin at all.

Now all I need to do is find a nice set of 18x9 wheels that are light and will accept the TPMS sensors, and that look cool!

stevebez

What about 285/35/18's ...will they go on a stock rim ? Think this is a sweet fit with mbe a 2.82 diff ratio ... more grip and more leverage ... gives these in gear speeds

MPH@6100rpm
Suggestion..............Stock
1st...46.4...............48.3
2nd...76.1..............79.2
3rd...118.2.............123.1
4th...166.7.............174.6
5th...200.8.............209

Gets car to 200mph bang on with full delimit... should you ever need to do this of course....

So that sorts out the rears ... what would you suggest with stock rims for the fronts 255/35's?

Any thoughts ?

Torquey55

I have referred to Loren's comments on the "wiggle" a few times in other tire related threads. I suffer the same problem with 295 PS2's. They are definitely too wide (at least in my application). After I hasten their demise I am definitely going with 285. I don't know if this will help you jangy, but I wanted to give my 2 cents. Obviously you put a lot of effort in your wheel/tire testing & I appreciate the time you took to describe your thoughts here.

Loren's thread on this issue:
https://mbworld.org/forums/showthrea...ght=295+wiggle

E55 RUSS

285 will also rub sometimes with lowering...

jangy

Thanks for the feedback, fellas. I have only heard of this fish tailing thing. Can someone plese explain it to me and especially why fatter tires cause it?

Is it is the differential waggle that I have felt in other cars: This would happen even in a straight acceleration and you can simple feel the differential working. If this is the problem, then i do not mind or blame the tires. That is the car NOT handling the traction smoothly. I would hope that the LSD may help.

Another thing to keep in mind is that I stayed with 18" and kept the overall diameters (front and rear) almost stock. I have seen no attempts on here to simply go wider. Everyone seems to want the blink look and I want the rail feel. I do assume that much of the observations has to do with 19s and or 20s, or at least I hope so. i do know that my friends with 19s complain much more about it and they are running 285s.

jangy

Oh yeah, let me just summarize:


The rear rims fitted with 275/35 PSs work well in the front. NO RUBBING. EVER. I driven the car VERY hard and it has at least 2cm at all corners.

295/30/18 DOES NOT RUB, if it is setup properly. This means taking great care to get the proper offset. Look under your E.

Again, all of this may be different than what your current dogma says, but I really do think it has to do with staying with the 18s.

At any rate, I've read loren's thread, but i am still a bit confused about the waggle.

pas

The wiggle is caused by the tires rubbing, on my car you couldn't hear or feel the rubbing but the tires touched just enough to cause some confusion in the ESP computer, this results in the computer applying the rear brakes one side at a time in an attempt to solve whatever problem it sees due to the rubbing.

The brake application makes the car lean to one side then the other, back and forth until hard acceleration has stopped. It is very annoying and really kills the rock solid feel of the car.

If someone else has a better or more correct explanation please provide it.

Rafal

I also got PS2's 255F and 285R in 19", and thought the combination worked very well. Unfortunately I had a side wall puncture in my 285 and now cannot get a replacement PS2 from anybody in the World!
I am effectively stranded and am considering tossing the remaining three tires out to replace with something else, like 245/275/19 PS2 combination or even 255/285 in RE050A.
Speaking of fishtailing, I get it with all rear tire sizes, 265,275 and 285 when I kick down to FIRST- is the 295 "wiggle" any different?

Torquey55

I'm with pas on this one. His explanation seems to make the most common sense to me for what I am experiencing. I have seen rub marks on the insides of the wheel wells on my car although I can't feel anything rub. To me it seems logical that the back and forth application of brakes could be causing the "wiggle". Hell, I dunno...

jangy

I'm confused. I don't see how there can be enough rubbing to cause ESP to kick in if there is no damage? I just don't see it. Can anyone explain how I can duplicate the waggle when I have the 295s on? I'll test it and tell you. Does the ESP light flash when it is wagging? If so, are you guys sure you aren't talking about 295/19s? 295/18s are what I am talking about. As I said before my final diameters are alsmost identical to stock. That is key to me.
Thanks for the help!!

Torquey55

Jangy, I am referring to 295/19. I can't speak for the 18's as I swapped mine out for the 19's 2 days after I got the car. I am not sure how close to OEM diameter I am with my particular application. The "wiggling" seems to happen under heavy to wide open throttle. It's kind of difficult to describe the sensation, but it's very noticable even to passengers when it happens. It actually scared my wife a few times. The ESP light does not come on at all during the wiggling. When doing some 1/4 mile runs I felt it really bad, almost like a sideways see-saw. It feels just like a fish tail looks as it's swimming with the side to side motion. I'm sure it cost me a couple of tenths if the ESP in fact did kick in. As soon as I saw Loren's thread on this topic last December, I knew I wasn't the only one with this strange problem.

jangy

What profile are your 295/19s? Mine are 295/30/18.

As for the sensation you are describing, that again, sounds like the rear differential. The 295s would grip better and cause the diff to try to work harder to put the power down instead of just spinning. Actually, now that I think of it, it has only happenned to me in German cars. My M3 did it at launch and my friend's 993TT (track car) did it real bad with slicks on. He eventually upgraded the rear end and it cured it.

I wonder if we don't have a few different things going on here. If it is the differential waggle, then I do not blame the 295 tires. If that is not it, then I'd like to find it before I either hurt my car or decide to buy more 295s!!

Torquey55

I'm running 295/30/19 and I am still a little confused about this issue. Maybe it is the differential after all? I really don't have a clue here, but what Loren and pas said makes real good sense to me. I am definitely going to get 285 (if available) or even 275. There's not a lot of life left in my 295's, I am a couple of big burnouts away from belts being exposed. I am looking forward to seeing if the narrower tire cures this. My 2003 M3 with the SMG never did this, and I thrashed that car every time I drove it.
Good luck with whatever you decide to do. Hope I helped a little here...

pas

Jangy, in my case it was the fault of the 20" wheels the rears were 20x10 with 285/30/20 Pilot Sport A/S. They came off a buddy's CL600 and they really don't fit the E55 quite right with the 285/30, from talking to other people a 285/25 and possibly playing with some spacers would have cured it. The ride was bad enough with the 285/30 so I didn't see the point in having even less sidewall and went back to the stock wheels with PS2's in the stock size.

The ESP light does not illuminate when the wiggle is happening, and I am not 100% sure my explanation is perfect, but my car now drives perfectly. I have also run BFG DR's on the stock wheels with no issues (275/35) so it is not a problem caused by excessive traction or poorly designed differentials. You may have a different problem because as soon as I put the 20's on I remembered the threads I had read about the "wiggle" and immediately knew what it was.

It happens under hard acceleration, you feel the rear of the car lean to one side then to the other oscillating back and forth until you ease up on the gas. It really sucks. If you take the rear wheel off you might see evidence of the sidewall slightly rubbing the inside of the wheel well, but you don't hear or feel it.

Try this from 30mph floor it up to 100mph if the rear moves left to right about .5 sec per side until you let up you have the wiggle and somewhere your tires are making contact.

jangy

Wow!! I am still not getting the rubbing bit, but I really am starting to believe that the diameter has alot to do with it.

I am not trying to be rude or beat a dead horse. I just really care about handling.

Here are a few figures to think about:

A few things to note when going from stock to my chosen sizes:
Front: I went from a 25.7 to a 25.6 inch diameter, or a difference of -1%.
Rear: I went from a 25.3 to a 25.0 inch diameter, or a difference of -1%.
Overall, the car height aspect is exactly -1% at all 4 corners. This is important, since all the ECU cares about is revs, not traction.

In contrast, note the MASSIVE difference caused by increasing ONLY the rim diameter (note, I am only comparing rear wheels / tires for now):
Going from an 18 to a 19 raises the differential by 5%
Going from a 19 to a 20 raises it another 5%

Overall, even 275/35/19s are 6% LARGER in diameter than the 295/30/18s that I am running!!