V8 forever

Last time I lost the race by 1 meter / 3 feet

Reason was the bad traction at launch.

Dumb question : Did anybody ever try to add some ballast into the spare-tire opening ?

I have some weights on hand, they would fit perfectly.
2 pcs. of 20 kg (appr.44 lbs each)
1 pc. of 10 kg (appr.22 lbs)

Is it worth a try ?

Stefan

Improviz

You can probably get a 255/40-17 on the stock rims, which will help. Or, you can upsize to 18" rims and throw a 265/35-18 on there. I recently did the latter, adding a set of 18x9" E55 rims on the rear and 265/35-18 on them. There is a marked improvement in traction, I have had no rubbing issues.

I got the idea of sticking with the front 17's and adding 18's in the rear from Corvettes, which are set up this way from the factory. With the rear wheelwells on the CLK55 being slightly larger than the fronts, it actually balances out quite nicely, and you are also spared the higher impact jolts you'd have with 18's all the way around.

It works great. I haven't gone to the strip yet, but based upon GTECH runs, I've been able to pick up 0.1 to 0.2 in my 60' times, which translates to 0.2 to 0.4 in the 1/4 mile, roughly ten to twenty meters in a race, more than enough for you to close the 3m gap! I am actually able to brake-torque the car now with the traction control off, which I could never do with the stock setup. I have actually gotten launches as high as 1,500 rpm without severe wheelspin. With stock setup, even at 800 rpm tires would often meltdown.

V8 forever

Improviz,

thank You for sharing Your knowledge.

Meanwhile I have tried the ballast method by putting 50 kg/110 lbs into the spare tire opening.

Went to the track and got 13.8 and 13.9 instead of 14.1 and 14.2 times without the weight in last September.

It was the same track, no changes at the car, may be less tire inflation, air temperature also not much different.

I ,and some other guys too, were surprised about the outcome.

I`ll think over what to do with wheels and tires.

Your combination of wheels and tires never would be O.K. here (illegal), but let me know Your track times, please.

Regards

Stefan

Improviz

Hello -

My best track time with the stock rubber was a 13.4@106, which was obtained simply by flooring the throttle from a dead stop with the traction control off. I could not apply throttle w/brake on before starting (brake-torquing), as this would result in severe wheelspin, even with 800 rpms.

I have not taken the car to the track (yet) since getting the new setup, but I have perfomed some GTECH runs. I did five 0-60 runs, all of which were remarkably consistent, around 4.9x seconds in 80 degree (F) weather. This was with extremely careful mounting, centering, and leveling of the GTECH before each run. These times are about 0.2 seconds faster than the best I ever got with the stock rubber, so I anticipate a 13.2, possibly a 13.1, on my next track outing, entirely due to the lower 60' times made possible by the larger tires.

It is illegal to have 17's front/18's rear where you are? Interesting...here in the US, Corvettes come stock with this setup, which is where I got the idea. Given that the stock 17" fronts/rears are different widths/offsets anyway, which makes rotation impossible, I'm at a loss to see why they would outlaw such a setup. Anyway, I stuck with the 17's up front to minimize degredation in ride quality, which worked very well.

In any case, you could also put 18's all the way around if that's what it takes!

V8 forever

13.4 - Impressive time

Here, wheel and tire dimensions are part of the registration.
If you make changes without the permission of our technical surveillance institution called "TÜV", You drive an illegal vehicle.
This can cause severe problems with the insurance in case of an accident, or even at an road control.

There are several ways to get the permission of the "TÜV", the normal way for the individual is, to show an approval from the manufacturer (here Daimler/Chrysler or AMG).

Daimler/Chrysler/AMG does not approve 17 s front/18 s rear.

I am not happy with the factory setup for the track, on the other side, I would like to keep the stock look...

Compromise would be to put 255 s in the rear, stock wheels.
I`ll try to get the approval for.

Stefan

bverotti

Where in Germany is there a 1/4 mile track ?

Thx.

V8 forever

The event was held at BITBURG airfield

The event was organized by 1on1 Motorsports, next will be in June, look at

http://www.1on1-motorsports.de/events.htm

There are some others occasionally too, in Hockenheim and Luckau, but I never was there.

Stefan

bodyart27@aol

.... and a lot of 13.7s

no traction control, no spare tire, just a hint of power braking (easy to spin the tires) and easy on the throttle off the line

pocholin

I've done a lot of testing at the track about tracktion, everytime I power brake to bring rpm up I spin, even if I try 1000 rpm, here is my best advise, and look at my time, as stock car it ran 13.300 a couple of times, so it works:

power brake to ~800 rpm max, have your rear tires at around 27 lbs, no spare tire, 1/2 tank of gas or less.
If you still spin then do not power brake at all.

V8 forever

Improviz wrote
I called AMG whether I could have an approval from them to put the 255/40-17 on the stock rims.

I was told that the resulting different outer diameter would bring the ESP out of calibration, so no approval.

I´ll try power braking next.

Thank You for Your input !

Stefan

Improviz

You might be able to manage it if you've got a very sticky track surface, but with the stock tires I was normally unable to get the car to launch without massive wheelspin when powerbraked, even below 1,000 rpm!

So they're claiming that larger wheels throw the ESP out of calibration? Do you have contact info for them? I'd like to get in touch and see if there is a potential danger here, because I really don't want to give up the added traction I've gained!

I really can't believe that they put such narrow tires on a car with this much torque. It is quite honestly laughable. Even Camaros and Trans Ams with less torque come with 275's standard!

V8 forever

I have called

Mercedes-AMG GmbH
Daimlerstrasse 1

D 71563 Affalterbach

Phone No 07144 302 0
From the US ..... 49 7144 302 0

and asked for the technical support regarding tires

As I understood, the problem is the outer diameter change of the tires at one of the axles.

Regarding the poor traction in first gear, I knew about from first tests in magazines in 1999 and from test driving myself before I bought the car.

I bought it mainly because of its potential at the Autobahn.
Driving at even highest speed is nothing less than perfect, maybe because of the stock tire-setup ?

Not that I always drive full speed, but being in a well respected position in the picking order makes driving much pleasurable over here.

I go to track just for fun, try to improve the time a little without modfying too much and loosing the stock appearance.

Stefan

V8 forever

Here is my best 1/4 mile result until now.

Drove against 2002 Camaro LS 1 American Spec ,stock

My result is 13.920 at about 1150 feet altitude.

My question is : Did You ever race such an Camaro,if yes,with which result ?
As I have read, Camaros should be able to do 13.6-13.8 s.

Stefan

Improviz

...the 1150 ft. altitude is robbing you of some power (magazines normally correct to sea level). Here is a page with altitude correction factors:
NHRA Altitude Correction Factors

So, your corrected time using 1200' figures (close enough!) would be 13.74@104.54 . Judging by your 60' time, there is some room for improvement, a tenth or two anyway, on the stock tires. Are you turning the traction control off? What launch technique are you using?

His comes out to 13.89@103.12. So, his time is not bad for a stock LS-1.

Stock to stock, the CLK55 should handle an LS-1 Z28 without any problems, but it is very easy to pick up some serious hp on that motor with mods, and lots are available. Modded, I've seen them run hi 11's and better.

burat

I doubt it will have poblems with the ESP.

E55AMG99

Lower your tire pressure to 25-27 PSI. Best times on my E55 were obtained with lower pressures. Just remember to pump them back up for the ride home.

Improviz

Mine has trouble with the ESP, even with the 265's! It isn't *nearly* as bad as w/ the 245's, but I still have to be careful, or up in smoke they go (ESP off). If I leave ESP on and try to get out of the hole quickly, I still have ESP throttling things back pretty severely.

burat

2 weeks after doing the 18/17 setup and put 1500 miles on it, I was on a stop light early Sunday morning. I pressed the brakes while reving up to 2000 RPM then let go of the brakes while putting the gas pedal all the way down. The car's ESP went on flashing for a moment and catapulted the car better than when it had the 17's. Before it would sway the car from my left side. This time I can feel that it had more grip. So I think the ESP's intrusion is the same as it was before.

02 Black/Opal CLK55

V8 forever

I tried several times with TC off, always was about o.1 sec slower.
The same with power braking at 1000 RPM.

So, I am quite satisfied with the outcome, because I lost some times against a GERMAN SPEC Camaro in the first races last year.
The driver was new to drag races too.

These cars have 285 hp instead of 305 hp American spec.

With the CLK you seem to need some more experience than a Camaro driver to achieve reasonable times, despite the traction gimmicks on our cars.
Not to forget better tires than the stock ones.

These facts were quite surprising for me, solving the problem was fun and entertainment on the other hand

Stefan

pocholin

V8 forever, how much is a Camaro worth in Germany?

V8 forever

In early 2000, when someone offered me a used 99 model Z 28 with leather and T-tops, I checked at some dealers. Best offer was 48 000 DM for a brand new one.

At that time about 23 000 Dollars if remembering correct.

I do not have the prices for the used ones nowadays.

Stefan

pocholin

That's not that bad for that time.

Improviz

Get a set of drag radials! If your time decreases w/traction control off, sounds like you've still got a spin issue. Do they sell drag radials in Germany? If so, those should help you get more traction off the line and improve your times. Good luck, and keep up the good work!

Improviz

With mine, it really dials back the power severely, almost feels like I took my foot off the gas. Without it on, I can still fry 'em if I'm not careful.

I know that bodyart27 was getting times about 0.2-0.3 slower with it on than with it off when he took it to the strip, fwiw.

V8 forever

Drag radials are sold here.

Not so with my car. I just recognize it by the better ET,s.

Seems, the TC is working different on our cars.

Mine is an early 2000.

One more race in October, after that I`d better ship the car to Jacksonville and have some runs in South Florida

Stefan