noka

Road and Track (11/04)
0-60 -> 5.0 s
1/4 mi -> 13.5@106.6
Braking from 60 mph -> 135 ft

Motor Trend 11/04
0-60 -> 4.9 s
1/4 mi -> 13.3@107.3
Braking from 60 mph -> 116 ft

0-60 and 1/4 mi times are not so different but what's
with the braking?

Rgds,
Norm

Vomit

R&T used the parking brake

rrf

116

noka

I'm sure we all want to use the lower number.

Rgds,
Norm

AMGhunting

just goes to show how much you can trust this mags

rguy

The answer is that they are all right. Every single stat is a cross-section of the variability in the performance of a vehicle. Variance includes the stickiness/available traction of the road surface, temperature, altitude, how long the car has been running, driver variation, manufacturing tolerances, and about a million other things all can produce wildly different numbers.

To be more specific, the track or road surface was probably poorly prepared for the R and T test and greatly prepared for the Motor Trend test. Again, the fact that they most likely used different cars is significantly affective on changing outcomes.

I hope this explains it. By the way, Car and Driver probably gives the best answers to these questions because they correct for variability in environment. This standardizes their numbers for comparison. Some might argue the validity of their adjustments though. At times, I might be one of them.

noka

I was not able to find the C&D numbers.

Rgds,
Norm

rrf

There are many ways the R&T could have made this error in the braking stats.
But it is either a typo (probably) or a huge testing error (doubtful).

You simply cannot believe 135, whereas 116 is believeable.
Just look at data for other cars, including the C32.

The acceleration data is just variations in the cars/testing.

rguy

C and D got 4.7 sec 0-60 ; 13.3 1/4 @ 108 ; 70-0 in 165 feet. No 60-0 reported.

rrf and all others,

Upon further review......

c55 60-0 135 ; 80-0 232
s4 60-0 143 ; 80-0 256

This is not a car problem anymore. This is either a track surface problem (damp, oily, so hot that the tarmac is fluidic) or crap driving. I would hope it is the former and not the latter, but hey, who knows? Maybe they hot lapped the cars simultaneously and then went and did braking tests causing tremendous fade.

Anyway you slice it. This is not a typo. It is real world data. The environment is not described, but these fine vehicles had nothing to do with these heinous times and distances. Check yourself if you don't trust my data : november 2004 Road and Track.

Hope this quells the mystery. Onward and upward.

BlackC230Coupe

The best i ran was a 13.2 with 19s, over a half a tank of fuel and with spare tire etc... I know this car is capable of breaking into the 12s stock. I am just not the best at launching.

rguy

I believe the car could make 12.9 but that is about it. The tires are very under tractioned for the vehicle. The lack of a LSD and the rear tubbing make launching very challenging, and 60 ft times less than could be acheived.

I would like to see your 60 ft times, because I am curious how much time is to be gained over your 13.2 . I know you can't do apples to apples due to non-linearities, but it could be a rough approximation of how much time we are talking about getting out of the hole with.

P.S. ride is looking killer. what tire sizes are you running? sorry for the ee cummings off topic P.S. message

BlackC230Coupe

Yes, a 12.9 should be possible. I also dont know how much more it can do stock. Here is a copy of the slip. I dont have a scanner, so i just took a pic of it. I am on the right car #5585. Like i said, this was with the 19's, over a half a tank of fuel and spare. I would like to get a better lauch, take the spare out, and have less then 1/4 tank of fuel to see how good it can get. I also will be getting a set of drag radials in the very near future which should help a bit. One day the renntech ECU and airbox along with drag radials should make it capable of a 12.7 atleast.

Thanks alot btw. I am running 235/35/19 front and 265/30/19 rear.

rrf

rguy, I agree that there must be something unusual at work in the R&T braking test, but for the sake of 1 to 1 comparison, that particular 60-0 data should be ignored. It just doesn't compare to anyone else's testing. R&T owes an explanation of why their data is 15% outside of everyone else's if they expect anyone to believe in their testing techniques.

There are 5-6 articles testing C32s at 116 feet or thereabouts [check out the articles on C32life] and a Supertest of a C55 at 120.4 feet from 100km/hr (62mph). Other C55 test data will be nice to have, but 116 looks like an OK number for people to hang their hat on for now.

rguy

I think we are now in violent agreement that something is wrong with the testing of the cars. But before I made you privy to the full test information, your contention was that it was probably a typo. I want to make it clear that I think it is a crap number, and yes, I think they should do a much better job explaining conditions, but they only seem to find that appropriate when doing single car tests rather than comparisons. I find it always appropriate to qualify your numbers or they don't mean much. Particularly, when they do single car tests they describe their launch technique, which is great information because it lends a lot of info about where the torque and power is and how the rest of the drivetrain is setup to use it.

Anyway, I am more than comfortable saying that on a good day with good tires and a good surface, the C55 will produce 116 foot stops. Obviously conditions exist that make the car brake like crap. These, again, may be any conglomeration of crap driver, crap roads, crap tires, or crap weather. In an emergency situation, you should plan on making a 130 foot stop. That way when you actually make a 120 foot stop because it rained that morning you aren't four feet into a car or a barrier. RRF, I know you know this, but some don't, and it is mainly for their benefit that I mention it. Lots of people read these boards without being members. I don't think that people translate specs into a real situation very often and that is why I can't get to the hospital on time in the mornings.

rguy

BlackC230Coupe,

Do you mind starting another thread about dragging and tires, etc. I think there is more to discuss on launch technique and where to go, but I don't want to hijack this worthy thread.

Thanks.