markabcls55

I was checking out this thread...

https://mbworld.org/forums/cls55-amg...ast-night.html

I decided to visit the app store and see where my car stands. I realize this is not apples to apples testing, as compared to a true timed race track.

I made several runs over several days on a non-public closed area. I have made 4 or 5 back to back runs...and it doesn't seem to shut the S/C down.

My last and best time was 11.91s @ 125.00 mph with 60' at 2.17 secs 0-60 @3.91 secs 0-100 @ 8.00 secs.

A couple of days before this my best was 12.63s @ 119.65 mph with 60' at 2.35 secs 0-60 @ 4.54 secs 0-100 @ 9.36 secs with ambient of about 15° cooler than above.

Well it's obvious that I'm having trouble getting out of the hole with stock tires, and looking around on this site at stock CLS AMG's the later number look more inline with other 55's.

Could I have a fluke with the iPod software...or perhaps the previous owner did some "work" to the car?

Anyway, I'm starting to get the mod bug and researching my options.

TIA

juicee63

Where are you located?
Car stock would never hit 119 mph. I have been told the application is different then how the 1/4 mile is measured so trap speed is usually not similar to a real drag strip.

Your car stock would have trouble hitting 125 mph in any condition, however a tuned, pullied ECU , headers, cams could certainly could hit 125.

I would suggest doing this again take all of your runs and do an average.
a stock CLS 55 would trap between 111-116.

A modified stage 1 car could do 11.9-12.3 @116-119
A heavily modded car 11.4-11.7 @121-125

Thanks for sharing your results in order to make a true comparison I would need to know what the app is measuring especially at the end of the 1/4 mile

markabcls55

Wichita

T - 78°
H - 69%
BP - 29.78"
DP - 67°
Alt - ~1300'

I'm not saying that the app is gospel, but SOP felt really quick on that run...My assumptions tend to think the previous (lower) number would seem to be closer to reality.

I did not make any corrections to my reported #'s due to DA.

I'll make a few more runs over several days and report back...to the best of my knowledge, completely stock <the dealer tech lead me to believe that as well>

I may hit the local track up, once the "Plains Monsoon" gives up around here and get a real time slip to compare to.

I'm still leery of a GPS/G-force based app...but its very handy.

There are a couple of dyno's here locally, but never used them nor do I know what type/brand they are. Still researching my options on my mod list.

Improviz

.....used to live in Wichita years ago, got out as fast as I could! My condolences on being stuck there.

Seriously, welcome to the forums. I agree w/Juicee, that speed sounds quite high...two questions:

1) did you make sure to run the calibration routine on a very, very level surface before doing the runs?

2) did you wedge it very tightly into a position in which it could not move during the run?

Failing to do either of these could screw up your results, fwiw.

markabcls55

Yeah, it's different.

I work on each coast on a pretty regular basis 3, 4, 6 months, year at a time <including the Gulf coast>
...and always end up back here. Believe me when I say, I've worked in more *'d places than this.
Kind of the nature of the work I do. It pays well.

1) Yes, calibration was done on a smooth level granite surface (wanted to make sure I "tuned it" correctly...w/o the ref you'll read in #2 )

2) Yes, I have a funky rubber protector around it <since I tend to drop it on the concrete on a regular basis> which is extremely sticky and was placed <wedged> in the center cup holder's extended position, top angled to the rear of the vehicle.

I will make some more non-public passes, as soon as we get the "all clear" signal to come out of our basements gotta love this time of the year.

Improviz

Something's odd, then....as Juice said, to trap 125 you're talking some pretty heavy mods. I'd get it to a strip and see how it fares, if it traps in that range then, you'll know for sure.

Definitely remember the weather up there...and hey, at least you guys have basements; down here in TX the soil's got too much clay, so basements are right out. When I was in Wichita, no biggie, when the tornado sirens would sound we were off to the basement...here, you've gotta sweat it out at ground level.

Anyway, I'd either dyno it or run it at a strip, the rwhp/traps will tell the tale. If it's trapping 125, someone put some serious mods into that thing!

Arclight338

I actually have had the app for a few weeks and finally got a chance to try it out with my 09 C63. I didn't do a quarter mile run. Condition were mid 80's at around 750 ft. altitude. The car has new rear P-Zero's.

My phone was just updated with the 4.01 whatever Apple software and the app was updated also as well as calibrated. These are the results of one run. The trans was in the C mode inadvertently. The light lit up GO and I went WOT from a dead stop-no power braking-traction was good-the ESP was ON. I closed the throttle after passing through 60mph or so-and was coasting when the app "beeped" that it captured data-it also stated the car pulled .76g of acceleration.


0-10 MPH: 1.12 sec
0-20 MPH: 1.75 sec
0-30 MPH: 2.37 sec
0-40 MPH: 3.08 sec
0-50 MPH: 3.87 sec
0-60 MPH: 4.77 sec
0-70 MPH: 5.90 sec
Elapsed Time



60': 2.63 sec @ 33.0 MPH
330': 5.97 sec @ 68.9 MPH
1/8 mi: 9.00 sec @ 70.1 MPH

I listed the weight at 4000lbs. The results indicated 363 rear wheel horsepower which given a 20% driveline loss is reasonably close for a cell phone app. The 0-60 time isn't too far off. Its the only run I had a chance to do. Overall,I'm amazed that the phone and app work as well as they do. I have no desire to compare them to real runs on the drag strip.The 60' time wasn't great,but it was an easy launch. The car is dead stock,other than new rear P-zero's with 7100 miles.

juicee63

Looks accurate for the conditions and transmission settings.

Your car @ 60 degrees and 750 ft elevation would be mid to low eights @ 80-83 mph

good info, some of the apps are within a .100 of what is run on the strip on street tires. Comfort mode slowed ya considerably

Arclight338

juicee63,appreciate the info. I'm a sprint car guy and not a drag racer!!Yeah,inadvertently leaving the trans in C mode and trying to manage the iphone in the cupholder slowed me a little-but for $10-I think the app kicks ***.

After replacing the rears with around 4 thou (2800 miles of the 7K were on my winter tire set) I have been trying to heat cycle them over and over-just to see what happens as far as tire life. (Getting it in the middle of February and running the P-zeros wasn't a great idea either....

I am going to scale the car though-I'd really like to see the corner weights and it would be nice to have the exact weight. Plus, I KNOW the last tank of gas was **** quality. All in all, the app is worth buying. I'm glad somebody with real strip experience chimed in.I'm sure a harder launch would have really picked up my 60' time. Its one hell of a car. Appreciate it.!!

juicee63

Unfortunately street tires really do not hold temp well. Best thing is to clean em off with a quick cycle, roll into your start vs. power braking. The wheel spin is not going to help and the best way to launch is to start in d/s with a manual shift down to 1st . After the car indicates it is in 1st gear barely hold the brake , make sure oil temp is between 78-100C. Do not hit the floor until the car is over 2800 rpm then depress fully.

Most pften what hampers this car is a "quick" shift out of 1st usually around5800 rpm, many cars are shiofting out 5800-6300. Try and get the car to rev to 7-7200 from 2nd to 3rd and from 6800 plus out of first.

As you practice the car learns in a similar fashion as the driver. High octane is enjoyed.

Good luck, this app seems really close