JToups386

I went to Houston Raceway Park yesterday to verify the published numbers on the C55. I was optimistic, as the car feels relatively quick. The results however were very disappointing. Mine is a pig compared to what I assumed it should run!

Car weighed 3920 lbs w/ me in it, (and approx 75 lbs in truck items), etc.
Temps were 72* at start and 67* by end of night.
Barometric pressure was 29 inches. HRP is at sea level.

1st run = 2.22 60', 8.93 @ 82.22 mph 1/8, 13.68 @ 104.01 mph 1/4.
ESC in "off" position, yet it still kicked in enough to kill the run.

2nd run = 2.22 60', 8.94 @ 82.26 mph 1/8, 13.67 @ 104.65 mph 1/4.
ESC in "off" position, yet it still kicked in enough to kill the run.

3rd run = 2.08 60', 8.74 @ 82.58 mph 1/8, 13.47 @ 104.19 mph 1/4.
Put car in Dyno mode, and manually shifted it myself.

The car felt like it was being held back by something. I honestly expected 107+ in the mph. I've gotta' figure this out, as these results do not sit well with me. I realize part of my disappointment stems from going from a mid-11 second daily driver to a mid-13 second driver, but I honestly expected to get much lower results

I remember reading something about bad catalytic converters with a MB recall or TSB on a certain range of the C55's, and I'm wondering if I might have some restrictive clogging there. Anyone know about this?

Eurocharged Rick

Honestly, a stock C32 runs about a 13.3 @ 103...i think that your car is right on par considering the conditions...

jturkel

+1

my stock C32 ran a low 14 with our conditions down here. i think your times are definitely on par!

1Lop2K5C

The C55 stock numbers is around there, 13.2@ 105-106mph avg. But I'm wondering how did you weigh in at 3900lbs, a stock C55 curb weigh is only 3540lbs. Fuel couldn't be that much

Brabus C55

I have seen a few mag C55 trap speeds ... 106 & 108 ... w/ 13.2-ish times ... IIRC. Obviously the best after many attempts. (ps. 108 sounded pretty high... cold day?).

Get rid of the **** in your trunk & pick up nearly a .1 sec (rule 'o thumb 100lbs=.1 in the 1/4 ... but I'm sure you know that). that stuff might have helped w/ weight transfer though.

[ start rant ] The 2.08 60-foot time is a move in the right direction! Since a stock C55 has no f'ing LSD, all that power is going through essentially one wheel (SHAME ON AMG!). [ end rant ]

Anyway numbers seem to make sense @ about 4000 lbs

Have not heard about CAT issues ... yet.

Have fun & be safe

PS what was your 11.5 sec daily?

ProjectC55

I would imagine it's the GN( 467whp Grand National) in his sig.

ProjectC55

Once you start doing the exh wrk and the SW she'll wake right up. Trust me! Your times are pretty normal for an almost stck car with just air filters. Sometimes it can also depend on the track pep and the altitude or DA your running at that day.

c55asleep?

Good numbers, don't bang your head with it. Next time try going to the track with i 1/4 tank of fuel. My C55 with me in it weighs 3780 with 1/4 tank. My weight is 200. Try getting the headers and a custom exhaust and you will lose plenty of pounds there 50 approx. and get some extra hp.

c32used

(and approx 75 lbs in truck items)

Everytime I did drag runs I was on about half tank and car empty besides driver and camera....this approximate 75lbs could of held back the car a little at least enough to lower your trap speeds...

moosejaw

Time to lay off those cuban pastries Rolly

crazeazn

thank god i weigh 150 lbs, that should make a huge difference :lol:

c55asleep?

Maybe if i lose about 50 pounds i can make it into the 11's lol. Btw those pastries are great the ones with guava and cream cheese!!!!!!!

crazeazn

that just sounds yummy

wawy

JToups386,

What condition were your tires in? What brand?

JToups386

Okay, here's a little followup and answers to the questions above.

1. My previous mid-11 sec daily driver was my '99 383 stroker LS1 Z28, which consistently ran 11.50's on Nitto drag radials.

2. The C55 gas tank was 1/2 full, and maybe a hair over.

3. I weigh 187 myself (Thanks to Wendy's Baconator), and I did not empty anything from the trunk as I normally would at the track. The excess weight is estimated 75-100lbs. We did not have a front row secure area and I did not want to lose another toolbox and battery jump starter, 4-way, and various other items as I have had stolen at the track before when not parked up front.

4. My tires on the rear are sadly mismatched at the moment (the way I bought the car). It had a new Goodyear F1 on the driver side, and a BFG g-Force T/A KDW 2 on the passenger side. I have a new F1 I'm going to put on it to match the other, per it being the newest of the two, but I'm waiting to get another rear wheel refinished this week first. The previous owner apparently did a lot of curb scraping, so I acquired two additional wheels and have been alternating getting everything restored to new condition. Then the other F1 will go on the rear.

I fully realize 100 lbs is worth approximately .10 in the 1/4, and if I had the ability to secure my stuff I would've tried shedding some weight. However, I don't think it accounts for nearly 3mph difference, based on the advertised 13.2 @ 107.3 for the C55. Also, per anything GM I've ever owned, I always run better than the advertised numbers which tend to be conservative. My bone stock LS1 Z28 was advertised at 13.6 @ 104. My first pass in it was a 13.35 @ 105, and then by removing the air filter it went 13.15 @ 105.5, which was impressive. I guess I had the same hopes for the C55, in that it would run as well, or better than the advertised numbers.

All in all, I'm okay with it I suppose, based on all things considered. I just have to re-adjust to not being one of the faster vehicles on the street anymore...

Thanks for the encouragement and input!

MB_Forever

I agree with the others that those times are not too bad. What was the other conditions of the track: track prep, humidity, DA?

When I ran my C32 at a DA of 3100 ft, I was never able to get any lower than 13.9, but then when I ran it again at a DA of 1300 ft, I managed 13.4 second passes.

JToups386

Houston Raceway Park is rated as one of the fastest tracks in the country, and usually is where many of the NHRA records are broken each year. It's at sea level, about 20 miles from the coast.
The humidity was not bad, approximately 30-40% compared to Houston's usual 90+%. Barometric was 29".

I did forget to mention we had a 7mph angled headwind most of the evening, which certainly played a slight role in the mph loss.

Fifth Ring

It's not your car. I think it's the track. This is the kind of track where a C55 belongs:

http://www.youtube.com/watch?v=Gxv8_6H6r5M

Schiznick

While some of your comments infer that you have a bit of drag racing experience, why are you so shocked at your results?

Every trip to the track is going to produce slightly different results. I have run my fastest trap speeds with higher et's in my SL65.

My quickets et runs have been 3 to 4 mph slower than my quickest trap speeds.

60' foot times are really where it is at from my perspective and that is all tecnique and track prep.

Your car looks to be running on par with where it should be. As for outperforming the numbers, who's numbers are you trying to match?

If you are trying to match magazines......

I have never seen AMG quote a 1/4 mile time or speed only 0-60.

Schiz

cldriver

Those numbers are about right, I ran a stock best of 13.3 at 104/105 (don't remember exact, gotta dig up the slip).

Looking to go back in spring and check out how she does with new mods(lsd, headers, ecu).

///AMG4EVER

JToups386 - next time you go to the track, let me know. I wanted to go Sunday but I was too lazy to go by myself.

I guess I know what you mean with your results, however, it looks like you didn't prep the car properly to squeeze out the best time. I'm not an expert by any means but come on - two different tires? 75 extra lbs? What's up with that!?

I think you can do better if you watch out for the details. I'll do an oil change and clean my filters at least.

Brabus C55

Had a 95 T/A droptop (bolt ons + Koni DA's + lots of Global West goodies +275's) ... fun to suprise many more "sophisticated" cars @ autox's & road courses ... being in CA, a built 383 wasn't an option due to CA smog *****.

Possibly look into a Quaife LSD to get some power down & possibly wider rears... I've got 265's out back on 19's.

JToups386

Yes, yes, yes, I'm quite aware of "the details". I've been an avid drag racer since 1991, and back in the day of Westheimer gatherings, I had quite a bit of "street cred" per my countless nights of street racing, before the ricer crowd killed it for everybody. I've also spent countless time at the track, with many event wins. So, I fully acknowledge the problem w/ the extra weight in the trunk, but as I stated previously --- I wasn't willing to allow some schmuck to walk off w/ my tools and stuff, per us not having a secure pit area this time.
Now, regarding the mismatched rear tires, that's irrelavent since I was able to get a 2.0 60' out of them. You really cannot expect much better than that from any radial tire aside from a drag radial, which these are not. The lousy 2.22 60' times I had on my first two runs were per allowing the car to think for itself and engage the ESC even with it being in the "off" position. Once I switched it to "dyno mode", and manually shifted it myself, the 60' time dropped by 2 tenths, which typically would equate to a drop of 3 tenths in overall 1/4 times, but this time it only worked out to an even .20 drop for whatever reason.

As for trying to match a magazine time, well, "yes" I had hoped to at least get close to the Motor Trend published times. My past dealings w/ magazine times is that I've always matched or beaten them in various GM vehicles I've owned, ie my Grand National(s), and my Z28. I've grown accustomed to having vehicles that were underrated by the OE MFR, as opposed to ones that appear to be accurately stated, ie my C55.

I'm not complaining about it. I was just a little disappointed because I tend to over achieve w/ track results, and this time I did not. However, it simply gives me something to shoot for by making some improvements, as well as taking care of the givens such as weight. Next time I'll get to the track in time to claim an upfront secure pit spot, therefore emptying all "dead weight" out of the trunk.

I'll also probably put some fresh plugs in it, as I don't like having 53k miles on any set of plugs, regardless of what the factory says they're good for. Personally, I'll take a good copper plug over any "long lasting" platinum plug any day, as I know a copper plug has a better burn rate overall, but it simply won't have it for as long of a timeframe, ie 100k miles. And I'll also change my oil before the next track trip, as I don't agree w/ MB's once a year plan, or 10k+ mile plan for oil changes.

So, to summarize, I agree I had some "rookie mistakes" per the weight issues, but I still expected a little more. Maybe I've just grown a bit greedy as time has gone on, and come to expect more, with less... Either way it's nothing we can't overcome in the future, and I look forward to posting some better times thereof.

c32used

I seen it mentioned in several threads but me being a newbie at drag racing I am lost...why does everyone put so much stock in the 60'? I always thought if you take off right with no spin its the best all around.

mdncn2762

http://www.rbracing-rsr.com/nhraxtreesp.html

Racing Tree