c32AMG-DTM

Well, took the C32 to the track tonight on its maiden voyage (both for the car, and for me personally). My best run (ET) was my first run of the night... which was funny, because on my first run especially, I felt like my heart was going to beat right out of my chest. Overall, the track was really busy, so unfortunately I only got 3 runs (was there for about 4 hours). Was told that the DA tonight was about 1100-1400. Temp was in the 70s-80s.

Anyway, here're the times... I'm cringing to even type them:

(60 ft, 1/4 mi E/T, 1/4 mi trap)

1st run: 2.105, 13.495, 103.36
2nd run: 2.572, 14.060, 104.82
3rd run: 2.338, 13.725, 105.46

I'm running the following mods:

LET Stage II (w/181mm pulley), LET HE, CM30 pump, LET phenolic spacers, stock intake w/ K&N panel filters. For the track only, I left my front tire psi alone, but lowered the rear to 26 psi. Tires aren't the greatest for traction... Kumho SPT's (came on the car from dealer); fortunately I'll be upgrading this in the near future.

Approach I took was: "ESP off, downshift to 1, left foot brake, brake-torque up to about 1100 rpms, leave on the last yellow, releasing the brake and rolling quickly into the throttle, letting the tranny upshift at redline." I realize the 60 ft. times are really bad... not sure what I could've done differently...?

The good news was, even with the bad times, I smoked two of the three cars I was matched up against. First, a lightly modded VR6 Jetta on drag radials - super nice guy, he ran a 16.713 @ 85.18 (had trouble with his launch); second, a modded previous-body-style Mustang GT that ran a 14.48 @ 96.99. The last run of the night, I was matched up against a brand new Z06 - which made me laugh. His R/T and 60 ft. were bad, but he still caught me easily... he ran a 12.6 @ 119.58.

I'm leaning towards "subpar, inexperienced driving technique; high temps; hard tires" in that order, for the most likely explanations for my poor times. Any ideas other than "practice, practice, practice"? I'm contemplating going back Sunday morning - they're having a test-and-tune open to the public starting at 8am. Overall I had a blast, and met some really nice people (and got a lot of compliments on the C32)... but I'd really like to improve my times to fully realize the car's potential. I was datalogging the runs, but haven't downloaded it yet.

Stock, my car dyno'd 297/288 @ the wheels - I don't know what it's at currently, however I have a post-mod dyno appointment scheduled for early Sept.

TIA for any tips/tricks/ideas to consider

DarkXerox

Prob could improve your 60' somehow. However even those other cars looked to be going slow, esp the Z06. Kind of strange as your first run would be close to a stock C32.

c32used

Seems especially based off your 60'..that you had alot of initial spinning..keep learning to launch your beast you should be easily in the high 12s...I did a personal best in May drag day and on the same Kumho SPTs which was 13.19 at 108ish but 13.29 at 105ish when stock...These cars modded are ALOT harder to launch..practice makes perfect...hopefully this next weekend at the US41 Drag meet I can break into the 12s...which I feel the my car can do but its driver has to launch better

practice practice practice

(I also ran Nitto 555R DRs and really couldn't best my Street tires either)

c32AMG-DTM

Thanks for the tip!

I was back at it this morning - ran a best 13.20 @ 105.7. 60' was 2.11 on that run. I did manage a 1.97 60' on one run, but it actually was a couple ticks slower (13.24 @ 104.6). It was about 85 degrees and the humidity's been climbing the last couple days... so I think 12's might be achieveable once some cooler weather gets here.

Your 107 trap is strong - I haven't managed a 106 yet. Good luck at the US41 drag meet! Wish I lived closer... would've signed up in a heartbeat.

loungn14

Looks like high temps and a little wheel spinning did you in.

Did you tune it? If not there is where your also missing some of the high end.

c32AMG-DTM

Yeah, those reasons, plus an inexperienced driver... but working on it...

And yep, tuned specifically for the mods by the one and only Mr. AMG Jerry of LET

splinter

So, you improved from 13.49 to 13.20 during the course of a hot August weekend?

That’s more than two car lengths at the finish line. Well done!

kindafast

Niice improvement!
I think you had problems hooking up your first night.

loungn14

Ah the Jerry Tune....

Run it again in november and you will get better results...

I had Jerry run it the first time we had it dialed in and he ran a 12.5....I got in the car and got a wonderful 13.3 the next pass...

Gotta feather that throttle...

SRTpowa

If you want the best out of your 1/4 mile times I highly suggest you pick up a set of Hoosier drag radials. I have aftermarket 19's and traction is a problem. When I put my Hoosiers on, problem solved. Since I bought them I have pretty much left them on the car(not my daily). They ride good on the street and I have even got caught in some heavy rain(crawled home at 35mph).
I also finally figured out how to launch this beast the other night at the track.
I stall the car up, with my left foot on the brake, until I can feel it lurching forward trying to push through the beams. When it's time to go a very quick and crisp stomp on the gas pedal while simultaneously lifting off the brake. It's gotta be one smooth motion and it feels good once you have it down. Without some sticky tires it might not work .

M_M

I think the major cause would be the traction. after the mods, your tires can't really handle such a massive tq., hence power loss. my car is even slower from 0-60mph than when it was stock, since I can't manage to get rid of the wheel spin.

by the way, I don't see there would be a problem launching a AUTOMATIC car.

c32used

Is the Hoosier DRs a certain name or just as you stated and a rough price please...also do you think they will fit a 17" application?

c32AMG-DTM

Since I don't know how to do the fancy "quote multiple posts from different authors in the same reply" I'll just do it this way:

splinter - thanks!

kindafast - yes, definitely... Sunday was better in that regard. Still room for improvement though IMHO... I'll keep working at it.

loungn14 - gotta feather the throttle indeed... still think I'm probably going WOT too quickly. What was your 60' on your 13.3 run, do you recall? What's your personal best E/T and mph, and what variation do you typically see through the course of a normal track event?

SRTpowa - thanks for the advice. Do you know if the SRT-6 shares the same bolt pattern and wheel offset as the C32? My guess is that it might not... either way, can you share the wheel size and tire size that you're running? I've thought about doing the same as C32used, and buying the 245/45-17 Nitto 555 DR's to have mounted on the factory 17 x 8.5 rear wheel. Online reviews I've read say it's better than a street tire at hooking up, but doesn't wear out as fast as M/T's or Hoosier.

Thanks for all the tips and kind words guys, I appreciate it. Will keep you posted as I get more runs under my belt...

c32used

I wanted to know the size since after talking to Discount tires rep said I can't fit it in my C32 like I do the Nitto 555Rs...even Discount tires said that Nitto didn't make a tire that fit...but after research I got them to give me the Ebay pricing they had for 2 555Rs they had listed thru Ebay...if you need the size just let me know I will look for you here.

The 555Rs definitely felt as though they gripped alot better then my Kumho or former Dunlops which I still have but I think its better launching that will yield the best results...GL

loungn14

Keep playing with the launch...you should only have slight spin if doing it correctly. Keep in mind that last track day I beat a M5 as he was spinning half way down the track.

I believe my 60 was 2.16 at the 13.3. My personal best was 12.4 at 109 ish...

I can easily see a 1 second variation on hot days after a couple of runs...the high temps really kill the top end...

Gotta remember to bring the bag of ice and put it on the supercharger between runs...

c32used

The size I have Nitto 555R DRs is 245/45/R17 I was told by Discount tire Hoosier DR 275/40/R17 will fit on my OEM rim

Any thoughts?

c32used

Uses Hoosiers DR 255/50/16

loungn14

I know this all to well.......

SRTpowa

I think our bolt patterns are the same 5x112, but my factory offset is a 20mm on a 19x9. My Hoosiers are 275/40/17 mounted on a 17x9 40mm Voxx Missano wheel(discontinued). The offset is not ideal and makes the wheel look a little sunk in the fenderwell, but it works. $200 per tire from summitracing.
The hoosiers are a lot lighter than most radials. They make a 255/50/16 as well.
http://www.hoosiertire.com/specdrag....0Drag%20Radial

c32AMG-DTM

Yeah, I figured the 245/45-17 was the closest fitment. Stock is a 245/40-17, so in theory the 245/45's sidewall is a little too tall... but since you run DR's at much lower psi (at least, at the track) it might be roughly equivalent to a street 245/40.

Fitting the 275/40-17 would be iffy at best, I'd think. Even if it was possible to mount it up on an 8.5" rim width (which I'm not sure of), I would think you could easily run into fender-rubbing issues/headaches. I'd say stick with 265 or skinnier, and if you need more traction switch to a stickier brand (e.g. Hoosiers or M/T's) - obviously, I'm really new to this, but logically that's what I'd do at least. If someone has fit a 275/40-17 to their C32 without any bodywork, I'd like nothing more than to be wrong about this...

mustang281man

ohlord

16's in a street compound.That is if you like your 722.6 transmission
They hate hard launches and really hate them with soft compound drag radials.
Change your trans fluid and filter.MB spec fluid only.Add a high capacity trans cooler,in place of the stock unit. modified valve body and a 2100 stall converter,stage shallow and You could knock off 7/10ths with some practice.
Without the transmission mods and hard launches trying to drop your 60ft times,I don't see a long and happy future for your 722.6 5 speed.

c32AMG-DTM

A guy at the track gave me similiar advice about the tranny - he commented that the valve body houses a spring, that from the factory is pretty soft in most automatics. He said you can switch to a stiffer spring (or, if you're really hardcore, a solid block of metal) which will result in quicker shifting... at the expense of slightly harder shifting. He commented that he's seen IS300's drop almost half a second off their E/T by doing so.

Has anyone persued this mod on the C32/SLK32/SRT-6? If so, what was the cost, and how well was it received?

c32AMG-DTM

Hey mustang281man - what rim width are you running your Hoosiers on? The only 16" wheels I've seen are 16x7 or occasionally 16x7.5 without going with a custom wheel - that sounds too narrow for a 255 tire... is it?

mustang281man

they are a 16" S class wheel. they fit ok. they do the job.