Finally got back to RENNtech today to have them dyno my RENNtech stage 2 C63 AMG. They were even nice enough to flash it back to stock for baseline dyno numbers and then reflash it again to the stage 2 ecu flash. The temp was ~ 92 degrees F / ~ 68% R.H. and they had 1 large fan blowing toward the engine. Anyway, here are the numbers ...

C63 AMG Stock baseline: 366.82WHP / 353.83 lb.-ft. RWTQ

C63 AMG RENNtech stage 2 ecu flash: 411.82WHP (+45WHP) / 368.29 lb.-ft. RWTQ (+14.46 lb.-ft. RWTQ)

Assuming 20% drivetrain loss, then it would mean:

C63 AMG Stock baseline: 459HP / 442 lb.-ft. RWTQ (fairly close to MB's advertised 451HP / 443 lb.-ft. TQ )

C63 AMG RENNtech stage 2 ecu flash: 515HP / 460 lb.-ft. RWTQ!!!!!
Although the 'after ecu flash' TQ seems a bit low, the HP # is exactly what I had expected; I'm very happy with the RENNtech ecu flash tune...great job, RENNtech!!!

 

great stuff, now go get us some 1/4 mile times so we can see what it does.

 

Good numbers. You were in 5th great right?

 

No, 4th gear pulls I believe. I'm fairly certain these dynos are done and should be done in 4th gear on these cars.

 

Just curious as to what was RENNtech's explanation regarding the torque number?

You managed to get up to 460 lb.ft. while their claims are 480 lb.ft. following the tune. 20 lb.ft. of torque less is kind of a large discrepancy and does not match their published statement. Did you ask them about this and what did they say?

There site states:

RENNTECH ECU upgrade 2 $3495

511 HP @ 6800 RPM; 480 LB-FT @ 5200 RPM

 

Why is renntech so expensive? My shop had it at 3500$ as well but dont you get Kleeman K1 for around 1500$ Is the result the same (around 510hp) for K1 and Renntech upgr.2?

 

Although I was a bit disappointed about the slightly lower TQ #, I figured the fact that it was ~ 92 degrees F / 65% RH (and b/c they only had 1 large fan blowing on the engine) may have had an impact on the numbers. I suspect on a cooler, drier day, the numbers would be slightly higher (maybe good for another +5 lb-ft RWTQ???), including the TQ. In addition, it appears ppl w/ the Kleemann K1 ecu flash are also getting similar increases in TQ; I believe one Forum member recently posted about his Kleemann K1 and now K2 packages and initially saw an increase of +19 lb-ft RWTQ with his K1 flash...this is only slightly more than my +14.46 lb-ft RWTQ with my RENNtech ecu flash.

It appears that with just an ecu flash, there's a good increase in HP (I saw +45WHP / ~ 515BHP), but a smaller increase in TQ. As we know, most if not all of these ecu flashes (RENNtech, Kleemann, etc.) are flashing the C63's "factory detuned" engine to bring it back up to the specs of the other (6.2L) 63 AMG engines...and if you notice, the other 63 AMGs produce >500HP but <500 lb-ft TQ, so I'd say we're "right there."

 

Update...

So I finally took my C63 AMG to the track and was somewhat satisfied with my best of three runs (especially considering it was my first time at the track with my C63 ). I ran 12.456 sec. @ 115.12mph (with a horrible 2.048 sec. 60ft. and an 1/8th mi. of 8.154 sec. @ 89.15mph). My timeslip is posted on DragTimes.com. I'm guessing with a better launch and 60ft. time, I could probably run ~ 12.1-12.2 sec. @ 116+mph. But for right now, I'll just chalk it up to "driver error."

Now, please understand that I'm replacing my shot set of rear tires this weekend, and that may be one reason why I spun so much at the line and couldn't get a good launch and 60ft. time. The first time, I tried running in Sport mode with traction control fully off, and just spun at the line for what seemed like a several seconds. The second run, I put it in the more familiar Manual Mode (I drive in manual mode all the time, everyday) with traction control set to "sport" mode...this gave me my best ET and trap.

So, considering the last time I ran my car at the track, I was in my PROcede v3 BMW 335i and ran 12.8sec. @ 110mph (with the highest trap speed of 111mph that night), I left the track that evening in my C63 AMG somewhat satisfied as I indeed now drive a much faster, more powerful car than my last one.

A couple days pass, and I receive an e-mail from Bob @ RENNtech. He tells me that he noticed my DragTimes.com timeslip posting, and the guys at RENNtech felt my run was a bit "slow." They asked me to swing by to have them check out my car at no charge, just to make sure everything was in check. How cool is that? I agreed and today, I went to RENNtech to have them check it out. I just can't say enough good stuff about RENNtech!!!

Well, after they ran the diagnostic on my ecu and verified that the RENNtech ecu flash was intact, they put my car on the dyno and did a couple pulls. Well, it turns out that I actually now have more HP/TQ than before...my new numbers are:

417.29RWHP / 381.88 lb-ft RWTQ (~ 521HP / 477 lb-ft TQ)

Stock dyno:

366.80RWHP / 353.83 lb-ft RWTQ

Original post RENNtech ecu flash dyno on 9/17/09:

411.82RWHP / 368.29 lb-ft RWTQ


So, since my "slow" 1/4 mi. track time was caused by almost treadless rear tires and "driver error," here's the question...

Did my RENNtech tuned C63 AMG just gain almost 6RWHP / 14 lb-ft RWTQ on its own over the past few months or did my high-flow secondary cats give me that much more HP/TQ or was it a combination of both?

Either way, it's ok with me as are the guys at RENNtech!!!!!

Here's my re-dyno from today...

 

Very Cool man, ya lower that 60ft, better launch, stickier tires, and good weather and you'll be seeing high 11's trapping 117-118. Awesome numbers btw!

 

91 degrees versus 76. Do your dyno on a 50 degree day and

Track performance is greatly enhanced by cooler air which is why few bother to run during the summer in Florida.

 

True. Maybe I would've dyno'd higher a few months ago if the weather was cooler; it's certainly possible that my high-flow cats didn't provide any gains whatsoever. In fact, the guys @ RENNtech said they felt the car just got more powerful as I drove it the past few months.

I really do feel that on a ~ 55 degree day w/ low humidity, I would probably run close to 12.0 flat @ 117mph with a better launch & 60ft. time. But, as I said before, I was somewhat pleased with my ET & trap the first time running the 1/4 mi. in my C63 AMG...it's really one damn fast car!

 

sflgator - it will get faster with time. I am sure the high flow cats did net you some HP. If you can get some cooler weather you'll run high 11's in the high teens mph!! These cars are a BLAST and very fast!! The N/A nature of these cars LOVE cold air!! Be safe!! Hope to race with you some time.

 

Cool. Thanks. Yeah, I heard you were at PBIR (for your record run...congrats btw ) that previous Wed. night. My buddy was there in his record, black custom Cobb tuned GT-R; he said he was quite impressed by your run. The day I went to PBIR (the following Sat), he ran 10.7 sec. @ 129mph, and it was crazy running next to him, lol!!!! His record is 10.6 sec. @ 132mph...they love him there!