I'm going to the track, these are my mods right now:

185 pulley, code-3 style intake + K&N's, Johnson pump. I'm also on 19" wheels with 275's on back.


Guess what my ET and trap(MPH) will be.



Also, guess what they will be after I get an ECU tune and regap plugs to .034"

How large of a difference to expect at the track with a tune?

I will assume by your post count this will be the first track experience.

13.1 with traction issues

After tune and practice

12.8-12.9

I used to drag race on weekends in various cars, fastest being 10.40s, slowest low 13's. I've probably made somewhere around 100 passes.

You don't think running lean with the 185 and NO ECU tune will effect the ET much?

You must be running too lean, it is not safe for ur engine (pistons). Get a tune.
It is not a guess to see difference of a car with 185 pulley and without a tune.

+1

So you're going to run '***** to the wall' on the dragstrip with a 185 pulley + air intake........but without a tune??

You're a brave man! Be safe and have fun!

I agree, I say don't do it until you get your tune. It runs way too lean with the 185 without a tune.

How did you get 275s on the back of your car?!
Get the tune first. Not worth blowin her up just as you cross the 1/4. Even if you didn't not worth the risk.
With the tune and good traction I will say 12.8 (depending on your location, elevation, temps, etc.)

+1.....i would also recommend getting a Heat Exchanger or your car will get very very hot and heat soaked quickly

+1

Guys:

Just a few words:
1. YES he needs a tune to be safe, even though our electronics do a DARN fine job of compensating, aka I road raced with a pulley and NO TUNE. And yes I checked the plugs and A/F ratio

2. Heat soak is really a matter of timing. What I mean is that even with a STOCK H/E the 1/4 mile will do VERY little to hurt you, as the temperature will STILL spike no matter WHAT size H/E you have. The ONLY thing a large H/E does is to allow you to RECOVER quicker. It is the the SOLE responsibiltiy of the INTERCOOLER to prevent the spikes with its surface area. PERIOD. If and I do say IF our intercooler is TOO small, regradless of whatever H/E you use, the ECU will still pull timing due to the the increase in IAT's. YES a larger HE will help INTIALLY with the temps, but if the intercooler is TOO small, regaurdless of the size HE, you will have the ECU pull timing. This is the problem that the W211 guys are having by the way.

I ran the code3 HE with NO problems during a 20 minute session with a LARGE pulley and the STOCK intercooler.

All in all, what I am trying to say is that Heat soak is LARGLY over rated on our C32's. If you don't road race, I HIGHLY doubt you have EVER experienced it, IMHO. I know some of you guys DO drive hard, and have propably hit the limits. But a single 1/4 pass?

See yeah

PS: Sorry for the rant

Thanks for all of the replys! Can we throw around TRAP SPEEDS instead of ETs though? They're a much less volatile indicator of how fast your car is.

For the ECU, Vadim states the stock ECU is more than flexible enough to compensate for the pulley. Jerry also confirms that he advances the base timing tables upon which the timing maps are built. 240SRT has dumped loads of fuel into the injectors(to the point it should have flooded the engine) and not corrected the "lean" condition. It's probably because the MAP sensor is maxed out. An adjustable fuel pressure regulator is more than likely a sound investment and probably a mandatory mod a couple years from now as we learn about the cars.

MRAMG reconfirms my viewpoint on the heat exchanger which with proper cooldown before the run shouldn't make a difference at the dragstrip. Highway pull? Yeah, you'd better have an upgraded HE.


My biggest concern is cutting a good 60' time. I don't have sticky tires and I've got 19" wheels which both work against me BIGtime at the dragstrip. Anyone want to swap their stock AMGs for some black 19"'s with a polished lip? Also, you can fit 275s in the rear with the correct wheel offset.



Has there ever been a reported case of a C32 AMG "blowing up"(headgasket, piston, seal, etc) from running lean and detonating? We don't even know the potential of the internals(which are forged) yet. It's definitely upwards of 450rwhp. I understand thats no excuse for doing it, but I'm just saying.




Lets keep them coming! I'm particularly interested in hearing about trap speeds(MPH) with the 185...

Traps speed are various I believe highest I seen was 113/114mph I believe. But without Tune its hard to say...The current fastest C32 time is loungn14s 12.3 but on 19s and with Tune among other things. He did a 12.4 on just Tune and 185 Either way GL

All I can tell you is that when I pushed my 185 without the proper tune, I threw some missfire codes and once went into limp mode.

I do NOT want to do that again.

I have since been re-tuned, but am still running lean in high RPM's in 3rd gear and getting some sputtering.
I'm waiting to get properly dyno tuned when LET comes to the Bay Area in the middle of May.

I have one in my shop right now getting new internals, boring, and new pistons for that very reason....

Hi guys
After tune what is your A/F ratio with 185mm pulley at the end of the 4th gear?

Yeah they been nuked before...

Yikes... don't recall any "my car blew up" threads - what was the story on that one?!?

pretty much don't run the car hard before she has warmed up. The owner is on the forums, but hasn't posted about it.