A-Train

The car was bone stock, including MB-recommended tire pressures. Dyno mode was never used nor were burnouts. Temp was 80 degrees, humidity at 55-60%, sunny skies. Each time slip has 3 different dates printed but the actual date was 13 July 2005.

First pass of the day was my best for ET and for trap speed: 11.947 at 119.08. Time slip for that pass is attached. My reaction time left a lot of room for improvement, however.

The next two passes (these first three were the best ones) were 11.952 at 118.95 with a reaction time of .642 (.500 is perfect) and 11.979 at 117.26 with a reaction time of .653. These first 3 passes were all in fully automatic shifting mode with traction control on. The 3 passes were videotaped by a spectator with my camera. I can edit and then post video clips later.

I did a total of 9 passes. The latter 6 were traction control off and/or steering wheel button shifting. Those 6 never matched my first three runs in ET or MPH.

All runs were single lane passes. That is the format for these “test and tune” sessions at New England Dragway in Epping, NH. (The staff there was excellent, by the way.)

Thank you,
A-Train

Bux

stock 11's, very nice!

AMG2GO

Awesome times. That NH crowd must have been thinking "what the hell".... where are you at? I may take a run there before and after my renntech upgrades, it would be nice to go with someone else with a CL.

x-tian-230k

A-train,

Do you drive on 93 north bound at all... I was driving to work one morning, it might have been monday or something and i am cruising along and i see a CL come cruising but going towards NH. I look over and its the V12 Biturbo sign on it.... it was sooo HOT.... is that you?

MikaelSS

Cool.


When i go with my E55 people go nuts, i bet they were all over you.

CE750

I drove my Bro-in-laws CL55 to the dealer and picked up his CL65 for him last month. Needless to say, the CL55 was a rocket, as fast as I would ever want. The CL65 was, well... it was wrong... just wrong... there should not be a car with that much power to the wheels in the hands of anyone. with ESP off, the thing just sits in the same spot eating up rubber...

RennTechV12

We run our turbo benzes and Porsches at the dragstrip often. It usually works out that your 1st run is your best because that is when your turbo intake temp is the coolest and therefore creates the most power. As you take more runs your intake temp increases and starts to rob your car of HP.

I find it best to run your car with; ESP off, Trans in D (in S mode) the car's trans computer can shift much more efficiently than you can, ABC off, do a small burnout (in front of the water, not in it), brake torque the car to about 1400-1900rpm before launch (this allows the turbos to be already spooling when you leave the line). I also use 100 octane unleaded race fuel on race day, the higher octane makes your forced induction (turbo/supercharged) motor run much more efficiently. I have noticed as much as .4 sec difference with 100 octane.

Let me know about your results when you use these methods, you won't be dissapointed.

I am taking both 600s to the track tonite, I'll post my results later.

AMG2GO

Good info man, thanks. What kind of exhaust is that on the SL in your sig?

RennTechV12

It's Eisenmann

I love it! It makes the SL sound like an exotic.

AMG2GO

Its not loud during cruising? I was going to get one, I have a CL600, I really like how quiet the car is, so I didn't want something obnoxious. If its loud at throttle its OK, but I don't want any drone while I am cruising. They also have the dual 83mm round and dual oval, I am trying to decide, did you look at the dual ovals?

A-Train

I’m out of Boston. Really, I was just another car, in terms of how everyone interacted. From the handful of people I spoke with, they didn’t really know what the CL65 was, anyway. Everyone was friendly. These Wednesday afternoon “Test and Tune” sessions are limited to 30 cars. It is on a first-come, first-serve basis if you do not call to reserve a space beforehand. They also charge a healthy premium versus the Wednesday and Friday night “Street Nights” which is for street-tired cars only, no open exhausts, 2 cars at a time, and no limit on the number of cars. Test and Tune is primarily just track staff, drivers, and drivers’ crews; virtually no spectators. I was the slowest car there, no kidding. And I was 1 of just 2 cars on street tires; both of us also were the only ones not coming on a trailer hitch or transport container. Most guys did 4-6 runs over the 4 hour session. After each run, most drivers would let their cars cool down and pull out their tool sets to work on the car. It’s a different crowd than Street Nights, which also brings hundreds of spectators.

No, wasn’t me.

Yes, it was pretty apparent the heat was beginning to take its toll on the car. Next time I run, I am going to experiment more with ESP and look into running 100 octane. They sell it there. I was brake-torqueing to about 1500 rpm except on my first (and best) pass, which I did with a simply left foot on the brake and right foot resting on the accelerator pedal and ready to hit it at the same time my left foot came off the brake. I might also bring wrapped ice packs to cool down the engine bay between runs. I actually had them with me for the runs above but didn’t use them.

Let us know how your runs go...

------------------

Thanks, everyone.
- A-Train

davepl

You should be able to get an 11.7 out of it with a pair of Nitto drag radials, ESP disabled (dyno mode) and a good waterbox burnout. At least I was able to get an 11.8 out of my CL600 that way.

I found I lost MPH over the evening even though the air cooled down. Definately a heat soak issue on the turbo cars.

Tempted to throw some dry ice into the air-water intercooler tank, but didn't want to crack something either :-)

Thanks for taking your CL to the track! I've been on here probably 3 years and its the second CL timeslip I've seen!

SLK55_AMG

not bad for a cl 65 , imagine if it was very light , it will get less...

the prob. with cl that they just dont corner well...

just waiting for my 997 GT3 ...

medici78

Gee, thanks for pointing the obvious, genius!!!!
In case you didn't notice, the thread is about drag strip results.

WayneE

If your car is tuned to deliver maximum boost and ignition timing with 93 octane (or whatever pump gas is used in your area/tuner), you will not see any difference with anything higher. The car doesn't know what's in the tank, it just reacts to knock events if it's lower than what is required.

If you have a race gas tune, it can make a HUGE difference.

vraa

Well, if you put in 100 versus 93, the ECU will advance the timing (I think that's the right term) for the better gas, giving you a tad bit more power.

AMG2GO

Ricky I think WayneE might be right on this one. The knock sensors will retard ignition to save the engine but I don't think the ECU will advance the ignition any further unless it is programmed to do so.

vraa

Ah I gotcha, I was always under the impression that putting something like 100 or higher, the ECU would adjust to the change.

Well, I guess it's time to call RENNtech then!

AMG2GO

Retardation is not a smooth thing. There are constant spikes... there is the map, a knock, and a retardation.... the ECU then goes back to its map, another knock, another retardation. It's the engine limping.

For this same reason, advancement would never be smooth. It is too hard to do... and impossible to evaluate the gas. The map is what the engine does. If it wasn't, these tuner mods would produce no effect. However most tuner mods are also optimized maps for pump gas with almost no room for error. The engine is definitely more suceptible should anything go wrong.

Putting in 100 octane should do little if anything at all, if the ECU is not mapped for it. I think RenntechV12's better times are a result of the fact that the higher octane produces a slightly cleaner burn and the temps are therefore cooler. On a turbocharged car that makes a difference and can translate to better numbers. But it will be a small gain. If the ECU was tuned for 100 octane, the difference would be significant.

I must warn that many racing fuels contain aditives that are harmful to both oxygen sensors and catalytic converters. Long term use can definitely result in some damage. Most of these fuels are designed for race cars that do not have any emission equipment.

TMC M5

It is my understanding that the CL65 was developed (coming out of the factory) to produce maximum power with 94 octane gas. So the 100 octane should be picked up by the sensors and actually help advance the timing a little bit. It may not be a substantial improvement but every little bit helps.

Tom

AMG2GO

What sensors are you talking about? there is no sensor that evaluates the gas. If you are talking about a knock sensor, it only senses detonation. There is nothing in the car that will advance the timing past the map in the ECU Tom. Read my post above, I think the cleaner burn may help a bit but I just don't see how 100 octane will make it run faster than a good 94 (unless the ECU has a more aggresive map).

RennTechV12

Our premium unleaded here in AZ is only 91octane. I think that this may be a big contributing factor.

AMG2GO

Are you kidding? that's the best that is available? why is that?

AMG2GO

You put 91 octane in your Carrera GT?! nice cars man! You must be in a good business.

RennTechV12

NOOOOOO! absolutely not.

There's a station down the street that's got 100 at the pump.