awiner

Got the chance to make 3 dyno runs today on my 2003 CL55.

Put the vehicle into Dyno mode which disabled ESP,ABC and BAS.

Did three runs, one in 3rd gear and other two in fourth gear.
22,500 miles on the odometer and the engine as of now is stock.

Temperature was 78.24 - 79.01 degrees F. Elevation was 984 feet above sea level.

Runs were made on a DynoJet 424x (4-wheel drive inertia style chassis dyno). Of course only the rear drum was used (which is a DynoJet 224x). SAE correction was set at 1.01.

Air/Fuel ratio was measured with a tail pipe probe vs a bung into the exhaust, therefore the A/F measurements may be 1 tick low.

The first image shows all three runs on the graph.

The first run (Blue) was made in 3rd gear and terminated at ~6200 RPM.

The second run (Red) was made in 4th gear and terminated at ~5500 RPM.

The third and best run (Green) was made in 4th gear and terminated when the 155 MPH ECU induced governor stopped our fun at a little over 5300 RPM.

With 5th gear still unused, there is little doubt that unrestricted this car would run up-wards to 200 MPH given the right stretch of road and tires.



The second image is a graph of only the third run.



The third image in a breakdown of the Air/Fuel ratio during the third run.




Using a 18% loss factor, the third run ended up yielding 532.97 flywheel HP (437.04 Rear Wheel HP) and 579.48 flywheel ft-lbs of Torque (475.18 Rear Wheel ft-lbs Torque).

Factory HP/TQ is listed as 493 HP and 516 ft-lbs Torque at the flywheel.

Renntech has said they have had several V8 Kompressor motors dyno out stock at the numbers I achieved. Therefore, I assume Mercedes/AMG under quotes the V8 Kompressor engine as they did with the V12 Twin Turbos.

1 BAD BURB

wow! awesome numbers!! my dad might be buying an 05' CL55 soon..its a toss up b/w the SL55 or the CL55.. but damn, the numbers u posted..very impressive! wonder why MB under rates their vehicles by soo much....

either way, whatever car my dad gets, i'll be dynoing it soon after... LOL

any mods planned for the ride of urs?
good luck!
Aj

awiner

As for engine mods, I have looked into the Kleemann Stage 2 system as well as the Renntech ECU/Pulley.

Not sure what I will do if anything yet.

SL BRABUS

That is a nice number......... I got my car dyno at Brabus when I got the engine.......Like what you say.....The power always under quotes....How much it cost you to get your car dyno? ..........Time to take it to the track and see what kind of timing you get with the over power engine...... :v

speedybenz

WOW, your Air/Fuel ratios on the upper rpm levels are so rich as to be shamefull. I would really look hard into installing a ECU tuner to get the A/F ratios to around the 12.8:1 ratio and watch the Hp number climb.

Jeff

awiner

Yes. The factory ECU fuel map makes sure we won't be leaning out the engine now doesn't it.

One of the major benefits of an aftermarket ECU would defiently be getting a optimized and safe A/F ratio all throughout the RPM powerband.

dgussin1

Nice numbers. When our e55 was stock it dynoed 420/480 on a dynojet.

on an edit. 12.8 a/f is safe for a n/a car, but for a blower car you want to maintain a 12.0-11.6 a/f for optimum performance and safety.

BenzoBoi

Where exactly did you get your dyno done at? I would like to see my dyno also because it seems like my car is a lil "under-powered"...

awiner

PM me for details.

Evolution Marine

awiner - Just curious why you used an 18% drive trane loss factor and not 15% like is used for most rear wheel drive cars when Dyno'd on a chasis dyno. The 15% loss factor would put your car at the 515 CHP that Mercedes claims. - Bob

dgussin1

automatic transmissions always have more parasitic loss than manual trannys, hence the 18% usage. Some would say that 20% is more accurate for autos and usually 15% for manuals.

RossN

Don't Mercedes automatic transmissions come with the "lock-up" feature designed into them?

Meaning, after the gear change happens, the "lock-up clutch" feature would lock the torque convertor with the Driveline and there by have the same driveline losses as a Manual, until the next gear change.

reggid

i don't think that using either 15 or 18 or 20% is absolutely correct since the losses vary slightly with speed and other operating conditions, and just because one auto has xx% losses that doesn't mean that all autos fit in the same category. If you use 15,18 or 20% you get quite a bit of variation so how do you know what your losses are! The only way to verify the crank hp is to pull the thing out and thats not practical (i hope oneday someone does though).

One thing that i think can safely be said is that you have >500hp (if 12.5% losses which is not likely since its likely higher).

awiner

The major tuners use a 18% loss. The reason ? They have tested the engine outside the vehicle on a flywheel (crank) dyno at some point. They quote the 18% loss as they know how much the 'typical' loss there is once that same type (model) engine is mated to the transmission and then re-dynoed on a chassis dyno.

The good news is, using 15% or 18%, the engine is producing more power than AMG claims, which is always a good thing.

Maff

My CL55 is going to the dyno on Monday, so i'll post the results and we can see how they compare (granted, it will be a different dyno)

davepl

I used a 20% figure to go from my 510rwhp to my 638 flywheel number. I normally use 15-18% for automatic cars, but the CL has a giant heavy trans plus independant rear suspension, the latter of which adds more loss.

Even though I too am one of those guys that does the math and then quotes flywheel numbers, I think its suspect to do so. Chassis dyno numbers are really only useful for comparing the same car to itself on the same dyno, preferably under the same conditions.

Comparison to the stock mfr numbers is pretty pointless, at least within the margin of error we're dealing with.

That said, RWHP is, afterall, what matters. I'm pretty happy with 510, since its more than the non-lockup differential can deal with anyway :-)

In the end, even RWHP doesn't matter, its 0-60 and 1/4 ET that counts!

victoryroad

Adam
Aside from more power/torque what are the potential benefits and detriments of ECU/pulley mods? As it is, very few cars will outgun the stock CL55 from 20 or 30 mph to terminal speed (at which point even on track contests would quickly get very dangerous). Of course, the new Ferrari 430 may present a serious threat to the stock CL55 on straights at normal speeds, but in the turns there is not much we can do about staying with true sports cars.

Maff

I've done a little bit of research in this area, and the companies which I have spoke to basically say that an ECU mod alone would remove the 155 limiter (which I'm having done in preparation for a rally to Germany and back next year) and give an extra ~20bhp. It also sharpens throttle response too.

Combine this with a pulley and the gains are ~50bhp

I don't think I will be going as far as a pulley, however when they remove the limiter I might as well get the couple of extra ponies for the small price difference.

Regards,

Matt.

awiner

I need to research the ecu/pulley's a little more and see where the gains show on the tuners dynos.

davepl

When I upgraded my ECU (BiTurbo, not Supercharged) I also installed the CL65 transmission controller. Supposedly this commands quicker shifts and higher line pressures, but I'm not convinced its worth it or needed.

FWIW, it still lifts the throttle during shifts. I know its hard to built a trans that will shift while holding 700+ ft/lbs, but it'd be nice to bark the tires a little on the upshift

hantzis

for autos ~ 18-22%
for manuals ~ 15-18%

http://dynoperformance.com/article_details.php?ID=13

str8ridin

Nice numbers! Curious, how did you put your car into "dyno" mode?

awiner

https://mbworld.org/forums/showthrea...highlight=dyno

str8ridin

Nice! I'll have to check this out on my CLK to see if this works.

JasonC32amg

According to RennTech the richness on the top end is for sustained high speed activity...something that is unfortunately difficult to achieve here