Guys
This relates to info on the Renntech Performance Package thread that has strayed onto this subject. I have just finnished speaking to a MB technician who worked on Mick Doohan's (ex World Motor Cycle Champion) specially prepped CLK55, used for an Australian street rally known as Targa Tasmania. They achieved 320KW without a capacity increase.
Refer to the renntech performance thread for screen shots, but this is what my guy had to say.
1. Ignition. The best setting is base. The 93 RON setting actually retards the timing from the base setting. The car expects at least 95 RON petrol to run on this setting. ie premium unleaded. The latest round of 98RON unleaded work fine too. I do not know how this relates to US pump gas ratings.
2. The cars standard fuel setting is base for Aust and Euro cars. 1 is slightly enriched, 2 is more so and 3 is much richer and is designed to combat pinging on poor quality fuel. He recommended setting 2.
3. He also advised that there are firmware upgrades available from MB for the transmission computer as some autos shift a little slowly and on early models a replacement control module.
4. There are resonable gains to be had from a K&N, or similar, air filter.
5. a change to a single 3.5" exhaust system provides significant gains.
He has given me the mobile phone number of the MB Aust guy who actually ordered the parts for and specced the motor for this 320KW beast to get details on suppliers etc for the other mods.

I hope this info is of use to you and will keep you posted as new info comes to hand.

I am going to try the car tonight with the new settings and see what performance improvements I get.

Stephen

 

I had my fuel setting changed in my ML55 yesterday and to be honest it feels slower! Just to be sure I ran it against my e430 sport (w/K&N), which in the past I have pulled away from, and we ran neck and neck. Please clarify - Did your tech say it is actually faster at the "normal" 91 octane setting? The tech here could not find any "stage" settings for the ML55, he just changed the fuel setting to 93.

 

The 93, 91 and 89 RON Octane settings are ALL for reduced quality fuel. The BASE setting is just that and when set you ignition adjustment setting will say "Base". These other settings are all for retarding the ignition for poor quality fuel, but you MUST use 95RON or better premium unleaded to utilise.

 

I have read that 93 octain and 98 ron are the same just two diffrent standards. For a US spec car the 93 octain port is the highest setting for the timeing. I have not found the fuel quanity setting on the US spec car.

Randy

 

Randy
Your original post and link http://www.infopages.net/renntech/fu...ings/index.htm is what got me started (thanks by the way). All the settings relate to RON (Research Octane Number) Standard unleaded US pump gas has an Octane rating of 87 which is 90RON compared with 95RON for ROW, this is why US power outputs for most performance motors are lower, in fact I believe you miss out on some cars that won't run on your fuel. Most fuel companies have a website that list Octane ratings and settings. I just checked the Exxon site to get some details for conversions. If you use US 91 Octane this is equivalent to 95 RON which is what the car is designed for. Looking at the Exxon site I have drawn up a conversion table
US Octane Euro Octane
87 90 Standard US Unleaded
89 93 Premium US Unleaded ie Exxon Plus
91 95 ROW Premium Unleaded
92 96 Super US unleaded ie Exxon Supreme
The car is designed for 95RON fuel, so as you can see setting it for 91 or 93RON detunes the motor from ROW specifications which is why the motor is rated at 349HP in the US and 354HP everywhere else. To maximise performance run Exxon Supreme or equiv and set timing to "base" ie no correction. Do not use any of the three correction settings as they ALL detune the motor. The requirement to use the "base" setting is US 91 Octane fuel. If you are going to run US 89 Octane gas ie Exxon Plus, you must use the correction setting 1. for 93 RON.
There is no point in advancing the ignition if you don'y use the right quality fuel otherwise you will at best lose performance at worse suffer from detonation.
The screens on the computer were slightly different than those provided in your link. My dealer is majority owned by the MB factory and may have later software perhaps which also allows for base fuel setting as well as three correction settings?? It doesn't make sense that your ignition settings use European standards, but don't get the fuel adjustments.
By modifying the fuel settings alone (ignition is already set to base in Australia) I have manged to pickup up .2sec 0-100Kmh and it took less than 5 mins to configure!!

Stephen

 

i am a bit confused. is this applicable to all models like my c-coupe?

i set the setting to 93 b/c all the premium fuel in my area only comes in 93 (no 91). but that is wrong? what's the setting it should be at? base?

 

No, not because of that, but because the measurement methodology in the US is different than in other countries. Different ambient tepmerature and elevation above the sea level (higher => less oxygen) contribute to the difference.

 

Ok, how about this:

Randy's coupe has an upgraded pulley. This results in a higher boost pressure, meaning more air is supplied to the cylinders. Now, wouldn't the engine benefit from the "rich" fuel setting now that there is more air induced?

 

You are almost correct. DIN horsepower is used by most of the world, while the US uses SAE hp. 1 DIN hp = 0.9860294117647058 SAE hp. 354 DIN hp = 349.05441176470583 SAE hp.


http://www.flash.net/~lorint/lorin/convert.htm

 

ok, i think the key piece of info that was ambiguous to me is that the DAS settings use the euro RON numbers. so by setting the RON value to 93, i've basically set it to use US Octane of 89.

 

I posted this previously in the W210 board.

My 2002 E55 has 355Hp (SAE) per my owners manual. I am still shocked.

 

please drop me a line, geoffm3@hotmail.com

 

...Chip-tuning? What more does someone like Upsolute do that is beyond what was just discussed (for a N/A engine)? So to clarify for me: Base is the highest setting...retard X number of degrees for 93 Ron...minus a couple more for the next and so on...correct?

 

Young
You are right. Setting the car to 93RON is the same as setting it to use US 89 Octane. If you look at the Mercedes website it is designed to use a minimum of US 91 Octane (95 RON for rest of world.)
Lynn
You are also correct. The US horsepower readings are actually DIN the rest of the world uses SAE. There is a bit of controversy by releasing SAE HP figures in the US for the new S Type R, which is 400HP SAE and 393DIN.

The fuel eeeeet setgs are designed to correct miscalibrations in the fueling system. The factory ECU maintains set air/fuel ratios based on the computer "map". If you put a bigger exhaust, cam or inlet on the car, the ECU ll automatically adjust the mixture to get to the predetermined ratios. These settings only help if your cars standard a/f ratio is incorrect. (Mine was running lean which is why enrichening it improved performance)

Stephen

 

Steph
Thats right. Chip tuners generally advance the timing and richen the mixture to increase the performance. Good ones put your car on the dyno and map the chip to your car. These are generally the chips that work best

 

US horsepower readings are SAE (Society of Automotive Engineers). European horsepower is DIN (Deutsche Industrie-Norm) which translates as German Industrial Standard. The SAE figure is smaller than DIN. 400 DIN hp (Europe) equals 394.4 SAE hp (US).

http://www.flash.net/~lorint/lorin/convert.htm

 

Yes, had it back to front.