I have spoken to Bob Brady at Rennechs headquaters in Lake Park Florida a couple times and he has told me that if you were to buy the renntech pulley from them that the fuel setting are best on base and stage 2 is not needed, and as he said "does not serve a purpose to change". So the way it seems base is not to bad afterall.

Good Renntech could give us the answer to that.

I belive KLEEMANN and me posted that it was not necessary to change to step II almost a year ago.

With that said.....

I think it's time for me to purchase my Kleemann pulley

Thanks for the info tberry

Regards,
Matt

You both probally did, but it does not hurt to check around from other Very good tuners.

KLEEMANN recommended Stage II or III for pulley users on 7/27/2002 in the tread "MB DAS Settings?" by edvpt who has a Kleemann pulley.

I equate this to the guy who hits himself in the head with a hammer because it feels good when he stops.

I recommended Stage II (and still do) to those people who are convienced that they need it (the linh's of the world). It wont hurt anything- and yes, the dynos will show a nice fat 12.5:1 AF but no power gain.

Absolutely wrong, please do not mislead people.

Please elaborate.......

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Lets put it this way:

I install a Kleemann pulley kit, I then have to option of leaving my fuel settings at stage 1 or (with little or no effort) have the option of going to the dealership and having them changed to stage 2. Which would be optimal and why?


KLEEMANN, your company obviously did rigorous testing prior to distributing this product. After all of those tests, which setting did the "KLEEMANN C23K" end up being left on? And why? Stage I or II.

I look forward to reading your responses.

Regards,
Matt

All right, since you asked the short answer is yes it is too lean.

Now for the long explanation of why...

Stoichiometry is the term for the theoretical optimum mixture of elements for complete combustion.

For gasoline stoich turns out to be approx 14.7 a/f or the inverse .0680 f/a (which is what the engineering community uses). So for best efficiency this is where the engine likes to run and sure enough when we calibrate engines for part throttle operation we cal to .0680 f/a

For peak power, it turns out this number is different...
12.5 a/f, or the inverse .0800 f/a, is where it should be for peak power if, and it's a big if,exhaust gas temperature is not an issue...

So here's what happens in real life...

When an engine is calibrated during development peak power is run at .0800 f/a. this works fine until either; knock is encountered, or there is too much backpressure in the exhaust tract.
When knock is present spark timing has to be pulled out and when that is done the exhaust gas temperature (EGT) rises. When the EGT rises past critical levels (determined by the quality of the exhaust valves and other parts) the only way to cool things down is to add fuel.
Backpressure can also cause EGT to be too high and require fuel to be added to cool EGT, so you start at .0800 f/a and possibly go richer, but not leaner.

Now leaners mixtures, which produce more heat, cause knock to happen sooner (easier). More power (better cylinder filling) also lowers the knock threshold. You have both of these conditions with the pulley. If the engine knocks and if it has active knock sensors it will pull spark out and without extra fuel EGT would be too high. This also kills power so if you start with the correct amount of fuel you will make more power and reduce the tendency to knock.

13.9 is much too lean and is hurting power.

Supercharged (vs naturally aspirated) engines are not as sensitive to rich mixtures (under 12.5 a/f or over .0800 f/a) hurting power but are more sensitive to lean mixtures causing problems.

Now that being said, engines tolerate these conditions for short periods of time OK, which is why everyone has gotten away with it so far. If you go out on the freeway and run full throttle for more than a few minutes, your could easily do some damage.

ok, tired of typing, let the flames begin...

Well i apprechiate the reply, i must say that i am not as happy as i was before i read your reply. I was supose to have my pulley installed today but the guy cant do it till friday, and since not one dealer in my area will change my fuel settings i am not as comfortable as i was before, especially since i like to floor my car ALOT during normal driving.

Not trying to scare you, just put some facts out here.

You do need to look into getting the fuel mixture correct but in the mean time, buy the best fuel you can and I doubt you can hold it to the floor long enough to kill it. Unless you live in Montana

Engines tolerate short bursts of abuse because heat does not build up.

If you can find a shop with the right facililties, and are willing to spend the dough, you should verify a/f ratio on a dyno. Think of it as an insurance policy.

I like this reply. It's time for KLEEMAN and Lucas to defend their position.

well i better not kill it. i only put in 93 octance fuel which is the highest we have here in florida. i just hope with my day to day racing a full throttle and going to the track wont cause any damage for at leat 2 more years till i get rid of my car.

oh, yeah? well, what do you know about harmonic dampers?!

Matt-

Change the setting to Stage II- this will add a flat % increase to the base map at cold start and WOT. WOT is what you are concerned with. The are few, if any, places in the US where you can operate at full load for any meaningful length of time. Operating an engine at 13.9:1 at full load for an extended period of time could cause problems with heat/knock and the ability to dissipate it.

If you can have the settings changed with a DAS machine by all means do it. The average person lacks the ability to effectively persude a SM at a dealer to do anything with the DAS- you wouldnt belive the stories I have heard.

Long story short: Change to Stage II if possible, a wide safety margin. In this country you will probably never have the opportunity to operate your car in a way that any damge will ever occur at "baseline".

how long do u consider long to be at full throttle for any damage to likely occur?

and what are somethings u would reccomend to say to a Service rep how to change the fuel settings?

thanks

For the sake of the board (and myself ) I will do everything in my power to convince my MB dealer to change fuel setting to stage II (even if it means bribing with food/$$...) then spend the $90+ for dyno with A/F ratio again (although I will try with 105 octane gas for maybe one of the runs to see if any difference). So far after doing research my car is seeing about the right amount of power I'm supposed to be and have all the textbook cases (a tad on lean side). I wont be able to do this till Jan 11th or so will keep you guys posted.

First let me say that in 4+ years of producing many, many hundreds of pulleys for SC'd M111 engines world wide we have never had any engine damage occur. Therefore I cannot imagine what operating circumstances would bring about any damage.

HOW to change the settings anyone in service will know, its the WHY US dealers seem to have a problem with. The problem is you are venturing into an area the average dealer has never been: performance enhancement. What seems to work best is ismply asking the to change the setting because you want them to. Its perfectly legal and within the EPA, MBZ etc to do so. The settings do nothing to violate the certification of the car.

DCX, that was a very well writen response. It's good to learn how the engine actually works. I will be sure to have my settings changed to Stage II regardles of how difficult it is.

KLEEMANN, its good to hear that you agree to have the settings changed. I own several of you products and rate them second to none. I appreciate your help on the subject and look forward to experiencing the pulley system in my car.

Regards,
Matt

Try to talk to the technician yourself and build a relationship. I have the benefit of dealing with a very small dealership with only two MB techs. One of the techs is more trained and speciallizes in electronics. I try to see him whenever my car needs service.

For the fuel settings have the vehicle serviced for AudioPilot setting changes and then provide the tech with info from this board on the fuel settings.

Well i am glad that you did not hear any damages to occur with base settings. (hopefully some had them at base)

Also, i have talked to several dealers (service dept) and just told them that i want my fuel settings changed and they all ask why, so i said that i just want them changed, and of course they ask why again, and at that point i ran out of things to say so i just said i heard it runs better that way, and then they said we would not think of changing any sort of fuel settings in the ECU. I spoke to the service manager and emailed him a screen shot of the pic i belive is from you how to change the the settings and he told me that will void my warrenty and its against the Emissions. which i know is BS. So i really do not know what else to say. I would be happy to hear something else.

last, reading this thread over you say that stage 2 settings do not give u any HP and about 2 weeks or so i called KLEEMANN, and i spoke to corey and he told me that with the settings at stage 2 you gain 7 HP?

i would love to try to talk to a tech but my 2 deales near me are probally 2 of the biggest dealers there are. there is no way to speak to a tech, never on the phone, and when i go there and ask if i can just ask them a question they say that techs do not speak to customers. i cant even walk in the back to the garadge because the cars go back and threw there with a sedcurity guard and there is a gate. Even if i was to walk there i think my dealer has 100 bays, so i dont know if i could ever find my car.

If you are close to West Palm Beach, get Renntech to change it for you.

Cory is our technical service person, as such he gets more personal feedback than I. It has been my experience that on cars we install pulleys on in our shop I see no additional gain in HP (although AFs do drop to the 12.X range).

Here is the potential problem: We have a DAS machine so we can do settings on the dyno and test immediately after the cahnge (back to back runs). An average person will dyno test one day, go get settings done another day and return for another dyno in a week. Is the temp outside the same, is the cars temp the same, fuel quality, air over the IC, etc. There is easily 7hp worth of ambient change that can mislead one to think the settings are the cause. Conversely these same issues can lead to drops in power as well.

I am not that far away from west palm beach, i could drive there in under an hour but i called renntech and they said if they see a soild 1 peice pulley in the car such as KLEEMANN or ASP they will refuse to work on the car at all as they think that will cause major damage to the car. And i think he said that he would charge 100$ to do it if i had there pulley on my car since they think the change is useless.


Very True. Was there anything else YOU can reccomend me telling my dealer to convince them to make the change?

thanks