Rescu2000

Are there any resources here for discussing and sharing custom HP Tuner tunes for our E550's? I am starting the process of learning how to tune cars and would like to read as much as I can before I start my first tune.

Chevota

Not really much here. The best info is on the HP forum. Still, it's slim pickins there too. It seems to me the people that really know how are do it for a living, so they won't share without paying. The rest of us are the blind leading the blind, so a great deal of trial and error for me.
I've been tinkering with mine for ~18 months and think I have it pretty much figured out. I don't believe it's possible to squeeze more from it than I have, considering my only mods are K&N filters and 50% Ethanol. 0-100 in 8.25sec is my latest best. I'm 2wd so my starts are problematic, but once moving it goes pretty frikkin well. I will share for free btw
The Ethanol simply allows more spark timing, but I also made a spark map for 91 Oct gas if you want. If you've used the Scanner you already know the oem spark is too much for 91. Adding ~30% Eth allows the oem map to work, 50% allows a little more
I was going to say post over there but I see you have... C u there!

Rescu2000

Yes I read many of your posts over there. I saw that you had some sort of "mysterious issue" that was forcing you to make non-typical tunes. I'll message over there and we can work on projects together.

Thanks!

nkx1

I'm just a layperson with regard to tuning (don't know ***** lol), but I'm nonetheless curious about your statement on OEM spark being "too much for 91." Can you elaborate a bit?

Chevota

Meaning timing is too advanced for 91 Oct so the engine pings. When it pings it pulls too much timing, plus pulls boost and/or throttle so you lose more power than you should. It's just the programming trying to protect the engine, but it's overzealous.
For my eng to work with 91, I simply retard the oem timing just enough, and only where needed, so it won't ping. I net a nice chunk of power simply doing that. Free power basically, that was there all along but the overcautious ECU took it.
I'm not sure if your eng pulls as much power in response or not. My guess is no, but it's likely pulling some.
Optionally I can use the oem timing if I add ~30% Ethanol. What octane that nets I don't know, but probably 95? So you could try Oct booster or Ethanol and see if your car responds to it. I don't know how much Eth you can add to yours before you run into issues. For me it's ~55%, where the fuel system can't keep up. My tune also uses a lot more fuel than stock, so if I were to remove the tune I bet I could run straight E85. My car is not Flex Fuel btw, but it can adapt none the less.
Your car, who knows. Maybe it can take 30% Eth, or even pure E85 no problem, or maybe 10-20% would melt your pistons in seconds. I doubt it, but I just don't know enough about your engine.

nkx1

Gotcha, thanks very much for taking the time to respond. Yeah, I didn't initially notice that you have the M278. Totally different ballgame from the M273 I guess.

yaknart33

For the 2010 E550 coupes you can't squeeze much more out of it without major upgrades .The best tuners can get around 26 HP and 20 Ft lbs torque from stock motor.The cost of this is $1500 approx ,not much bang for your buck .If you want more giddy up and go you have to crack the bank acct open .I read about a guy that got close to 1000 hp but it took close to $40 K to get it .Major engine ,trans,exhaust,air and fuel systems upgrades were done. That had to be one fun ride .And the $40 K did not include cost of the car .

nkx1

Yeah, that's consistent with what I've read previously (not a whole lot you can squeeze out of a stock M273). Considering I only paid $20k for the car (plus some ancillary costs), spending thousands of dollars on HP isn't worth it. I agree though- 1,000 would be very fun.

Oh well, glad to see that the M278 guys might be able to do some self-tuning. Pretty cool.