Surprising/disappointing dyno numbers
 

Long story short, I got my E550 two months ago, I got a stage 1 tune mapping on it a few weeks ago, and I got it dynoed last night.

(Edited to remove my name because I'm weird like that.)
https://cimg7.ibsrv.net/gimg/www.mbw...5682bd50b9.png

A couple of things here:
- During the dyno run if the guy pushes it full throttle at around 3700ish RPM it will knock really loudly and spew black smoke (red line shows him backing off the accelerator because of this)
- There's no really consistent curve
- The one spike the guy said was in 4th gear and it seemed to produce the most power, but when he did another run in 4th he couldn't duplicate it
- Butt dyno (and friends' reactions to the car accelerating) tells me these numbers are low

While the numbers are disappointing what I care about most is the knocking. The knocking doesn't occur under normal acceleration or at idle, it just happened twice during testing. Could this be due to the tune?

I have seen stock dyno pulls around here in the 370+ range if I remember correctly. The M278 is underrated at 403 HP and is closer to 430 and 515+ torque.
Your engine is way off the mark.

Yup, exactly. Even given that the car has 100k miles it shouldn't have lost that much HP. Is it possible that the dyno is just... wrong? I would also think if power were THAT reduced something would be severely wrong with the car... no?

Not sure what is going on with your car. These Bi-turbo engines accelerate like no tomorrow in stock form. If there are no obvious fault codes stored it could be many different things causing it to be down on power. Knocking and smoking is never a good sign. Start there.

Yeah, at this point I'm basically regretting the tune ("if it ain't broke..."). The car pulls like a cat with its tail on fire though. I've been in 300HP cars and this thing shames them... and the one car I put it up against was a 5.0 that was in my rearview after the intersection. I guess I'll just take it to my mechanic and see if I can get him to give the engine a once-over.

Check all of the intake areas, fuel injectors, and maybe you have some serious carbon build up that is causing your smoke issue. Why not go the Renntech tune route and gain some real world Horsepower? 100+
The price is not that much for some serious HP gain. This engine can produce close to 600HP with ECU tunes.

Thanks for the advice. I think my prepurchase inspection checked the intake, but I'll ask. Again though, the smoking doesn't and hasn't ever happened (that I've seen) except the two times on the dyno where it knocked and that happened simultaneously. The rest of the time it was running on the dyno it was fine, and I've never had knocking or smoke while driving.
Also, OE Tuning is supposed to be "real world" results (albeit, maybe not as high). The reasons I went with them is because they're local and they offered end of the year sales prices and it seemed like several other people on here have gone with them.

http://www.oetuning.com/products/mer...0-e500-biturbo

But from what I've read you need to have other engine/exhaust/pipe mods to really capitalize on a higher tune.

It may be of value to be able to not only check for fault codes, but to scan real-time engine operating parameters when duplicating the dyno run. It would be interesting to see short/long term fuel trim and timing especially, along with O2 values, MAF sensor, etc. Sometimes the more aggressive nature of a tune uncovers moderate issues that may not have been uncovered (yet).

Ok, for some reason I thought you were going the Race chip route. I guess I misunderstood. oops.

Thanks Mud! Is it possible for a fault code to be thrown that I can't see somewhere on the dash or a screen? How would I be able to scan the engine parameters? Would that require something fancy dancy that plugs into the OBD-2?

It's all good. Probably thought that because I mentioned in another post that I was originally considering it before I went with OE Tuning (since I was able to get their ECU tune for basically the same cost as RaceChip would've been).

Yes, sometimes pending codes or past codes that have cleared from a certain number of drive cycles won't trigger the money light (CEL).
Also, yes, you need a diagnostic scanner to access the ECM. I use icarsoft for MB on the E350 because it is able to read all of the modules on the car. I also have a pretty good generic scanner (Konnwei KW850) that can be used on this or any OBD2 car. In both cases, these scanners will display selected real-time data. IMO if you own a car you need a scanner :)

Thanks! Wishing I spent that dyno money on this instead. Should I get the V2.0 for the icarsoft? Or is the V1.0 sufficient?

V2.0, but don't rush, look into additional scanners as well to be sure they will show what you need. For me, the ones I mentioned work fine. A member here - Kajtek - is very knowledgeable on this.
Here's a past post when I had asked about scanners:
https://mbworld.org/forums/e-class-w...bd-scanner-aga

My opinion. I think that before getting a tune, especially on a just-bought used car, a diagnostic should be run to verify running parameters, along with mechanical checks, especially when turbo equipped.

I would hope that the pre-purchase inspection I had performed would include a diagnostic... but I didn't know to ask and I wasn't told... so I'll confirm. Thanks for the helpful info and the link. I'll read now!

(Also, looks like the link was cut off. Here's the full one if anyone else looks: https://mbworld.org/forums/e-class-w...ner-again.html )

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hopefully you had it done at the dealer, or reputable indy with correct diag tools. if maintenance has not been confirmed on dealer records or carfax i would do a set of spark plugs and fuel treatment. they should have found issues with a 100k mile car and given you a quote for something

Fair question. Yup, reputable indy shop. They pretty much do only BMWs and MBs. Tons of great reviews, lots of high end cars up on racks, etc. There were a few issues (replaced radiator, coolant pump, plugs, cabin filter) that they found that I had them perform. Carfax did show regular service, but since this is my first MB I'm not really sure what's the "norm" for these cars. Fuel treatment isn't a bad idea. Anything you'd recommend?

Also, While I'm on this topic I'll E-Mail the mechanic right now and ensure he did a diag.

M278 in the S550 pulls like a bat out of hell in pure stock form! Can you reverse the mods back to stock, you might be better off.
years ago tried some mods on my M113K and had nothing but problems and driveability issues, was more than happy when returned to stock..

Absolutely considering it. I have no idea if my tuning place has the stock tune anywhere to load it back (or whatever they do), or if I would have to pay them a full price to do it or...? It might even be cheaper to just purchase a new stock ECU.

Anyone happen to know if I get a new ECU, will I need to get a mapping put on it or will it be good to go after being installed?

you cant even order one easily, its a "Theft Relevant Part (TRP)" has to be coded to car and they want old one for core. basically a pain to deal with. if you have the handheld from OE you can flash back to stock, or mail it in and go back. 2nd ecu would probably be more cost effective used, and get flashed with stock or modded

it should be quick with or without tune

Damn. Well, thanks for the really fast response. I was never unhappy with the speed of the car, was just hoping to get by the little bit of throttle lag it has and try to add a little more power that I know the engine and turbos can eeeasily provide.

Nice video. Much better launch the second time. ;-) Is that fully stock? (Guessing not, based on your sig.)

thanks, mods in sig. these 550's dont launch real hard, wish i could enable launch control

Does E550 has a launch control to enable ?

No launch control. This is luxury car. :wootrock: