HoustonC230

Ok - so I've got a problem here...

I had before / after dyno's run on my car (had the ASP prototype pulley installed - but that's another story - on another forum). Anyway, both times, my car was only making about 140-150rwhp. The car has been in for service a month or so ago, where they replaced 2 coilpacks and all the plugs. The car idles alright, a little rough, but nothing that seems unusual.

The shop is a reputable one... (one of the biggest porsche shops around), but they don't do much work on MB's. They weren't able to pick up a voltage to get the RPM's - so all they could get was hp vs. mph. Right up near the top, the computer just starts dumping fuel in and the a/f ratio goes to hell. Again, we didn't have the tach, but in driving, this seems to happen about 4-4.5k RPM. Car was in dyno mode for all runs.

Anyway - my question is - what could contribute to such a drastic loss in power? (I got these numbers both BEFORE and after the new pulleys were installed). I have one of the runs with a/f ratios in excel, that I can post if that would help...

Some things that have been suggested to me already:
Check the gap in the plugs (don't think this would cause such a huge drop in power though)
Bypass valve stuck open?


Any info is appreciated.

pshek

"Houston, we have a problem." :v

Sauceboy01

Well, your car stock produces right around 160 RWHP.. so you're not down all that much!

HoustonC230

All the dyno's I've seen for the M271 were up around 170. For me to get 150rwhp, that would be 21% drivetrain loss - which seems pretty damn high to me for a manual. (140rwhp = 26%)

If I came up with a 160 - I could accept that... being a 16% loss...

I think I'm going to check my plugs, recheck all the piping - make sure nothing's loose after pulling apart the front end.

respdoc

Doesn't the M271 (1.8L) list at 189 hp. at the crank ? A true 170 at the wheels would be nice but that seems like an extremely low amount due to drive train loss compared to almost any other vehicle I know. Also taking into account the type of dyno used and mileage on your car.....true h.p. numbers in the 150ish range does not seem that unreasonable..

white_w203

being a manual you should lose at least 15-percent to the wheels, and if hp is at 189 and 15-percent should be in the 150-160 area stock. so 140 is pretty low even with mods.

did you only get the pulley installed. if you changed the pulley you have to mess the ecu..... now to match the a/f ratio since more air is going in the car. there could be a lot of factors......injectors, fuel pump, chipped, etc....

remember the kleemann pulley kits comes with a k-box, which is a piggy back for the ecu.

Sauceboy01

Well let me tell you this much. I had my car Dyno'd stock right around 8k miles. On a good cold run i got in around 165 on a warm run i got 158.. so you're not that far off. Mine is a manual as well. check your plugs, you'll maybe gain about 4-5 hp

Outland

Where the hell did you seem an M271 with 170 at the wheels?

161 is a 15% loss, perfectly normal for a manual transmission car. Autos are higher loss. Clearly your car has some problems, without the pulley.

Also, the Kleeman K Box that shipped with there M271 did something to the fuel...brand never did say what. Perhaps that's why your asp pulley isn't showing any gains. First things first, your car is down some serious HP.

Moviela

Prior to the dyno run did you replace the air filter(s)? Install clean synthetic oil? Change Kompressor Oel? Fill with fresh premium fuel? Inflate the tires to the top of the range? Disable the alternator field? Unplug the AC clutch? Blow air over the radiator to keep the fan clutch spinning free? Didn't the computer have an inductive pick-up to clamp on a plug wire to compute the rpm? These items alone contribute little to the measured Hp, but together can make the difference you report.

The rough idle might be your largest clue. If two coil packs were reporting bad to the computer, I'd check the quality of the ground connection between the engine and the frame. Look carefully at the insulation of the engine wiring, especially where it connects to the coils.

I hope you can get the numbers you are paying for.

HoustonC230

I'm not paying for anything - except a rental car while they installed the pulleys. All dyno's/parts/installation was provided at no charge.

There's at least one dyno floating around (I rememeber more, but could only find one during my 10 second search) where they got around 170hp. Reading a little more on the one that I found, it was a new car though, with only 20 miles... Mine has 40k.

As far as not getting any real measurable gains from the pulley - not too concerned about that. I realize that the other kits have a chip/"box" that come with them for a reason - and looking at my "after" dyno's, I'm pretty sure why. That's no big deal, I'll work on that later.

Reading everyone's posts, going back through the #'s, and settling down after getting pissed about not hitting my (unrealistic) expectations - I realize I'm not too far off where I should be. Granted I think I'm still losing a few hp here or there - it's not the 20-30 I was thinking before.

Sauceboy01

Ok, so with the pulley alone you should gain about 20-25hp..

RedKen06C230

has anybody dynoed a 06 w/ the 2.5???

Outland

No. Get your own thread.

Outland

170 is a lot for the 1.8. Most stock M111's dyno in the 170 range.

As odd as this may sound, many cars, if not all, gain some power as they age- if its kept in tune-. As the engines wear, tolerances increase, reducing internal friction. In addition, carbon buildup on the top of the piston raises the compression slightly as well. Obviously, this doesn't go on forever, but a car with 40K shouldn't be 15HP in the hole already.

Properly running, there's a lot less headroom in the 1.8 compared to the 2.3...no one should be expecting a 35HP bump from this pulley. Honestly, I think 10 is about all you'll see, once the fuel and spark issues are resolved.

HoustonC230

I'll be happy if I get 15-20hp from the pulley (+chip tune). If it works out, MSRP on the combo would be half of the kleemann kit... but that's a BIG if. We'll see.... regardless it's fun seeing what happens (and frustrating at times)

Outland

Well, I wish you luck. If I recall correctly, a fully massaged Kleemanized 1.8 is only 207HP(crank). That's only an 18HP improvment, with all the kit and kaboodle. A far cry from the 35-40HP the pulley yields on the M111. I think the increase in pulley size is much more modest, as the supercharger on the M271 already pumping 11 psi in stock form, versus the 5 or so on the M111.

ctC230K

Right here. 177 actually.

That would be me. The car had about 3k miles on it when the dyno was done.

hobie

To determine if it's the plugs or the coil pack: swap the coil packs with good cylinders and see if if the misfire code follows the pack. M111s hate cheap plugs, even slightly lesser NGKs (not sure about the M271s). Pay the man $55 and get the NGKs with the MB Star logo. Buy yourself an OBDII reader for the pricy dyno time, they're down to around $100. Better yet, do as I did and buy your brother one for a present and borrow it when needed. Good luck.

lokisdog@yahoo.

You'll want to take into account that unless you are comparing your car to another car run on the same dyno you very well may be getting a false comparision, esp. if you're comparing an inertia dyno result to an eddy current result.

Factory Pro eddy current dynos read 14 to 15 percent lower than say, a Dynojet inertia dynamometer in the 90 to 100 horsepower range, with even more difference at higher power levels. I see this alot on racebikes, my GSXR-750 shows lower HP than my teammates even though I pull him on the straights every time, he runs on an interia dyno and I tune on an eddy dyno.

- Eric

hobie

If you pay a dealer to diagnose the car, ask the tech to see how fast the rear O2 sensor is ticking off. It's just a glorified thermometer, but it will deteriorate significantly prior to setting a code. Common scanners just read the code, MB laptops reads the data stream.

I have a new puppy named Loki (really).