Done a few weeks ago.

Engine Mods:
Power Chip ECU tuned for 91.
K&N Filters.
VP Racing 100 Octane Full tank.
Resonator Delete.

Seems kinda low from what others are telling me, should it have been higher? Also I just did a fresh oil change today and doing my NGK Iridiums in the morning. Just doing it for peace of mind since the car performs well.

Throwing in some car pics too.

looks about standard car numbers maybe your dyno ?.

All dynos vary, should have done a before mods run on the dyno.

Well I'm mainly on Bimmerforums(don't hate prior M3 owner), anyways, I post my dyno and they compare their E34 & E39 540i with 250ish whp stock. I've read C55 have 280-300whp stock. How is it that their car's don't lose that much hp but I have magically lost around 81 horse power on a dyno? 540i are around 280-290hp.

Mercedes tends to have around 18-20% drivetrain loss, seems like e39 around 15%.

maybe your tune ?.

I've seen the dynos of many a 32/55 and your 55 numbers are about right. I agree with the above ^^^^that the "stock" C55 seems to be going about 280-300 stock and you're on the higher side of that with the tune and 100 octane. Not to state the obvious, BUT we all agree that many dynos differ and some can even differ on various runs and days. This is why I believe a more accurate test of a cars performance is the 0-60, qtr mile and top end, rather than just strapping it to a dyno. A dyno means nothing when drag (CD) , tires, DAs, driver skill etc come into play...................

Car #s look fine
I would ask your tuner what gains to expect from the tune.
Now you have your base map

What gear did you run in - 3rd or 4th?

Just for a reference point, I pulled 305HP/316LB-FT with a Renntech Airbox and K&Ns on a Mustang Dyno running in 4th gear:

I notice the OP is tuned for 91 but used 100 Octane?
Why?

It is because you were running 100 octane! 100 octane contains more alcohol which has less energy in it. The 100 octane fuel has less energy than 91. Put some 91 in and run it on the dyno.

Powerchip ecu, you have a choice of a 91 or 93 octane tune. Since i live in cali i chose 91. I used 100 octane for a few days because ecu are adaptive and change to suit whatever octane you have. The runs were a mixture of 3rd and 4th gear, he tried to find the sweet spot. I agree that all dynos are different. I just wish i did a before and after with the ecu tune. I dont really understand dynos so thats why i wanted you guys to look at it and let me know if i was too rich or lean or if power was inconsistent. Hopefully my next actual mod is a carbon fiber intake or supersprint exhaust.

This i find hard to believe as i heard the higher the octane the more possible to gain more horsepower by upping the boost due to lower chance of pre detonation. Since im not supercharged or turboed i know gains would be minimal. True, i should have ran at 91, but i cant believe that 100 octane would worsen the dyno numbers.

Also people "claim" their cars are faster after a few gallons of race fuel. All i noticed was improved response, very minimal gains.

Anyways, did some research online and it sounds like you do lose hp for using 100 octane vs 91 octane. Next time i stick to 91. Always use the recommended octane for what your car is tuned for.

My base run was 284hp and 295tq with exhaust work and K&N filters. There were some conditions that made it that low I believe.

The reason you can up the boost is because the 100 octane is more knock retardent and can handle higher cylinder pressures without pre-igniting. You LOST power. Your ignition timing curve is tuned for a 91-93 octane burn rate. 100 octane burns slower, the higher the octane the slower burn rate. Higher octane fuels require more advanced ignition timing than lower octane fuels because of this.

I can go into it a lot further but I think you get the point now.

Those are stock numbers..... Contact powerchip... Or try to dyno somewhere else?

hmmm

All dynos are different. The only way to tell is to do a before and after dyno and see the percentage gained.

He won't get any more on a different dyno, just different numbers. I seriously doubt that the tune he has made much of a difference and the 100 Oct only makes matters worse. If he were not NA, then the 100 oct would have allowed for more advance. I doubt the difference between the 91 and 100 will be dramatic on a NA car anyway

. I think that Mike showed us that the best you'll get out of a NA tune on the C55 is maybe 16 HP. Mike K, didn't you only get about 16 HP out of the EC tune??? He can always try a SB and think he's faster ....

And how hot was it when u ran on the dyno?

+1

The dyno is a tool. Absolute values aren't particularly useful. If you don't have a "pre" run on that same dyno, then a "post" run can't really provide much insight unfortunately.

Higher octane allows for greater timing advance regardless of N/A or F/I.

OP, I don't know how Powerchip tunes... but many tuners' programming will benefit performance-wise from dumping in some higher octane fuel. Even if you have a 91 map, the ECU will likely adapt to running as much advance as the map allows without sensing knock. C63 guys have shown it time and time again - sure, a dedicated 100 octane map is ideal, but running (or adding) some 100 octane to the tank with a pump-gas tune in the car yields greater output, shown both on the dyno and at the track.

I got 305hp/315tq on a dynojet with K&Ns, secondaries replaced with an X pipe and a Eurocharged tune last week for comparison. I can post a pic for you to compare if you would like.

yes, i got about 15 hp gain I believe with the tune. unless you count when I hit the NOS for fun and hit over 500 rwhp

** IN his case, I doubt the 100 oct is making any difference and if it does, its minimal................

On any car it'll allow for advance, BUT its much more pronounced on a FI engine. A car really ought to be tuned for it to allow for even MORE advance. Ask Jerry at EC, he'll tell you all about it. He's the one who worked on the Tune for the C55.

since my cats are stock and still in the car then our numbers are similar. i wanted to stay legal for smog in cali. also i heard that the 06' C55 had a bit more hp, is this just rumors? the car is still fast so i'm happy.

You should be fine in cali with smog if you take out your secondary cats..