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Nice! Where does the x-pipe go? Did you replace the secondary cats or the resonators? Sounds good.
All my cats are still in place, x-pipe replaces the resonators. I am very happy with the sound. A little more bark on startup, not obtrusive at all in cruise, no drone, no rasp. Louder at WOT.
Thanks guys for the positive feedback! I am very happy with the car. I am a new C63 owner and an enjoying this car immensely!
Factory crank HP rating 481
Measured wheel HP 438
Drive line losses 17% estimated EDIT: Estimated crank HP 528 (438/.83=528bhp)
Estimated crank 528bhp - factory crank 481 = 47 hp gain
This next part is a bit of a guess... EDIT:30 hp from tune EDIT:10 hp from X-pipe EDIT:7 hp from ROW air boxes
Thanks guys for the positive feedback! I am very happy with the car. I am a new C63 owner and an enjoying this car immensely!
Factory crank HP rating 481
Measured wheel HP 438
Drive line losses 17% estimated
Estimated crank HP 512 (438x1.17)
Estimated crank 512hp - factory crank 481 = 31 hp gain
This next part is a bit of a guess...
21 hp from tune
5 hp from X-pipe
5 hp from ROW air boxes
Guys I'm sorry but your estimation of gain per mods is wrong.
I doubt ROW airboxes net you +10! Barely +5!
You get your main gain from the tune and the X-pipe which frees up a little bit more airflow. If you want a bit more gain you do a 2nd CAT delete.
Now OP has a performance package car so gain of +30 something over stock is correct. Depending if you originally have a strong build from factory.
Op, did you do a dyno pull stock?
Guys I'm sorry but your estimation of gain per mods is wrong.
I doubt ROW airboxes net you +10! Barely +5!
You get your main gain from the tune and the X-pipe which frees up a little bit more airflow. If you want a bit more gain you do a 2nd CAT delete.
Now OP has a performance package car so gain of +30 something over stock is correct. Depending if you originally have a strong build from factory.
Op, did you do a dyno pull stock?
I did not do a dyno pull stock unfortunately. It would take me about 4 hours to convert everything to absolute stock. The dyno is 5 min from my house, $100 for 3 pulls. Wrestling the x-pipe on and off the car is that main thing holding me back from a stock dyno run. I guess it would be a lot easier the second time around. I would use a band clamp at the cut. Looking at the air boxes I would guess they net a bit more than 5hp but that's what everyone claims based on the forum. Air boxes are the only mod I have done that screwed with the airflow enough to throw a CEL until fuel trims compensated. I agree removing the cats would be the next step, my main concern is making the car a little too loud at that point.
What are the odds! this is an old buddy of mine that I have known for around 15 years. We haven't talked in months and he picked up a c63 6 weeks ago and I picked one up 3 weeks ago and I comment on his thread not even knowing it was him................LOL. Damn the world just shrunk
Crazy! What's the chance of running into to someone you know randomly in your thread? I guess common interest = common forum subscriptions. I was reading your dry rot tire post and didn't realize it was you or even know you bought a C63. Weird!!!!
I think it is a false assumption everybody makes where you take a constant percentage for drivetrain losses.
Drivetrain losses is the power lost from turning crank, pulleys, pumps, driveshaft, transmission gears and wheels (and everything in bvetween). When you tune the car for more power, none of the mass of the rotating parts that are part of the drivetrain losses has changed. The losses are the same because the engine/tranny/shafts/wheels are the same.
So, our engines make 450hp stock and dynos 375rwhp. Then there is 75hp used to turn the engine/tranny/wheels etc. If you tune and get 430rwhp you just add those 75hp and you get 505hp. Not 375/450=.83 or 17% hp loss then 430rwhp/.83=516hp like everybody does.
Not a huge difference, but I believe everybody is over exagerating their gains by adding % losses to the same drivetrain.
W204 C63 Bone Stock; E36 M3 Supercharged 400WHP; X5 parts eater
Originally Posted by g-f
I think it is a false assumption everybody makes where you take a constant percentage for drivetrain losses.
Drivetrain losses is the power lost from turning crank, pulleys, pumps, driveshaft, transmission gears and wheels (and everything in bvetween). When you tune the car for more power, none of the mass of the rotating parts that are part of the drivetrain losses has changed. The losses are the same because the engine/tranny/shafts/wheels are the same.
So, our engines make 450hp stock and dynos 375rwhp. Then there is 75hp used to turn the engine/tranny/wheels etc. If you tune and get 430rwhp you just add those 75hp and you get 505hp. Not 375/450=.83 or 17% hp loss then 430rwhp/.83=516hp like everybody does.
Not a huge difference, but I believe everybody is over exagerating their gains by adding % losses to the same drivetrain.
Power is the rate of doing work and is time dependent. If your car goes faster and spins those drivetrain components faster (in less time) then absolute drivetrain losses goes up so then 430rwhp/.83=516hp is correct. Think about spinning the wheels from 0 to 100 in 10 seconds vs 9 secs. Those wheels are requiring more power from the engine and therefore more drivetrain loss.
05-12-2015, 06:52 PM
