[boredassdru]

All pulls were in 5th gear. The after dyno was done about a week after the exhaust was installed. The valve is controlled by an Exhaustmeister. I have planned to do the Dinan Stage III ECU Tune tomorrow morning and may dyno next week to see if the power curve changes.

My buddy dyno'd his Stage VI E90 M3 and was able to squeeze out 337hp for reference.

Run 3 - Dinan Stage II ECU Tune
381hp & 425tq
Run 5 - Dinan Stage II ECU Tune With Cruzur System (Valve Closed)
374hp & 401 tq
Run 7 - Dinan Stage II ECU Tune With Cruzur System (Valve Open)
380hp & 409tq

[///M5Driver]

Sweet!! Wait a minute...

[combatbmw]

Thats strange, I gained power so did another member .. before and after.

hmm

[///M5Driver]

Dyno graphs or it didnt happen =)

[combatbmw]

Originally Posted by e46beater

Dyno graphs or it didnt happen =)

Its in the Shteigen exhaust thread, thats where it happened.

[///M5Driver]

Originally Posted by combatbmw

Its in the Shteigen exhaust thread, thats where it happened.

Yeah I looked in your thread when the OP started the thread to compare but I didn't see any graphs. Maybe missed it in the 13 pages.

[combatbmw]

let me find it and post.

Im still wondering how he lost power it doesnt make sense.

[The_Transporter]

Very interesting. I have the same exact setup on my 2012 550i so very curious to see what happens. For the record I haven't done any before or after dynos but it certainly feels stronger. Not sure how you would lose power from l a better exhaust, I feel like at worst case should stay the same as before. Keep us posted!
Thanks!

[ARC550]

Should have Done M5 Mufflers brahh ahahhahahhahha

beautiful Power curve..

[///M5Driver]

I'm curious to see combat's graph. I know on the subies the 2.0L guys would do 3" turbo back's and lose torque as well at near stock boost levels. My 07' Sti made great power on a catless downpipe & midpipe with stock axle back muffler until 21psi then needed a new muffler. A little bit of back pressure helps sometimes!

It's also possible there was a decent weather change between his stock run and new exhaust.

[boredassdru]

Originally Posted by e46beater

It's also possible there was a decent weather change between his stock run and new exhaust.

Before Dyno was 84 F @ 95% humidity
After Dyno was 75 F @ 70% humidity

Although, when they do dyno, they open the shop doors to the showroom and fan in AC'd air.

None the less, I'm not chasing any numbers and Im quite happy with the exhaust with the addition of the Exhaustmeister. It really has 2 different exhaust tones and loudness levels with the valve open and closed.

[///M5Driver]

Originally Posted by boredassdru

Before Dyno was 84 F @ 95% humidity
After Dyno was 75 F @ 70% humidity

Although, when they do dyno, they open the shop doors to the showroom and fan in AC'd air.

None the less, I'm not chasing any numbers and Im quite happy with the exhaust with the addition of the Exhaustmeister. It really has 2 different exhaust tones and loudness levels with the valve open and closed.

Interesting.. sounds like it's time to turn up the boost lol

[Simple5]

Curious how a free (er) flowing exhaust and lighter weight can lose power. Kind of makes me glad I got my m5 cans.

[combatbmw]

Originally Posted by Simple3

Curious how a free (er) flowing exhaust and lighter weight can lose power. Kind of makes me glad I got my m5 cans.

It doesn't lose power.
I gained power so did the test car that was bone stock before and after next day.

You made the right choice getting m5 cans.

[combatbmw]

e46beater
Found it, I actually made a new thread.

http://f10.5post.com/forums/showthre...=shtiegen+dyno

[combatbmw]

After looking at dru's dyno post again,

His tq peak had a really strange spike w/out the exhaust. Between 3250-3500 rpms.
Also, run 2 was cut off in the beginning.

I would go to another dyno see what happens, if you even care enough.. I personally wouldn't.. To much of a hassle to swap exhausts just to dyno.

Odd indeed.

Peak numbers for the stock n63 that I linked were not amazing but it went up.
its the powerband that had the biggest increase.

Same w/my car.

Anyways Im sure you love your new exhaust.. I put alot of miles and was out over 8 weeks in the development of this (being the test bitch).

Enjoy it

[boredassdru]

Originally Posted by combatbmw

After looking at dru's dyno post again,

His tq peak had a really strange spike w/out the exhaust.

I wonder if this is due to when the valve would have opened naturally with the stock exhaust. I did get the Dinan Stage III ECU flash yesterday and the biggest difference was that my car got washed at the dealership. I may go for another dyno next week to see if the Stage III does anything before I lower the car and put new wheels on.

[combatbmw]

Originally Posted by boredassdru

I wonder if this is due to when the valve would have opened naturally with the stock exhaust. I did get the Dinan Stage III ECU flash yesterday and the biggest difference was that my car got washed at the dealership. I may go for another dyno next week to see if the Stage III does anything before I lower the car and put new wheels on.

Cool bro.
You should always dyno w/valve open.

Peak numbers wont be huge but powerband numbers (which to me are more important) should be significant.

Did you read my post about one of your runs not registering on the dyno properly.

And you TQ spike before the dyno looks way off.

the 425tq max was a weird spike that went up and right back down in a loop.

At t he end of the day it doesn't matter, you know you gained power, sound is amazing. So I would just redyno to see what your stage 3 did.

keep us posted.

[FenixMike]

If its one thing I've learned, its that the BMWs are a strange animal as far as what the computer does to power. Temperature is usually compensated through the dyno with the weather station, however without a scanner or datalogs on the car while it was on the dyno, there is no way to see if boost or timing was changed for the pulls, if it was heat soaked more etc. My car lost 10 horsepower between a 6 day period (baseline dyno, then a week later a before and after dyno with the piggyback) and obviously I didn't just magically lose 10 horsepower, but if the engine had stored different data for the timing takes and/or knock, that can have a big impact. Could also be something simple like a poor tank of fuel. The moral of the story is don't focus so much on a dyno... their purpose is for tuning, but too many people take them as the word of God on what is or what isn't.

[combatbmw]

Originally Posted by FenixMike

If its one thing I've learned, its that the BMWs are a strange animal as far as what the computer does to power. Temperature is usually compensated through the dyno with the weather station, however without a scanner or datalogs on the car while it was on the dyno, there is no way to see if boost or timing was changed for the pulls, if it was heat soaked more etc. My car lost 10 horsepower between a 6 day period (baseline dyno, then a week later a before and after dyno with the piggyback) and obviously I didn't just magically lose 10 horsepower, but if the engine had stored different data for the timing takes and/or knock, that can have a big impact. Could also be something simple like a poor tank of fuel. The moral of the story is don't focus so much on a dyno... their purpose is for tuning, but too many people take them as the word of God on what is or what isn't.

Perfect.