[shockin330i]

Originally Posted by jpsimon

Shiv went a while back. Catback + meth only he did:

12.389@117.151 with 2.030s 60'
12.327@117.406 with 2.146s 60'

http://www.e90post.com/forums/showth...ight=n55+track


/edit/ err a 135 isn't an e90

Lol

[ciomas]

I just got my AR downpipe today and did a baseline dyno. Will have my BMW service put it on for me tommorrow. Ive scheduled another dyno run for tommorow evening. I dont have high expectations as Im running on stock ECU...also spoke to some flashing companies here in Poland and they are hoping to be ready by early spring....needless to say, the AR downpipe is jewelery quality

[papiti]

I don't know. That doesn't make any sense. Because of this.

http://www.e90post.com/forums/showthread.php?t=429954

And this.

http://www.e90post.com/forums/showthread.php?t=416803

[shockin330i]

Hhmmm

[htt760]

Originally Posted by papiti

I don't know. That doesn't make any sense. Because of this.

http://www.e90post.com/forums/showthread.php?t=429954

And this.

http://www.e90post.com/forums/showthread.php?t=416803

This is really confusing ... the JB dyno is almost making the same power as the Filter install????

[Juiced46]

Originally Posted by Matt@Camber-Toe

Dont forget that boost is still falling off in the high end. If you made a solid 15-16 psi across the board you would be making some very good gains up top.

Correct, but boost was falling off even with the stock DP so this is an equal comparison. If I made MORE boost with the DP up top and picked up power, then the comparison wouldnt matter because it would be with more boost. Plus who is running 15-16psi on an N55 and holding it? I dont think that is possible just yet.

Same tune, same dyno, same AF, same Boost equals what I dynoed.

Originally Posted by htt760

Juice,

I have to agree with the 4 inch downpipe as overkill because who really drives there car above 5500 rpm's that often... Only during hard pulls is when we actually use that type of power gain. A more suitable downpipe in the 3 to 3.5 inch would be way better. Doesn't the Icarbon have a 4 inch as well? And I called Vishnu and on the waiting list to purchase a Vishnu tuned downpipe...

Im kind of dis appointed that AR didn't bother doing any research for this downpipe, let alone some RD with some tuners to find the best possible combo. Very Nice downpipe though....and great welds.

JUICE - are you felling that missed torque on the bottom end? Like maybe several hundred rpms later for that torque to kick in?

Not really feeling the loss of TQ since its not that drastic. The car feels the same down low to me. Above 5500 I definitely feel the power gain.

Originally Posted by htt760

This is really confusing ... the JB dyno is almost making the same power as the Filter install????

sigh- First off my car is AWD, more of a loss compared to the RWD cars that dynoed. Plus I use a Mustang Dyno, which is loaded, with SAE correction (just about as accurate as you can get) The drop in filter dyno, was done on a dynojet (which produces higher #s then the MD) and was done with STD correction (which will also make the #s higher) and that car was RWD. There are WAY to many variables between the 2 cars to compare that drop in filter car vs mine, or Burgers Dyno vs mine. They both used dynojets with STD correction

To give you an example. A customers 04 Cobra I built this spring. We used the loaded mustang dyno (same I use for my BMW) to tune the car (best for tuning) and the car made 675rwhp SAE. We drove over to the dyno jet on the same day (because the owner wanted a big # dyno sheet to display @ car shows) and it put down 737rwhp SAE with zero changes.

IMO dynos are used as tuning tools. The only way to get an accurate comparison is use the same dyno when making a change. Comparing 2 different types of dynos will never net the same results. Some may be closer then others but like I said, so many variables play a role in it. Weather, correction factor, AWD/RWD, elevation, type of dyno, loaded/unloaded, type of tires, air pressure in the tires etc etc etc

[Juiced46]

Also just to explain my point alittle more about correction factors and how it can affect #s. Here is the same pull, but all with different correction factors. There is a difference of 17 and 40 hp from going SAE to STD and Uncorrected.

SAE



STD +17hp



Uncorrected +40hp over SAE and +23hp over STD

[FrankiE90]

Juiced46 do you feel that dip in torque between 3-4 grand?
and have you tried to put your stock exhaust back on. That may
help.
Remind me, the N55 XI exhaust, doesn't it have the cats
on the system.

on a side note
it interesting to see the JB Dyno baseline for the N55 135
with a dip on the torque curve between 3-4 grand. dips down around 250 ft-lbs.
I baseline'd with the torque line pretty consistent, can someone fill me in
on that.

i got to re-dyno now. I wanna see that dip.


edit-
btw, Juiced46 u explained urself well.
i'm sure htt760 and papiti get it.
did u get a baseline dyno for ur N55 XI>?

[Juiced46]

Originally Posted by FrankiE90

Juiced46 do you feel that dip in torque between 3-4 grand?
and have you tried to put your stock exhaust back on. That may
help.
Remind me, the N55 XI exhaust, doesn't it have the cats
on the system.

on a side note
it interesting to see the JB Dyno baseline for the N55 135
with a dip on the torque curve between 3-4 grand. dips down around 250 ft-lbs.
I baseline'd with the torque line pretty consistent, can someone fill me in
on that.

i got to re-dyno now. I wanna see that dip.


edit-
btw, Juiced46 u explained urself well.
i'm sure htt760 and papiti get it.
did u get a baseline dyno for ur N55 XI>?

I really can feel no difference between 3-4 grand. Its about a 10ftlb loss in that area so its very minute. If it were like 30+ you would be able to feel it.

Its funny you mentioned if I put my stock exhaust on. I removed my AMS Catback (which I dynoed with) and installed my stock catback on Sunday. I felt zero difference in performance, just a tremendous difference in sound. The XI exhaust has resonators/cats on the stock pipe.

As far as the dip, I need to look at some logs. But it almost looks like on the initial hit, boost sort of spikes higher then normal, drops, then levels out, hence you seeing a dip. I remember watching one of my logs on the dyno (didnt record it) spike to 13.5-14psi on the initial spool up, drop to around 9ish then level off around 11. This could be causing that initial up and down we are seeing.

What type of dyno did you dyno your car on? Do you have the graph?

Also I do have a baseline of my car sort of. It was stock with the AMS catback. I also overlayed it with the AR and Tune dyno for you guys here for comparison.

[FrankiE90]

well that's good that u didn't feel a difference in performance
with exhaust swap'n.

any chance u'll re-dyno soon?

the gains look pretty decent.
I know it's not like the N54 - if someone chimes in.
it's just that the N55 is going threw it's
growing pains.
it's a bit frustrating knowing what can be
done to previous engine model.

it'll be nice at some point to get more data from
other n55 owners.
personally can't wait for a big single turbo upgrade.

[shockin330i]

Originally Posted by FrankiE90

well that's good that u didn't feel a difference in performance
with exhaust swap'n.

any chance u'll re-dyno soon?

the gains look pretty decent.
I know it's not like the N54 - if someone chimes in.
it's just that the N55 is going threw it's
growing pains.
it's a bit frustrating knowing what can be
done to previous engine model.

it'll be nice at some point to get more data from
other n55 owners.
personally can't wait for a big single turbo upgrade.

Look how long it took to get there for the n54...

[Juiced46]

Originally Posted by FrankiE90

well that's good that u didn't feel a difference in performance
with exhaust swap'n.

any chance u'll re-dyno soon?

the gains look pretty decent.
I know it's not like the N54 - if someone chimes in.
it's just that the N55 is going threw it's
growing pains.
it's a bit frustrating knowing what can be
done to previous engine model.

it'll be nice at some point to get more data from
other n55 owners.
personally can't wait for a big single turbo upgrade.

Not sure when Im going to redyno. Honestly it probably wont be until I get a new tune. Be it if Terry comes out with a Stage 2 or Cobb, or whatever route I decide to take.

Im trying to provide as much accurate data as possible, even if some people dont want to believe it. I may be actually making a custom cold air kit since nobody has come to the table with one. I have heard rumors of tuning issues, no power gains etc with it. But I may give that a try soon, especially if COBB comes out with their N55 stuff and pro tuner. I have some very good connections to get a custom tune when its available. Im not a newbie to the car scene or modding/tuning. I have been in the game for many many years just not with BMW modding. I work for BMW fulltime and I build Mustangs on the side as a part time business. I have built many high horsepower new edge mustangs ranging from 400-1000hp. So this stuff is not unfamiliar to me. Hopefully my information helps some guys out.

Also the intention of this thread is not to bash AR, or down talk their product. These are the results I got. No smoke and mirrors, no BS, this is what happened for me. The DP is actually a very very nice design, fits great and sounds badass with an aftermarket exhaust! My videos do not do it justice for how it sounds in person. I really wanted this DP to perform like everyone else. Can more power be had? Possibly. Only time will tell. The N55s are still new. The longer they are out, the more we will find out about it and the more power we will be able to unleash from it. Heck the tunes themselves have only been out a few months. Once complete fuel control is had, we will start seeing some nice gains like the N54 guys for sure! Until then, we are all guinea pigs.

[FrankiE90]

Originally Posted by shockin330i

Look how long it took to get there for the n54...

yes.



Juiced46, CAI would be nice.
I was think'n of tap'n the side of the box like the dinan intake
and try to squeeze some plumbing down below for more air.
and it's a tight space. prob wouldn't need a filter at the end of that
but more air.

[shockin330i]

Originally Posted by FrankiE90

yes.



Juiced46, CAI would be nice.
I was think'n of tap'n the side of the box like the dinan intake
and try to squeeze some plumbing down below for more air.
and it's a tight space. prob wouldn't need a filter at the end of that
but more air.

That might work. I really need to head up to dallas and just leave my car with stett.

[Jesse@MBRP]

Originally Posted by shockin330i

Hey bro! Any wrd on the catback??

Working on it...drone is a pain on the N55 cars.

[shockin330i]

Originally Posted by Jesse@MBRP

Working on it...drone is a pain on the N55 cars.

Thats cause the stock piping has no cats or resonators. Might want to try using the same logic that bmw uses with their cross pipe connecting the two mufflers. Dunno if that matters or not lol.

[black e]

Originally Posted by Jesse@MBRP

Working on it...drone is a pain on the N55 cars.

+1

[shockin330i]

Originally Posted by black e

+1

I had a muffler delete and it droned. I wonder what what it would sound like now with my dp.

[black e]

Originally Posted by shockin330i

I had a muffler delete and it droned. I wonder what what it would sound like now with my dp.

it would rattle your car to death!

[shockin330i]

Originally Posted by black e

it would rattle your car to death!

I think I'm going to try it

[ciomas]

jesus! dont do it

[theriz]

Originally Posted by shockin330i

I think I'm going to try it

do it.
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