[WhiteBeard]

Ok last question before I pull trigger today for midpipes: does anyone know if they will fit without adjustments to xi and automatic? I've read some posts that they had to modify them for xi and some shops advertise midpipes for manual tranny only? I'm a bit confused

[Taskmaster]

Super Sprint midpipes are on sale at Turner I believe, it's what I have. And yes, they fit all versions of the N52 E90.

[Taskmaster]

Originally Posted by GermanInCA

TheAxiom can you describe the difference between BPC Stage I tune (I assume that's the only street-legal one from BPC) and AA tune?

I'm on AA myself right now, and curious just how much better (if at all) BPC is.

Well for one, it will absolutely make more power. And if you want to expand on it in the future, I KNOW their header tune is superior.

[WhiteBeard]

Originally Posted by TheAxiom

Super Sprint midpipes are on sale at Turner I believe, it's what I have. And yes, they fit all versions of the N52 E90.

Do you know if they are 2.25 or 2.5 diameter?

[Taskmaster]

Originally Posted by WhiteBeard

Do you know if they are 2.25 or 2.5 diameter?

Around 2.25, like 56-58mm I think?

[WhiteBeard]

Originally Posted by TheAxiom

Around 2.25, like 56-58mm I think?

Thank you! I am debating if AFE midpipes will be better since they are 2.5' vs 2.25 SS midpipes? I'm only looking for best sound with my PE - that's all. Which one would you recommend to buy?

[Taskmaster]

Originally Posted by WhiteBeard

Thank you! I am debating if AFE midpipes will be better since they are 2.5' vs 2.25 SS midpipes? I'm only looking for best sound with my PE - that's all. Which one would you recommend to buy?

Go with the SuperSprint. They are cheaper, they will flow as well. I believe the AFE pipes actually lost some exhaust velocity and caused torque to drop a bit.

[WhiteBeard]

Ok, so I ordered SS mid pipes and 2 gaskets between SS and headers. However, I can't find bolts anywhere (I believe I'll need 4 bolts). Anyone has links? Thank you

[tdavis42]

Originally Posted by TheAxiom

Go with the SuperSprint. They are cheaper, they will flow as well. I believe the AFE pipes actually lost some exhaust velocity and caused torque to drop a bit.

Do you get the occasional backfire? I get some loud burbles and every once in awhile I get a low backfire(at least I think it's a backfire) when I let off the gas.

[tdavis42]

Originally Posted by WhiteBeard

Ok, so I ordered SS mid pipes and 2 gaskets between SS and headers. However, I can't find bolts anywhere (I believe I'll need 4 bolts). Anyone has links? Thank you

http://www.realoem.com/bmw/enUS/show...diagId=18_0587 bolts and nuts

[WhiteBeard]

Originally Posted by tdavis42

http://www.realoem.com/bmw/enUS/show...diagId=18_0587 bolts and nuts

tdavis, on this view http://www.realoem.com/bmw/enUS/show...88#18107549447 I was just wondering if I need parts # 4,6,7,12,13 - I guess I don't need them, I can just reuse old ones right? It's just that I think maybe your drone is due to one of these missing or not properly tightened, no?

[tdavis42]

Originally Posted by WhiteBeard

tdavis, on this view http://www.realoem.com/bmw/enUS/show...88#18107549447 I was just wondering if I need parts # 4,6,7,12,13 - I guess I don't need them, I can just reuse old ones right? It's just that I think maybe your drone is due to one of these missing or not properly tightened, no?

I edited the original link to reflect the correct exploded view. Click the link again.
should be;
4 x #5
4 x #7
2 x #6

That's four bolts, four nuts, and two elastomer seals that will go between the headers and midpipes.

I think I found my slight rattle......it was the heat shield on the wire for an O2 sensor. I think

[STR8-6IX]

Originally Posted by WhiteBeard

Ok, so I found out that primary cats are must have, but secondaries are not MUST haves to pass emission test in Ontario. So given that new (for me) info - I'm confused: does deleting secondary cats increase, decrease or do nothing in terms of power gain? Searched on forum and some say it steals away 5-10 hp, others say it adds 5-9hp and many say it basically does nothing in terms of gain since they are not at all restrictive (unlike primary cats). Not sure who is right. Educate me please guys?

The secondaries are somewhat restrictive. while its no primary cat - type restriction, they are fairly close to the motor and do rob power. I noticed a roughly 4-5HP increase and maybe 2-3 FT/LB of torque along with better throttle response. Engine sounds alot more "Racey" and performance like - lots of deep exhaust sound coming from underneath the driver. from 4000rpm onwards to redline, top end pull has noticeably improved. there ARE gains to be had from deleting secondaries and its often the first step to be considering when looking into exhaust modifications.

[STR8-6IX]

Originally Posted by WhiteBeard

If I remove secondaries, how loud will PE become? I'm just afraid it to get too loud or drone, no? And what is best to weld in instead of secondaries - I mean any straight pipe of same diameter at any local muffler shop or should i order some brand pipes? Thank you

Exhaust note wouldnt be that much different - just a tad deeper. you will get more engine sound and it WILL NOT drone. Mid pipes are a waste of money, just get it done at any half-reputable exhaust shop.

[Mike.]

Originally Posted by 6IX-F10-N52

Exhaust note wouldnt be that much different - just a tad deeper. you will get more engine sound and it WILL NOT drone. Mid pipes are a waste of money, just get it done at any half-reputable exhaust shop.

strange my secondary cat delete with PE drones at like 3K

[3002 tii]

Turner notes the SS section 1 can work with oe exhaust but requires trimming the SS pipes, anyone know how much need to be cut off? And any reason you can't just cut the oe pipes do fit SS instead of other way around?


Fitment note: this Supersprint section 1 is longer than the section 1 of the stock exhaust. By cutting some of the pipe from the Supersprint you may be able to mount this to the stock exhaust. The factory BMW sleeve clamp (or similar 55mm clamp) must be used (BMW # 18307560778).

[STR8-6IX]

Originally Posted by Mike.

strange my secondary cat delete with PE drones at like 3K

thats what the performance exhaust does. its likely due to the fact you dont have your resonator. if you want good exhaust flow without drone, upgrade the muffler and remove seconaries. retaining your resonators WILL NOT cause any drone.

[sprp85]

Originally Posted by 3002 tii

Turner notes the SS section 1 can work with oe exhaust but requires trimming the SS pipes, anyone know how much need to be cut off? And any reason you can't just cut the oe pipes do fit SS instead of other way around?


Fitment note: this Supersprint section 1 is longer than the section 1 of the stock exhaust. By cutting some of the pipe from the Supersprint you may be able to mount this to the stock exhaust. The factory BMW sleeve clamp (or similar 55mm clamp) must be used (BMW # 18307560778).

http://www.e90post.com/forums/showthread.php?p=17652907

Dug up old FS thread stating it required trimming of about 3 inches.

Just get both sections

SS1 and SS2.

[Rogue-OP]

I'm also in a similar boat (looking to increase performance of my N51). Anyone got a link to the Bpc tune? I can't find it on their web store.

https://bimmer-performance-center.my...m/search?q=N51

[1QuikWS6]

Originally Posted by Rogue-OP

I'm also in a similar boat (looking to increase performance of my N51). Anyone got a link to the Bpc tune? I can't find it on their web store.

https://bimmer-performance-center.my...m/search?q=N51

Page 4 on their site...

https://bimmer-performance-center.my...e39-dme-tuning

N52=N51
Just let them know you have N51 with factory installed 3 stage

[tdavis42]

Originally Posted by Rogue-OP

I'm also in a similar boat (looking to increase performance of my N51). Anyone got a link to the Bpc tune? I can't find it on their web store.

https://bimmer-performance-center.my...m/search?q=N51

I just installed the BPC tune and on an AT it feels great. Bob has been awesome with support. First gear is still way too short(no fault of BPC's) I'm just glad I can launch in second where the car feels more natural.

[Rogue-OP]

Originally Posted by 1QuikWS6

Page 4 on their site...

https://bimmer-performance-center.my...e39-dme-tuning

N52=N51
Just let them know you have N51 with factory installed 3 stage

Thanks for the info and link!

I'm reading this on that page and am a bit confused as I live in California.

Not for sale or use on any pollution controlled vehicle in the state of California.