My search for more NA power (Dyno time)

Originally Posted by aggieE46

Burns got me the PN I need for the merge.



This is what they use for the E30 M3.

Still has a small step, but not nearly as long. The merge into the neck is much smoother, too.

Just need to get some money together. Dang, so many things to do.

By the way, if anyone wants to donate to help with this research, I accept Paypal

I actually had one very nice Fanatic donate to help with this dyno. I won't name him, because I don't think he'd want everyone hitting him up for cash, haha! (But, thank you very much, it is appreciated).

what is the cost for that collector?

$230

Originally Posted by vi6ious

what is the cost for that collector?

dayum, I have to run to class. I'll be back to throw some ideas at you...

AggieE46, take a look:



Dyno chart of 3,5 inch bimmerworlld race exhaust for M3 e46

note a massive torque loss below 4400 rpm. And quote:
The factory uses their common twin-pipe exhaust design on the E46 M3 which is great for packaging - it fits nicely in tight places. But we have been around the block a time or two and built few exhausts for our pro cars, track cars, and project cars along the way and we are good at making things fit. We have also had our fingers in the S54 engine in various environments and we are well-versed in making power. Behold the result - even more impressive than we had hoped when we started building it!

Universal Header Fitment - Direct bolt-on for any standard E46 M3 header, including stock pieces with converters if you have to run them. Due to our necked-up primary piping, cars using the larger diameter Supersprint V1 Stepped Header can also fit this part by cutting off the short reducer section and welding the included flanges onto the pipes for unrestricted flow.

Race-Quality Merge Collector - Primary pipes flow directly into a hand-built merge collector, specifically designed to increase exhaust scavenging. An oxygen sensor bung is placed after the merge to add a wideband sensor for dyno work or normal monitoring if desired.

Full 3.5" Diameter - It is extremely tight in some areas, but we made it fit, and very close to the body of the car - no low hanging points to drag on your trailer, entrance curbing, etc. V-band clamps connect the exhaust sections for a clean, tight seal with no gasket required. The 3.5" diameter requires hand-piecing mandrel-bent pipe sections together instead of bending longer pipe sections, but we are not willing to sacrifice our goals for ease of production. The final judge is the dyno, and a 3.5" exhaust makes more power than 3" in even a stock engine - and is an absolute requirement for more modified powerplants.

Now, even though they had applied their "specifically designed to increase exhaust scavenging" collector, they couldn't improve low end. Also, 3.5" made 10hp, let's say 3" made 5hp. Very little gains, and such diameters were used on the engine which produces around 300 whp stock, where M54b30 make less than 200 whp stock.

You could always think that maybe the magnaflow was a good designed exhaust. Maybe if you didn't have that before hand you would have made more power over something different.

beemka good post

Good info.

I just got done fabbing my exhaust and went with 2.5" partly because I couldn't find a 2" to 3" Y.

I wanted quiet and lighter weight. Objectives met.

http://r3vlimited.com/board/showthread.php?t=183420

I've seen those charts and I've actually asked Bimmerworld if they would consider making one. Seeing that was another encouragement to swap to this exhaust.

Originally Posted by beemka

AggieE46, take a look:



Dyno chart of 3,5 inch bimmerworlld race exhaust for M3 e46

note a massive torque loss below 4400 rpm. And quote:
The factory uses their common twin-pipe exhaust design on the E46 M3 which is great for packaging - it fits nicely in tight places. But we have been around the block a time or two and built few exhausts for our pro cars, track cars, and project cars along the way and we are good at making things fit. We have also had our fingers in the S54 engine in various environments and we are well-versed in making power. Behold the result - even more impressive than we had hoped when we started building it!

Universal Header Fitment - Direct bolt-on for any standard E46 M3 header, including stock pieces with converters if you have to run them. Due to our necked-up primary piping, cars using the larger diameter Supersprint V1 Stepped Header can also fit this part by cutting off the short reducer section and welding the included flanges onto the pipes for unrestricted flow.

Race-Quality Merge Collector - Primary pipes flow directly into a hand-built merge collector, specifically designed to increase exhaust scavenging. An oxygen sensor bung is placed after the merge to add a wideband sensor for dyno work or normal monitoring if desired.

Full 3.5" Diameter - It is extremely tight in some areas, but we made it fit, and very close to the body of the car - no low hanging points to drag on your trailer, entrance curbing, etc. V-band clamps connect the exhaust sections for a clean, tight seal with no gasket required. The 3.5" diameter requires hand-piecing mandrel-bent pipe sections together instead of bending longer pipe sections, but we are not willing to sacrifice our goals for ease of production. The final judge is the dyno, and a 3.5" exhaust makes more power than 3" in even a stock engine - and is an absolute requirement for more modified powerplants.

Now, even though they had applied their "specifically designed to increase exhaust scavenging" collector, they couldn't improve low end. Also, 3.5" made 10hp, let's say 3" made 5hp. Very little gains, and such diameters were used on the engine which produces around 300 whp stock, where M54b30 make less than 200 whp stock.

I DEFINITELY think that the Magnaflow is a well engineered exhaust. Not a doubt in my mind! In fact, as I was sitting outside the shop waiting for a cooldown after I saw my torque loss, that was my first thought.

Originally Posted by secono330ci

You could always think that maybe the magnaflow was a good designed exhaust. Maybe if you didn't have that before hand you would have made more power over something different.

Looks/sounds great!

Originally Posted by hoveringuy

Good info.

I just got done fabbing my exhaust and went with 2.5" partly because I couldn't find a 2" to 3" Y.

I wanted quiet and lighter weight. Objectives met.

http://r3vlimited.com/board/showthread.php?t=183420

For reference, here's a better shot of the current Y.

The problem is the Y pipe, period. There is no loss in power going to larger and larger pipe after the merfer. The merger must expand too fast, causing the exhaust gases to cool and slow down, which is why there is a loss of low end power. I've pointed this out before.

The Single 3" pipe has just a bit more surface area than dual 2" pipes, and when the merger is designed correctly, there should be no loss in power. Period.


From Bimmerworlds graph, I don't see a loss in power, but I do see a dyno run that was started later than the inital baseline, which causes a huge dip at the begining as the engine revs under load.

I agree, although after sending the picture of my current Y to Burns, he said it's pretty close to how they do it. I sent him a better pic to review.

It's on my list, I just need to get some cash together. Another $230 plus welding wasn't in my budget for this, yet.

Also working on getting some parts together for another small project, plus buying a head, and still trying to save up for the ATI damper. Ugh...

Originally Posted by Iceman00

The problem is the Y pipe, period. There is no loss in power going to larger and larger pipe after the merfer. The merger must expand too fast, causing the exhaust gases to cool and slow down, which is why there is a loss of low end power. I've pointed this out before.

The Single 3" pipe has just a bit more surface area than dual 2" pipes, and when the merger is designed correctly, there should be no loss in power. Period.


From Bimmerworlds graph, I don't see a loss in power, but I do see a dyno run that was started later than the inital baseline, which causes a huge dip at the begining as the engine revs under load.

Then the only thing left to do is find the proper placement of the Y pipe. Active Auto (and BMW) place the Y pipe around the transmission and driveshaft coupling area.

I'd like to see graphs.

Originally Posted by Iceman00

Then the only thing left to do is find the proper placement of the Y pipe. Active Auto (and BMW) place the Y pipe around the transmission and driveshaft coupling area.

Sounds like I should have just gone with the HKS system (which I'd still LOVE to see a dyno on):



That would put the Y pipe right where you're describing it.

Originally Posted by Iceman00

I'd like to see graphs.

Me, too. Still waiting... I need to call him.

Originally Posted by Iceman00

Then the only thing left to do is find the proper placement of the Y pipe. Active Auto (and BMW) place the Y pipe around the transmission and driveshaft coupling area.

This is what i was hinting at a few days ago. If you look at the y pipe from a 323. It's much further back.

Well, if I end up moving the Y pipe back, I'll more than likely scavenge some of that low end torque, but will I sacrifice any gains I made in the process? (Thus wasting my time?)

Aggie, I say save the cash for now, and have the Y pipe placed further back. When I get home, I'll show you what I found.

Originally Posted by aggieE46

Well, if I end up moving the Y pipe back, I'll more than likely scavenge some of that low end torque, but will I sacrifice any gains I made in the process? (Thus wasting my time?)

No, you should be able to have your cake, and eat it too.

I'm 5 days into cutting sugar back out of my diet. No need to rub it in

I'm easily frustrated by things like this situation. Bleh.

Originally Posted by Iceman00

No, you should be able to have your cake, and eat it too.