Akrapovic E82 1M Downpipes

[Ilia@IND]

Originally Posted by EIN M

OK, so I'm a little confused.
a) How does the composition of the "ends of the downpipe" affect flow? Wouldn't the shape be the determining factor?
b) Does this mean that entire DP is not 100% SS?

The composition itself does not affect flow, but using a casting process to create the end pieces allows for much more complex shapes than simple tube bending and hand fabrication. The bellmouth shape of the cast flange portion improves flow.

The downpipe is still composed of 100% stainless steel.

Originally Posted by PHANTOM

I hate to sound ignorant but what exactly is the benefit of changing out downpipes? And how involved is the install on the 1M?

Aftermarket downpipes eliminate the catalytic converters found in the factory downpipes and improve flow by a substantial margin. The 1M engine bay is a bit tight, so I’d suggest a professional install.

Originally Posted by fastauto

+1. I am new to the bmw world but have been having fun with turbo cars for a long while. I am shocked to see so many people not looking for a true 3" setup. Is it because the majority of people running these engines retain the stock turbos thus you dont need the larger plumbing?

The 2.5” downpipe only has to flow enough air for 3 cylinders, and the link pipes and collectors remain 2.5” throughout, so there are two pipes going all the way to the middle of the car. I believe that you can achieve a very high power figure before choking such a setup.

[TUNEDM3]

Does Akra sell anything to delete the cel once these downpipes are installed on a car that is running stock software?

[RaptorKTM]

Originally Posted by TUNEDM3

Does Akra sell anything to delete the cel once these downpipes are installed on a car that is running stock software?

No. Using an ESS tune will solve the issue though

[Ilia@IND]

Correct, ESS solves that problem, and gives the car a great deal more power to boot.

[fastauto]

Originally Posted by Ilia@IND

Correct, ESS solves that problem, and gives the car a great deal more power to boot.

does it simply mask the cel on the dashboard or does it do more? I had revo software on my old car that had no cats and it masked the cel on the dash but during a new york state inspection it would still not pass.

[ZCP M3]

Nice looking pipes. Cost?

I'm interested to see the difference in power between a 2.5" and 3" setup but if the 3" pipe gets choked down to 2.5" anywhere along the way it should be negligible.

[Ilia@IND]

Originally Posted by fastauto

does it simply mask the cel on the dashboard or does it do more? I had revo software on my old car that had no cats and it masked the cel on the dash but during a new york state inspection it would still not pass.

ESS' software de-activates the secondary O2 sensors for racing and off-road use. This way your check engine light still functions as it should to give you any other error codes the car may show, just not the "catalyst malfunction" error. You will still fail inspection with the 02 sensors disabled.

[sparoz]

How much louder is the system with downpipes? Is there any droning at cruising speed? In Aus we have a report the dreaded drone is gone with evolution without the dp.

[mpiligrim]

1 Price?
2 Can I just use them with stock system/ (as far as I understood from previous posts, yes)
3 Any other software except for ESS?

[Nate@IND]

Originally Posted by mpiligrim

1 Price?
2 Can I just use them with stock system/ (as far as I understood from previous posts, yes)
3 Any other software except for ESS?

1. $1650.00
2. Yes they work with the OEM system
3. Evolve tuning or Dinan