[BeemerBaron]

Trying to work out what is the best Downpipe for an M240i G42

Are all F series B58 catalytic down pipes suitable for a G series? Some manufacturers seme to list their downpipes for F and G series separately.

AA seems to be the only guaranteed to not through a CEL but Fabspeed also have a very high quality HJL which states it doesn't throw a CEL and is 100 cells less and uses a higher quality cat material then the AA, however fitment is only listed for F series Beemmers.

[TheJerseyDon]

Fabspeed shows G20? Pricey tho...

https://www.fabspeed.com/fabspeed-bm...downpipe-2019/

[BeemerBaron]

Originally Posted by TheJerseyDon

Fabspeed shows G20? Pricey tho...

https://www.fabspeed.com/fabspeed-bm...downpipe-2019/

I ended up ordering one of these. Waiting for it to be shipped out - look forward to installing and giving it run.

[TheJerseyDon]

Please let us know how you get on with this version.

[H2O_Doc]

Originally Posted by Slingray

I ended up ordering one of these. Waiting for it to be shipped out - look forward to installing and giving it run.

This is interesting. Sounds like they've engineered it so it has better flow and still does a good job reducing emissions. I'd be happy to pay a little more to keep my tailpipe emissions in compliance. Going catless really spews out a ton of nastiness.

That said, not sure how the various catted DPs stack up against stock for emissions.

[BeemerBaron]

I received this from FabSpeed:

"Thank you for choosing Fabspeed, we sincerely appreciate your business! Your order is in process. Items that require fabrication have been scheduled in manufacturing, lead times will vary. Items that are in stock will be allocated, and if domestic delivery is indicated, will be partially shipped. "

I suspect it needs to be fabricated, so may be a while. I've emailed for an ETA

[kumizi206]

As far as I know, Fabspeed is the only licensed distributor for HJS cats in the US. So if you want the best performing cat that will also last the longest, they're #1.

[TUG_H1LL]

I am wondering if I install an intake and down pipe would I need a tune ?

Just wondering the requirements for a tune with particular parts installed….

I’m a first time BMW Owner each of my other cars are different in requiring tunes for parts…


I herd some b58 Supra owners are saying good things about the active auto works catted down-pipe
Has anyone have good experience with this ?

[TheJerseyDon]

Originally Posted by TUG_H1LL

I am wondering if I install an intake and down pipe would I need a tune ?

Just wondering the requirements for a tune with particular parts installed….

I’m a first time BMW Owner each of my other cars are different in requiring tunes for parts…


I herd some b58 Supra owners are saying good things about the active auto works catted down-pipe
Has anyone have good experience with this ?

It depends on whcih DP you use. If its a version that does not throw CEL then no tune required. IF it does then yes a tune to make the CEL go away. There is also another tread on DP on this forum with more details on various DPs and even some YT vids.

[BeemerBaron]

Originally Posted by TUG_H1LL

I am wondering if I install an intake and down pipe would I need a tune ?

Just wondering the requirements for a tune with particular parts installed….

I’m a first time BMW Owner each of my other cars are different in requiring tunes for parts…


I herd some b58 Supra owners are saying good things about the active auto works catted down-pipe
Has anyone have good experience with this ?

You don't need a tune to take advantage of the downpipe, the turbo will spool better once the DP is installed. If you do however apply a tune, you can run the turbo a little harder due to the reduced back pressure.