BM3 stage 1 plus catted downpipe?

GA/\/\/\/\A_CT · 02-07-2021, 10:42 AM

Hey Motor Heads!

Does it make sense to add a catted downpipe to my 2016 340xi if my only other mod is stage 1 flash from BM3?

My goal is actually to reduce strain on turbo, so I don’t necessarily want a lot more power, and definitely don’t want to force the turbo to do more work...

Thoughts?

M140_BCS · 02-07-2021, 11:02 AM

There isn't a big increase in boost pressure going from Stage 1 to 2.

Ignition timing advance is increased to add more power.

Randy Johnson · 02-07-2021, 11:14 AM

You should still see a 15-20 hp gain with the catted downpipe. And the exhaust has a little more volume. I think it's worth it.

T_H_O_M_A_S · 02-07-2021, 11:48 AM

Quote:

Originally Posted by GA/\/\/\/\A_CT

Hey Motor Heads!

Does it make sense to add a catted downpipe to my 2016 340xi if my only other mod is stage 1 flash from BM3?

My goal is actually to reduce strain on turbo, so I don’t necessarily want a lot more power, and definitely don’t want to force the turbo to do more work...

Thoughts?

run stock ??

GA/\/\/\/\A_CT · 02-07-2021, 11:51 AM

Thanks guys!

For the extra power gained by catted downpipe, is it mostly down low in RPMs or more on top end?

G.Newt · 02-07-2021, 09:57 PM

I'm up here at elevation and did not have a good time on stage 1 with my catted DP.

GA/\/\/\/\A_CT · 02-08-2021, 12:25 PM

Quote:

Originally Posted by G.Newt

I'm up here at elevation and did not have a good time on stage 1 with my catted DP.

Uh oh! What happened? Feel free to PM me if you prefer!

dmanb2b · 02-08-2021, 01:43 PM

I was on bm3 stage1 for a few weeks. Wasn't happy with how touchy the first 10% of throttle was and flat top-end. Having recently moved to stage 2 93 and a AA Catted DP, there is very little reason to stay stage 1. I find stage 2 to have much smoother power delivery than I had on stage 1. With stock downpipes selling for $700+ and no CEL on the AA catted DP, was the best move ever for me. Trans is also tuned xhp3. Hope this helps you.

G.Newt · 02-08-2021, 03:47 PM

Quote:

Originally Posted by GA/\/\/\/\A_CT

Uh oh! What happened? Feel free to PM me if you prefer!

Throttle closure. My throttle in the logs looked like a sin wave from trigonometry lol. Stage 2 behaved much better. Stage 2 E30 is almost mint.

BAKKI · 02-08-2021, 04:44 PM

Wanted to know the same thing: am ST1 and want to add a catted DP. I'm hesitant to go ST2 since I'm MT and many have had clutch slippage at 400+ WTQ.

I'm in CA and can only run 91 if that makes a difference.

Wires · 02-13-2021, 04:22 PM

Keep in mind map versions of BM3 when you say there are issues. The 2.x maps are MUCH better than the 1.x maps.

Personally, do the DP + Stage 2. Why not? Power is intoxicating.

les anderson · 02-14-2021, 01:28 PM

Even a high flow catted dp is going to smell, and I personally would not take that on unless you are going to fully leverage it.

mike@x-ph.com · 02-16-2021, 10:33 AM

Quote:

Originally Posted by Wires

Keep in mind map versions of BM3 when you say there are issues. The 2.x maps are MUCH better than the 1.x maps.

Personally, do the DP + Stage 2. Why not? Power is intoxicating.

Wrong section again

Agree with going stage 2 if he has a downpipe

Wires · 02-16-2021, 01:57 PM

Quote:

Originally Posted by mike@x-ph.com

Wrong section again

Agree with going stage 2 if he has a downpipe

Not sure what you mean by wrong section?

If he's doing the catted DP, might as well do stage 2. Others above said they had issues with the stage 1 maps, which you need to be careful since the 1.x maps were a lot more "harsh". Just pointing out that might be an irrelevant data point, and moot for the OP.

340abaan · 02-16-2021, 04:23 PM

Think you should be good. I ran a catted Downpipe for a year and a half no issues

dmanb2b · 02-17-2021, 08:01 AM

Quote:

Originally Posted by les anderson

Even a high flow catted dp is going to smell, and I personally would not take that on unless you are going to fully leverage it.

AA catted DP does not smell after few seconds on a cold start. Cold start smell is just like any other vehicle with a slightly older cat setup. Can't speak for other brands.

mike@x-ph.com · 02-17-2021, 10:19 AM

Quote:

Originally Posted by Wires

Not sure what you mean by wrong section?

If he's doing the catted DP, might as well do stage 2. Others above said they had issues with the stage 1 maps, which you need to be careful since the 1.x maps were a lot more "harsh". Just pointing out that might be an irrelevant data point, and moot for the OP.

I posted a reply about needing an intercooler then realized its the wrong section and edited the response

Wires · 02-17-2021, 10:50 AM

Quote:

Originally Posted by mike@x-ph.com

I posted a reply about needing an intercooler then realized its the wrong section and edited the response

Ahhh.. ok then! Thought I was drinking again.

mike@x-ph.com · 02-17-2021, 02:20 PM

Quote:

Originally Posted by Wires

Ahhh.. ok then! Thought I was drinking again.

02-07-2021, 10:42 AM	#1
GA/\/\/\/\A_CT Lieutenant 217 Rep 584 Posts Drives: ‘20 m340ix Join Date: Jan 2018 Location: CT iTrader: (0)	BM3 stage 1 plus catted downpipe? Hey Motor Heads! Does it make sense to add a catted downpipe to my 2016 340xi if my only other mod is stage 1 flash from BM3? My goal is actually to reduce strain on turbo, so I don’t necessarily want a lot more power, and definitely don’t want to force the turbo to do more work... Thoughts?
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02-07-2021, 11:02 AM	#2
M140_BCS Lieutenant 238 Rep 413 Posts Drives: 440i Gran Coupe Join Date: Dec 2019 Location: UK iTrader: (0)	There isn't a big increase in boost pressure going from Stage 1 to 2. Ignition timing advance is increased to add more power. __________________ 2017 440i F36 - Drexler LSD - B58TU HPFP - MHD Stage 2 - xHP - 200 Cell DP - MPE
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02-07-2021, 11:14 AM	#3
Randy Johnson M340i 392 Rep 967 Posts Drives: BMW M340i Join Date: Sep 2019 Location: South FLA iTrader: (1) Garage List 2021 BMW M340i [10.00]	You should still see a 15-20 hp gain with the catted downpipe. And the exhaust has a little more volume. I think it's worth it.
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02-07-2021, 11:51 AM	#5
GA/\/\/\/\A_CT Lieutenant 217 Rep 584 Posts Drives: ‘20 m340ix Join Date: Jan 2018 Location: CT iTrader: (0)	Thanks guys! For the extra power gained by catted downpipe, is it mostly down low in RPMs or more on top end?
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02-07-2021, 09:57 PM	#6
G.Newt Major 811 Rep 1,452 Posts Drives: CT4-V Blackwing 6MT Join Date: Feb 2017 Location: CO -> TX iTrader: (0)	I'm up here at elevation and did not have a good time on stage 1 with my catted DP. __________________ 2022 CT4-V Blackwing 6-speed SOLD: 2016 340i xDrive 6-speed DAW v2.5 turbo E40 \| Dorch S2 \| VRSF DP \| MST intake \| AWE catback \| 335is clutch \| CSF heat exchanger \| RK Autowerks intake manifold \| Orange M Perf Brake Kit \| KW Street Comfort coilovers \| GTS taillights V2
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02-08-2021, 01:43 PM	#8
dmanb2b Banned 2123 Rep 3,368 Posts Drives: G07, F97, F30, E90, E46, E30 Join Date: Jul 2016 Location: NY iTrader: (5)	I was on bm3 stage1 for a few weeks. Wasn't happy with how touchy the first 10% of throttle was and flat top-end. Having recently moved to stage 2 93 and a AA Catted DP, there is very little reason to stay stage 1. I find stage 2 to have much smoother power delivery than I had on stage 1. With stock downpipes selling for $700+ and no CEL on the AA catted DP, was the best move ever for me. Trans is also tuned xhp3. Hope this helps you.
	Appreciate 0 Quote

02-08-2021, 04:44 PM	#10
BAKKI Private 19 Rep 77 Posts Drives: 2017 440i Join Date: Jan 2020 Location: CA iTrader: (0)	Wanted to know the same thing: am ST1 and want to add a catted DP. I'm hesitant to go ST2 since I'm MT and many have had clutch slippage at 400+ WTQ. I'm in CA and can only run 91 if that makes a difference.
	Appreciate 2 e_b_d_i18.00 mgeller51.50 Quote

02-13-2021, 04:22 PM	#11
Wires Brigadier General 1646 Rep 4,876 Posts Drives: 2016 340i xDrive Join Date: Apr 2008 Location: Calgary iTrader: (0)	Keep in mind map versions of BM3 when you say there are issues. The 2.x maps are MUCH better than the 1.x maps. Personally, do the DP + Stage 2. Why not? Power is intoxicating.
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02-14-2021, 01:28 PM	#12
les anderson Second Lieutenant 146 Rep 201 Posts Drives: 340i Join Date: Jan 2019 Location: Miami iTrader: (0)	Even a high flow catted dp is going to smell, and I personally would not take that on unless you are going to fully leverage it.
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02-16-2021, 04:23 PM	#15
340abaan New Member 0 Rep 10 Posts Drives: BMW 340xi Join Date: Feb 2021 Location: New York City iTrader: (0)	Think you should be good. I ran a catted Downpipe for a year and a half no issues
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