Not another down pipe thread...

DrivenAgain · 04-07-2021, 01:22 PM

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OK yes its a dead horse, BUT, I have yet to get any feedback from someone who has purchased catted primary/catless secondary's.
I need a bit more mid range TQ and Im on stock downpipes. I have JB4 and run Map 3 E30 with Project Gamma intake, best Dragy 60-130 6.84, best 1/4 10.45 @ 134.89 all runs in slightly neg DA. The down pipes should get me a bit deeper into the 6s but looking for feedback from anyone running catted/highflow.

Quinn A · 04-07-2021, 02:42 PM

I have a JB4 with secondary cat deletes. installed at the same time so tough to tell if any difference other then sound.

schnell1982 · 04-07-2021, 02:51 PM

I believe there are tests proving that removing the cats on this platform does not increase performance like other turbo engine platforms.
I recall reading a few software development companies doing back pressure tests etc.
Also I think on n54tech website they post the same stating they reccomend oem over catless

boost4breakfast · 04-12-2021, 12:48 PM

I'm running HJS catted downpipes. Their dyno shows 120 torque gain at 2500 rpm. Car is much faster and sounds means

mspired335i · 04-13-2021, 10:18 AM

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04-07-2021, 01:22 PM	#1
DrivenAgain MFJWADE 120 Rep 351 Posts Drives: 2018 BMW M5 Join Date: Dec 2020 Location: MD iTrader: (0)	Not another down pipe thread... Featured on BIMMERPOST.com OK yes its a dead horse, BUT, I have yet to get any feedback from someone who has purchased *catted primary/catless secondary's*. I need a bit more mid range TQ and Im on stock downpipes. I have JB4 and run Map 3 E30 with Project Gamma intake, best Dragy 60-130 6.84, best 1/4 10.45 @ 134.89 all runs in slightly neg DA. The down pipes should get me a bit deeper into the 6s but looking for feedback from anyone running catted/highflow.
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04-07-2021, 02:42 PM	#2
Quinn A Second Lieutenant 122 Rep 243 Posts Drives: 2016 M3 Join Date: Apr 2018 Location: Chicago iTrader: (0)	I have a JB4 with secondary cat deletes. installed at the same time so tough to tell if any difference other then sound. __________________ 2020 M8 SMB full boltons and tune 2022 CT5-V Blackwing 2019 GT3RS full headers exhaust and tune 2022 Cayenne Turbo coupe Catless/ Tune 2022 Huracan STO
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04-07-2021, 02:51 PM	#3
schnell1982 Captain 345 Rep 966 Posts Drives: FAST Join Date: Dec 2015 Location: Southern California iTrader: (0)	I believe there are tests proving that removing the cats on this platform does not increase performance like other turbo engine platforms. I recall reading a few software development companies doing back pressure tests etc. Also I think on n54tech website they post the same stating they reccomend oem over catless
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04-12-2021, 12:48 PM	#4
boost4breakfast Enlisted Member 3 Rep 38 Posts Drives: 992 GT3 24 M4C 21 M5C (gone) Join Date: Jan 2021 Location: CLE iTrader: (0)	I'm running HJS catted downpipes. Their dyno shows 120 torque gain at 2500 rpm. Car is much faster and sounds means
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04-13-2021, 10:18 AM	#5
mspired335i Second Lieutenant 40 Rep 221 Posts Drives: 2021 M5 Join Date: Feb 2013 Location: NY iTrader: (2)	Subscribed
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