What does "cat-back" mean and tuner question

Jamestab · 03-03-2021, 09:15 AM

Hello, i have a 2011 328i e92 n51, and I'm looking at exhaust modifications. I want to do afe catted headers so i can pass emissions, but am curious what "cat'back" exhaust setup is. Is this all the way back from the catted headers? Is this going back from a second cat further in the exhaust? Do i need all cats to not get an engine light? How far deep into the exhaust can i go removing cats until i get an engine light? Sorry for the billion questions, this is an issue I've struggled with understanding for awhile.

Also, who's a good tuner for the N51 that i can be confident will take my 3 stage intake with disa valves into account and all my other mods? Maybe if they can tune e85 too? Currently i have an off the shelf tune from turner and am not confident my 3 stage was tuned. I would like a custom tune. Any ideas?

neilvan · 03-03-2021, 09:41 AM

Cat-back means after the cats; on these cars it would be considered behind the secondary cats (primarys are considered part of the headers/exhaust manifold).

Removing secondaries will have no codes and not affect anything unless you have a visual inspection; removing the primaries will show a code unless you do something about it.

I know bimmerlabs has mentionned doing N51 tunes(they also do performance ones) but I believe its just "off the shelf" ones unless someone can correct me on that.

Biginboca · 03-03-2021, 09:52 AM

Leanped · 03-05-2021, 04:07 PM

After you get headers, you could look into Stage FP for a tune.

DO NOT try to go for E85, it's only good on cars that have a turbo. It won't hurt anything but you'll make less power and waste money.

If you're not going fully catless, I honestly recommend saving some money and following the steps on bimmerlabs to get a basic tune. Good luck!

Jamestab · 03-05-2021, 06:21 PM

Is that actually true about E85? It's a 900$ kit plug and play and claims 10-15% gains at the wheels. Also, what are you referencing with the basic bimmerlabs tune? I have an intake and tune already, and I'm looking for more legal power ie catted headers, open exhaust behind it, and i was hoping the E85 claims were true. I'd like other opinions but im certainly glad i asked. I was looking on ecstuning and they had a flex fuel sensor that was plug and play.

aphael · 03-05-2021, 08:59 PM

Quote:

Originally Posted by Leanped

After you get headers, you could look into Stage FP for a tune.

DO NOT try to go for E85, it's only good on cars that have a turbo. It won't hurt anything but you'll make less power and waste money.

If you're not going fully catless, I honestly recommend saving some money and following the steps on bimmerlabs to get a basic tune. Good luck!

This is misinformation. E85 is a much higher octane fuel than 91/93. BUT you need a tune that advances the timing enough in order to make use of the higher octane, or else your wasting money. It is good on turbo cars that is correct but to say its wasting money and less power is false. E85 just has very small gains on na motors through mechanical tuning.

Bimmerlabs is great but I have had an awful experience with their custom tune. I have been waiting 5 months for a custom tune and haven't gotten anything after paying.

10-15% is a bit optimistic, I would say closer to 5%

Jamestab · 03-06-2021, 09:18 AM

This quotea is what the device says it does. It says it should be compatible with my tune i already have. My brother is insisting it will not communicate with the motor and i will not see gains unless specifically tuned for e85, is this true? Is the engine still going to basically make no adjustments to the motor unless tuned? This sales page makes it seems like you plug it in and it should make engine adjustments automatically. Here is the link and info on page

https://www.ecstuning.com/b--advanced-fuel-dynamics-parts/proflex-commander-adaptive-e85-flex-fuel-system/pfc-e90328-k~dk/?pdk=AQ

Product Details
True plug and play flex-fuel for your BMW in about an hour with no tuning required.

ProFlex Commander Features:

Complete system - everything you need to run E85
100% Dyno tested for safety, durability and power gains
Easy DIY installation - Under an hour with common tools
Patented BlendSense technology adjusts in real-time with a 30-millisecond refresh rate
True flex-fuel - switch from gas to ethanol and back anytime
Improved injector management for more power on gas or E85
7-10% More wheel HP and torque on E85 (dyno proven)
No tuning required - Compatible with stock or performance gas tunes; instantly adapts to new tunes
Cleaner emissions and cooler cylinder, oil and coolant temps
Race grade fuel at the pump - high octane, low cost
Compatible with power adders and bolt-ons
ProFlex Connect app provides accurate, real-time ethanol content on your iPhone or Android device via Bluetooth
Cold Start Plus - improves fuel atomization for easier starting in cold weather

03-03-2021, 09:15 AM	#1
Jamestab New Member 2 Rep 12 Posts Drives: Bmw 2011 328i e92 n51 coupe Join Date: Nov 2020 Location: Racine iTrader: (0)	What does "cat-back" mean and tuner question Hello, i have a 2011 328i e92 n51, and I'm looking at exhaust modifications. I want to do afe catted headers so i can pass emissions, but am curious what "cat'back" exhaust setup is. Is this all the way back from the catted headers? Is this going back from a second cat further in the exhaust? Do i need all cats to not get an engine light? How far deep into the exhaust can i go removing cats until i get an engine light? Sorry for the billion questions, this is an issue I've struggled with understanding for awhile. Also, who's a good tuner for the N51 that i can be confident will take my 3 stage intake with disa valves into account and all my other mods? Maybe if they can tune e85 too? Currently i have an off the shelf tune from turner and am not confident my 3 stage was tuned. I would like a custom tune. Any ideas?
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03-03-2021, 09:41 AM	#2
neilvan Major 868 Rep 1,379 Posts Drives: 09 E90 335i M-Sport 6MT RWD Join Date: Nov 2017 Location: Ontario, Canada iTrader: (0) Garage List 2007 BMW E61 530xi [0.00] 1993 Mazda Miata [0.00] 2009 BMW E90 335i [0.00]	Cat-back means after the cats; on these cars it would be considered behind the secondary cats (primarys are considered part of the headers/exhaust manifold). Removing secondaries will have no codes and not affect anything unless you have a visual inspection; removing the primaries will show a code unless you do something about it. I know bimmerlabs has mentionned doing N51 tunes(they also do performance ones) but I believe its just "off the shelf" ones unless someone can correct me on that.
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03-03-2021, 09:52 AM	#3
Biginboca Colonel 3800 Rep 2,738 Posts Drives: 2009 E92 328i 6MT Join Date: Jun 2017 Location: Boynton Beach, FL... USA iTrader: (3)	__________________ My E92 328csl Build Thread My 328csl Instagram Page
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03-05-2021, 04:07 PM	#4
Leanped New Member 9 Rep 29 Posts Drives: 2007 BMW 335i ST MT Join Date: Aug 2020 Location: Minnesota iTrader: (0)	After you get headers, you could look into Stage FP for a tune. DO NOT try to go for E85, it's only good on cars that have a turbo. It won't hurt anything but you'll make less power and waste money. If you're not going fully catless, I honestly recommend saving some money and following the steps on bimmerlabs to get a basic tune. Good luck!
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03-05-2021, 06:21 PM	#5
Jamestab New Member 2 Rep 12 Posts Drives: Bmw 2011 328i e92 n51 coupe Join Date: Nov 2020 Location: Racine iTrader: (0)	Is that actually true about E85? It's a 900$ kit plug and play and claims 10-15% gains at the wheels. Also, what are you referencing with the basic bimmerlabs tune? I have an intake and tune already, and I'm looking for more legal power ie catted headers, open exhaust behind it, and i was hoping the E85 claims were true. I'd like other opinions but im certainly glad i asked. I was looking on ecstuning and they had a flex fuel sensor that was plug and play.
	Appreciate 0 Quote

03-06-2021, 09:18 AM	#7
Jamestab New Member 2 Rep 12 Posts Drives: Bmw 2011 328i e92 n51 coupe Join Date: Nov 2020 Location: Racine iTrader: (0)	This quotea is what the device says it does. It says it should be compatible with my tune i already have. My brother is insisting it will not communicate with the motor and i will not see gains unless specifically tuned for e85, is this true? Is the engine still going to basically make no adjustments to the motor unless tuned? This sales page makes it seems like you plug it in and it should make engine adjustments automatically. Here is the link and info on page https://www.ecstuning.com/b--advanced-fuel-dynamics-parts/proflex-commander-adaptive-e85-flex-fuel-system/pfc-e90328-k~dk/?pdk=AQ Product Details True plug and play flex-fuel for your BMW in about an hour with no tuning required. ProFlex Commander Features: Complete system - everything you need to run E85 100% Dyno tested for safety, durability and power gains Easy DIY installation - Under an hour with common tools Patented BlendSense technology adjusts in real-time with a 30-millisecond refresh rate True flex-fuel - switch from gas to ethanol and back anytime Improved injector management for more power on gas or E85 7-10% More wheel HP and torque on E85 (dyno proven) No tuning required - Compatible with stock or performance gas tunes; instantly adapts to new tunes Cleaner emissions and cooler cylinder, oil and coolant temps Race grade fuel at the pump - high octane, low cost Compatible with power adders and bolt-ons ProFlex Connect app provides accurate, real-time ethanol content on your iPhone or Android device via Bluetooth Cold Start Plus - improves fuel atomization for easier starting in cold weather
	Appreciate 0 Quote