Downpipe without a tune?

dphjr · 07-10-2015, 09:30 PM

So my Shifteck catless dp came in today, and I have been reading up on whether or not it is bad to install it without getting a tune. I plan on getting a jb4 next month. Should I wait or go for it? As I said before I have read a lot of threads and some say yes and others no.

ocN55 · 07-10-2015, 10:27 PM

It's a no for me, gains would be marginal without a tune and you will get a CEL unless you get a jb4.

dphjr · 07-10-2015, 11:07 PM

but will it be detrimental to my engine? I'm not so concerned with gains right now as I am getting this done earlier in the summer before I become busy in the fall. I have heard people mention that it could cause my afr to become unstable and possibly hurt my motor. Also as long as it doesnt hurt my engine I could live with a cel for a month.

Buckeyes · 07-10-2015, 11:37 PM

The downpipe will give you a cel but will not hurt performance or the engine.

CONTROL ONE · 07-11-2015, 12:17 AM

What about a downpipe with a BMS Stage 1 tune? Would there be any benefit there?

ocN55 · 07-11-2015, 12:37 AM

Quote:

Originally Posted by dphjr

but will it be detrimental to my engine? I'm not so concerned with gains right now as I am getting this done earlier in the summer before I become busy in the fall. I have heard people mention that it could cause my afr to become unstable and possibly hurt my motor. Also as long as it doesnt hurt my engine I could live with a cel for a month.

Won't be detrimental but car wouldn't be running as efficiently. And you will get a CEL. What's holding you back in getting a JB4 right now?

Quote:

Originally Posted by CONTROL ONE

What about a downpipe with a BMS Stage 1 tune? Would there be any benefit there?

No, you practically need a JB4 to run a dp

dphjr · 07-11-2015, 01:52 AM

Quote:

Originally Posted by ocN55

What's holding you back in getting a JB4 right now?

Don't have the money at the moment, cars are to **** expensive!

daveslaine · 07-11-2015, 02:04 AM

I'm a little held up on getting a er cates as I'm afraid my car will smell like an 80s car. Is this any true?

ocN55 · 07-11-2015, 03:30 AM

Quote:

Originally Posted by daveslaine

I'm a little held up on getting a er cates as I'm afraid my car will smell like an 80s car. Is this any true?

Yea it will smell, it's catless duh. Won't smell anything with windows up.

I thought you were getting an m4 brah

JibHonk · 07-11-2015, 11:00 AM

I have a brand new never installed armytrix downpipe catless with simulators for sale. $420 shipped.

mike@x-ph.com · 07-11-2015, 08:56 PM

Running catless downpipes with no tune is fine. You will not take 100% advantage of what Catless DP offer but you will not damage your engine.
That being said i strongly recommend using JB4 for maximum performance gains.
Stage 1 would work as well, you need to get the BMS can flap module to clear the CEL code.

zipphreak · 07-11-2015, 08:59 PM

Quote:

I'm a little held up on getting a er cates as I'm afraid my car will smell like an 80s car. Is this any true?

Sorry is it just me or does this guy just deliberately acts like an imbecile on the forum

Of course it's going to smell worse! It's the carbon monoxide, nitrous oxdide, and poisonous hydrocarbons that are spitting into the atmosphere.

The computer uses the first O2 sensor to tune the A/F ratios, but it uses the post-cat O2 to validate the CAT's efficiency and operation. If there is no CAT then you get a CEL. The JB4 is constantly clearing the codes in the DME, you will not pass inspection, and you will not be street legal.

DfVgyCjmFQnu · 09-09-2016, 02:34 AM

Bump on this. Seems there is no damage to engine in running a catless downpipe without a tune, and no performance benefit. Should be a nice sound benefit though!

chobit · 09-09-2016, 06:36 AM

Back in the days when I have my 06 STi, doing CAT-less DP without a tune is not recommended, because you can run into issue going WOT such as Boost Creep, or if the car is running lean during boost. With that being said, I am new to BMW, and if someone can explain how this potential problem won't matter to our M235i ?

Anthony235 · 09-09-2016, 10:25 AM

Quote:

Originally Posted by chobit

Back in the days when I have my 06 STi, doing CAT-less DP without a tune is not recommended, because you can run into issue going WOT such as Boost Creep, or if the car is running lean during boost. With that being said, I am new to BMW, and if someone can explain how this potential problem won't matter to our M235i ?

Easy. STi blows it's motor if you look at it wrong.

You will get a small bump in power with DP and no tune. You can feel it too.

The smell should not be bad unless you actually have an exhaust leak where the DP is. Most of the smell will come from your tailpipes when stopped and the wind blows the fumes towards the front of the car. Even then it's not bad.

mike@x-ph.com · 09-09-2016, 10:51 AM

Quote:

Originally Posted by qafwfk7pNkou

Bump on this. Seems there is no damage to engine in running a catless downpipe without a tune, and no performance benefit. Should be a nice sound benefit though!

As Anthony235 said you do get a small bump in power with the DP without the tune. Your turbo will spool faster as well

Anthony235 · 09-09-2016, 10:54 AM

Quote:

Originally Posted by mike@x-ph.com

As Anthony235 said you do get a small bump in power with the DP without the tune. Your turbo will spool faster as well

The faster spool is where you will feel it for sure. Means more power down low. I'm not a "butt dyno" fan, but you can feel it in this case.

Jeff@TopGearSolutions · 09-14-2016, 10:39 AM

Quote:

Originally Posted by Anthony235

Easy. STi blows it's motor if you look at it wrong.

This made me chuckle a bit haha.

But yea these cars a lot more forgiving and smarter.

07-10-2015, 09:30 PM	#1
dphjr New Member 139 Rep 225 Posts Drives: Alpine White M235i Join Date: Jan 2015 Location: DMV Area iTrader: (0)	Downpipe without a tune? So my Shifteck catless dp came in today, and I have been reading up on whether or not it is bad to install it without getting a tune. I plan on getting a jb4 next month. Should I wait or go for it? As I said before I have read a lot of threads and some say yes and others no. __________________ 2015 ///M235i \| Alpine White \| 8AT \| RW Carbon Front & Rear Lips \| Autotecknic Paddles \| MP Side Decals \| AWE Axelback \| Shifteck DP \| MHD Stage 2+ \| BMS Intake \| FTP Charge Pipe \| VRSF FMIC
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07-10-2015, 10:27 PM	#2
ocN55 Lieutenant Colonel 560 Rep 1,503 Posts Drives: '15 M235i 6MT/ '16 M3 Join Date: Dec 2013 Location: LA iTrader: (18)	It's a no for me, gains would be marginal without a tune and you will get a CEL unless you get a jb4.
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07-10-2015, 11:07 PM	#3
dphjr New Member 139 Rep 225 Posts Drives: Alpine White M235i Join Date: Jan 2015 Location: DMV Area iTrader: (0)	but will it be detrimental to my engine? I'm not so concerned with gains right now as I am getting this done earlier in the summer before I become busy in the fall. I have heard people mention that it could cause my afr to become unstable and possibly hurt my motor. Also as long as it doesnt hurt my engine I could live with a cel for a month. __________________ 2015 ///M235i \| Alpine White \| 8AT \| RW Carbon Front & Rear Lips \| Autotecknic Paddles \| MP Side Decals \| AWE Axelback \| Shifteck DP \| MHD Stage 2+ \| BMS Intake \| FTP Charge Pipe \| VRSF FMIC Last edited by dphjr; 07-10-2015 at 11:13 PM..
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07-10-2015, 11:37 PM	#4
Buckeyes Captain 353 Rep 939 Posts Drives: 2013 335i M Sport Join Date: Jan 2013 Location: Atlanta iTrader: (2)	The downpipe will give you a cel but will not hurt performance or the engine.
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07-11-2015, 12:17 AM	#5
CONTROL ONE Second Lieutenant 69 Rep 210 Posts Drives: 2014 BMW M235i Join Date: Mar 2014 Location: Toronto, Canada iTrader: (0)	What about a downpipe with a BMS Stage 1 tune? Would there be any benefit there?
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07-11-2015, 02:04 AM	#8
daveslaine Banned 84 Rep 193 Posts Drives: Coming soon Join Date: Mar 2015 Location: Calabasas iTrader: (0)	I'm a little held up on getting a er cates as I'm afraid my car will smell like an 80s car. Is this any true?
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07-11-2015, 11:00 AM	#10
JibHonk Private First Class 69 Rep 165 Posts Drives: 15 m235i Join Date: May 2015 Location: NEPA iTrader: (0)	I have a brand new never installed armytrix downpipe catless with simulators for sale. $420 shipped.
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07-11-2015, 08:56 PM	#11
mike@x-ph.com Joint Chiefs of Staff 24171 Rep 190,750 Posts Drives: 07-335/12-328/18-M4/21-M4CP Join Date: Sep 2013 Location: Las Vegas iTrader: (23)	Running catless downpipes with no tune is fine. You will not take 100% advantage of what Catless DP offer but you will not damage your engine. That being said i strongly recommend using JB4 for maximum performance gains. Stage 1 would work as well, you need to get the BMS can flap module to clear the CEL code. __________________ Check out our current sale by clicking on this link! https://x-ph.com/sale/ Phone number 702-494-9435
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09-09-2016, 02:34 AM	#13
DfVgyCjmFQnu Private First Class 117 Rep 163 Posts Drives: 2015 m235i Auto Coupe Join Date: Jan 2010 Location: Space iTrader: (0)	Bump on this. Seems there is no damage to engine in running a catless downpipe without a tune, and no performance benefit. Should be a nice sound benefit though!
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09-09-2016, 06:36 AM	#14
chobit New Member 11 Rep 25 Posts Drives: 2016 M235i xDrive Cab - Blue Join Date: Aug 2016 Location: Seattle iTrader: (0)	Back in the days when I have my 06 STi, doing CAT-less DP without a tune is not recommended, because you can run into issue going WOT such as Boost Creep, or if the car is running lean during boost. With that being said, I am new to BMW, and if someone can explain how this potential problem won't matter to our M235i ?
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