[T_flare]

so base on what i am reading (and im sorry this is my first car Im tuning) going with a 400 cattless vs 850 catted, you're only spending more to save the enviroment? performance wise, the cattless is your better bet?

[Mike_L]

Originally Posted by T_flare

so base on what i am reading (and im sorry this is my first car Im tuning) going with a 400 cattless vs 850 catted, you're only spending more to save the enviroment? performance wise, the cattless is your better bet?

To save the environment and your car. As I've said before, if you get stopped at an EPA checkpoint and have no cat, your car will be impounded. Same thing in a state with visual inspections. No cat, you will not pass.

Obviously catless will be better for power production because theres less back pressure. Its a trade off. Is 2 or 3 more horsepower worth risking your car and a couple hundred dollars?

[smithf80]

Originally Posted by Mike_L

To save the environment and your car. As I've said before, if you get stopped at an EPA checkpoint and have no cat, your car will be impounded. Same thing in a state with visual inspections. No cat, you will not pass.

Obviously catless will be better for power production because theres less back pressure. Its a trade off. Is 2 or 3 more horsepower worth risking your car and a couple hundred dollars?

I think its a waste on the N20 (only reason I ever considered was for sound) and that's just because I don't think there is a point in trying to push that much power out of this engine past a simple tune, but almost everyone I know with a tuned 335i is running catless DP's.

[bahasad]

Originally Posted by Mike_L

To save the environment and your car. As I've said before, if you get stopped at an EPA checkpoint and have no cat, your car will be impounded. Same thing in a state with visual inspections. No cat, you will not pass.

Obviously catless will be better for power production because theres less back pressure. Its a trade off. Is 2 or 3 more horsepower worth risking your car and a couple hundred dollars?

1) I have never heard of any of these mobile EPA inspection points you keep mentioning. Any references? Or just whisper-talk?
2) As can be seen from the experiences here, the catted DPs don't offer much benefit because CELs show up. I want to know that if i buy a catted DP the CEL won't show up within the duration of ownership (i.e. 3 years).
3) The difference in more like 5-10 hp/ft-lbs.

IMO, if you're going to get a downpipe might as well go all the way and go catless on the N2x. That is because the catted don't offer a guarantee of no CEL within a certain time frame and I've never heard practical/real-life of people getting hit by the EPA for DPs.

Originally Posted by smithf32

I think its a waste on the N20 (only reason I ever considered was for sound) and that's just because I don't think there is a point in trying to push that much power out of this engine past a simple tune, but almost everyone I know with a tuned 335i is running catless DP's.

There are decent gains to be had from the DP, but I think the motor's internals aren't strong enough to handle it for a long enough amount of time, unlike the N54/N55.
Lot of annoyances to deal with when you have a DP on a new, warrantied car though.

[Mike_L]

Originally Posted by bahasad

1) I have never heard of any of these mobile EPA inspection points you keep mentioning. Any references? Or just whisper-talk?

Search on Google. There was about a month a couple years back when they were all over California. There have to be articles on it. I've also personally seen them.

Obviously they aren't going to be publicized. They exist to catch people breaking the law, so they want to be as far under the radar as possible.

[FSociety]

Quote from a blog i read "A catless downpipe will almost always cause a Check Engine Light without a tune to match, and whenever you’re stopped at a red light you’re going to smell that unburnt fuel. How much the smell bothers you and your passengers is a key factor to consider before making your decision. Is this your “weekend” car, or do you drive your kids and spouse around often in it?

On the other hand, a Catted Downpipe won’t smell, makes slightly less power than catless and costs more – but there’s a reason for that. Usually a catted downpipe has a 200-CPSI (Cells Per Square Inch) “Sport” Catalytic converter – and no, unless otherwise noted, none are CARB legal in California, but some catted downpipes are 49-state approved. Catalytic converters are expensive for a reason. Every catalytic converter is filled with a good bit of rare-earth metals like platinum, gold and other expensive heavy metals – this is why a few years back thieves were stealing the catalysts from Toyota 4runners due to the extremely high “scrap” value. Catted downpipes typically DO NOT cause a check engine light with the stock tune, and the catalyst keeps the car a little quieter and keeps the car from smelling like gas.

Evolution Racewerks Competition Catted Downpipe for N20 like their catless system, is specifically designed for a smooth HP and torque increase across the powerband. Featuring 4″ piping as well, this catted downpipe offers a gain of +13whp and 24wtq, and its catted design offers an HP peak that’s higher up in the rev band for a more balanced downpipe. This ER downpipe doesn’t specify whether or not it can cause a CEL, so to err on the safe side we’d still advise using it with a tune – which again, you want to do anyway to reap the maximum benefit of a performance downpipe. These downpipes are available in standard finish as well as a black ceramic high heat coating for a stealthy look.

Then we have this BMW N20 328i catted downpipe from Remus Exhaust. The Remus system increases power by 13whp/8wtq, but that’s quite conservative and the tradeoff is EEC-approved, so as to not cause a check engine light and features the same high standard of quality you can expect from a REMUS Exhaust system. This means you’ve got a high performance cat that works together with the stock ECM and even better with a tune (of course). Remus put together this video that shows it off better than a photo can.


Last but not least is Wagner Tuning’s Catted Downpipe for BMW N20 Engines – including BMW F30 328i. This is a brand new item from Wagner Tuning and fits most late model N20 engine applications, as well as the F30. This high quality cat is a direct replacement for the OEM BMW Catalytic Converter and like the others, also features a 200CPSI sport cat. This design reduces backpressure and offers OEM-level, perfect fitment for a straightforward bolt-in installation. The gains aren’t yet well documented, but it’s reasonable to expect 10-13whp or so without a tune, and like the Remus catted downpipe, the Wagner Tuning N20 Catted Downpipe WILL NOT cause a check engine light.

http://blog.**********s.com/best-bol...pipes-exhaust/
"

For those without a JB4 and have another tune get a OBDLINK Scantool either Bluetooth (Android) or WiFi (iPhone).
I got OBDLINk LX since it also has a free app called OBDLINK Tool (I read temps, monitor gauges etc and also read/clear codes) I also have Dash Command and Torque Pro apps. With them I can have auto-clearing codes

[MyFragileHalogen]

I seem to see few people withdrawing from ER DP concerning it may blow up the motor as we saw two people blew them up with ER cattless DP + JB4 map2. I am interested in getting an ER catted DP and using it with JB4 map 1 which I expect wtq up to ~320 lbs/ft. My concern is if it would be safe enough for few years.

[MyFragileHalogen]

Originally Posted by goon

Just installed my ER catted DP last week. Love it but it did trigger a CEL. I was told by ER to either go with the jb4 tune or install an O2 sensor spacer. I'm going to do both.

How louder did it get? How does it drone? Do you have a stock exhaust? Thanks.

[FSociety]

Originally Posted by MyFragileHalogen

I seem to see few people withdrawing from ER DP concerning it may blow up the motor as we saw two people blew them up with ER cattless DP + JB4 map2. I am interested in getting an ER catted DP and using it with JB4 map 1 which I expect wtq up to ~320 lbs/ft. My concern is if it would be safe enough for few years.

Can you post those links ?
I don't know what the JB4 is doing but if you start mixing those e85 wires and other crazy stuff something is bound to happen.
I'm also going to go with catted

[jinnrice]

http://www.bigdaddiesgarage.com/mini-cat-cel-fix.html

[MyFragileHalogen]

Originally Posted by ROBNYC

Can you post those links ?
I don't know what the JB4 is doing but if you start mixing those e85 wires and other crazy stuff something is bound to happen.
I'm also going to go with catted

If you can't easily find those posts, they must've been deleted. Actually one post was deleted very quickly. As far as I remember, one person was running e85 mix + JB4 map 2 + ER catless and other 91 octane + JB4 map2 + ER catless. I think they both said it happened while highway driving in D mode.

[goon]

Originally Posted by MyFragileHalogen

If you can't easily find those posts, they must've been deleted. Actually one post was deleted very quickly. As far as I remember, one person was running e85 mix + JB4 map 2 + ER catless and other 91 octane + JB4 map2 + ER catless. I think they both said it happened while highway driving in D mode.

If they were deleted that quickly I'd question whether they were true. at the same time, personally I'm stopping where im at, no e85 or any of that.

[Sherhart]

Originally Posted by Mike_L

To save the environment and your car. As I've said before, if you get stopped at an EPA checkpoint and have no cat, your car will be impounded. Same thing in a state with visual inspections. No cat, you will not pass.

I never understood why the manufacturers don't weld a fake cat shell on catless downpipes. As long as it has a bung and you have management to defeat the cel, you would never have a single issue with the mid-pipe cat still in place.

Seems like such a no brainer for the exhaust guys.

Jimbo

[FSociety]

The catless downpipe will pull a CEL every single time. The CEL is basically the car detecting if the cat is present and in working condition. Since in a catless downpipe, it is not there anymore, the car will detect it.

With ER catted downpipes, it usually does not pull a CEL light. On a small percentage of cars it will however. Due to the nature of it not working on 100% of the cars, they do not advertise that it will not pull a CEL. They cannot predict which cars will or will not pull a CEL. It is a luck of the draw deal. There is a fix to this however. For all the cars that do get a CEL, they put an o2 spacer on the secondary o2 sensor. So far, this has worked every single time. The spacer is $25 so at the worst, you will have to spend an additional $25.

The catless will always outperform the catted downpipe. The catless will make from 13-18 whp and 15-20wtq. The catted downpipes is between 8-13 whp and 10-15wtq.

This is what I was told by ER .. so thanks to them for clearing that

[MyFragileHalogen]

What is making me to hesitate to order the dp is that I have an AA exhaust and its deep bassy tone is already loud enough for my neighbors to notice whenever I start my car. I would have to switch to MPE, but paying another 1k for tiny exhaust tips isn't much convincing me to spend 2k total.

[Jadar]

Originally Posted by ROBNYC

The catless downpipe will pull a CEL every single time. The CEL is basically the car detecting if the cat is present and in working condition. Since in a catless downpipe, it is not there anymore, the car will detect it.

With ER catted downpipes, it usually does not pull a CEL light. On a small percentage of cars it will however. Due to the nature of it not working on 100% of the cars, they do not advertise that it will not pull a CEL. They cannot predict which cars will or will not pull a CEL. It is a luck of the draw deal. There is a fix to this however. For all the cars that do get a CEL, they put an o2 spacer on the secondary o2 sensor. So far, this has worked every single time. The spacer is $25 so at the worst, you will have to spend an additional $25.

The catless will always outperform the catted downpipe. The catless will make from 13-18 whp and 15-20wtq. The catted downpipes is between 8-13 whp and 10-15wtq.

This is what I was told by ER .. so thanks to them for clearing that

Can you by any chance tell me where I can pick up one of these O2 spacers? Thanks.

[FSociety]

Originally Posted by dd1981

Can you by any chance tell me where I can pick up one of these O2 spacers? Thanks.

They don't always work from what I hear.. You're better off with a Flash Tune since they can do Catless CEL delete via software.

[mike@x-ph.com]

Originally Posted by MyFragileHalogen

What is making me to hesitate to order the dp is that I have an AA exhaust and its deep bassy tone is already loud enough for my neighbors to notice whenever I start my car. I would have to switch to MPE, but paying another 1k for tiny exhaust tips isn't much convincing me to spend 2k total.

If you think the AA is loud, my guess is that after you get catless downpipes you will sell the AA and keep stock exhaust

[FSociety]

Originally Posted by mike@x-ph.com

If you think the AA is loud, my guess is that after you get catless downpipes you will sell the AA and keep stock exhaust

Looks like I'm going to get Exhaust soon, i have cold-start delete so maybe thats why my custom catless downpipe w/ stock exhaust is pretty quiet unless WOT.

[mike@x-ph.com]

Originally Posted by ROBNYC

Looks like I'm going to get Exhaust soon, i have cold-start delete so maybe thats why my custom catless downpipe w/ stock exhaust is pretty quiet unless WOT.

Keep in mind what might sound loud to some is quiet to others.

I have a 335 with catless DP and stock exhaust. I think this is the loudest i can go on a daily driver. Most of my customers / friends have catless DP + aftermarket exhausts, some of them did a muffler delete because they think car is too quiet

[FSociety]

Originally Posted by mike@x-ph.com

Keep in mind what might sound loud to some is quiet to others.

I have a 335 with catless DP and stock exhaust. I think this is the loudest i can go on a daily driver. Most of my customers / friends have catless DP + aftermarket exhausts, some of them did a muffler delete because they think car is too quiet

Definitely DP + Stock Exhaust on 335 is

[mike@x-ph.com]

Originally Posted by ROBNYC

Definitely DP + Stock Exhaust on 335 is

I think this is the best combo one can get. Full performance gains + louder exhaust without being obnoxious