[BMW///]

Can someone tell me the power differences between catted and catless. Also other pros and cons.

[Fronttwelv]

Minimal unless you have a tune. Even on a tune the gains between sport cat and catless will be negligible. You may see small gains with a custom tune to take advantage of not having a cat. If you have the cheddar go catted, it will help save the atmosphere and your nose.

[mike@x-ph.com]

There is no power difference on stock cars between catless and high-flow catted.

The catted option is better for the stock turbo; it's louder than stock but not raspy and has a deeper mid-range tone.

Catless is louder than both but also raspy and generates a fuel smell.
the only pro for catless over high flow catted is the cheaper cost.

[1QuikWS6]

And catless is illegal and car won't pass emissions in any state that requires a IM test

Never had any issues on both my BMWs with AA hi flow catted DP installed (guaranteed no CEL & to pass emissions here in PA) that I purchased thru Mike @ XPH

[BMW///]

Originally Posted by mike@x-ph.com

There is no power difference on stock cars between catless and high-flow catted.

The catted option is better for the stock turbo; it's louder than stock but not raspy and has a deeper mid-range tone.

Catless is louder than both but also raspy and generates a fuel smell.
the only pro for catless over high flow catted is the cheaper cost.

Do you recommend CTS catted or VRSF catted? Which one of them will not throw a CEL? If any of them do, how to get rid of it.

[AM340iMiami]

Active Autowerke is the only one garunteed not to throw a cel.

[peelerec]

Originally Posted by BMW///

Do you recommend CTS catted or VRSF catted? Which one of them will not throw a CEL? If any of them do, how to get rid of it.

Neither. AA Catted Downpipe guaranteed no cel and is of top notch quality.

[mike@x-ph.com]

Originally Posted by BMW///

Do you recommend CTS catted or VRSF catted? Which one of them will not throw a CEL? If any of them do, how to get rid of it.

Originally Posted by peelerec

Neither. AA Catted Downpipe guaranteed no cel and is of top notch quality.

+1

If the CEL is a concern, get the Active Autowerke

If it's not, CTS or MAD catted will get the job done.

[Info@mad-us.com]

The difference will depend on the cat you choose. Our catless and catted are very similar in hp because we use a 200 cell which is extremely high flow. The only downside of the 200 cell is it will not pass emissions and will throw a cel.

However if you are tuned or don't live in a state where they test and you want catless but do not want the smell our 200 cell is the ticket.

200 cell- https://mad-us.com/mad-b58-4.5-catte...chassis-supra/

4.5 inch- https://mad-us.com/mad-b58-downpipe-...chassis-supra/

5 inch- https://mad-us.com/mad-2052-mad-bmw-...40-m440-supra/

[vcammara]

I installed the AA catted on my 2023 M440i and it significantly increased sound and throttle response with the stock exhaust. Worth the price as quality and flow is excellent and no CEL. The stock downpipes on the B58 are very restrictive. This should be the first item to swap before any exhaust upgrade.

[imported_nick]

Why would anyone be concerned about a CEL? It's easily coded out with the tune. If you are not tuning, don't get a downpipe -- that simple

[mike@x-ph.com]

Originally Posted by imported_Mike

Why would anyone be concerned about a CEL? It's easily coded out with the tune. If you are not tuning, don't get a downpipe -- that simple

lots of customers have a locked DME and they use a piggyback which does not hide the check engine light.

[brianachambers]

Originally Posted by Info@mad-us.com

The difference will depend on the cat you choose. Our catless and catted are very similar in hp because we use a 200 cell which is extremely high flow. The only downside of the 200 cell is it will not pass emissions and will throw a cel.

However if you are tuned or don't live in a state where they test and you want catless but do not want the smell our 200 cell is the ticket.

200 cell- https://mad-us.com/mad-b58-4.5-catte...chassis-supra/geometry dash lite

4.5 inch- https://mad-us.com/mad-b58-downpipe-...chassis-supra/

5 inch- https://mad-us.com/mad-2052-mad-bmw-...40-m440-supra/

Yeah! Thanks for share with all member in this forum

[Info@mad-us.com]

Originally Posted by brianachambers

Yeah! Thanks for share with all member in this forum

[cyam]

Originally Posted by imported_nick

Why would anyone be concerned about a CEL? It's easily coded out with the tune. If you are not tuning, don't get a downpipe -- that simple

EXACTLY - I can't see the point in a DP without a tune. I ran a DP without a tune for a while before I tuned my car. Yeah a little quicker turbo spool and a better sound - but THAT's IT.

If you have to spend money on a DP that won't throw a cel - which is a number of times more expensive than a (higher-flowing) 200cell or catless DP - it just makes no sense at all to me. My strong recommendation is just stay stock.

If you need a Femto unlock - I'd STILL do that and get a 200cell or catless DP. Works out about the same cost or a bit more than just a DP which won't throw a cel (which won't flow quite as good as a 200cell or catless).

If you are doing it for sound - much cheaper ways to get your exhaust louder - like a muffler delete or open airbox etc.

[mike@x-ph.com]

Originally Posted by cyam

EXACTLY - I can't see the point in a DP without a tune. I ran a DP without a tune for a while before I tuned my car. Yeah a little quicker turbo spool and a better sound - but THAT's IT.

If you have to spend money on a DP that won't throw a cel - which is a number of times more expensive than a (higher-flowing) 200cell or catless DP - it just makes no sense at all to me. My strong recommendation is just stay stock.

If you need a Femto unlock - I'd STILL do that and get a 200cell or catless DP. Works out about the same cost or a bit more than just a DP which won't throw a cel (which won't flow quite as good as a 200cell or catless).

If you are doing it for sound - much cheaper ways to get your exhaust louder - like a muffler delete or open airbox etc.

The sound is so much better with the upgraded downpipe, and you get extra power.

I get it if it's not for everyone, but I can see the reasoning for getting downpipes with no CEL. That's what i did on my car because it made the most sense.

[RTPenland]

DP through stock exhaust is really nice

[phanamous]

How much louder is the AA catted DP? Does it drone at highway speed? Thx.

[peelerec]

Originally Posted by phanamous

How much louder is the AA catted DP? Does it drone at highway speed? Thx.

With what exhaust? Need more info.
For ex. AA catted DP with MPE = no drone

[phanamous]

AA catted DP with stock M340i exhaust. Would like more performance with not too much noise to appease the wife basically. Trying to gauge how much louder it is compared to stock. Thanks.

Originally Posted by peelerec

With what exhaust? Need more info.
For ex. AA catted DP with MPE = no drone

[Vortexshifter09]

Originally Posted by mike@x-ph.com

There is no power difference on stock cars between catless and high-flow catted.

The catted option is better for the stock turbo; it's louder than stock but not raspy and has a deeper mid-range tone.

Catless is louder than both but also raspy and generates a fuel smell.
the only pro for catless over high flow catted is the cheaper cost.

Can I run stage 2 bm3 or mhd with AA catted dp? I read somewhere that stage 2 is only for catless or 200 cel catted but the AA dp has 400 cel. I won’t be going crazy with the pop tunes I’m keeping the sound stock not changing it tune wise

[cyam]

Originally Posted by phanamous

AA catted DP with stock M340i exhaust. Would like more performance with not too much noise to appease the wife basically. Trying to gauge how much louder it is compared to stock. Thanks.

You cannot/won't get more hp or torque with just a dp. The only thing you'll achieve is a bit faster spool up of the turbo, but no more power.

You simply can't get more power with just a dp because fueling, ignition and boost are all the same. It's just a bit quicker spool up (slightly less turbo lag) with a dp.

As for sound, it will be slightly louder than stock. The cats act like a muffler and so with a higher flow dp you get a bit more volume. Most volume is with a catless, next loudest is a 200 cel and then 400 cel is a little louder than stock. I'd say a 200cel is maybe 10-15% louder on startup (only in sport modes) and WOT than stock. Normal driving can hardly tell any difference.