Secondary Cat Removal VS Downpipes

[XRAVE]

Reading some reviews, it seems that there is some drone when adding catless downpipes, especially highway cruising.

I plan on just doing a JB4, but $1200 for downpipes seems a bit excessive. Coming for a 135i and downpipes in the $4-500 range with minimal power gains, I don't think I'll be doing them on my m3 with a price tag installed at $1400.

I think the secondary cat removal is a more viable option. I haven't gotten any pricing but I'm thinking in the $200 range? Any thoughts on that or anyone that has had it done? Would removing them add any power/reduce turbo lag when compared to doing downpipes?

[iamwingman]

Good question. . Anybody know how easy or difficult a secondary cat removal is when done at a good shop? How much louder than stock would it be?

[dmk08]

Originally Posted by XRAVE

Reading some reviews, it seems that there is some drone when adding catless downpipes, especially highway cruising.

I plan on just doing a JB4, but $1200 for downpipes seems a bit excessive. Coming for a 135i and downpipes in the $4-500 range with minimal power gains, I don't think I'll be doing them on my m3 with a price tag installed at $1400.

I think the secondary cat removal is a more viable option. I haven't gotten any pricing but I'm thinking in the $200 range? Any thoughts on that or anyone that has had it done? Would removing them add any power/reduce turbo lag when compared to doing downpipes?

Welcome to the "M Tax" my friend. Where bent pipes quadruple in value.

If you are just cutting them out for strait pipes I would think less than that at a good muffler shop.

If you want to remove them and add resonators or something it could easily be $4-500.

I wouldn't expect much power gains from removing the secondaries.

[supremepower]

Sent a PM

The secondaries will give minimal 1-2 gains if any at all.

[///M Villain]

I've been thinking about removing the secondary cat's myself. Haven't had the time to get to a shop. But I would love to know how the stock exhaust sounds with this done.

[TeKiZeRo]

I have catless downpipes on my car and removed the secondary cats as well. I don't really get any drone when cruising.

[Ranoz]

I can feel the differences with cattless dp on highway cruise, but definitely no drone. again it is very subjective sometimes.

[tom @ eas]

Originally Posted by XRAVE

Reading some reviews, it seems that there is some drone when adding catless downpipes, especially highway cruising.

I plan on just doing a JB4, but $1200 for downpipes seems a bit excessive. Coming for a 135i and downpipes in the $4-500 range with minimal power gains, I don't think I'll be doing them on my m3 with a price tag installed at $1400.

I think the secondary cat removal is a more viable option. I haven't gotten any pricing but I'm thinking in the $200 range? Any thoughts on that or anyone that has had it done? Would removing them add any power/reduce turbo lag when compared to doing downpipes?

Expect little to no power gains from doing so, not worth the effort as the primaries are the bottleneck of the exhaust system.

Simply save and get a set of quality catless downpipes.

[YMB_F80]

Originally Posted by tom @ eas

Expect little to no power gains from doing so, not worth the effort as the primaries are the bottleneck of the exhaust system.

Simply save and get a set of quality catless downpipes.

Tom speaks the truth op!! I came from a 335i also and though the prices were ridiculous but you got to remember how much the car is now compared to our old cars. Other than that, I love my ER downpipes with stock system. I didn't have much drone, if there was it was very minimal.

[F82_M4]

Originally Posted by TeKiZeRo

I have catless downpipes on my car and removed the secondary cats as well. I don't really get any drone when cruising.

i would love to hear a sound clip of that if you don't mind.

[MaX PL]

If I get DPs, is there really a point in getting an exhaust as well?

I don't really care about sound, just power gains with a JB4.

Would DP+JB4 be > than Exhaust+JB4?

Would DP+Exhaust+JB4 be > DP+JB4?

[supremepower]

Originally Posted by MaX PL

If I get DPs, is there really a point in getting an exhaust as well?

I don't really care about sound, just power gains with a JB4.

Would DP+JB4 be > than Exhaust+JB4?

Would DP+Exhaust+JB4 be > DP+JB4?

Our car put down some pretty big numbers running stock exhaust, JB4, 100 octane(?).

Here's the dyno:

[MaX PL]

Thanks, but I'll never run on 100 octane so that doesn't help me too much.

Do you have 93 octane #s with the same setup?

[TeKiZeRo]

Originally Posted by F82_M4

i would love to hear a sound clip of that if you don't mind.

I made a sound clip, but it rips apart the mic at some parts because its so loud with the valves open lol. If you still want to hear it, send me a PM and I'll get you a YouTube link .

[Tiago@VRSF]

Originally Posted by XRAVE

Reading some reviews, it seems that there is some drone when adding catless downpipes, especially highway cruising.

I plan on just doing a JB4, but $1200 for downpipes seems a bit excessive. Coming for a 135i and downpipes in the $4-500 range with minimal power gains, I don't think I'll be doing them on my m3 with a price tag installed at $1400.

I think the secondary cat removal is a more viable option. I haven't gotten any pricing but I'm thinking in the $200 range? Any thoughts on that or anyone that has had it done? Would removing them add any power/reduce turbo lag when compared to doing downpipes?

We'll have a price-conscious solution available shortly

[BenX9]

Originally Posted by MaX PL

Thanks, but I'll never run on 100 octane so that doesn't help me too much.

Do you have 93 octane #s with the same setup?

Would also like to see gains with stock exhaust + JB4 + 93 oct

[pikkagtr]

Originally Posted by Tiago@VRSF

We'll have a price-conscious solution available shortly

As in a set of downpipes with flex sections for less than my kidneys on the black market?

[Tiago@VRSF]

Originally Posted by pikkagtr

As in a set of downpipes with flex sections for less than my kidneys on the black market?

Nothing with flex sections any time soon but they will be very competitively priced and offer the same investment cast SS304 flange/pipe transition as our N54 V2's do.

The thousands of sets we've sold for the N54 do not require the flex sections (OEM N54 downpipes also have flex sections) and the N54 exhaust is way less braced in comparison to the M3/M4 setup. If the N54/N55 cars don't need them, these certainly won't either

[pikkagtr]

Sweet ! Will wait for announcements

[Bluesun]

Originally Posted by Tiago@VRSF

Nothing with flex sections any time soon but they will be very competitively priced and offer the same investment cast SS304 flange/pipe transition as our N54 V2's do.

The thousands of sets we've sold for the N54 do not require the flex sections (OEM N54 downpipes also have flex sections) and the N54 exhaust is way less braced in comparison to the M3/M4 setup. If the N54/N55 cars don't need them, these certainly won't either

Tiago always seems to come through with good news. Any time I see you post in a thread, I get excited.

(Don't have an M4 just yet...but seriously considering parting out my N54 and nabbing one up)

[AW BMW]

Originally Posted by Bluesun

Tiago always seems to come through with good news. Any time I see you post in a thread, I get excited.

(Don't have an M4 just yet...but seriously considering parting out my N54 and nabbing one up)

Do it, I parted out my 335 n54 and sold it a few days ago. I should be picking up my M3 sometime next week.

[RingMeister01]

Originally Posted by dmk08

Welcome to the "M Tax" my friend. Where bent pipes quadruple in value.

If you are just cutting them out for strait pipes I would think less than that at a good muffler shop.

If you want to remove them and add resonators or something it could easily be $4-500.

I wouldn't expect much power gains from removing the secondaries.

Any idea where I can get resonators to replace the secondaries?