[codelinx]

Looking for some opinions as this is my first mod ever, first mod on my new-ish X3M Comp.

Main task: Deciding on a set of downpipes

Possible downpipes:
- Evolution Racewerks Catted
- Project Gamma Catted

Possible catless:
- Evolution Racewerks
- HCP+BM3+Project gamma collab downpipes (Found here:https://www.bm3tuning.com/bmw-f9x/s58-catless-downpipes)


Things i would like to know if anyone has info.

- In NYC having catless would mean 2 things: fume smell in the cabin in my dd, and i would have issues with passing inspections, is this correct?
- Catted vs Catless there is not huge performance gain from what i have seen, am i wrong?
- Should i get thermal coating? i am not going to track this, DPs are just for added fun getting groceries and rides to dinner.
- Would High flow catted downpipes still be loud and provide a nice performance boost on a stage2 bm3 or f80 tune?
- How much would the install on these downpipes be in NYC? Any ideas or quotes from anyone...

[hellcat2m4]

I think Ill be going with evolution Racewerks.

I also had SSR in the running with your two brands as well.

[AlexFL]

I had high flow ER downpipes with ceramic coating on my X3M. Great product, greatly improved sound. But then I added the full Akra exhaust with a catless midpipe and the sound became too raspy, so I switched back to the OEM downpipes. Basically, I highly recommend the ER catted downpipes as long as you plan to keep the midpipes OEM.

[floating.spirit]

Originally Posted by codelinx

Looking for some opinions as this is my first mod ever, first mod on my new-ish X3M Comp.

Main task: Deciding on a set of downpipes

Possible downpipes:
- Evolution Racewerks Catted
- Project Gamma Catted

Possible catless:
- Evolution Racewerks
- HCP+BM3+Project gamma collab downpipes (Found here:https://www.bm3tuning.com/bmw-f9x/s58-catless-downpipes)


Things i would like to know if anyone has info.

- In NYC having catless would mean 2 things: fume smell in the cabin in my dd, and i would have issues with passing inspections, is this correct?
- Catted vs Catless there is not huge performance gain from what i have seen, am i wrong?
- Should i get thermal coating? i am not going to track this, DPs are just for added fun getting groceries and rides to dinner.
- Would High flow catted downpipes still be loud and provide a nice performance boost on a stage2 bm3 or f80 tune?
- How much would the install on these downpipes be in NYC? Any ideas or quotes from anyone...

I am also interested in learning the differences in impact of catted versus cattless downpipe's.

[to_riffic]

My X3M is catless and to be honest, the ER catless hasn't been that bad, as far as fumes go. I was surprised the garage didn't smell as bad as I thought it would be. That's just my opinion though. But I have had a lot of catless vehicles and nothing as bad as some of my other cars. My Ducati is far worse, just letting it start up for a minute will leave quite the smell in there!

[r33_RGSport]

As long as you are keeping the mid-pipe where secondary cat is, you won't have smell issue.

Inspection wise, it will depends on your state law and regulation.

Thermal coating, good to have if you are in hot climate or full time racing, but for daily car is not needed.

[codelinx]

Originally Posted by AlexFL

I had high flow ER downpipes with ceramic coating on my X3M. Great product, greatly improved sound. But then I added the full Akra exhaust with a catless midpipe and the sound became too raspy, so I switched back to the OEM downpipes. Basically, I highly recommend the ER catted downpipes as long as you plan to keep the midpipes OEM.

Wow this is incredible info. The pics are great also. If you don't mind me asking where are you located and how much was the install + dp?

[codelinx]

Originally Posted by r33_RGSport

As long as you are keeping the mid-pipe where secondary cat is, you won't have smell issue.

Inspection wise, it will depends on your state law and regulation.

Thermal coating, good to have if you are in hot climate or full time racing, but for daily car is not needed.

Great info. I saw you posted this info before in your other post. Thanks

[codelinx]

Originally Posted by to_riffic

My X3M is catless and to be honest, the ER catless hasn't been that bad, as far as fumes go. I was surprised the garage didn't smell as bad as I thought it would be. That's just my opinion though. But I have had a lot of catless vehicles and nothing as bad as some of my other cars. My Ducati is far worse, just letting it start up for a minute will leave quite the smell in there!

Do you have any other mods done? I was just planning on doing the dp no mid pipe

[hellcat2m4]

Decided on evolution racewerks, placed my order!

[codelinx]

Originally Posted by hellcat2m4

I think Ill be going with evolution Racewerks.

I also had SSR in the running with your two brands as well.

Have you made a decision yet and installed anything yet? Interested in hearing the difference and the reasoning for the choice.

[GOLFFRR]

Catless DPs will make a dramatic change in the sound of your ride. I have had ER DPs and never had any issues with them. They make a great product at a good price.

The last three M4s I had I ran Akra full exhaust with ER DPs and rarely had the smell issues. Some state they get a ton of smell others state no smell. I def know you will get some smell but the amount seem to be based off your sensitivity of smell. I also would try to look into some sort of valve controller unit bc for me the DPs made such a HUGE change in sound which was awesome but wasn't something I wanted all the time and neither did my neighborhood want

[to_riffic]

Originally Posted by codelinx

Do you have any other mods done? I was just planning on doing the dp no mid pipe

ER catless and BM3 tune, that's it. I don't drive the X3M much but still wanted to sound a bit better than stock. BM3 tune was necessary to remove the CEL and, at times, rough idle/engine malfunction issues I was getting. So all in all, solid performance on just dp's and a tune.

[hellcat2m4]

I didnt go with the coating, so hopefully I didn't screw myself there since I live in a hot climate and drive...shall I say...spirited? haha

[DKX4///M]

I plan on running these with dual boost activated 3" exhaust dumps (with turndowns) before the secondary cats, along with a electronic boost solenoid...

(I've had exhaust valves on both turbo cars Ive owned, My 2003 Evolution 8, full bolt ons, HKS Camshafts, and Evo 10.5 hot side, and meth injection...) Open vs Closed, just tuned to avoid boost spikes and the reduced IAT's from the reduced heat of the turbo added almost 30whp...

While I never got to dyno my M2, and I never got to tune it to take advantage of the reduced heat and back pressure, along with the less restrictive stock exhaust I expect much less than 30awhp, like the EVO...

I also ran either QTEC Electronic valve dumps, or boost activated dumps on all the shop full race and customer cars that were turbo charged and looking for the most power possible...With night and day results vs similar setups running even full2.5" or 2.75" straight pipes...


But on an X4M running very high boost, I suspect exhaust dumps placed properly and tuned to take advantage will add a noticeable amount of power, and an obnoxious sound which some will love and some will hate.

But also the advantage of a very reserved sound when closed, no more tickets, no more pissing off neighbors, and absolute lowest lag time, with absolute peak possible HP from exhaust flow (when openeed) ...At 1/10th the price of most quality after market exhausts...

Just something you may want to think about, obviously not for everyone...

[James Cole]

Originally Posted by to_riffic

ER catless and BM3 tune, that's it. I don't drive the X3M much but still wanted to sound a bit better than stock. BM3 tune was necessary to remove the CEL and, at times, rough idle/engine malfunction issues I was getting. So all in all, solid performance on just dp's and a tune.

Was it much louder than stock?

[to_riffic]

Originally Posted by James Cole

Was it much louder than stock?

Not at a level that I would deem obnoxious in any way.

[codelinx]

Wow this is some great info. Have to look into these post in a little bit.

[1FSTTA]

Anyone tried P2uned down pipes?

[e92hunter]

Originally Posted by DKX4///M

I plan on running these with dual boost activated 3" exhaust dumps (with turndowns) before the secondary cats, along with a electronic boost solenoid...

(I've had exhaust valves on both turbo cars Ive owned, My 2003 Evolution 8, full bolt ons, HKS Camshafts, and Evo 10.5 hot side, and meth injection...) Open vs Closed, just tuned to avoid boost spikes and the reduced IAT's from the reduced heat of the turbo added almost 30whp...

While I never got to dyno my M2, and I never got to tune it to take advantage of the reduced heat and back pressure, along with the less restrictive stock exhaust I expect much less than 30awhp, like the EVO...

I also ran either QTEC Electronic valve dumps, or boost activated dumps on all the shop full race and customer cars that were turbo charged and looking for the most power possible...With night and day results vs similar setups running even full2.5" or 2.75" straight pipes...


But on an X4M running very high boost, I suspect exhaust dumps placed properly and tuned to take advantage will add a noticeable amount of power, and an obnoxious sound which some will love and some will hate.

But also the advantage of a very reserved sound when closed, no more tickets, no more pissing off neighbors, and absolute lowest lag time, with absolute peak possible HP from exhaust flow (when openeed) ...At 1/10th the price of most quality after market exhausts...

Just something you may want to think about, obviously not for everyone...

Are these the same thing as the O2 Dumps? I had an Evo X awhile back and I remember these becoming hot. I’m really interested in this setup, can you tell me if you get a setup going and I’ll buy one too!

[James Cole]

For those who installed catless did you notice a reduction in lag?

[DKX4///M]

Originally Posted by e92hunter

Are these the same thing as the O2 Dumps? I had an Evo X awhile back and I remember these becoming hot. I’m really interested in this setup, can you tell me if you get a setup going and I’ll buy one too!

Yea after I put one on my Evolution 8 in 2003, QTEC started making them for Evos and Sti's I remember that... Those were the crappy electric cutouts...they leaked a bit unless u closed them just right....And the plates always fell off, However QTEC (Quicktime performance replaces them for free for life)...And it got annoying opening and closing it...

But I did get a ton of hp on the evo open vs closed and literally instant 20psi...

Same with the m2 power wise ....i put the "loudvalve" boost activated valve on 3 years ago, now i see EAS is selling a kit with a electric boost solenoid, so you can shut them off...you can also use a manual boost controller so they open higher that the official 5psi also. They also seal well especially if you put a bead of liquid exhaust gasket around it closed...

I never thought to put it on a boost solenoid... And at 5 psi the valve opens even during daily driving, mine on the m2 was set for around 10psi which was perfect. If I can find some wire that goes 12v in OEM Performance exhaust valve mode, Ill hook the solenoid to that so I can use the stock exhaust button to turn in on and off...(Hoping the stock exhaust valve is on a 12v switch or ground, if its a low voltage signal that triggers a relay, Ill just have to hook up another relay to the boost solenoid....

I plan on doing this 1st thing when I pick this damn truck up...Its taking forever...

Supposedly there is not a ton of power to gain with primary cat delete, but I'm guessing its bc the secondary cats, resonator and muffler...Its hard for me to believe a 3 liter pushing 25PSI cant gain a lot of power from open downpipes, I mean once spooling at high RPMS turbos are very little exhaust restriction, especially with twin turbo...

Ill let you know how it works out...

Heres a pic on the M2 where I welded the 3" y pipe in...before I had the valve welded on (which I shouldve done first, duh:doh: