Resonators and MPE

[deeldoo]

Guys,

I have an MPE with catless DPs and this car is so damn raspy and creates a ton of drone and vibrations through the car just from this damn exhaust.

Is there any resonators i could place? Do the midpipes already have some?

I am completely ignorant to exhaust and sound dynamics and just need help.

I just need this drone to stop.

[E92inSG]

The problem is the MPE doesn’t have the midpipe resonator like stock or ZCP. I’ve gone thru multiple downpipe setups: catless, catless resonated, hi flow cat. And all sounded absolutely horrible. I’ve since gone back to stock cats and it’s much more pleasant. And tbh there wasn’t any perceivable drop in power delivery. I’ve logged run both with stock downpipe and catless downpipes to be able to say that confidently, even with upgraded turbos

[rborane]

Originally Posted by E92inSG

The problem is the MPE doesn’t have the midpipe resonator like stock or ZCP. I’ve gone thru multiple downpipe setups: catless, catless resonated, hi flow cat. And all sounded absolutely horrible. I’ve since gone back to stock cats and it’s much more pleasant. And tbh there wasn’t any perceivable drop in power delivery. I’ve logged run both with stock downpipe and catless downpipes to be able to say that confidently, even with upgraded turbos

I also went back to stock Downpipes recently from catless downpipes, and prefer OEM much more. If anything it feels like the car regained a little bit of torque and responsiveness, and sounds much better. Sticking with OEM Downpipes from now on.

[E92inSG]

Catless + MPE = baaaaaaad

[Bluer2]

Do you guys have the secondary cats still on the car? I wonder if the secondary cats do anything to reduce the rasp or sound.

[ntg44]

Originally Posted by Bluer2

Do you guys have the secondary cats still on the car? I wonder if the secondary cats do anything to reduce the rasp or sound.

Only thing they reduce is the smell if you have no primary cats. When I replaced my secondaries with resonators on otherwise completely stock exhaust, the tone improved a lot. Got rid of the rasp at the cost of a flatter tone. But there was less drone and much less interior bits buzzing inside the cabin afterwards.

OP, since your primaries are out, you're going to need at least a 10-12 inch resonator on each side to have any hope of a pleasant tone. The bigger issue is where to put them.

Due to where the stock exhaust is cut to mate to MPE, you're going to need to hack up your MPE midpipe. Some people are less comfortable doing this than others considering the price of the exhaust, but at the end of the day, that's what it's going to take. If you go to a fabricator, maybe have them cut the MPE right before the H pipe so that it can easily be welded together if needed to be reversed for resale. It's just piping, but some people are weird about that kind of stuff.

Good luck.


Here's a clip of my stock exhaust with 2nd cats swapped with 4 inch resonators to give you an idea. Obviously MPE and catless will require much longer ones.

[E92inSG]

Originally Posted by Bluer2

Do you guys have the secondary cats still on the car? I wonder if the secondary cats do anything to reduce the rasp or sound.

I gutted my secondary cats. the secondary cats are actually more of a restriction than the primaries in the downpipe. My friend (F80) did a before and after dyno with the secondary cats removed, and showed consistent 20+ hp gain.

My setup with stock downpipe, gutted secondary cats and MPE results in a pleasant sound for me. it might be a little quiet for the hardcore guys, but that's the way I like it. perfectly civilised with valves closed and sporty sounding with valves open

[deeldoo]

Would buying a single mid pipe like the VSRF or AA work and could i add resonators to that?

I get buzzing in the interior and rasp on this setup and even for me the car is too damn loud, it sounds like i am in a airplane operated by chainsaws vs motors.

[MJ6]

I had a similar situation when I added high-flow catted downpipes to my TGM system: insane rasp and cabin drone. I ended up experimenting with different resonator sizes and ended up using two Magnaflow 14416's (14" x 4") and it cleaned it up entirely: no rasp at any throttle position and minimal if any cabin drone.

Now obviously the MPE and TGM systems are different so your mileage may vary, however the 14416's were the largest resonator I could reasonably squeeze in the exhaust track where the secondary cat's previously resided without hitting the heat-shield or doing some serious fabrication. Due to the different materials (titanium vs. stainless) you'd likely have to have them clamped in though.

[Nitrile]

I wouldn't suggest anyone doing downpipe if they do not want the increased rasp in MPE, if you want a deeper tone... you have to get a new mid pipe but that's also means u have to cut the titanium mid pipe which I don't think is worth doing.

[TopJimmy]

Originally Posted by deeldoo

Would buying a single mid pipe like the VSRF or AA work and could i add resonators to that?

I get buzzing in the interior and rasp on this setup and even for me the car is too damn loud, it sounds like i am in a airplane operated by chainsaws vs motors.

Yesterday I sent a PM to Andrew@AA asking if the pair of resonated extensions from their EL Midpipe kit will fit the Single Mid. I'm hoping yes. It would be an added level of drone and rasp reduction for those of us who like to drive valves-open all the time.

[RickyBooby813]

Originally Posted by TopJimmy

Yesterday I sent a PM to Andrew@AA asking if the pair of resonated extensions from their EL Midpipe kit will fit the Single Mid. I'm hoping yes. It would be an added level of drone and rasp reduction for those of us who like to drive valves-open all the time.

@TopJimmy did you happen to get a reply from AA if the EL resonators would work with fabrication into the single mid?

[bsmf8x]

Originally Posted by ntg44

Only thing they reduce is the smell if you have no primary cats. When I replaced my secondaries with resonators on otherwise completely stock exhaust, the tone improved a lot. Got rid of the rasp at the cost of a flatter tone. But there was less drone and much less interior bits buzzing inside the cabin afterwards.

OP, since your primaries are out, you're going to need at least a 10-12 inch resonator on each side to have any hope of a pleasant tone. The bigger issue is where to put them.

Due to where the stock exhaust is cut to mate to MPE, you're going to need to hack up your MPE midpipe. Some people are less comfortable doing this than others considering the price of the exhaust, but at the end of the day, that's what it's going to take. If you go to a fabricator, maybe have them cut the MPE right before the H pipe so that it can easily be welded together if needed to be reversed for resale. It's just piping, but some people are weird about that kind of stuff.

Good luck.


Here's a clip of my stock exhaust with 2nd cats swapped with 4 inch resonators to give you an idea. Obviously MPE and catless will require much longer ones.

I want this tone except louder. I have a non ZCP stock f82 like you, but flap unplugged.

I want to keep the resonator's H-pipe because that greatly reduces the rasp as H pipes do.

Did you try just running secondary cat delete , did the tone sound like that except louder?

My fear with sec cat delete is increased rasp.

Another thought is doing exactly what you did & then putting an h pipe in place of the resonated h pipe on the stock exhaust. That's a lot of work and cutting/welds though I'd rather Just cut the secondaries out

[bsmf8x]

Originally Posted by deeldoo

Would buying a single mid pipe like the VSRF or AA work and could i add resonators to that?

I get buzzing in the interior and rasp on this setup and even for me the car is too damn loud, it sounds like i am in a airplane operated by chainsaws vs motors.

I'd sell the MPE & put on an OEM muffler (doesn't need to be ZCP) + single midpipe.

MPE is great with a OEM downpipe, with a catless downpipe it just sounds like a straight pipe lol. Sell it while it's worth money and you can buy a 650$ VRSF single mid and your car will sound perfect.

[ntg44]

Originally Posted by murdrdf82

I want this tone except louder. I have a non ZCP stock f82 like you, but flap unplugged.

I want to keep the resonator's H-pipe because that greatly reduces the rasp as H pipes do.

Did you try just running secondary cat delete , did the tone sound like that except louder?

My fear with sec cat delete is increased rasp.

Another thought is doing exactly what you did & then putting an h pipe in place of the resonated h pipe on the stock exhaust. That's a lot of work and cutting/welds though I'd rather Just cut the secondaries out

Based on my experience and exhaust experiments, I do not recommend only a 2nd cat delete with no resonator to replace them. It becomes fartier than stock. The audio was recorded on an iPhone with a lot of tire noise from the nearby highway. I strongly recommend trying the 2nd cat swap for Magnaflow resonators and leaving valves open before replacing the center resonator with an H pipe.

Full throttle with the resonators swapped in is louder than stock, but it drones less with valves open and the interior rattles less than completely stock with valves open. Everyone has different tastes and the best answer is always to make changes in iterations until you find the perfect tone.

Personally I think the easy way to get a better and louder tone is to get the AA single mid pipe and be done with it. This is more of a budget friendly solution and has diminishing returns the more you spend on it. I was more than happy with just the resonators in place of 2nd cats, at least until I started my equal length projects

[papasmurf_m3]

I adjusted the exhaust flap to highest setting on my Ecutek using the slider on the app.

I'm Catless with MPE and AA single mid pipe.

I just drive efficient mode and the car sounds great going through the muffler still get whistles and above 4K when you're hard on the gad the exhaust opens up for a moment under 4K it's through muffler and I love it this way.

Even though sound is much deeper with single mid pipe I don't like to drive around like that unless I'm gonna play.

[bsmf8x]

Originally Posted by ntg44

Based on my experience and exhaust experiments, I do not recommend only a 2nd cat delete with no resonator to replace them. It becomes fartier than stock. The audio was recorded on an iPhone with a lot of tire noise from the nearby highway. I strongly recommend trying the 2nd cat swap for Magnaflow resonators and leaving valves open before replacing the center resonator with an H pipe.

Full throttle with the resonators swapped in is louder than stock, but it drones less with valves open and the interior rattles less than completely stock with valves open. Everyone has different tastes and the best answer is always to make changes in iterations until you find the perfect tone.

Personally I think the easy way to get a better and louder tone is to get the AA single mid pipe and be done with it. This is more of a budget friendly solution and has diminishing returns the more you spend on it. I was more than happy with just the resonators in place of 2nd cats, at least until I started my equal length projects

By farty do you mean the loud noise that happens when you let off/shift? Because I love that lmao

Or do you mean raspy throughout the powerband

[ntg44]

Originally Posted by murdrdf82

By farty do you mean the loud noise that happens when you let off/shift? Because I love that lmao

Or do you mean raspy throughout the powerband

On boost, it's rasp city.

[TopJimmy]

Originally Posted by RickyBooby813

@TopJimmy did you happen to get a reply from AA if the EL resonators would work with fabrication into the single mid?

I got a reply that the resonated extensions will fit the single mid. They have a backlog of workorders due to the EL craze but you can request a pair from Andrew.