Fabspeed Mid pipe (advice) and wanted / where to buy

[SE7EN335]

Originally Posted by dannyz_M4

Doesn't look like this group bug is going to happen.. quotes are around $2163aud, delivered to your door all taxes paid... which is on par with quotes directly through fabspeed factoring in taxes, individually anyway. Still confirming a few things... will keep you all posted.

Im in the talks with a VERY GOOD custom exhaust fab shop here in Sydney to do a custom single midpipe that replicates the Active Autowerke midpipe and customise it for the MPE and they have given a guarantee that it will fit with using my M3 with the MPE as a guinea pig. Quotes are looking very good and would be quite cheaper than ordering the AA midpipe from the States. I'll keep everyone updated. PM me if youre interested and we can organise a groupbuy or group fitting (if you're in Sydney) HAHA

[dannyz_M4]

Well PLEASE keep me posted on this one.. I am in Melb but if it's fabricated and fits an m3/4 with MPE I'm sure it will fit mine... 👍

[A'PEXi]

Will the midpipe also fit standard rear muffler? May be interested if it does.

[FR00ZN]

Originally Posted by A'PEXi

Will the midpipe also fit standard rear muffler? May be interested if it does.

I'm in Sydney, also interested and also have the standard exhaust... Please share updates

[SE7EN335]

Originally Posted by A'PEXi

Will the midpipe also fit standard rear muffler? May be interested if it does.

No this will be a custom fabrication suited for the MPE so that we don't have to cut the MPE. If you have standard rear muffler, best to just buy the AA midpipe as its a guaranteed and perfect fitment. AA midpipe will not fit the MPE unless you cut into the MPE which im pretty sure none of us want to do to a 8 Grand exhaust

[SE7EN335]

Originally Posted by FR00ZN

I'm in Sydney, also interested and also have the standard exhaust... Please share updates

Read my comment above

[RevNev]

This is what needs to be done with the M3/M4 exhaust and I can't for the life of me understand why no one's doing it and they're paying stupid prices for this aftermarket and M Performance crap that sound awful anyway.

The fartyness is caused by the dual exhaust where the cylinders are grouped 1,2,3 and 4,5,6. It sounds like an HQ 202 panel van with split extractors and dual exhaust or a V6 Commodore with a twin system and no balance pipe.

The M3/M4 mid pipe "must" be joined just after the down pipe flange and this is really easy fabricating and welding in a large capacity X pipe. This turns the exhaust into a single system pulse wise and gets rid of the fartyness.

The secondary cats need to be removed with two 16" hotdogs welded in Lukey Mufflers do some nice stainless hotdogs and they'd be great. They "must" have resonators before the valves to remove the raspyness.

The resonator after the secondary cats need to top cut open to see what's in there and I believe there's a balance pipe and perforated tube. That needs to packed with stainless wool and the top welded back on.

With the valves open at full throttle, this will sound magic!!, a high pitched smooth scream, not quite as loud as a non-muffled mid pipe but the note will be good, no fartyness and no rasp.

With the valves closed with a stock rear muffler, it won't have the farts and rasp entering the rear muffler and it will likely be quieter and that's ok because when you floor it, the valves open and bypasses the rear muffler to get the noise and the note.

That's about $1200 to $1500 worth for a good exhaust fabricator to knock that up. They're off their chops with 7K+ exhaust systems as there's absolutely no rocket science in this.

[SE7EN335]

Originally Posted by RevNev

This is what needs to be done with the M3/M4 exhaust and I can't for the life of me understand why no one's doing it and they're paying stupid prices for this aftermarket and M Performance crap that sound awful anyway.

The fartyness is caused by the dual exhaust where the cylinders are grouped 1,2,3 and 4,5,6. It sounds like an HQ 202 panel van with split extractors and dual exhaust or a V6 Commodore with a twin system and no balance pipe.

The M3/M4 mid pipe "must" be joined just after the down pipe flange and this is really easy fabricating and welding in a large capacity X pipe. This turns the exhaust into a single system pulse wise and gets rid of the fartyness.

The secondary cats need to be removed with two 16" hotdogs welded in Lukey Mufflers do some nice stainless hotdogs and they'd be great. They "must" have resonators before the valves to remove the raspyness.

The resonator after the secondary cats need to top cut open to see what's in there and I believe there's a balance pipe and perforated tube. That needs to packed with stainless wool and the top welded back on.

With the valves open at full throttle, this will sound magic!!, a high pitched smooth scream, not quite as loud as a non-muffled mid pipe but the note will be good, no fartyness and no rasp.

With the valves closed with a stock rear muffler, it won't have the farts and rasp entering the rear muffler and it will likely be quieter and that's ok because when you floor it, the valves open and bypasses the rear muffler to get the noise and the note.

That's about $1200 to $1500 worth for a good exhaust fabricator to knock that up. They're off their chops with 7K+ exhaust systems as there's absolutely no rocket science in this.

Wow thanks for all that info! Im trying to visualise what is needed for that custom build? Could you please possibly draw a diagram to explain?

[FR00ZN]

Originally Posted by RevNev

This is what needs to be done with the M3/M4 exhaust and I can't for the life of me understand why no one's doing it and they're paying stupid prices for this aftermarket and M Performance crap that sound awful anyway.

The fartyness is caused by the dual exhaust where the cylinders are grouped 1,2,3 and 4,5,6. It sounds like an HQ 202 panel van with split extractors and dual exhaust or a V6 Commodore with a twin system and no balance pipe.

The M3/M4 mid pipe "must" be joined just after the down pipe flange and this is really easy fabricating and welding in a large capacity X pipe. This turns the exhaust into a single system pulse wise and gets rid of the fartyness.

The secondary cats need to be removed with two 16" hotdogs welded in Lukey Mufflers do some nice stainless hotdogs and they'd be great. They "must" have resonators before the valves to remove the raspyness.

The resonator after the secondary cats need to top cut open to see what's in there and I believe there's a balance pipe and perforated tube. That needs to packed with stainless wool and the top welded back on.

With the valves open at full throttle, this will sound magic!!, a high pitched smooth scream, not quite as loud as a non-muffled mid pipe but the note will be good, no fartyness and no rasp.

With the valves closed with a stock rear muffler, it won't have the farts and rasp entering the rear muffler and it will likely be quieter and that's ok because when you floor it, the valves open and bypasses the rear muffler to get the noise and the note.

That's about $1200 to $1500 worth for a good exhaust fabricator to knock that up. They're off their chops with 7K+ exhaust systems as there's absolutely no rocket science in this.

I'm going to try this out. Will source the lukey mufflers "hot dogs" in place of the secondary cats. Then test the sound and drive etc

If no good then I'll open up the centre resonator and pack with stainless wool packing, weld back up and see again.

If still no good then I'll have to source a h pipe or x pipe which is resonated

I'll start a new post when I get it all started

[A'PEXi]

I think this is roughly what RevNev was saying, can someone try this out and report back?

Single probably 4"? From down pipe, split back into 2 for the lukey resonators, then baffle the standard resonator.

Excuse the dodgy 'paint' job.

[FR00ZN]

Originally Posted by A'PEXi

I think this is roughly what RevNev was saying, can someone try this out and report back?

Single probably 4"? From down pipe, split back into 2 for the lukey resonators, then baffle the standard resonator.

Excuse the dodgy 'paint' job.

Reputable exhaust shops saying it's illegal to remove secondary cats and put in resonators. If you are involved in an accident or are stopped and checked you may be in all sorts of trouble both by Police and not covered by insurance.

So I've been told

[HiFi]

but there are primary cats in the downpipes, as long as there is 1 cat in the exhaust path I can't see how this is illegal.

[domino_z]

Originally Posted by FR00ZN

Reputable exhaust shops saying it's illegal to remove secondary cats and put in resonators. If you are involved in an accident or are stopped and checked you may be in all sorts of trouble both by Police and not covered by insurance.

So I've been told

Technically yes

If your car does not meet ADR's or has been modified outside of their underwriting guidelines, your insurer can deny a claim

You'd need to come across a very prudent assessor that knows the car well to spot a custom fab exhaust, but it is entirely possible

Most of the time assessors look for worn tyres, brakes, frayed seat belts, that kind of stuff

With exhaust you're more likely to get done at a road side EPA test for having no/fewer cats

[ntg44]

I just replaced the secondary cats with 2 Magnaflow 14156 resonators. Bought a second OEM midpipe for cheap just to make swapping back to stock easier, but no reason you couldn't just use the one from your car.

As far as I can tell, all rasp is gone, and if you stick with your existing midpipe, runs you under $400 with install. No X pipe/custom fabrication needed. Sounds fantastic now. I laughed when I saw the price of the fabspeed pipe. At least the Borla 2nd cat delete is somewhat affordable at ~$500.

[domino_z]

There was talk of the borla fitting, but I don't think anyone ever tried it

[A'PEXi]

Originally Posted by ntgarage44

I just replaced the secondary cats with 2 Magnaflow 14156 resonators. Bought a second OEM midpipe for cheap just to make swapping back to stock easier, but no reason you couldn't just use the one from your car.

As far as I can tell, all rasp is gone, and if you stick with your existing midpipe, runs you under $400 with install. No X pipe/custom fabrication needed. Sounds fantastic now. I laughed when I saw the price of the fabspeed pipe. At least the Borla 2nd cat delete is somewhat affordable at ~$500.

so you're saying your entire exhaust system is stock, other than replacing the 2 secondary cats?

[FR00ZN]

Originally Posted by ntgarage44

I just replaced the secondary cats with 2 Magnaflow 14156 resonators. Bought a second OEM midpipe for cheap just to make swapping back to stock easier, but no reason you couldn't just use the one from your car.

As far as I can tell, all rasp is gone, and if you stick with your existing midpipe, runs you under $400 with install. No X pipe/custom fabrication needed. Sounds fantastic now. I laughed when I saw the price of the fabspeed pipe. At least the Borla 2nd cat delete is somewhat affordable at ~$500.

I wonder what sound hi flow cats would produce VS the resonator route.

How much louder is it with the magnaflow resonators?

[ntg44]

Originally Posted by A'PEXi

so you're saying your entire exhaust system is stock, other than replacing the 2 secondary cats?

Yep. Cut out secondary cats, installed 2 magnaflow 14156 resonators, and valves unplugged so they're stuck open. Sounds fantastic now. No more rasp as far as I can hear. It's no louder than stock, but the snarl under full throttle is gone and there's a tiny bit more bass in the exhaust note. Believe it or not it actually drones less than stock. My shifter used to buzz when cruising around 2-3k rpm. No longer does that with these resonators.

[ntg44]

Originally Posted by FR00ZN

I wonder what sound hi flow cats would produce VS the resonator route.

How much louder is it with the magnaflow resonators?

Please see my other reply in this thread

I'll also have a video up next week. Will update and link to this thread.

[RevNev]

All you need to do is join the twin pipe together between the flange and front exhaust hanger to sound the same as an X pipe. Joining the pipes turns a twin system note wise into a single. Balance pipes or H pipes are too small to maximise the effect. Ideally the mid pipe needs to enter an oval pipe section about 5" long and exit dual.

This is "easily" done with stock mid pipe by cutting out the inside half of the twin pipes and welding a plate top and bottom. The modification only needs to be 4" to 5" long replicating a "large" balance pipe.

The farty sound and raspyness on the M3/M4 is no different than a V6 Commodore with a dual exhaust. If you join the twin pipes together makes a V6 sound like a straight 6 with a single exhaust.

The twin turbos on the M3/M4 are grouped into cylinders 1,2,3 and 4,5,6 and with an exhaust outlet on each turbo and has the same effect note wise as splitting the headers on a 6 cylinder Falcon into a dual exhaust and produces the same farty note as the M3/M4.

The exhaust on a turbo engine only needs to flow and doesn't need to scavenge like an naturally aspirated engine when the turbos blow the exhaust gas out so to speak. Exhaust design isn't as critical to make power, it's about flow. Doesn't matter how the twin pipes are joined as long as it doesn't restrict flow. The power restriction in the stock mid pipe is the secondary cats not the pipe design.

Paying 2k plus for a trick mid pipe when the only thing "trick" about it is the absence of secondary cats and it's joined to remove the farty sound is a waste of money. I think the trend is if you can afford an M3/M4, you can afford to pay stupid prices for exhaust mods.

[domino_z]

thread bump as i found another one of dubs' videos on youtube, and the mpe definitely sounds better with the fab mid - it's a subtle change in tone, but if you've spent a while with the mpe you can easily spot it

has anyone bought the fab since, looking on ebay, it's around 2300 shipped customs all in

[drgmt]

Originally Posted by domino_z

thread bump as i found another one of dubs' videos on youtube, and the mpe definitely sounds better with the fab mid - it's a subtle change in tone, but if you've spent a while with the mpe you can easily spot it

has anyone bought the fab since, looking on ebay, it's around 2300 shipped customs all in

It made a nice difference to my MPE on the previous M3. Sold it off. I know there have been fitment concerns but mine fit the car like a glove.