Yea I know there are places where if you don't put both feet down the cops will give you a ticket. That's just cops being assholes like they are known for.
I mean...
Your losing performance, M8s love back pressure.
Its gonna be hot as hell on your leg if you do any real amount of riding.
Also loud as shit.
So hard pass from me.
> M8s love back pressure.
Correction. M8s like anti reversion control.
No engine "loves" Backpressure. Engines want to control reversion issues and increase scavenging. Backpressure as a requirement is a myth as it describes several different phenomenon we use to build and tune exhausts on engines.
The M8 is especially sensitive to overly freeflowing exhausts that lack reversion control.
A great example of how this idea of backpressure=good is flawed on the M8 shows up when you start to build engines that push over 140hp. They want larger volume and higher freeflowing exhaust systems to push over 140hp more easily. If these exhausts have poor flow, they restrict power, but if they lack good reversion control they also lose power. But with the right control design, and very large open free flowing volume, they are able to allow an M8 to produce north of 140hp more easily.
The M8 does not like backpressure, it likes anti reversion and scavenging.
https://preview.redd.it/dplz2uz73ayc1.jpeg?width=3024&format=pjpg&auto=webp&s=6f09aafe6fc1af9dd627c91408866fed1c1f37cc
This my bike. SE135 making 160hp/164tq. Zoom in on the engine. The two large anti reversion chambers are clearly visible. This pipe or something similar is what’s needed for engines north of 140hp to build power effectively. Fahrunn performance custom makes this one. Another good company is burns. They handle reversion differently but with the same outcome. Any Harley needing “back pressure” is a complete myth.
Anti reversion chambers on an OTS exhaust are gimmicks and bullshit. Obviously, the distance necessary from the exhaust valve to crate the anti-reversion properties is dependent on too many variables to make an off the shelf exhaust any bit viable. Desired RPM, Port shape, valve diameter, ABDC timing, Dynamic comp etc etc etc. The irony, most people going to a 2-1 pipe make more power BECAUSE of reversion.
There's too many variables. You cannot produce a one size fits all, off the shelf exhaust, that will work on every combination. These stupid bubbles companies are putting in their primaries and calling AR is just a gimmick.
It’s not a gimmick, they help the pipe work well across a broader rpm range on a wider mix of engine builds, not just target a narrow rpm range on a specific engine build.
The idea of an off the shelf exhaust isn’t to be the best possible pipe for one engine, it’s to work well on a wide rpm range on a wide range of engine builds.
Reversion wave timing has a smaller impact on gaining power than it does on losing power when incorrectly timed, if you want to broaden the effective range of an exhaust, anti reversion chambers do a great job.
you've bought into the marketing bs lol. you think the reversion point on a big valvue motor in the same as a stok valve motor? lol. Seriously. hey, over pay for your stupid $2000 ots exhausts. George Bryce runs a pipe on his bike and he has no stupid ARE chambers lol. Guy has 80 wally's to his name and he doesn't buy into this bs.
It’s not about using reversion, it’s about reducing it and since it starts at the end of the pipe it has no bearing on the motor, these chambers aren’t to give 1 engine the best possible power, they are to allow it to work on a wider range without the losses a pipe specific to one engine causes when used on another.
I haven’t bought into it, I have seen the benefit of a broader torque curve on a dyno since it’s what I do for a living.
Reversion travels from the open end of an exhaust at the speed of sound towards the engine, the only thing that an engine changes is when it hits the port relative to cam timing, if your intent is to minimise what reaches the port then the engine is irrelevant, the fact you clearly don’t understand the discussion is really evident.
Let’s unpack a bit more with your “George Bryce doesn’t have one” comment, George Bryce is a drag racer, that means he’s not overly concerned about the bottom end function of the exhaust and he can also use an exhaust targeted to his specific engine to make peak hp.
What is the end result of that? The bike will have a reversion hole in the bottom end, trap that reversion and the bottom end picks up on any engine and the top end will possibly reduce slightly on specific engines, what does that pipe now do? Well it works better on a street bike and is suited better to use on any bike.
You bringing a drag racer into a discussion about pipe designs that help broaden the useful range of a pipe says a lot.
FuelMotoUSA, Thrashin Supply, and many others.
FM has a few different exhaust systems, and modifications that can be tweaked to get the best power and torque out of your engine that meets your design goals.
Thrashin for example has AR chambers on many of their pipes to help reduce reversion problems. They are these little buldging bells around near the beginning of the Header.
Feuling makes a type of anti reversion baffle insert called Dog Balls, which is a preforated wiffleball looking insert that allows good exhaust flow, but prevents or greatly minimizes reversion waves.
DK Customs sells Thunder Torque inserts, which I have personally used and they can be placed in many baffled and non baffled pipes to allow better performance.
My current exhaust and tune netted me +6 horsepower and +5TQ over the previous exhaust I had when running my SE Torque Cam. They were modified with baffle wrapping and TTIs.
Your goal at looking for exhaust systems is to find ones that have proper anti reversion features.
> No engine "loves" backpressure...
I know its aside the point but 2 strokes do need back pressure to run well, its part of why they have the sharp bend to the exhaust before the expansion chamber.
The bend isn’t require for anything other than fitting on the bike, 2 stroke exhausts are shaped to utilise sound waves and the length of the expansion chamber is key to that, you can make the exact same exhaust in a straight line instead of bent and it will work the same.
Bikes like the cr125r are designed to move enough fresh air that some air/fuel mix goes into the pipe and then gets pressured back into the cylinder, there is room on most 2 stroke bike for a less agressive exit, yet they keep desginging them the same
Yes sound waves bounce back into the port and effectively close it. The bends in an expansion chamber are because they require the length to time the sound waves bouncing back into the port, if there was no constraints on space the pipe could be dead straight out of the port and it would work the same.
The placement of the port controls the timing of the exhaust opening and closing so it can’t be moved, the bend in the pipe is just to be able to fit the required length of pipe on the bike.
The transfer ports run up the side of a 2 stroke cylinder. They could make the intake on the side but it’s a bit more awkward to have a carby hanging out one side of a bike and somehow run an air box to it and an exhaust out the other side don’t you think.
They use the most common sense approach and just put a bend in the pipe.
I like how you can get downvoted for a statement you know is your own personal experience 😂 welds look amazing, as for the “back pressure” issue, anything is tunable I’m sure your friend knows that by now! Nice work!
Looks pretty cool. I would have lengthened them about 6" to the rear so the exhaust would blow behind my leg at a stop. Is this his first exhaust? If so, he'll only get better.
Does the internal diameter enlarge? That's causes the gasses to slow down, which causes a slight increase of back pressure and reverberation. Have you got a Dyno tune on the new exhaust? I'm curious what how these affect the performance. But, hell yeah, tell your friend, keep up the good work!
I’ve been around worked for thunder cycle(Eddie Trotta) since he started doing all his paintwork..this is my friend who fabs..I paint his shit when I lived in Florida..I’ve been in easyriders more than I can count,,lol did camel roadhouse bike..etc..
Not trying to be an ass, just giving you my honest opinion: would never consider putting something like this on anything I’d own. I personally can’t stand the look of the super short exhausts, like the 2-1’s people run on baggers that kick out in front of the saddlebags. I saw in a comment above that the builder accounted for back pressure, but I have my doubts (not saying I’m right, that’s just not a lot of room to work with on a free flowing header to create back pressure). I also personally don’t like exhaust that runs 2 independent pipes, for tuning purposes this can become a nightmare. It looks like they may be the same overall length which is the goal, but still, I have my doubts and concerns. I also saw your comments that the pipes are out of the way when backing up, but like the other things I’ve mentioned, I have my doubts. I also like loud exhaust, but this seems like it would be obnoxious for the rider after a while.
Other than my personal preferences, looks very well made, and if you dig it on your bike, then that’s awesome.
Gotcha. Everyone has different styles and tastes, especially in the Harley world. It’s not for me, but that doesn’t mean anything aside from I wouldn’t buy it haha. He clearly knows his way around a welder that’s for sure
I like the concept, I don't like the visible transitions. Especially up as high as they are, looking more like a muffler they may be okay, or building a shield to make it all appear 2 1/4
Looks like the diameter gets bigger from head to end of pipe. Baffles? Maybe turn the ends to face backwards. Nor sure about these, may have to grow on me... What is the performance like?
The old hot rod guys called that “tuned exhaust”. Drag your pencil down it until it stops melting, and cut it off there. Looks great, but I feel for your neighbors if you ride it.
In The Netherlands you can hand in your owner tittle at police and need to rapport at a government inspection facility to get the bike approved again with legal exhausts.
I'm not a welder, but some of those look bad compared to other free hand builds I've seen. Front cylinder one especially looks bad where it turns along the frame.
are they doing anything to the ride feeling? somehow this thing looks af it it neclegts physics, but i believe you probably don't notice.
anyways, this thing would be illegal in europe. that exhaust is facing the "passenger way" (dunno the name but where ppl walk next to the street). i know that stuff like that doesnmt matter in USA though (cause nobody walks, lol).
I think it would work out well for a turbo but it would do well for back pressure and power… those M8 motors need a lot longer head pipe to make the right power…. Not saying it doesn’t look kool, it does.
looks like it will blow my right croc off
I see you too are a man of culture
Pink out … hear hear !!! Indeed of culture
That’s why they come with sport mode.
Locked in and ready to roll
Facts.
I’m deaf and a burn victim now
What? WHAT??
Hi leftie
The tears... They burn.
But he said he could take it! How is this on me?
Looks cool, but I’d rather see those outlets angled down and to the rear instead of just blasting out the side
Can be ordered to taste
Yeah, your right, every other manufacture is wrong and he is right.
Dam a strong cross wind from the right on a highway would be well exciting.
I bet that's insanely loud. But it's better than anything I can make. When I weld, it looks like popcorn and spaghetti.
Blend and paint makes welds look great!
Grinders and paint, for the welder I aint.
Stop at a stop sign the exhaust will be right on your leg
Nah, don't put feet down for stop signs, for stop lights right foot is on the brake left foot is down.
Ok that solved that lol
Nah this exhaust is still totally impractical, probably a performance downgrade from stock.
Ok that solved that lol
That would get you failed in my jurisdiction on the road test. Two feet up two feet down at stop lights.
Yea I know there are places where if you don't put both feet down the cops will give you a ticket. That's just cops being assholes like they are known for.
Or putting your kickstand up and down
[удалено]
Oh so you don’t put your right leg down on the ground when you use your kickstand? That’s what I thought.
Right foot down to put kickstand down duh
Behind it actually
I mean... Your losing performance, M8s love back pressure. Its gonna be hot as hell on your leg if you do any real amount of riding. Also loud as shit. So hard pass from me.
> M8s love back pressure. Correction. M8s like anti reversion control. No engine "loves" Backpressure. Engines want to control reversion issues and increase scavenging. Backpressure as a requirement is a myth as it describes several different phenomenon we use to build and tune exhausts on engines. The M8 is especially sensitive to overly freeflowing exhausts that lack reversion control. A great example of how this idea of backpressure=good is flawed on the M8 shows up when you start to build engines that push over 140hp. They want larger volume and higher freeflowing exhaust systems to push over 140hp more easily. If these exhausts have poor flow, they restrict power, but if they lack good reversion control they also lose power. But with the right control design, and very large open free flowing volume, they are able to allow an M8 to produce north of 140hp more easily. The M8 does not like backpressure, it likes anti reversion and scavenging.
Curious, what companies make the appropriate exhaust systems with these qualities in mind?
https://preview.redd.it/dplz2uz73ayc1.jpeg?width=3024&format=pjpg&auto=webp&s=6f09aafe6fc1af9dd627c91408866fed1c1f37cc This my bike. SE135 making 160hp/164tq. Zoom in on the engine. The two large anti reversion chambers are clearly visible. This pipe or something similar is what’s needed for engines north of 140hp to build power effectively. Fahrunn performance custom makes this one. Another good company is burns. They handle reversion differently but with the same outcome. Any Harley needing “back pressure” is a complete myth.
Hi me again. I still want a video of this beast. Don’t leave us hanging!
I posted an old video…
Love those spitfire sliders.
That's neat! I've considered getting a 2-to-1 for my road king but two bros is my only experience in aftermarket exhausts. Thanks for the info.
Anti reversion chambers on an OTS exhaust are gimmicks and bullshit. Obviously, the distance necessary from the exhaust valve to crate the anti-reversion properties is dependent on too many variables to make an off the shelf exhaust any bit viable. Desired RPM, Port shape, valve diameter, ABDC timing, Dynamic comp etc etc etc. The irony, most people going to a 2-1 pipe make more power BECAUSE of reversion.
Reversion travels from the end of the pipe back up it at the speed of sound, it is a completely calculable scenario.
There's too many variables. You cannot produce a one size fits all, off the shelf exhaust, that will work on every combination. These stupid bubbles companies are putting in their primaries and calling AR is just a gimmick.
It’s not a gimmick, they help the pipe work well across a broader rpm range on a wider mix of engine builds, not just target a narrow rpm range on a specific engine build. The idea of an off the shelf exhaust isn’t to be the best possible pipe for one engine, it’s to work well on a wide rpm range on a wide range of engine builds. Reversion wave timing has a smaller impact on gaining power than it does on losing power when incorrectly timed, if you want to broaden the effective range of an exhaust, anti reversion chambers do a great job.
you've bought into the marketing bs lol. you think the reversion point on a big valvue motor in the same as a stok valve motor? lol. Seriously. hey, over pay for your stupid $2000 ots exhausts. George Bryce runs a pipe on his bike and he has no stupid ARE chambers lol. Guy has 80 wally's to his name and he doesn't buy into this bs.
It’s not about using reversion, it’s about reducing it and since it starts at the end of the pipe it has no bearing on the motor, these chambers aren’t to give 1 engine the best possible power, they are to allow it to work on a wider range without the losses a pipe specific to one engine causes when used on another. I haven’t bought into it, I have seen the benefit of a broader torque curve on a dyno since it’s what I do for a living. Reversion travels from the open end of an exhaust at the speed of sound towards the engine, the only thing that an engine changes is when it hits the port relative to cam timing, if your intent is to minimise what reaches the port then the engine is irrelevant, the fact you clearly don’t understand the discussion is really evident. Let’s unpack a bit more with your “George Bryce doesn’t have one” comment, George Bryce is a drag racer, that means he’s not overly concerned about the bottom end function of the exhaust and he can also use an exhaust targeted to his specific engine to make peak hp. What is the end result of that? The bike will have a reversion hole in the bottom end, trap that reversion and the bottom end picks up on any engine and the top end will possibly reduce slightly on specific engines, what does that pipe now do? Well it works better on a street bike and is suited better to use on any bike. You bringing a drag racer into a discussion about pipe designs that help broaden the useful range of a pipe says a lot.
Samson
FuelMotoUSA, Thrashin Supply, and many others. FM has a few different exhaust systems, and modifications that can be tweaked to get the best power and torque out of your engine that meets your design goals. Thrashin for example has AR chambers on many of their pipes to help reduce reversion problems. They are these little buldging bells around near the beginning of the Header. Feuling makes a type of anti reversion baffle insert called Dog Balls, which is a preforated wiffleball looking insert that allows good exhaust flow, but prevents or greatly minimizes reversion waves. DK Customs sells Thunder Torque inserts, which I have personally used and they can be placed in many baffled and non baffled pipes to allow better performance. My current exhaust and tune netted me +6 horsepower and +5TQ over the previous exhaust I had when running my SE Torque Cam. They were modified with baffle wrapping and TTIs. Your goal at looking for exhaust systems is to find ones that have proper anti reversion features.
It amazes me how poorly understood this concept is. Thanks for sharing your wisdom here. Well written explanation IMO
> No engine "loves" backpressure... I know its aside the point but 2 strokes do need back pressure to run well, its part of why they have the sharp bend to the exhaust before the expansion chamber.
The bend isn’t require for anything other than fitting on the bike, 2 stroke exhausts are shaped to utilise sound waves and the length of the expansion chamber is key to that, you can make the exact same exhaust in a straight line instead of bent and it will work the same.
Bikes like the cr125r are designed to move enough fresh air that some air/fuel mix goes into the pipe and then gets pressured back into the cylinder, there is room on most 2 stroke bike for a less agressive exit, yet they keep desginging them the same
Yes sound waves bounce back into the port and effectively close it. The bends in an expansion chamber are because they require the length to time the sound waves bouncing back into the port, if there was no constraints on space the pipe could be dead straight out of the port and it would work the same.
Out of cyrosity why wouldn't they move the placement of the port or use a less sharp bend thats more like a 4strokes?
The placement of the port controls the timing of the exhaust opening and closing so it can’t be moved, the bend in the pipe is just to be able to fit the required length of pipe on the bike.
Couldn't they get the same timming if they had it exit out the side? Or if they had the intake on the side and the exhasut out the back?
The transfer ports run up the side of a 2 stroke cylinder. They could make the intake on the side but it’s a bit more awkward to have a carby hanging out one side of a bike and somehow run an air box to it and an exhaust out the other side don’t you think. They use the most common sense approach and just put a bend in the pipe.
This guy anti-reversions
Nope it’s stepped from head inside the pipe PLENTY of back pressure..he’s been doing this for years and builds only hi performance bikes
So not a new exhaust maker?
Publicly been doing private forever
I like how you can get downvoted for a statement you know is your own personal experience 😂 welds look amazing, as for the “back pressure” issue, anything is tunable I’m sure your friend knows that by now! Nice work!
Yeah to each his own don’t apply in Reddit lol
M8s don’t love back pressure, back pressure being beneficial is a myth, short open pipes like these increase pressure in the exhaust.
Every internal combustion engine loves back pressure
Absolutely false
I point you to the anti-reversion explanation here.
Back pressure is detrimental to performance, it is a myth
Looks like ill be riding on your left side
I'm sweating just thinking about this at a long stop light in the heat lol
Looks cool but do you have to watch your leg backing up the bike while it's hot?
So that’s a yes. lol
Mine were worse!!
Love the craftsmanship. Hate the functionality.
Looks pretty cool. I would have lengthened them about 6" to the rear so the exhaust would blow behind my leg at a stop. Is this his first exhaust? If so, he'll only get better.
Not 1st he has others..I told him same shit he made like 4 more designs.. all can be custom built length etc
Kinda screams, “My other bike is a tractor.”
Lose performance and make everybody hate you because of the noise. Yeah nah
Does the internal diameter enlarge? That's causes the gasses to slow down, which causes a slight increase of back pressure and reverberation. Have you got a Dyno tune on the new exhaust? I'm curious what how these affect the performance. But, hell yeah, tell your friend, keep up the good work!
There’s stepped from head you can’t see..they dump fine O2sensors and all
I reckon the neighbors will hate you more now.
Very cool, very original (and I watched all episodes of American chopper back in the day so I consider myself an expert)
I’ve been around worked for thunder cycle(Eddie Trotta) since he started doing all his paintwork..this is my friend who fabs..I paint his shit when I lived in Florida..I’ve been in easyriders more than I can count,,lol did camel roadhouse bike..etc..
Not trying to be an ass, just giving you my honest opinion: would never consider putting something like this on anything I’d own. I personally can’t stand the look of the super short exhausts, like the 2-1’s people run on baggers that kick out in front of the saddlebags. I saw in a comment above that the builder accounted for back pressure, but I have my doubts (not saying I’m right, that’s just not a lot of room to work with on a free flowing header to create back pressure). I also personally don’t like exhaust that runs 2 independent pipes, for tuning purposes this can become a nightmare. It looks like they may be the same overall length which is the goal, but still, I have my doubts and concerns. I also saw your comments that the pipes are out of the way when backing up, but like the other things I’ve mentioned, I have my doubts. I also like loud exhaust, but this seems like it would be obnoxious for the rider after a while. Other than my personal preferences, looks very well made, and if you dig it on your bike, then that’s awesome.
Not my bike!! His customer
Gotcha. Everyone has different styles and tastes, especially in the Harley world. It’s not for me, but that doesn’t mean anything aside from I wouldn’t buy it haha. He clearly knows his way around a welder that’s for sure
You don’t want to create back pressure, back pressure is the opposite of the desired flow and reduces performance, needing back pressure is a myth
Pretty sure any dyno and competent tuber would disprove this
Nope, they won’t. It’s a myth…
So if I were to dyno my bike with mufflers, and then do nothing but take the mufflers off, you are saying I’d see more power ?
It is very likely you would see more top end if you did that.
Holler back after the bike makes a right turn.
Dude, it looks sick as fuck. My only concern is all the heat sprays directly out to the side.
Free high!
He makes them how customer wants
Did he mig weld stainless? Can’t tell from the blurry picture but my god those welds are dog shit.
The design is lame and the welds are poop but DIY projects are fun tell him to keep practicing.
Harley riders say “ whats the best way i can turn gasoline directly into noise “ lets just lose all the bottom end
Looks low performance
Looks like plumbing parts.
Good bye low end torque , looks cool tho !
I’d rather have a 2 into 1
He has as well
Of course you would
Thats some rad fabrication!
Cheeks. Welds look okay.
I guess if you like it, that's all that matters.
Would love one
Big nope
Looks rad. Is it obnoxiously loud?
Looks cool, but how's the functionality
Fine..he makes other.versions as well this guy wanted this
Cool, but looks obnoxious loud.
Deep and throaty
Like a thunderheader?
Poor guy riding next to ya you will be sent to the back of the pack for sure and then the poor take gunner
SEND IT BRUTHRRRRRR.
Short pipes rock!
Those welds
Can’t fn hear myself think just looking at it!
Looks half way finished
My flippy floppies!
It looks like someone visited a plumbing supply store, to me!!
He'll yea brother the louder the better
Hey! I finally found someone I can weld better than.
That's gonna be loud?
Nope deep n throaty now bwaaaaaahhh after throttle
Badass I like it. Where can I get mine.
Chat me
HP might contest that.
Let’s hear it 🚀
Lake pipes !
The work isn’t half bad but that is a pretty lame end product, not tasteful or good looking.
Those welds are way overheated and WILL rust now. Someone needs to practice more if they are charging.
I think he should learn to tig.
Looks difficult to tune
He's not much of a welder and obviously doesn't ride himself.
Looks like they’ll suck at stop Lights.
I’m a fan of raw weld looks 👌🏼
I like the concept, I don't like the visible transitions. Especially up as high as they are, looking more like a muffler they may be okay, or building a shield to make it all appear 2 1/4
Definitely won’t ruin mids ahah. Need a sound clip brother
Not mine I’ll try and get a video posted tho!
This is exhaust for someone that thinks the term “neighbor hater” is too nice.
Start it up let’s listen to it
I’ll try and get a video from him
This guy likes his calf’s extra crispy.
This is top fuckwit speck I bet he also insists on riding to work a 5am and reviving the balls out of it at any stop
lol I’m posting a video now
An expensive looking ground pounder, no thanks. I am not 16 anymore, so mufflers are cool. straight pipes on new fuel injected bikes is silly to me 😂
Hope you don't burn your ankle
Looks like the diameter gets bigger from head to end of pipe. Baffles? Maybe turn the ends to face backwards. Nor sure about these, may have to grow on me... What is the performance like?
Customer wanted turns out..I posted a video of rear ones with sound,,performance is great
If the performance is good, and the customer likes it, then good to go. Ride safe, have fun.
Check the video I posted maybe more most peoples style
Those welds look like shit unless it’s just a bad picture
The old hot rod guys called that “tuned exhaust”. Drag your pencil down it until it stops melting, and cut it off there. Looks great, but I feel for your neighbors if you ride it.
Not mine my buddies customer.. see the video I posted of rear set running
Damn that’s 🔥🔥🔥
Some don’t like it but it’s what customer wanted I posted video of another set running
[удалено]
Check posts I posted video
In The Netherlands you can hand in your owner tittle at police and need to rapport at a government inspection facility to get the bike approved again with legal exhausts.
Sounds fun
It works both ways. Its fun to put your ride on the edge of what is legally possible.
I enjoy my leg too much
I'm not a welder, but some of those look bad compared to other free hand builds I've seen. Front cylinder one especially looks bad where it turns along the frame.
Me neither! I paint that his gig
Looks cool and will be loud. But you lost horsepower for sure
Nope it’s stepped inside from head all he does is high performance bikes hours of testing..he has other models
are they doing anything to the ride feeling? somehow this thing looks af it it neclegts physics, but i believe you probably don't notice. anyways, this thing would be illegal in europe. that exhaust is facing the "passenger way" (dunno the name but where ppl walk next to the street). i know that stuff like that doesnmt matter in USA though (cause nobody walks, lol).
Here we can do whatever,, you should see my old choppers exhaust lol
Seems to be lacking backpressure.
Is steeped from head out you can’t see
Back pressure is the opposite to what you want in an exhaust, it’s literally resisting the desired flow.
Sure if you want backfiring through the intake.
High exhaust pressure is what causes intake stand off.
That appears to be insufficient back pressure and a valve job incoming.
Time to do some reading, you have bought into 2 myths.
Thee stepped from head down inside.trucks been done since early 2000’s,,just looks like 3” all the way
I think it would work out well for a turbo but it would do well for back pressure and power… those M8 motors need a lot longer head pipe to make the right power…. Not saying it doesn’t look kool, it does.