Top Gear Motorworks Equal Length Exhaust – My Review

[Danlnyc88]

Originally Posted by UnleashedF80

$3795 for an exhaust system.

How much do u think a full catback system should be worth? Very curious to hear your opinion. In comparison to other name brand companies we all know about.

Seems like you paid way less or know something. Please feel free to share.

[UnleashedF80]

Originally Posted by Danlnyc88

How much do u think a full catback system should be worth? Very curious to hear your opinion. In comparison to other name brand companies we all know about.

Seems like you paid way less or know something. Please feel free to share.

I'm on single turbo ATM. However, I used to pay around 4000 USD for brand new AA+ Remus(102 Carbon tips) combo which is worth for every penny and very high resale value. IMO this top gear 3800 axle back exhaust is Over priced!

[aBMWfan]

Originally Posted by UnleashedF80

I'm on single turbo ATM. However, I used to pay around 4000 USD for brand new AA+ Remus(102 Carbon tips) combo which is worth for every penny and very high resale value. IMO this top gear 3800 car back exhaust is Over priced!

IMO this is the best sound EQ length exhaust so far and worth it. If you don’t agree don’t buy it IMO at least you don’t need it for single turbo

[StanislavK82]

This thing sounds amazing in the videos! I can only imagine that it sounds even better in person!

[ntg44]

Originally Posted by StanislavK82

This thing sounds amazing in the videos! I can only imagine that it sounds even better in person!

I've been meaning to write this for a while. We all know how every other one of the exhausts for the most part really don't record on video well, and how everyone says they don't do it justice like in person. After hearing it outside the car personally, I can say the exact same thing about the TGM system, except that it sounds awesome on video. And in person, it's so much better. All I want to do is drive the car now and rev the snot out of it .

[StanislavK82]

So I have a question, I'm by no means an exhaust expert, but does the equal length exhaust change the pressure experienced by the turbos at all? Maybe the pressure spikes are reduced, but if the pressure spikes are added together could they result in lower turbo life? It would be interesting if anyone has some high speed pressure measurements at the turbos to see. I guess it's just mind blowing to me that this isn't the stock sound and maybe there's a reason for the different lengths. Of coarse I'm probably over thinking this.
Thanks

[ntg44]

Originally Posted by StanislavK82

So I have a question, I'm by no means an exhaust expert, but does the equal length exhaust change the pressure experienced by the turbos at all? Maybe the pressure spikes are reduced, but if the pressure spikes are added together could they result in lower turbo life? It would be interesting if anyone has some high speed pressure measurements at the turbos to see. I guess it's just mind blowing to me that this isn't the stock sound and maybe there's a reason for the different lengths. Of coarse I'm probably over thinking this.
Thanks

I think you’re overthinking it. Equal length designs aren’t unique to this car. They’re implemented in headers and in down pipes for almost anything that doesn’t have them already. The reason the S55 doesn’t have it is packaging. The front down pipe is 14 inches longer before the 2 sides merge in the middle resonator. That’s what gives the car its unique tone, for better or worse.

This is an unconventional way to change the tone that no OEM would intentionally do. In the end, the most efficient exhaust is as short and straight as possible. It’s just that since there’s really no room to extend the shorter downpipe 14 inches before the flange to the exhaust, the TGM system makes both paths as straight as possible while adding the length back to the shorter side before merging. I’ve attached a pic for your reference.

[StanislavK82]

Originally Posted by ntg44

I think you're overthinking it. Equal length designs aren't unique to this car. They're implemented in headers and in down pipes for almost anything that doesn't have them already. The reason the S55 doesn't have it is packaging. The front down pipe is 14 inches longer before the 2 sides merge in the middle resonator. That's what gives the car its unique tone, for better or worse.

This is an unconventional way to change the tone that no OEM would intentionally do. In the end, the most efficient exhaust is as short and straight as possible. It's just that since there's really no room to extend the shorter downpipe 14 inches before the flange to the exhaust, the TGM system makes both paths as straight as possible while adding the length back to the shorter side before merging. I've attached a pic for your reference.

Thanks, makes sense and looks like bmw chose their direction as a means to just reduce cost/complexity.

P.S. thanks for the quick response. Car looks good underneath, a thing of beauty.

[ra2289]

Originally Posted by ntg44

Hello all,

Now that there are enough videos to share, I want to introduce the first production equal length exhaust system available for the F80 M3/F82 M4.

Thanks for the detailed write-up/clips. Love how this thing screams with no ear cringing sounds to be heard. I so wish I could hear this thing in person.

With my current setup, and with the car properly warmed up, if the car sits for like 5 minutes or so—engine off—on start up I get like a mini cold start that sounds terrible with the valves open for a mile or so then it cleans up to the normal exhaust sound.

Question: Does this exhaust do that at all? Or rather, does it clean up that deep, grumbly, tractor sound the S55 is known for during the scenario above? Just curious. Hope my description wasn't as bad as I think it was.

[DanMpower]

Originally Posted by ra2289

Thanks for the detailed write-up/clips. Love how this thing screams with no ear cringing sounds to be heard. I so wish I could hear this thing in person.

With my current setup, and with the car properly warmed up, if the car sits for like 5 minutes or so—engine off—on start up I get like a mini cold start that sounds terrible with the valves open for a mile or so then it cleans up to the normal exhaust sound.

Question: Does this exhaust do that at all? Or rather, does it clean up that deep, grumbly, tractor sound the S55 is known for during the scenario above? Just curious. Hope my description wasn't as bad as I think it was.

Yeah with the stock tune, even after you shut the car off for a couple of minutes that "mini cold start" you describe sounds absolutely horrendous!

Once you get a tune and turn cold start off, the car will sound great anytime you get in and it won't sound like a thousand angry civics chasing you.

[ntg44]

Originally Posted by ra2289

Thanks for the detailed write-up/clips. Love how this thing screams with no ear cringing sounds to be heard. I so wish I could hear this thing in person.

With my current setup, and with the car properly warmed up, if the car sits for like 5 minutes or so—engine off—on start up I get like a mini cold start that sounds terrible with the valves open for a mile or so then it cleans up to the normal exhaust sound.

Question: Does this exhaust do that at all? Or rather, does it clean up that deep, grumbly, tractor sound the S55 is known for during the scenario above? Just curious. Hope my description wasn't as bad as I think it was.

I know exactly what you're talking about. That's definitely the cold start sequence, and to be honest I kind of like it haha. When I was stock with valves unplugged, getting out of the driveway and onto the street under low throttle was the coolest it ever sounded on stock exhaust.

I can't answer your question yet, but I will pay extra attention with valve open during this sequence next time I start the car and drive away. I know for a fact this does not happen with valve closed, but honestly, I see no reason to cold start with valve open despite how docile it is anyways. In the first post, I posted an Instagram clip of valve open cold start in case you haven't heard it already. But I'll get back to you next time I'm in the car.

So as of right now I have 2 requests.
- Interior sound clips
- Valve open cold start driveaway feedback

If anyone has any other questions, I can answer them during my next drive.

[ra2289]

Originally Posted by DumbAS55

Yeah with the stock tune, even after you shut the car off for a couple of minutes that "mini cold start" you describe sounds absolutely horrendous!

Once you get a tune and turn cold start off, the car will sound great anytime you get in and it won't sound like a thousand angry civics chasing you.

Yep. I find it very strange. Like my exhaust is trying to gargle mouthwash or speak while being waterboarded.

Originally Posted by ntg44

I know exactly what you're talking about...

Awesome, thanks.

I actually don't mind the first cold start of the day as much since it's settles down pretty quickly after I drive off. The one that happens when the car is warm is the annoying one since it seems to last a bit longer and sounds worse.

Appreciate the reply.

[kevBquick]

Originally Posted by ntg44

Hello all,

Now that there are enough videos to share, I want to introduce the first production equal length exhaust system available for the F80 M3/F82 M4. This project for me has been a total of 5 months in the making, and all started from my decision to take a chance on a custom fabricated exhaust implementing an equal length design, fabricated by Top Gear Motorworks in Downers Grove, IL. The overwhelmingly positive feedback from the community here convinced Top Gear Motorworks to go a step further and develop the first production equal length exhaust system available for F80 M3/F82 M4. Now that the system is officially available, I wanted to post my review.

Full Disclosure: In exchange for my funding of my multiple previous custom iterations which became the proof of concept for the production system, as well as lending my car and time to TGM for development of the production system, I was given the pre-production prototype unit as gratitude for my efforts. That is the full extent of my relationship to TGM and this exhaust, other than being a customer of theirs.

I was never asked by TGM or anyone else to post this review – I decided to of my own volition. This review and all sound clips were made on a 2017 M3 Base, manual transmission, with no other engine related modifications. My car is 100% stock other than the TGM exhaust.

The exhaust is a full cat-back system, which bolts to the downpipes-back. It contains 1 valve, which reuses one OEM valve actuator from your existing exhaust, and includes a resistor plug for the other unused harness to prevent any soft errors from showing up in scan tools. There is no CEL for an unplugged valve, but TGM included the plug for the other side so that it would not corrode/damage over time if not covered correctly.

Valve Closed Tone: Smooth and bass-ey. Under low load conditions, this mode is definitely family friendly and super stealth. I’d say it’s about the same as stock with valves open. When wide open, considerably louder than stock open, and the grumbly, raspy stock sound is replaced with a higher, smoothly ascending pitch. Those who are extra sensitive to the obnoxious cold starts will be very happy with this one – it’s a little louder than stock closed, only it doesn’t sound terrible like stock does. Your neighbors and even your family may thank you (my wife did )

Valve Open Tone: A little dirtier and higher pitched than closed mode. Under low load conditions, this mode is not noticeably louder than valve closed from inside the car. But instead, the pitch changes from a bassier to a higher note, and you can easily drive around with the valve open the entire time and not need to close it. With all 4 windows open, I’m driving in open mode 99% of the time just to hear the sweet, crisp tone.

Under full throttle, open mode screams like a banshee. Above 4000 RPMS the equal length high pitched tone remains, but a bit of added edge/snarl is added to the tone, giving it a little signature S55 character but with the inspiring pitch of the equal length design. When you are on boost, everyone around you is definitely noticing. But as loud as it gets under full throttle, it calms down just as quickly when you throw it in a higher gear to cruise.

Opportunities in the car scene like this don’t really happen to me, so I want to thank TGM and the Bimmerpost community again for the knowledge and enthusiasm that convinced me to pursue my original custom design last November, and which ultimately lead to this collaboration with TGM. In my opinion, the end result is pretty incredible, and I’m very grateful to have helped make this happen.

I’ve added some sound clips here to get a grasp of the tone. If you have any questions for me, please let me know. Thanks.

Pulls from outside the car:
https://www.instagram.com/p/B-lLrjjD...=1jr3uc6jb4eg2

Cold start:
https://www.instagram.com/p/B-imJznp...d=xlq5dg0jsels

Bumper footage, including standing revs, regular driving, and pulls (which start at 4:20 )

Standing revs from behind:

props on this....sounds amazing. I'm a longtime DG native...maybe i'll pop by their shop to check things out.

[ntg44]

Originally Posted by ra2289

Yep. I find it very strange. Like my exhaust is trying to gargle mouthwash or speak while being waterboarded.



Awesome, thanks.

I actually don't mind the first cold start of the day as much since it's settles down pretty quickly after I drive off. The one that happens when the car is warm is the annoying one since it seems to last a bit longer and sounds worse.

Appreciate the reply.

So I wasn’t able to record interior clips yet, but I took the car out today, and can confirm that sequence is basically unnoticeable with this exhaust. The first few minutes with valves open are just the same, just a tad bit louder. But it’s essentially the same exact tone

[Kilabyte]

Originally Posted by ntg44

So as of right now I have 2 requests.
- Interior sound clips
- Valve open cold start driveaway feedback

If anyone has any other questions, I can answer them during my next drive.

Place the camera behind the car and take off, rip it through the gears Everyone always does a one gear pull, I want to hear it between shifts

[ra2289]

Originally Posted by ntg44

So I wasn’t able to record interior clips yet, but I took the car out today, and can confirm that sequence is basically unnoticeable with this exhaust. The first few minutes with valves open are just the same, just a tad bit louder. But it’s essentially the same exact tone

Nice! Thanks for checking. I was hoping that would be the case.

[Capt Crunch]

Does this exhaust work with the stock valve system? That is, will it work with Sport/Sport+, or will we have to use the remote?

[ntg44]

Originally Posted by Capt Crunch

Does this exhaust work with the stock valve system? That is, will it work with Sport/Sport+, or will we have to use the remote?

You transfer one of the oem actuators from your existing exhaust. This allows for oem operation. In addition, a CG precision valve controller is included to operate valves with a remote, but it isn’t necessary.

[EvoFire]

I wish there was a catted version......

[ntg44]

Originally Posted by Kilabyte

Place the camera behind the car and take off, rip it through the gears Everyone always does a one gear pull, I want to hear it between shifts

Sorry for the late response! Okay, will do. My car is back at TGM for a while, but I'll see if I can get these clips up. I'm also experimenting with a different design, so not sure when I'll have the production exhaust back on. Depends on scheduling & the results of this project. But until then, I think the bumper cam pull at 4:20 and at 6:00 gives a great idea of what going through multiple gears sounds like.

[Euromotive Performance]

Originally Posted by EvoFire

I wish there was a catted version......

I believe this is catted, the TGM system is only a catback and this car has stock downpipes

[ntg44]

Originally Posted by Euromotive Performance

I believe this is catted, the TGM system is only a catback and this car has stock downpipes

I believe they're referring to secondary cats.