12-09-2019, 03:38 PM | #67 |
Major General
1561
Rep 8,971
Posts |
Just a thought..
Is there any mixing of the left / right gas streams inside the OE rear silencer or are they fully isolated from each other? Is having a H or X pipe even required? As it's turbocharged we don't have any pressure pulse scavenging effects like a naturally aspirated engine to worry about, we are only interested in sound. |
Appreciate
0
|
12-09-2019, 03:45 PM | #68 | |
Colonel
2891
Rep 2,146
Posts |
Quote:
|
|
Appreciate
0
|
12-09-2019, 03:58 PM | #69 |
Major General
1561
Rep 8,971
Posts |
Thanks.
So unmerged pipes will sound bad, even if equal length? I'll be keeping secondary CATs for emission checks as I'm going decat DPs but will look to replace OE centre box / H pipe with two separate mufflers before adding the equalizing length. Just considering options for rear box. I have an M2 competition by the way, so i need to get it on a ramp and measure lengths accurately. |
Appreciate
0
|
12-09-2019, 04:09 PM | #70 | |
Colonel
2891
Rep 2,146
Posts |
Quote:
But if you're going with 2 mufflers, just stick with my design and make the return of the U bend earlier, and make another 90 degree pipe bend at the center of the car. Then split with T pipe, attach the mufflers, and route both sides out the back. With a dual exit you don't need as big of mufflers anyways. |
|
Appreciate
0
|
12-09-2019, 05:02 PM | #71 |
Rainbow Racer
1014
Rep 2,540
Posts |
yep, basically without the merge, it will sound like two 3-cylinder engines competing for noise, basically how a stock car or aftermarket mid-piped car sounds like currently.
as for the stock muffler design, there is little merging effects on it, both sides are independent of each other (meaning there isn't a crossover effect as the pulses never meet each other). On that note, I do wonder how the importance it is to even remove the OE crossover section, technically since the flow through there already contains un-equally spaced pulses flowing through the crossover, would it even matter to delete this entirely? Couldn't you just leave that on there and run the U-bend and re-merge them again in equally spaced pulses after that section and achieve the same result? Since the waves are all traveling at the same rate, that would tell me that the OE crossover section wouldn't even impact the sound quality we are after because you can still evenly space them and merge them at the back of the differential. Just a thought in case anyone wants to try something 'new' compared to a what I or a few of us did Here are my prototype pics, they aren't pretty looking (warning...) CLICK ME
__________________
-Loe P.-
Prior Car:'14 Audi S5 3.0t DSG [ APR ECU/TCU | Pullies + basic bolt-on mods | 10.861@127.90mph ] Current Car: F82 M4cs | TT-RS | On Order: i4 M50 Last edited by spool twice; 12-09-2019 at 05:57 PM.. |
Appreciate
0
|
12-09-2019, 05:49 PM | #72 |
Second Lieutenant
72
Rep 211
Posts |
So beyond the custom piping you guys have done, what's the latest on an actual product that may be available to market soon?
Barring that, anyone in the North West Region know of a good exhaust fabricator? |
Appreciate
0
|
12-09-2019, 06:45 PM | #73 | |
Colonel
2891
Rep 2,146
Posts |
Quote:
I'm currently buttoning up a few last things with my exhaust, but I've been permitted to share the following: Thanks to the success of my exhaust experiment, along with the momentum that's been building here on the forum, I've been informed that TopGear Motorworks is pursuing a dual exit, valved, production version of my exhaust! In early January, My M3 will be entering the shop for development of a production system. That's all I can share for now. Obviously, nothing is set in stone, and everything is always subject to change. But to think that this project even got this far, to even be considered as more than just one guy willing to spend some money to fix his car's exhaust sound, is a testament to the enthusiasm of this community and the lengths we're willing to go to to push the platform forward. I'm just as excited as everyone else, and all I have left to say is be patient everyone - the future of S55 exhausts could be here sooner than we think! |
|
Appreciate
18
Montaver2547.50 bank14.50 smiff57.50 behindthen0thing842.00 Envy ///M327.00 SN95NIK1.50 Kilabyte3956.00 Bradycat773.50 EvoFire99.00 phoenx332.50 Redacre396.00 Tim_M56255.00 jstnstr966.00 ra2289314.50 jlhymb44.00 GOS768.00 moonshine89151.50 AYF8080.50 |
12-09-2019, 07:09 PM | #74 | |
Team Zissou
3119
Rep 10,199
Posts |
Hell yes! That's awesome.
Quote:
|
|
Appreciate
0
|
12-09-2019, 08:43 PM | #75 | |
Lieutenant Colonel
2548
Rep 1,815
Posts |
Quote:
|
|
Appreciate
1
Dark-Yoda25.50 |
12-09-2019, 09:28 PM | #76 |
Mr Bill
297
Rep 544
Posts |
Any thoughts if a 3.5" and a 2.5" pipe will fit for a short distance somewhere up front?
__________________
2018 GLC63
2016 Miata 2020 X3M (sold) Turbo Miata Racecar (sold) 1995, 2009, 2015 M3 (sold) |
Appreciate
0
|
12-10-2019, 01:17 AM | #77 | |
Lieutenant
533
Rep 565
Posts |
Quote:
|
|
Appreciate
0
|
12-10-2019, 06:02 AM | #78 |
Rainbow Racer
1014
Rep 2,540
Posts |
|
Appreciate
0
|
12-10-2019, 07:19 AM | #79 | |
Major General
1561
Rep 8,971
Posts |
Quote:
So as long as they left the tailpipes in sync?? Firing order is 153624, which is bank 1,2,1,2,1,2 in order, so pulses should emerge from tailpipes left, right, left, right etc. All theory.... |
|
Appreciate
0
|
12-10-2019, 07:28 AM | #80 |
Rainbow Racer
1014
Rep 2,540
Posts |
It wouldn't work that way, coming from a car that had fully equal-length left/right pipes (but without a crossover), adding a crossover changed it from two 3 cylinder sounds to a true V6 sound on my Audi S5. The idea is to have all cylinder exhaust pulses in each pipe to create the sound.
You are correct with the crossover though, it doesn't do much for forced induction applications for scavenging so it's location would not matter as much as a naturally aspirated car. It impacts more of sound quality coming out the tailpipes than anything else. Good luck to you on the pipes! I hope you don't have inspections like that German guy who has to go through inspections each year, sounds tough to get modifications done in Europe.
__________________
-Loe P.-
Prior Car:'14 Audi S5 3.0t DSG [ APR ECU/TCU | Pullies + basic bolt-on mods | 10.861@127.90mph ] Current Car: F82 M4cs | TT-RS | On Order: i4 M50 |
Appreciate
0
|
12-10-2019, 10:08 AM | #81 | |
Major General
1561
Rep 8,971
Posts |
Quote:
Less room behind the diff on an M2 comp than an M3/M4 UK mods are not too bad, no inspections for 3 years on a new car. Then I can pass the emissions test with only secondary CATs fitted thats why I want to keep them and go Decat primary. I did the same with my N54 335i, passed OK. |
|
Appreciate
0
|
12-10-2019, 01:42 PM | #82 |
Second Lieutenant
99
Rep 239
Posts |
ntg44
I probably should know this, but I don't since I hadn't planned on removing my cats, but do you get any warnings with removing the secondary cats? Also would the production exhaust be with or without the cats? |
Appreciate
0
|
12-10-2019, 01:46 PM | #83 | |
Colonel
2891
Rep 2,146
Posts |
Quote:
In lieu of calling this a "cat back" exhaust, to be clear, this exhaust will be bolt on from the stock downpipe connection -> back. |
|
Appreciate
0
|
12-10-2019, 04:32 PM | #84 | |
Private First Class
39
Rep 127
Posts |
Quote:
I will be one of the first people in Germany who will order this exhaust system immediately after launching it |
|
Appreciate
0
|
12-10-2019, 05:35 PM | #85 | |
6 Cylinders 3 Ways
396
Rep 484
Posts |
Quote:
Last edited by Redacre; 12-10-2019 at 05:41 PM.. |
|
Appreciate
0
|
12-10-2019, 05:46 PM | #86 | |
Colonel
2891
Rep 2,146
Posts |
Quote:
Just for the record, there's nothing for sale, and I will not be advertising anything related to the sale of this exhaust. I'm not a vendor, just a customer who is loaning his car for the development. |
|
Appreciate
0
|
12-10-2019, 06:48 PM | #87 |
Rainbow Racer
1014
Rep 2,540
Posts |
AA midpipe? Mating any equal-lengthed system after this midpipe wouldn't make a difference, and won't even come close to the sound quality when mated to that system or the VRSF single midpipe because they merge un-equally spaced pulses (read: they don't resolve the issue with the S55 sound and don't break any new ground).
If you do an equal-length design, those two pipes (or any midpipe that has a crossover) becomes paper weight, it's the harsh reality of it unfortunately. Last edited by spool twice; 12-10-2019 at 09:03 PM.. |
Appreciate
0
|
12-11-2019, 05:24 AM | #88 | |
Rainbow Racer
1014
Rep 2,540
Posts |
Quote:
It's an outside-the-box approach to resolve the space constraints. Last edited by spool twice; 12-11-2019 at 05:33 AM.. |
|
Appreciate
0
|
Post Reply |
Bookmarks |
|
|