Through the (modified) Rear Bumper Twin Exhaust

Started by Gibla, March 21, 2022, 09:52

0 Members and 1 Guest are viewing this topic.

Dev

Quote from: Gibla on March 22, 2022, 22:02





The car from Rugby (Tomasz's), this shows the exhaust really well imo. Group Buy?  :- Well I'm sure he would consider something


Those tips look nice. I like it when a little bit of the exhaust peaks out to make it look aggressive.




Dev

Quote from: J88TEO on March 22, 2022, 22:30Trouble is - I live in a flat with a small garage which has no electric supply.
Garage is just big enough to fit the 2!


You do need enough space. Im sure a solution will come about. I had this idea since 2005 but I waited about 12 years until I found a solution to get it to work for my liking. Its a very difficult mod to get right. If you chose the wrong sized tips or style it can throw off the look for the worst and I have seen some bad examples.

Dev

Quote from: Gibla on March 22, 2022, 23:01I agree @Dev , these are the ones he used https://nforcd.com/products/carbon-fiber-exhaust-tips-for-bmws-black?utm_content=Facebook_UA&utm_source=facebook&variant=39568272097468&fbclid=IwAR1HpVjRbNMmvHpEogqoIDsGKcxpecuM_LrRhYlpxz1bYDsYg67KYFYxSA8

 It took me about a year of searching the internet for tips. I had a few examples I would hold up to the car and then return. I then took a chance on some vintage chrome trumpet pipes. The only downside is chrome rusts easily so I have to polish them up but the gleam of chrome is way better than polished aluminum or stainless steel.

Gibla

stock 2001 green MR-S
stock 2003 solar yellow(currently for Sale, but ....)

Dev

 They look fine but just make sure when you get them you are absolutely sure with a test fit otherwise return them.There are many tips to choose from. I had some examples that just were proportionally off when I stepped back and looked at the car from a distance.

Petrus

I take my hat off to you blokes.
Both for the taste in looks and for the execution.
Mine is/are .... different. Gets lots of second takes from many. Not sure good of bad  :))

Since the photo put the cat back. Both for environmental feel good  ::)  and because there is a plethora of microphones fitted to traffic cameras now  :-X



J88TEO

Quote from: Gibla on March 22, 2022, 22:46tbf @J88TEO Tomasz already has a large waiting list and has recently experienced supply issues with the pipe suppliers quality of product on offer.

If genuinely interested, I suggest trying him via his FB profile (mentioned in op.)

Will do. Thanks.

Gibla

From the same source as the 'through the rear bumper twin'


This is a twin loop backbox, apparently de rigueur on Honda Mugen engines + a few other Japanes manufacturers of exotica in the late noughties ie circa 2008 on.

Again, it's meant to be modestly noisy but gives out the same power as a far larger backbox 
stock 2001 green MR-S
stock 2003 solar yellow(currently for Sale, but ....)

Gibla

Supposedly a technical description is given here (from a Mugen forum page)

''Okay, the simple explanation is that exhausts must have certain silencing characteristics in order to be streetable and tolerable to the everyday driver (ie, those that are driving next to you). Most aftermarket companies achieve this by creating a series of chambers inside the muffler that silence the car's exhaust sound. The Mugen exhaust silences by the use of the "twin loop", which effectively cancels the sound waves. This enables the exhaust to be quiet, as well as less restrictive (silencing through the use of the pipe versus chambers in the muffler).

Here is King Motorsports' description:
"Silencing characteristics and the quest for exhaust efficiency: the two requirements imposed on exhaust systems have a contrary relationship, and in practice it is extremely difficult to achieve both. At Mugen, we have continued to employ the straight configuration, with the design philosophy that low exhaust pressure must be provided, and that reducing exhaust resistance is an important part of the ideal exhaust system. The straight configuration is widely used in racing, and is ideal because, as the name suggests, it provides low exhaust resistance. However, large silencers are generally required, as there may be problems with mid to low frequency band silencing and scattering of sound absorbing material such as glass wool with the straight configuration. Incidentally, the inverted multi-layer expansion-type silencer widely used by automobile manufacturers provides stable silencing performance, as the sound passes trough several divided silencer chambers, but involves the disadvantage of some output loss and is larger and heavier than other silencers. As a result of our quest for the ideal design for racing engines, Mugen developed the "twin loop-type silencer," in which the pipe is twisted into two loops and passes straight through the silencer twice. This could be considered the ultimate arrangement, combining the concepts of "absorption" and "intervention" in an ingenious manner. It surpasses normal systems in power and torque over the full range, and provides the required silencing and the clear Mugen-Honda sound."
stock 2001 green MR-S
stock 2003 solar yellow(currently for Sale, but ....)

puma2

 :) i got to say just from looks alone its exotic and suites the 2s so well 8)  8)

TheTigerUK

through the rear bumper twin, I saw this in the metal today and it looked really good and when its finished it will look  so so good.
Say it with love, say it with flowers but never, never, say it in writing.

Not perfect and not cheap :)

Petrus

Quote from: puma2 on April 27, 2022, 07:28:) i got to say just from looks alone its exotic and suites the 2s so well 8)  8)

Aye, but less suits it fúnctionally more  :P

Gibla

Agreed @Petrus , looks alone wouldn't do it for me :-

 this car just did ~2000 miles over the last 7 days, the exhaust has transformed the mid and upper rev range performance (and aural pleasure :-) ) from humdrum stock to a totally different level.

The guy Tomasz works in combo with a team in Poland who thoroughly r+d their exhausts, I am so impressed with just this backbox that if I am able to assemble enough £$ a full custom exhaust will deffo be purchased, ideally a twin-loop with twin pipes 'thro the bumper'

 
stock 2001 green MR-S
stock 2003 solar yellow(currently for Sale, but ....)

Gibla

Quote from: TheTigerUK on April 27, 2022, 23:11through the rear bumper twin, I saw this in the metal today and it looked really good and when its finished it will look  so so good.

Sadly the 1st set of tips I purchased were the wrong size, the exhaust maker Tomasz is in the process of sourcing genuine BMW tips that would replicate his original concept. The tips should not only make the appearance 'finished' but should reduce the excessive noises from the exhaust(at low revs)in the cabin.
stock 2001 green MR-S
stock 2003 solar yellow(currently for Sale, but ....)

Petrus

#40
Quote from: Gibla on April 28, 2022, 05:08Agreed @Petrus , looks alone wouldn't do it for me :-

 this car just did ~2000 miles over the last 7 days, the exhaust has transformed the mid and upper rev range performance (and aural pleasure :-) ) from humdrum stock to a totally different level.

The guy Tomasz works in combo with a team in Poland who thoroughly r+d their exhausts, I am so impressed with just this backbox that if I am able to assemble enough £$ a full custom exhaust will deffo be purchased, ideally a twin-loop with twin pipes 'thro the bumper'

 

If I did not have the superbike muffler mod, I´d look at the loop. The cat though is also an effective silencer. The difference with the decat is more than 3 dB.

J88TEO

Quote from: Gibla on April 28, 2022, 05:08Agreed @Petrus , looks alone wouldn't do it for me :-

 this car just did ~2000 miles over the last 7 days, the exhaust has transformed the mid and upper rev range performance (and aural pleasure :-) ) from humdrum stock to a totally different level.

The guy Tomasz works in combo with a team in Poland who thoroughly r+d their exhausts, I am so impressed with just this backbox that if I am able to assemble enough £$ a full custom exhaust will deffo be purchased, ideally a twin-loop with twin pipes 'thro the bumper'

 
Let's us know when you have it installed!
Definitely interested. Messaged T on FB.

Dev

Quote from: Gibla on April 26, 2022, 18:31Supposedly a technical description is given here (from a Mugen forum page)

''Okay, the simple explanation is that exhausts must have certain silencing characteristics in order to be streetable and tolerable to the everyday driver (ie, those that are driving next to you). Most aftermarket companies achieve this by creating a series of chambers inside the muffler that silence the car's exhaust sound. The Mugen exhaust silences by the use of the "twin loop", which effectively cancels the sound waves. This enables the exhaust to be quiet, as well as less restrictive (silencing through the use of the pipe versus chambers in the muffler).

Here is King Motorsports' description:
"Silencing characteristics and the quest for exhaust efficiency: the two requirements imposed on exhaust systems have a contrary relationship, and in practice it is extremely difficult to achieve both. At Mugen, we have continued to employ the straight configuration, with the design philosophy that low exhaust pressure must be provided, and that reducing exhaust resistance is an important part of the ideal exhaust system. The straight configuration is widely used in racing, and is ideal because, as the name suggests, it provides low exhaust resistance. However, large silencers are generally required, as there may be problems with mid to low frequency band silencing and scattering of sound absorbing material such as glass wool with the straight configuration. Incidentally, the inverted multi-layer expansion-type silencer widely used by automobile manufacturers provides stable silencing performance, as the sound passes trough several divided silencer chambers, but involves the disadvantage of some output loss and is larger and heavier than other silencers. As a result of our quest for the ideal design for racing engines, Mugen developed the "twin loop-type silencer," in which the pipe is twisted into two loops and passes straight through the silencer twice. This could be considered the ultimate arrangement, combining the concepts of "absorption" and "intervention" in an ingenious manner. It surpasses normal systems in power and torque over the full range, and provides the required silencing and the clear Mugen-Honda sound."

That is a very interesting and efficient way of absorbing sounds using a double pass.
The problem with the stock set up is not enough exhaust length so what they did instead is add choke points on the down pipe and a large heavy muffler. However our cars bottle neck is the downpipe which is an easy 8whp.





Gibla

#43
Mods, please delete this comment :- it was garbage
stock 2001 green MR-S
stock 2003 solar yellow(currently for Sale, but ....)

steveash

Looks like Malian (it means beautiful horse by the way) are making a through bumper exhaust and bumper bar 'replacement'. The bumper bar's only function seems to be as a number plate holder as it comes in two pieces.

https://www.ebay.co.uk/itm/265678060075?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=7CxzegXbQX-&sssrc=2349624&ssuid=PEkREVRGQze&var=&widget_ver=artemis&media=COPY

TheTigerUK

Did you guys see this one on facebook ?

Say it with love, say it with flowers but never, never, say it in writing.

Not perfect and not cheap :)

Gibla

Quote from: TheTigerUK on May 16, 2022, 21:31Did you guys see this one on facebook ?



Interesting, have you got another piccy from a bit further away?
stock 2001 green MR-S
stock 2003 solar yellow(currently for Sale, but ....)

TheTigerUK

Quote from: Gibla on May 16, 2022, 21:55Interesting, have you got another piccy from a bit further away?

Sorry but no this was the only photo.
Say it with love, say it with flowers but never, never, say it in writing.

Not perfect and not cheap :)

steveash


J88TEO