OEM //M silencer mod
- Thread starter dalecan
- Start date
So - i've purchased two backboxes and i'm going to give this a go. I've got a few questions if anyone can help me figure it out.. or if dale can provide some insight. I'm hoping this is a bit deeper/louder than the bypass pipes mod.
* The replacement inner pipe - was that salvaged from the removed u-bend or manufactured separately?
* Any special tools/skills required other than some angle grinding, welding and painting?
Finally - anyone able to recommend a metalworkers who maybe interested in giving this a go? Or is this something i could tempt MM with perhaps (
)? Seems a pretty fun project if you've got the tools and skills!
If it works out, and i like it - i'll keep it on and bring it along to a meet for some forum review and approval!
* The replacement inner pipe - was that salvaged from the removed u-bend or manufactured separately?
* Any special tools/skills required other than some angle grinding, welding and painting?
Finally - anyone able to recommend a metalworkers who maybe interested in giving this a go? Or is this something i could tempt MM with perhaps (
)? Seems a pretty fun project if you've got the tools and skills! If it works out, and i like it - i'll keep it on and bring it along to a meet for some forum review and approval!
jimmybell said:So - i've purchased two backboxes and i'm going to give this a go. I've got a few questions if anyone can help me figure it out.. or if dale can provide some insight. I'm hoping this is a bit deeper/louder than the bypass pipes mod.
* The replacement inner pipe - was that salvaged from the removed u-bend or manufactured separately?
* Any special tools/skills required other than some angle grinding, welding and painting?
Finally - anyone able to recommend a metalworkers who maybe interested in giving this a go? Or is this something i could tempt MM with perhaps (
If it works out, and i like it - i'll keep it on and bring it along to a meet for some forum review and approval!
I introduced the "gutted silencer" mod on this forum in April 2012 shortly after buying my Z4MC and I thought that I'd previously written a "How To" on this subject on this forum but it seems that the details have been posted in other threads. I'd previously gutted many silencers for the Z3MC and written extensively about this on the z3mcoupe.com forum and from that experience I have learned various things about modifying silencers.
1. It's very easy to make loud and droning silencers but what you really want is civilised silencers which will come "alive" when you are at WOT (Wide Open Throttle).
2. The S54 engine is what it is and you can't make it sound like TVR in the same way that you can't make a Violin sound like a 'Cello but you can increase the sound "volume".
3. There are performance gains to be had if you also perform the "Eureka" Air Intake Mod I devised as described here: http://www.z4-forum.com/forum/viewtopic.php?f=9&t=51529&start=75
You will need more than an angle grinder (small and large) to cut through the internal pipework unless you make a much larger access window than I did. I use a plasma cutter for getting to the difficult places.
These are the photos that I'd previously posted showing the way that I'd gutted the silencers by opening the middle section of the silencers on the upper surface and removing the contents of the other 2 chambers from the access in the middle chamber.
With this configuration I found that I got a slight boominess when accelerating in higher gears between 1700rpm -2000rpm so I subsequently reopened the silencers and re configured my internal baffling as shown below and this is MUCH better.
Over the past few months I've been working with an engineer in Montreal who has been independently reviewing and testing my air-intake and exhaust mods, and in the light of my experience of modding the Z4MC's silencers I devised the "Exdos MkIII" silencer mod which he has recently fitted. The method is shown below.
With this modification, the central pipe is removed and the opposite faces of the inlet and outlet pipes are removed. The inlet and outlet pipes are then connected to each other at the top and bottom with perforated stainless steel so that the exhaust gases can go directly from inlet to outlet within the central chamber as well as following the OEM route. You can see this mod here: http://www.zpost.com/forums/showpost.php?p=14625499&postcount=12
Wow great - thanks exdos. I hadn't realised anyone UK side had done this! Do you have any vids of the change?
Out of interest - why the large opening in the centre rather than the single pipe as per dalecan? Living in a small London flat i have zero tools for this work so i'm going to have to find somewhere to help me out - which may potentially limit my design. Glad i've got a spare set of boxes to play with though.
to be honest i find flooring it in high gears between 1500-2000rpm gives a drone even on the OEM system, but sitting above 2krpm is fine. as long as this mod returns similar behaviour (so i can still drive on the motorway without earplugs!) then i'm happy.. the endgame is exactly that.. more noise when WOT, any pops/bangs are a bonus, and any extra deep noise when idle would be lovely too.
Out of interest - why the large opening in the centre rather than the single pipe as per dalecan? Living in a small London flat i have zero tools for this work so i'm going to have to find somewhere to help me out - which may potentially limit my design. Glad i've got a spare set of boxes to play with though.
to be honest i find flooring it in high gears between 1500-2000rpm gives a drone even on the OEM system, but sitting above 2krpm is fine. as long as this mod returns similar behaviour (so i can still drive on the motorway without earplugs!) then i'm happy.. the endgame is exactly that.. more noise when WOT, any pops/bangs are a bonus, and any extra deep noise when idle would be lovely too.
jimmybell said:
As far as I'm aware, nobody had done this mod until after I'd written about it. :wink:
To give you an idea of the sound, here's a video recording inside my car doing an acceleration in 3rd gear from below 2000rpm to the redline, which will give you some idea of the noise. I'm also running my Ramcharger II Mod ( air-intake mod I'm developing) in this run, which also increases the sound and performance. http://www.youtube.com/watch?v=-ZaDO7NbN_Y and this is from outside the car: http://s103.photobucket.com/user/exdos/media/sound clips/outsidecarto4krevs.mp4.html?sort=3&o=4
You ask why I have the large opening in the centre section: my primary reason for modifying OEM silencers is all about improving performance and any improvement in sound is a secondary consideration to me. My method of modding is based on my experience with modding the Z3MC's silencers from which I'd been able to achieve provable and significant performance gains (and improved sound) with the same S54 engine. http://www.youtube.com/watch?v=CK_qqogGCRo
I got the idea for the mod from exdos. I took his photos to an exhaust repair shop and they decided to change it slightly, by removing more of the internals. The new routing was manufactured from OEM exhaust parts (the middle section of the new connecting pipe), plus two connecting tubes from their collectin of pipes.
I'm really impressed with the mod, as its not too loud or intrusive (no drone). I also did the exdos airbox mod (at the same time as the exhaust). I never had the car dyno'd, but there is a noticlbe gain.
I'll get som in car footage uploaded.
Thanks for all the hard work John!
I'm really impressed with the mod, as its not too loud or intrusive (no drone). I also did the exdos airbox mod (at the same time as the exhaust). I never had the car dyno'd, but there is a noticlbe gain.
I'll get som in car footage uploaded.
Thanks for all the hard work John!
I'm verry pleased with exdos MkIII mod. It has a little drone below 1500 rpm but only for a fraction of second when cruising in high gear and flooring it or when engaging first gear from a stop. However, I only really ear it when top is down. Otherwise, the sound remains oem but a little bit louder at AOT and it is deeper at hidle. Like I have mentionned on the zpost forum, it gave me significant gains between 5600 rpm and 7500 rpm, but then I'm still runing with the US headers and can't say yet what it would give with euro headers.
Holy thread resurrection Batman!
So finally getting round to organising this to be done to my spare OEM set.
Did anyone do any testing of airflow comparing dalecan's mod (adding a pipe to route directly from single input to dual output), vs exdos' version (opening up the middle only, and 'allowing' airflow directly out by removing central pipes and opening up one side of the dual output).
I'm wondering if dalecan's version may be more efficient on the assumption that with exdos' mod, there is potential for confused airflow if you keep some of the existing pipes in the loop that aren't part of the critical path of airflow (and therefore potential that exhaust gas may travel in a direction that is not directly out of the box?)? I may be talking absolute horse **** though, i've not much experience with engineering air flow
My intention is 50/50 desire for performance and sound. Coupled with the improved ram air system by way of exdos' 'eureka' mod, it'd be nice to see improved power - but also a deeper sound at idle and more noise at WOT.
JB
So finally getting round to organising this to be done to my spare OEM set.
Did anyone do any testing of airflow comparing dalecan's mod (adding a pipe to route directly from single input to dual output), vs exdos' version (opening up the middle only, and 'allowing' airflow directly out by removing central pipes and opening up one side of the dual output).
I'm wondering if dalecan's version may be more efficient on the assumption that with exdos' mod, there is potential for confused airflow if you keep some of the existing pipes in the loop that aren't part of the critical path of airflow (and therefore potential that exhaust gas may travel in a direction that is not directly out of the box?)? I may be talking absolute horse **** though, i've not much experience with engineering air flow
My intention is 50/50 desire for performance and sound. Coupled with the improved ram air system by way of exdos' 'eureka' mod, it'd be nice to see improved power - but also a deeper sound at idle and more noise at WOT.
JB
dalecan said:I got the idea for the mod from exdos. I took his photos to an exhaust repair shop and they decided to change it slightly, by removing more of the internals. The new routing was manufactured from OEM exhaust parts (the middle section of the new connecting pipe), plus two connecting tubes from their collectin of pipes.
I'm really impressed with the mod, as its not too loud or intrusive (no drone). I also did the exdos airbox mod (at the same time as the exhaust). I never had the car dyno'd, but there is a noticlbe gain.
I'll get some in car footage uploaded.
Thanks for all the hard work John!
old thread but i can honestly say i wish i had these on my car.... something about the s54 makes it a very difficult car to stick an aftermarket exhaust on, its either too loud or drone ridden, or way to raspy.... this looks and sounds great... the RPI may sound great and weight nothing but the volume has become a problem for me now.... it may even be an age thing..... but.... i love the drama but only love it for around 15 mins, after that i becomes boring , however everyone outside loves it and regularly get a thumbs up..
Jimmybell, my new brake disc should be here tomorrow, so all going well I'll be able to let you know my thoughts tomorrow evening, even if i just nip round the block. "I've" done the mod with an internal pipe, rather than cut open like exdos's. Perhaps there will be a difference in sound, but I doubt you'll notice any performance on the road, even if John's data recording shows an improvement.
I need to know how do they sound so far???
Did you get them back on ok??
Did you get them back on ok??
Few good times
I am on the edge of me seat...
I am on the edge of me seat...
Also edge of my seat
Primarily as long as there is no performance degradation I'm happy. I think Exdos has done sufficient research and i cant fault it.
Dalecan seems confident his created no drone so thats good - vids definitely prove its a more throaty sound with pops/rasp!
Primarily as long as there is no performance degradation I'm happy. I think Exdos has done sufficient research and i cant fault it.
Dalecan seems confident his created no drone so thats good - vids definitely prove its a more throaty sound with pops/rasp!
I'm always amused when people talk of "pops and crackles" coming from the exhausts of S54 engines. As soon as you lift off the throttle of a "drive by wire" to a fuel-injected engine (i.e. S54) , the fueling is cut instantly, therefore there is no fuel over-run to create such pops and crackles as there might be with a carburetted engine with a throttle cable.
At the moment, many F1 fans are moaning about the lack of noise from the new turbo engines used in the latest F1 cars: the reason why they are so quiet in comparison to the previous normally aspirated engines, is all down to the different sound characteristics of different engines. No matter what the F1 engineers might do, the new cars will never sound like the previous generation F1 cars. Likewise, a S54 engine will always sound like a S54 engine: it can be made to sound louder and also have a drone, but it can't be made to sound like an American muscle car. You can't make a violin sound like a double-bass, but I'm happy for anyone to prove me wrong.
At the moment, many F1 fans are moaning about the lack of noise from the new turbo engines used in the latest F1 cars: the reason why they are so quiet in comparison to the previous normally aspirated engines, is all down to the different sound characteristics of different engines. No matter what the F1 engineers might do, the new cars will never sound like the previous generation F1 cars. Likewise, a S54 engine will always sound like a S54 engine: it can be made to sound louder and also have a drone, but it can't be made to sound like an American muscle car. You can't make a violin sound like a double-bass, but I'm happy for anyone to prove me wrong.