325TI - Project Mpact
Discussion
shalmaneser said:
amc_adam said:
BOBTEE said:
Agree 100% leave the aluminium, looks awesome! 
Another one, well i don't know 
theres going to end up being a voting poll soon 
Either way it's a stunning build.
But if you look at it and think it's maybe factory you'd also assume it's plastic. Most people who'd have a go at making that piece from scratch would have no option but to paint it as it'd end up looking a dog's dinner and they'd need to hide the body filler. You can't hide away that craftsmanship by painting it.
Edited by Escy on Saturday 26th January 20:43
I think some silver highlights against this blue will look good. If it's all blue that can be a bit too much. This is a one off build. Who cares or even wants it to look factory? If this is a show case to your skills as a fabricator then you need to do exactly that - show some bits off.
The majority of enthusiasts know full well it's not OE as it wasn't something BMW ever built but looking like a factory part is a testament to the OP's fabrication skills. That said, the OP is building it for himself, not other people and that's where the final decision lies. As an aesthetic it's all subjective anyway.
mark.c said:
Ah that makes sense now, I think I met you briefly as I bought the 320is from your brother, you had your caddy in the garage next to it at the time. The E30 was indeed spotless, sold on again a couple of years ago.
Coincidentally here it is next to my 325ti
Ah yes i remember, think my dad fell down the stairs holding a wheel at the same time. The Caddy is still sitting in the same place as you saw it!Coincidentally here it is next to my 325ti
I Saw the 320is on ebay a year or so ago for £33,000.
Didn't realise you had a Ti as well.
Thanks for the comments guys, regarding the rear valance i think it's going to be colour coded and sprayed blue. I'd like to keep it quite subtle and having a big silver bit on the back of the car will be a bit too 'in the face'.
I think having four shiney exhausts poking out will be enough
I think having four shiney exhausts poking out will be enough
Right, the next Ball ache.... Rear silencer.
So, with the rear valance made to now accommodate four exhaust tips like an M3 should, i needed to make a "Compact version" (see what i did there ) of the M3 silencer.
There are a few after market ways of making a Non-M cars have quad exhausts, some Companies make kits for saloons, coupes and tourings but very little i found for Compacts (not that i'd buy one ). Plus, being a 325ti it has the battery in the boot making space even tighter, i did not want to remove the battery box or relocate the battery else where. I wanted the exhaust to fit the car, not modify the car excessively to fit the exhaust.
As you will probably guess i have put a serious amount of thought into this, i didn't want to use any Powerflow or universal silencers as they wouldn't look right and i wanted to keep it to the OEM factory standard. After looking at other BMW systems and even Audi/VW systems i could adapt...... nothing really stood out for what i needed.
The stock E46 M3 rear silencer is Stainless, unsure what grade and bloody heavy (25-30 kg, maybe to keep some weight over the rear axle?). Also, i have one off the donor M3. Which i am going to be using.
So, here's the stock OEM E46 m3 silencer, it had been previously bodged with odd bits of pipe where the mid section clamps to the silencer,
After some time with a grinder and power file , these were definitely not made to come apart again! Notice one area has no packing in it, this is where the gases collect before they mix and exit the four tips.
All packing removed showing all the different chambers,
The M3 exhaust runs the entire width of the rear of the vehicle, which is twice the width of the space i have in the Compact and it's also an 'L' shape which is too long to fit between the subframe and bumper.
Out with the grinder again, emptied all the pipes and chambers leaving just two empty casings. With that i set about working out where to cut the casings down, this was the first attempt as a mock up to see what i had to work with, after this i ended up cutting another 80mm (it's around 600mm narrower than stock) off the width and 50mm off the length
With the casings empty and the right size, i now needed to work out how to cram all of the bits back inside. Yes it's going to be louder than a stock E46 M3 but that's not a bad thing.... as long as it's not ridiculously loud. Back pressure wise, no idea.
All i know is it's defiantly going to have more packing / bends and perforated tube than a aftermarket silencer to keep things quieter.
The internals,
I was going to be losing chambers, luckily only one... where the gases mix, and the other chambers are much smaller now. I wanted each exhaust tip to have it's own feed like stock and not just a 'Y' section where a single pipe splits into two at the tips.
With roughly an idea in my head of how it was going to look i needed to find some 60mm elbows with a very tight radius to be able to achieve what i needed, but no luck... many hours later on the bandsaw and deburring pie cuts i was left with a pile of bits which ended up looking like this,
As i was going to be losing the chamber where the gases mix in the silencer, i needed to find a point where the two pipes (each pipe carries the gases from three cylinders) could mix before it exited the silencer, the above pie cut sections had to be merged together to create almost an 'X' pipe on a 90* bend and a twisted section
(hard to explain) . The photos later will explain.
Fully TIG welded onto one of the original dividing chamber walls from the silencer, not the prettiest welds I've done,
And here's it all going together, you can now see where the two sections merge together,
Probably the busiest silencer ever, well i hope its going to silence it after all this!
So for the time being i'll leave it as that, more updates to follow........
So, with the rear valance made to now accommodate four exhaust tips like an M3 should, i needed to make a "Compact version" (see what i did there
) of the M3 silencer.There are a few after market ways of making a Non-M cars have quad exhausts, some Companies make kits for saloons, coupes and tourings but very little i found for Compacts (not that i'd buy one ). Plus, being a 325ti it has the battery in the boot making space even tighter, i did not want to remove the battery box or relocate the battery else where. I wanted the exhaust to fit the car, not modify the car excessively to fit the exhaust.
As you will probably guess i have put a serious amount of thought into this, i didn't want to use any Powerflow or universal silencers as they wouldn't look right and i wanted to keep it to the OEM factory standard. After looking at other BMW systems and even Audi/VW systems i could adapt...... nothing really stood out for what i needed.
The stock E46 M3 rear silencer is Stainless, unsure what grade and bloody heavy (25-30 kg, maybe to keep some weight over the rear axle?). Also, i have one off the donor M3. Which i am going to be using.
So, here's the stock OEM E46 m3 silencer, it had been previously bodged with odd bits of pipe where the mid section clamps to the silencer,
After some time with a grinder and power file , these were definitely not made to come apart again! Notice one area has no packing in it, this is where the gases collect before they mix and exit the four tips.
All packing removed showing all the different chambers,
The M3 exhaust runs the entire width of the rear of the vehicle, which is twice the width of the space i have in the Compact and it's also an 'L' shape which is too long to fit between the subframe and bumper.
Out with the grinder again, emptied all the pipes and chambers leaving just two empty casings. With that i set about working out where to cut the casings down, this was the first attempt as a mock up to see what i had to work with, after this i ended up cutting another 80mm (it's around 600mm narrower than stock) off the width and 50mm off the length
With the casings empty and the right size, i now needed to work out how to cram all of the bits back inside. Yes it's going to be louder than a stock E46 M3 but that's not a bad thing.... as long as it's not ridiculously loud. Back pressure wise, no idea.
All i know is it's defiantly going to have more packing / bends and perforated tube than a aftermarket silencer to keep things quieter.
The internals,
I was going to be losing chambers, luckily only one... where the gases mix, and the other chambers are much smaller now. I wanted each exhaust tip to have it's own feed like stock and not just a 'Y' section where a single pipe splits into two at the tips.
With roughly an idea in my head of how it was going to look i needed to find some 60mm elbows with a very tight radius to be able to achieve what i needed, but no luck... many hours later on the bandsaw and deburring pie cuts i was left with a pile of bits which ended up looking like this,
As i was going to be losing the chamber where the gases mix in the silencer, i needed to find a point where the two pipes (each pipe carries the gases from three cylinders) could mix before it exited the silencer, the above pie cut sections had to be merged together to create almost an 'X' pipe on a 90* bend and a twisted section
(hard to explain) . The photos later will explain.Fully TIG welded onto one of the original dividing chamber walls from the silencer, not the prettiest welds I've done,
And here's it all going together, you can now see where the two sections merge together,
Probably the busiest silencer ever, well i hope its going to silence it after all this!
So for the time being i'll leave it as that, more updates to follow........
amc_adam said:
Ah yes i remember, think my dad fell down the stairs holding a wheel at the same time. The Caddy is still sitting in the same place as you saw it!
I Saw the 320is on ebay a year or so ago for £33,000.
Didn't realise you had a Ti as well.
Ah yes you're right you're Dad did take a tumble! I remember texting Dan a week or so later and thankfully no damage done. I still have the guilty wheels in my shed. I Saw the 320is on ebay a year or so ago for £33,000.
Didn't realise you had a Ti as well.
Yes I sold the 320is to a chap who advertised it quite soon after and that would have been the advert you saw... I certainly didn't sell it for anywhere near that !
I ran my Ti for quite a few years and was cracking little car so I'm a big fan of these and your build. Superb work on the exhaust as we've come to expect!
mark.c said:
Ah yes you're right you're Dad did take a tumble! I remember texting Dan a week or so later and thankfully no damage done. I still have the guilty wheels in my shed.
Yes I sold the 320is to a chap who advertised it quite soon after and that would have been the advert you saw... I certainly didn't sell it for anywhere near that !
I ran my Ti for quite a few years and was cracking little car so I'm a big fan of these and your build. Superb work on the exhaust as we've come to expect!
Did you get anything to replace the 320is? hell of a price tag that chap had it up for!Yes I sold the 320is to a chap who advertised it quite soon after and that would have been the advert you saw... I certainly didn't sell it for anywhere near that !
I ran my Ti for quite a few years and was cracking little car so I'm a big fan of these and your build. Superb work on the exhaust as we've come to expect!
Thank you very much.
amc_adam said:
mark.c said:
Ah yes you're right you're Dad did take a tumble! I remember texting Dan a week or so later and thankfully no damage done. I still have the guilty wheels in my shed.
Yes I sold the 320is to a chap who advertised it quite soon after and that would have been the advert you saw... I certainly didn't sell it for anywhere near that !
I ran my Ti for quite a few years and was cracking little car so I'm a big fan of these and your build. Superb work on the exhaust as we've come to expect!
Did you get anything to replace the 320is? hell of a price tag that chap had it up for!Yes I sold the 320is to a chap who advertised it quite soon after and that would have been the advert you saw... I certainly didn't sell it for anywhere near that !
I ran my Ti for quite a few years and was cracking little car so I'm a big fan of these and your build. Superb work on the exhaust as we've come to expect!
Thank you very much.
I'm not sure if Dan mentioned but I had an E30 M3 when I bought the 320is which I've still got. I was using the 320is as a daily and as I'm sure you'll agree it was a bit too nice to use everyday and I was feeling guilty about it. That fact plus I had ( and still have) an E12 M535i undergoing a light refresh ( glacial pace!) I wanted a car that I wouldn't be worried about leaving anywhere.
That's where the 325ti came in.
It was an absolute belter but I missed something old and replaced it with a really really lovely E30 325i touring. I'm using it daily but it's as nice as the 320is was.....I never learn!
cb1965 said:
Love this project, have to say out of all the reader's threads here this is the one where the work impresses me the most. Some of your fabrication skills are unreal.
That's nice of you to say so, thanks. It's what many years of tinkering and having a restless mind brings 
Fordo said:
All time favourite readers car - amazing fabrication skills, beyond engineering - it's art!
Thank you, who would have thought that a BMW Compact would be a favourite readers car, the majority of people probably skip past it 
. It's nice of you to say so, much pride is taken in the tinkering. Gassing Station | Readers' Cars | Top of Page | What's New | My Stuff