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Mar 15, 2012 21:13:41 GMT
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I remember a thread on here a while ago before xmas about backboxes, how you can take a stock back box open it like a tin of sardines put an ajoining piece of tube in the middle and pack with loft insulation? to give a nice roarty sound and also to save a few pounds on paying £50 for one with a fancy tip!
also I can say 'I done that!'
can anyone confirm this I will be using a corsa b back box (standard) as I'm trying to do something a bit different and not just the usual buy and bolt on
cheers
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Last Edit: Mar 15, 2012 21:14:25 GMT by slammage
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Mar 15, 2012 21:16:25 GMT
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Mar 15, 2012 21:17:45 GMT
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Thats the guy and thread i remember reading! i mean how much loft insulation should i put in and how will it affect the sound/tone? just need to know before i tuck into this
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stealthstylz
Club Retro Rides Member
Posts: 14,961
Club RR Member Number: 174
Member is Online
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Making own back box?stealthstylz
@stealthstylz
Club Retro Rides Member 174
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Mar 15, 2012 21:21:25 GMT
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You usually get a very raspy/loud tone with loft insulation. I modified one for my old Uno, was stupendously loud.
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Mar 15, 2012 21:29:22 GMT
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what other insulation could i use then its an everyday car kinda, i want something with a bit of rasp/burbble to it but not too overboard?
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RobinJI
Posted a lot
"Driven by the irony that only being shackled to the road could ever I be free"
Posts: 2,995
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Mar 15, 2012 21:48:27 GMT
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There's not much in the way of options for the insulation as far as I'm aware, it's more down to the way it's packed. Too tight and it'll just block up the perforations and it'll act like a strait pipe, so it won't damp any sound, too loose and it won't damp the sound enough, so you want it somewhere in the middle. If you want it to damp the sound at all you need to use perforated pipe for the new 'link-pipe' so the sound has somewhere to get out into the insulation.
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Mar 15, 2012 22:01:01 GMT
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right ok so perforated pipe and so would you insulate the box about half full maybe a tad more of insulation then ? Also what way is best to secure the new perforated pipe to the one in the back box just weld the pipe where i can? cant wait to get stuck into this!  |
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Last Edit: Mar 15, 2012 22:05:28 GMT by slammage
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RobinJI
Posted a lot
"Driven by the irony that only being shackled to the road could ever I be free"
Posts: 2,995
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Mar 15, 2012 22:15:01 GMT
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Yeah, just a few stitches of weld would be fine, you're using perforated pipe anyway, so it's not like it needs to be air-tight.  You just need enough for it to be nice and secure. With the insulation, you want to fill the box to the top, but you don't pack it in, you want to leave it quite 'fluffy'. I've only ever packed boxes with proper exhaust wadding, which comes as a sheet that you roll loosely until it's built up to the right thickness to fill the box then slot in the end, but you can't do that as you've not got the end off the box. |
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Mar 15, 2012 22:36:36 GMT
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der blonde moment for me yup thats all good right need to measure the inside pipe and see if anyone has some scrap perforated pipe then!
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Mar 16, 2012 21:44:23 GMT
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perforated pipe is relatively cheap on the bay-of-e. Made my own sidepipe for my old Rover for the grand total of about £30 for the current Rover, I opened my backbox:  and found it was actually easier, to just add an extra hole at the end of the backbox, turning it into a "straight through" box, whilst still having 1/3 of the gasses go through the internal baffles, making it a bit quieter   always another option if yours is going to be difficult to weld up internally (being a diesel, mine was COVERED in soot, which would've made the steel bloody difficult/impossible to weld!) |
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You're like a crazy backyard genius! |
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You just need enough for it to be nice and secure.
