Backbox Mod

[Mr_Ke1th]

So I connected the twin pipes up in my backbox today but was a bit disappointed with the sound, it does have more of a grunt but still a bit tame and no pops on over-run. I cut the box open on both ends and fully welded the pipes thinking that would work the best, or should there be some gaps in the system? Also, where does the exhaust vent to where it exits the slotted parts of the backbox or does this build up some pressure?

Cheers

 

[bearded_ed]

Curious to see what the consensus is on this as I'm looking to mod my box too!

 

[G600]

I've done the same to mine but I drilled a dozen or so holes in the pipes and repacked the exhaust with fiberglass, sounds just right for me and I get plenty of gurgles when I lift off without it being too loud.

 

[tee.gilding]

I had this done by Leadfoot Racing in Wiltshire. They cut open the back box, linked the pipes, albeit with bends instead of welded corners, and packed it all with fibreglass. They also removed the resonator. Massive difference. Sounds immense and the overrun is infectious!

https://www.instagram.com/p/CBWFGKKHOkO/?igshid=12mjnrmo03y6h

 

[LittleZ4]

I had this done by Leadfoot Racing in Wiltshire. They cut open the back box, linked the pipes, albeit with bends instead of welded corners, and packed it all with fibreglass. They also removed the resonator. Massive difference. Sounds immense and the overrun is infectious!

https://www.instagram.com/p/CBWFGKKHOkO/?igshid=12mjnrmo03y6h

I had my back box delete done by leadfoot about 3 years ago.

 

[Mr_Ke1th]

It’s actually grown on me and I’m pretty happy with it. I can hear it better now that I’ve put the foam back in the pipe from intake. Sounds sporty, gives off a few cackles whilst not too loud and no droning

 

[Jsomerville]

I had this done by Leadfoot Racing in Wiltshire. They cut open the back box, linked the pipes, albeit with bends instead of welded corners, and packed it all with fibreglass. They also removed the resonator. Massive difference. Sounds immense and the overrun is infectious!

https://www.instagram.com/p/CBWFGKKHOkO/?igshid=12mjnrmo03y6h

Sounds great! How much did it cost you to have it done by them?

Also how loud is it at cold start and is there any drone at all from it?

 

[tee.gilding]

I had this done by Leadfoot Racing in Wiltshire. They cut open the back box, linked the pipes, albeit with bends instead of welded corners, and packed it all with fibreglass. They also removed the resonator. Massive difference. Sounds immense and the overrun is infectious!

https://www.instagram.com/p/CBWFGKKHOkO/?igshid=12mjnrmo03y6h

Sounds great! How much did it cost you to have it done by them?

Also how loud is it at cold start and is there any drone at all from it?

Best to get in touch with them direct for a quote. I had some other bits and pieces done as well, so can't really comment on how much that work specifically cost.

Its fairly punchy at start-up (won't make your neighbours happy if you leave the house at 6am every morning...) but its not earth-shattering. Not much drone unless you're hard on the gas.

 

[Jsomerville]

I had this done by Leadfoot Racing in Wiltshire. They cut open the back box, linked the pipes, albeit with bends instead of welded corners, and packed it all with fibreglass. They also removed the resonator. Massive difference. Sounds immense and the overrun is infectious!

https://www.instagram.com/p/CBWFGKKHOkO/?igshid=12mjnrmo03y6h

Sounds great! How much did it cost you to have it done by them?

Also how loud is it at cold start and is there any drone at all from it?

Best to get in touch with them direct for a quote. I had some other bits and pieces done as well, so can't really comment on how much that work specifically cost.

Its fairly punchy at start-up (won't make your neighbours happy if you leave the house at 6am every morning...) but its not earth-shattering. Not much drone unless you're hard on the gas.

Many thanks for the information! Just weighing up if I would be able to live with it on the day to day as my Z4 is my daily. I guess it's going to be quieter than a full back box delete anyhow!