Reduce the drone

[CHIMV8]

Anyone found a way to reduce the drone when back box removed and straight pipes added

Had the pipes fitting the other day,happy currently,going to test out for a few weeks/miles,but there is a drone at certain revs,which may get a little annoying unless the pipes bed in after a few miles

 

[Smartbear]

Anyone found a way to reduce the drone when back box removed and straight pipes added

Had the pipes fitting the other day,happy currently,going to test out for a few weeks/miles,but there is a drone at certain revs,which may get a little annoying unless the pipes bed in after a few miles

I can’t see how the pipes will “bed in” as they’re used & already have soot in them.
The best way to stop the drone is to fit a rear silencer... :?
Rob

 

[CHIMV8]

That’s the thing Rob, no soot in pipes???

 

[Silverzedtom]

I did a similar thing a couple of years back on my 2.5si and had pipes made and welded to replace the back box. As you have found the pops and crackles etc are great fun (I saw your other post ) and the drone isn’t as bad as you might expect, I’ve found myself wincing more and more when I get near home, or if there is an uphill stretch of motorway I find myself trying to balance the noise on the accelerator. It’s been great fun for a bit, and it’s taken a couple of years but personally I think it’s too much on my car, I’ve grown a bit tired of it and as Rob has said, the best way to remove the drone is to add a back box.

When funds / time allow I’m going to have a box made that will hopefully kill the drone but still let some throaty burbles through. Funnily enough, that was the original plan all along .

Have you considered adapting your oem box if you still have it? A lot of members seem happy with theirs.

 

[CHIMV8]

Does adapting the oem box kill the drone effect

 

[buzyg]

Anyone found a way to reduce the drone when back box removed and straight pipes added

Had the pipes fitting the other day,happy currently,going to test out for a few weeks/miles,but there is a drone at certain revs,which may get a little annoying unless the pipes bed in after a few miles

I can’t see how the pipes will “bed in” as they’re used & already have soot in them.
The best way to stop the drone is to fit a rear silencer... :?
Rob

Oh the cruel irony of truth. :rofl:

 

[Aaronb76]

You could try fitting some sound deadening around the battery box and carpets in the boot? Might help to keep the noise a bit more external. Personally though you get used to it

 

[Zikim]

The drone on my E85 3.0 when I changed to straight pipes was awful but I loved the overall noise. I tried sound proofing the boot as suggested above and it made no difference.

I didn't want to go back to standard box so I tried dB killers inserted where the cuts were made and it removed the drone but kept the overall noise improvement (slightly less noise - tested at track day at 98dB's). Similar dB's on eBay that I used search for the following
Motorcycle Steel Exhaust Muffler Adjustable Db Killer Silencer 60mm Durable New

 

[CHIMV8]

The drone on my E85 3.0 when I changed to straight pipes was awful but I loved the overall noise. I tried sound proofing the boot as suggested above and it made no difference.

I didn't want to go back to standard box so I tried dB killers inserted where the cuts were made and it removed the drone but kept the overall noise improvement (slightly less noise - tested at track day at 98dB's). Similar dB's on eBay that I used search for the following
Motorcycle Steel Exhaust Muffler Adjustable Db Killer Silencer 60mm Durable New

That sounds like the perfect solution my friend

 

[CHIMV8]

Understand they slide inside the pipe but why is it adjustable in length??

 

[CHIMV8]

Is that a fixing screw on the side,if so how do you get the joining clamp over it?

 

[CHIMV8]

Probably one like this will work

 

[Zikim]

I bought the shortest one for both pipes and just removed the screws. They were held in place snugly as I wrapped exhaust wadding around them that you can buy as a mat and tied with copper wire.

The neighbours could hear me from streets away but NO DRONE

 

[Zikim]

I bought the shortest one for both pipes and just removed the screws. They were held in place snugly as I wrapped exhaust wadding around them that you can buy as a mat and tied with copper wire.

The neighbours could hear me from streets away but NO DRONE

I took the end piece off the smaller end so it was just like a small 4" long reducer pipe straight through.

 

[LittleZ4]

I've heard adding weight to the exhaust can help, reduced vibration and drone......not sure what you would use or how to secure it properly though

 

[Big Bad Boris]

I had an annoying drone coming from around the passenger seat area....... found it stopped suddenly when I left the wife at home

 

[steve_naive]

The guy I bought my e85 off did some anti drone mod after a centre decat. Looks like two small bits of pipe coming off the top of the backbox?

Not sure if that rings any bells with anyone.

 

[Davz]

The guy I bought my e85 off did some anti drone mod after a centre decat. Looks like two small bits of pipe coming off the top of the backbox?

This sounds like a Helmholtz resonator and will kill drone if situated at the correct point of the system, usually fitted to the exhaust pipe and not the backbox

 

[Smartbear]

The guy I bought my e85 off did some anti drone mod after a centre decat. Looks like two small bits of pipe coming off the top of the backbox?

This sounds like a Helmholtz resonator and will kill drone if situated at the correct point of the system, usually fitted to the exhaust pipe and not the backbox

Those pipes on the back box just sound like bypass pipes for more sound & nothing to do with less drone? :?
Rob

 

[steve_naive]

The guy I bought my e85 off did some anti drone mod after a centre decat. Looks like two small bits of pipe coming off the top of the backbox?

This sounds like a Helmholtz resonator and will kill drone if situated at the correct point of the system, usually fitted to the exhaust pipe and not the backbox

Those pipes on the back box just sound like bypass pipes for more sound & nothing to do with less drone? :?
Rob

Ah right maybe that's what he meant, more noise but no drone because he retained the backbox?

Car has an afe air intake too, sounds good, get the odd pop and no significant drone that I can detect.