Best Test Pipe for Drone Reduction
06-23-2017, 06:30 AM
#31
Registered User
Haha, nothing like winding up the parents with a noisy exhaust 
Fingers crossed your alignment bolts arent seized, it could be quite an expensive job, luckily there's a lot of help on hand here, I think if your willing to do it yourself it can work out quite a lot cheaper.
Anyway back on topic !
Simon.
Fingers crossed your alignment bolts arent seized, it could be quite an expensive job, luckily there's a lot of help on hand here, I think if your willing to do it yourself it can work out quite a lot cheaper.
Anyway back on topic !
Simon.
06-24-2017, 06:12 AM
#32
UPDATE: Boot Deadening 80-90% Finished with Results
Okay guys, I have some results now that I've finished phase 1.5 of the boot deadening and laid the closed cell foam...
For anyone that just wants to know what the dB meter said without any context, it read approximately 2 dB less across the rev range. For those more interested in what my ears found, these were my findings; idle is much, much quieter in the cabin. The exhaust is honestly barely audible, whereas before you could absolutely, definitely hear it. I can now hear the note of the engine coming into VTEC as well as the exhaust, whereas before it was so loud that I couldn't hear the engine at all, and it was completely over powered. There's absolutely no road noise whatsoever with the roof up, this is another big difference and massively noticeable - it makes for a much nicer ride!
Now... The drone...
I'll hold my hands up and say, it's not as good as I was hoping for in terms of the 3-4krpm rev range. on wide open throttle, it is still very loud. However, I can now cruise at 70 mph in 6th gear, with enough throttle to maintain speed on a mild incline comfortably, with the dB meter reading around 91. (it was around 98 before) This is a massive reduction, my other half and I no longer need to shout at one another with the roof up. Outside of that 3-4k rpm rev range, even on WOT the car is so much more comfortable. With the roof off, noise is moderately reduced, but wind noise competes with the exhaust at higher speeds anyway, so it doesn't matter all that much.
Now, what did I spend on this project? I spent £44 on the Silent Coat sound deadening, which gave the most impressive results for money spent. I spent £30 on the Silent Coat sound insulation matting (2 rolls) and a further £10 on blades to cut and a roller to roll the foam and the deadening out. So in total I spent £84 and I managed to get some deadening in my driver and passenger door, and have one 4mm sheet left over which i'm planning to use at a later stage. In terms of time, I invested a day's worth of time in total doing this, and a further day understanding the science behind it (you wouldn't need to do this, as i've now saved you the bother and just posted results for you
)
So in summary, do I think it's worth it? Yes. Absolutely. Do I think it's worth it even if you have a standard exhaust? YES! There are absolutely no tings, rattles, road noise, tyre roar, or anything else coming into the cabin now. Honestly, I cannot tell you how impressed I am with this in terms of how dramatically these items have been reduced. Do I think it's worth it to reduce drone? Yes. Especially once the exhaust is warm, the drone is enormously reduced with the roof up, and moderately reduced with the roof down. Some of this may be my ears adjusting, but even my other half has suggested the car is quieter and journeys are less tiring.
Here are some quick pictures I took;
Underside of the boot well, very important to get deadening on this side of the well for maximum effect.
Notice how the deadening has been laid in such a manner than it is in the middle of any gaps? leaving some space between each piece? This is how to maximise gains per £ spent on your deadening. Do not cover your entire boot in the stuff, it's not necessary.
[img]https://teamawesomemotorsport.files.wordpress.com/2017/06/img_07891.jpg[img]
This is the area above the fuel tank and behind the rear bulkhead. There were some serious, serious reverberations going on back there when tapped. To be honest I'm not entirely happy with it and may re-visit now I have more knowhow.
Birds eye straight into the boot well. We have deadening on both sides and the factory stuff has remained in place. I could have probably added a little more here.
Finally the closed cell foam. Please note I am in no way proud of the lack of neatness to this, but the boot well was actually really tricky to work with and the foam was so sticky it immediately bonded when laid down. Very, very awkward product to work with IMHO.
So, what else can I do from here? Well, further noise cancelling acoustic foam (the egg carton style stuff) could be added on top of the closed cell foam to dull reflections of sound around the boot well area, and maybe up on top of the boot lid if I were to go crazy with it. However, I don't see the need to invest any further in the boot area. If I go any further with this it will now be cabin side, around the rear bulkhead where the roll hoops are / behind the seat - i'd follow the same deadening then CCF procedure I've done in the boot, and expect another 1-2 dB to drop off the in cabin noise at cruise. However, I'm probably going to leave this where it is for now in favour of building a sub into the boot well and then customising the rear trim with acoustics in mind.
I hope people have found this useful, I am more than happy to write a sticky / guide / FAQ on how to lay the deadening for best effects / bang for buck and put up a load more detail if theres enough demand.
Cheers,
Matt
For anyone that just wants to know what the dB meter said without any context, it read approximately 2 dB less across the rev range. For those more interested in what my ears found, these were my findings; idle is much, much quieter in the cabin. The exhaust is honestly barely audible, whereas before you could absolutely, definitely hear it. I can now hear the note of the engine coming into VTEC as well as the exhaust, whereas before it was so loud that I couldn't hear the engine at all, and it was completely over powered. There's absolutely no road noise whatsoever with the roof up, this is another big difference and massively noticeable - it makes for a much nicer ride!
Now... The drone...
I'll hold my hands up and say, it's not as good as I was hoping for in terms of the 3-4krpm rev range. on wide open throttle, it is still very loud. However, I can now cruise at 70 mph in 6th gear, with enough throttle to maintain speed on a mild incline comfortably, with the dB meter reading around 91. (it was around 98 before) This is a massive reduction, my other half and I no longer need to shout at one another with the roof up. Outside of that 3-4k rpm rev range, even on WOT the car is so much more comfortable. With the roof off, noise is moderately reduced, but wind noise competes with the exhaust at higher speeds anyway, so it doesn't matter all that much.
Now, what did I spend on this project? I spent £44 on the Silent Coat sound deadening, which gave the most impressive results for money spent. I spent £30 on the Silent Coat sound insulation matting (2 rolls) and a further £10 on blades to cut and a roller to roll the foam and the deadening out. So in total I spent £84 and I managed to get some deadening in my driver and passenger door, and have one 4mm sheet left over which i'm planning to use at a later stage. In terms of time, I invested a day's worth of time in total doing this, and a further day understanding the science behind it (you wouldn't need to do this, as i've now saved you the bother and just posted results for you
) So in summary, do I think it's worth it? Yes. Absolutely. Do I think it's worth it even if you have a standard exhaust? YES! There are absolutely no tings, rattles, road noise, tyre roar, or anything else coming into the cabin now. Honestly, I cannot tell you how impressed I am with this in terms of how dramatically these items have been reduced. Do I think it's worth it to reduce drone? Yes. Especially once the exhaust is warm, the drone is enormously reduced with the roof up, and moderately reduced with the roof down. Some of this may be my ears adjusting, but even my other half has suggested the car is quieter and journeys are less tiring.
Here are some quick pictures I took;
Underside of the boot well, very important to get deadening on this side of the well for maximum effect.
Notice how the deadening has been laid in such a manner than it is in the middle of any gaps? leaving some space between each piece? This is how to maximise gains per £ spent on your deadening. Do not cover your entire boot in the stuff, it's not necessary.
[img]https://teamawesomemotorsport.files.wordpress.com/2017/06/img_07891.jpg[img]
This is the area above the fuel tank and behind the rear bulkhead. There were some serious, serious reverberations going on back there when tapped. To be honest I'm not entirely happy with it and may re-visit now I have more knowhow.
Birds eye straight into the boot well. We have deadening on both sides and the factory stuff has remained in place. I could have probably added a little more here.
Finally the closed cell foam. Please note I am in no way proud of the lack of neatness to this, but the boot well was actually really tricky to work with and the foam was so sticky it immediately bonded when laid down. Very, very awkward product to work with IMHO.
So, what else can I do from here? Well, further noise cancelling acoustic foam (the egg carton style stuff) could be added on top of the closed cell foam to dull reflections of sound around the boot well area, and maybe up on top of the boot lid if I were to go crazy with it. However, I don't see the need to invest any further in the boot area. If I go any further with this it will now be cabin side, around the rear bulkhead where the roll hoops are / behind the seat - i'd follow the same deadening then CCF procedure I've done in the boot, and expect another 1-2 dB to drop off the in cabin noise at cruise. However, I'm probably going to leave this where it is for now in favour of building a sub into the boot well and then customising the rear trim with acoustics in mind.
I hope people have found this useful, I am more than happy to write a sticky / guide / FAQ on how to lay the deadening for best effects / bang for buck and put up a load more detail if theres enough demand.
Cheers,
Matt
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