It makes a HUGE difference. I'll detail it a bit more further down but Rattletrap makes a bigger difference than the MLV but they all help.
I ordered some mass loaded vinyl off Amazon and what came was not what MG had suggested I get. I tried ordering the VB4 MLV from the place MG specified -
Cascade Audio Engineering - and got frustrated with the ordering process. It required actually calling them, on the phone, several times. How do places stay in business like that? After a few tries I gave up and ordered something on Amazon which turned out to be not that great. So I went to the place that installed my stereo in the van and they had the good stuff. It was more expensive than if I'd bought it from Cascade but at least I got the right stuff.
Also, I asked them how much coverage they do for Rattletrap/Dyanmat and they said 100%. He said it makes a huge difference and if you've gone to the trouble to pull the entire interior why wouldn't you? While I was there I saw a very sweet custom Firebird and the entire interior was pulled and every square inch was covered in Dynamat. Now I'm going to go back over the wheel wells and cover them completely. He also asked if I'd pulled the side panels and done the walls yet which I hadn't. He strongly suggested that the walls get covered too.
So.
Here is full coverage with Rattletrap then full coverage with the VB4 mass loaded vinyl. Here you see it under the steel plates - two different layers of foam basically. But first a side note...
When I bought the MLV I took the 50" roll and unrolled it down the middle of the van for the ride home - you know, just to see. This stuff is amazing! I checked the Db's because I could suddenly hear the stereo way better and more clearly - it sounded much more solid. My suspicion was confirmed - the sound on the highway dropped to 74Db which was nuts. At this point it was very clear that all the noise was coming from the cab of the van - the back was super quiet. That's a 12Db drop from empty.
Anyway on to the frustrating day. As this was MG's very first test plate the holes didn't quite line up - he's since discovered that most vans aren't exact enough to line up. No problem as I bought it with the understanding that I'd have to make it work.
So my entire day was spent in the pursuit of drilling twelve holes. In order to not swiss cheese my fuel tank I put a sleeve of aluminum on the 1/2" drill bit which worked great as a stop. I drilled through first with a quarter than (later) with a 3/8" and then with the 1/2" and finally with the counter sink. I bought $100 of stainless 1/2" flat head bolts and nylock nuts and stainless fender washers for the underside.
I had to resharpen my 1/2" bit twice and I completely burned up my $50 countersink. Probably my own fault because I didn't want to do the job right - ie. pilot drill the entire plate and then pull the plates out to drill with cutting fluid on the saw horses and then reinstall. So I skipped the cutting fluid so all I had to do was vacuum the chips.
So after spending the day drilling the holes - okay, some of the day was spent prepping dirt bikes for tomorrow - I managed to get the holes all drilled and countersunk.
Once Rob and Lara came back over we attempted to bolt down the plates but we kept having trouble getting the nuts tight. It didn't occur to me that they could be galling until about the 5th one and the second that bound so tight we had to cut the head off. Is that really what's going on? I know stainless can gaul but this seems a bit excessive. It got dark before I could put some anti-seize on the bolts and test the theory. I'm a bit nervous as I've now got to remove about four completely gauled fasteners...
Okay but onto the sound. Like I said, with the MLV just laid out I was getting 74Db's or so. Once the plate was in the sound actually went up but still was less than the Rattletrap alone. Right now it's at about 76-78Db's so the MLV was worth 2Dbs but... BUT! I have to point out that now the van is very quiet in back. The sound is almost exclusively coming from the cabin which I know has not been treated in any way. So I think there's a lot of low hanging Db fruit waiting to be snuffed out with some Rattletrap on the floor and fire wall of the cabin. I'm tempted to just do it now even without removing the seats - just pull the mat and do whatever steel I can.
Evan is the MAN! Fun fact - he used to live one block from my house here in Portland. I've known him for almost 20 years and who'd have guessed I'd have moved into his old hood. He used to be the "motorcycle guy" in the hood and now that's me. Onto your question.
That bike was hand made by an engineer in Canada. It came up for sale and I wasn't in the position to buy it and then a few months later the chance came again and I jumped. My next goal is to build a similar but more refined airhead GS style dirt bike. This one had done a lot of the things I wanted to try and I'm looking forward to trying it out once I get it plated. It's a very highly modified BMW with lots done that isn't seen.
Anyway, the van isn't done darn it. I'd hoped I'd be finished by the end of the week but it hasn't come to pass. Hopefully next week.
And if you have advice on why the stainless would gaul - let me know. I'd hate to have to go back to steel but I know I wouldn't have that problem. I'm guessing I should have just put antisieze on them and it would have been fine.
Gregor
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