The Shitbox build - 151db+ on one DC Lvl 5 18" @36hz!!!

[the_garynator]

BIG UPDATE!!!!

Cliff Notes: Someone hit a 150.8 at 36hz on 1500wrms with a single 18 tuned to 30hz with half the recommended port area. Who? This Guy!

Little back story...back when I had my half dead 15" level 5 (2 dead coils), I managed to hit a 151.0 ONCE. Never was able to do it again. Kept getting close, but never hit it again.

When I swapped to the other 15" level 5, the best I could muster was just under 151...like 150.6-150.8 (door open at the dash of course). I believe this largely was to do with the fact that it was wired at 2ohm vs the half dead one at 1ohm. I never got a chance to clamp the last 15, but the half dead one was getting 3011wrms at around 2.3-2.4ohms after box rise.

After my recone to 18", I was rather disappointed and frustrated that I didn't gain anything. I mean I didn't expect to gain much as the new box didn't have nearly as much time into it (I figure the 15" box had 100+ hrs of work into it, not including design and testing). But I've been after that 151 for so long, it was rather frustrating and disappointing. No matter what I tried, I couldn't seem to get to that magical number again. I've been trying to hit it since I did the first time...we've spent hundreds of hours (even back when I still had the half dead 15) sealing things, experimenting, changing box designs, etc. It just wouldn't happen.

It was so frustrating that my buddy who had been helping with this project a lot since the start even lost interest a few months ago. After my testing recently, I came to the conclusion that unless aero ports will make that big of a difference (i'm still thinking they might), something else is holding me back. In the past it had been air leaks in the rear, but we checked, and everything is sealed up.

So I borrowed my buddy's clamp meter last night as I plan on doing a write up on box rise and how frequency and box tuning effect it. I threw it on before I pulled the sub last night for grins. After doing multiple tests, I found out that with the 3x 4" aero ports tuned at 30hz, I was only getting 1548 watts when I hit the 150.08!!! Box rise was insane, 6.2ohms after rise!

Anyway, we'll start from the begining of the night...I picked up some Tite Seal (same as peel & seal) and planned to swap ports back to the slot port for the time being and apply some of this. I have read all of the threads about it sucking and all, but I have not found anyone who has tested it for spl gains. The big vs. thread was only measuring vibration dampening.

I also understand that it does not deaden sound, but my main goal was to add an extra barrier to hopefully reflect more sound into the car vs losing it to the outside (basically keep the sound in the car). The secondary goal was to seal things up, which this stuff does wonderfully. I would have done real deadener, but I don't want to dump a bunch of money into this car as it may not last much longer (further evidence of this below lol). I may still add some deadener at some point, but I got a 9"x31' roll of this crap for $19 (24.75sq ft) so I figured I'd give it a try. I will be testing to see if I made any gains from it tonight, but I'm not sure I'll be able to get good results as they may be different after adding more power and I did not get a baseline after switching the ports back.

After I removed the sub, I decided to take a better look at the passenger side strut tower, the seam had been pulling apart, but until now, I didn't realize how bad it was.

Somewhat cleaned up

Still don't have a welder at my new shop (getting one later this month) so I couldn't weld on metal to reinforce it. I also didn't want to fiberglass it like I did in the section that had seperated behind it (all the red stuff is long strand fiberglass) because I plan on welding it since it's very structural and cleaning off fiber glass would be a HUGE PITA. Unfortunately it was bad enough that I didn't want to just leave it, so I grabbed a chunk of galvinized sheet metal I had laying around and some rivets. The steel is thin, but it's not much thinner than the stock metal (if at all), and I put in enough rivets that it should hold at least half ways decent. After driving the car later, it does seem to have helped noticably.

Did some more cleaning/prepping the surface. I scraped off some of the tape, chiseled off most of the seam sealer/deadener that was left. Then I soaked it in goo gone twice, then did a once over with wax and grease remover (basically prep-all). Now she was ready for the tite seal.

I applied it in the lower spots, up to 5-6 layers thick in most of those sections. My goal was to match the height somewhat to the raised metal sections, just to spread the weight more evenly. It seems to have helped a bit, but I probably need to do some more with it.

Passenger side rear wheel well.

Driver side rear wheel well

Added a bit more to the rear of the trunk

Added 2-3 layers on the hatch lid (I didn't remove the aluminum hvac tape, but it adhered really well and seems to be solid).

I also picked up some new screws to bolt the port on. I was getting really sick of breaking drywall screws off trying to remove them. I probably wasted 2-4hrs the last two times I removed the port just removing broken screws so I didn't wreck it. These screws are #12 x 2"...a lot more beefy.

Now onto the important stuff...Termlab results!

If I wasn't alone and totally shot (this was about 4am), I probably would have had a heart attack! 151.02 @ 36hz. ~2500wrms, 1.4ish ohms after rise (voltage drop like a mofo ).

Burped it at 43hz for grins and HOLY COW, almost a 152! I'm thinking with a bit more time, I may be able to crack a 52 (i.e. top off the batteries, mess around with vents and stuff, etc.)!

Sealed at the dash at 43hz.

Sealed at the dash at 36hz. Really surprised these were so close. Sealed scores seem a bit low, and the fact that the 43hz burp was done first and I would have guessed it would have been at least a half, if not more, of a db louder kind of makes me wonder if the cabin just can't hold the pressure or something. I'm going to do some more testing and also plan on pulling the dash at some point and making sure the firewall is sealed well.

And the money shot, Outlaw in the Kick. My highest score yet!

I'm going to try a hair trick for the first time since getting the 18. The 15 really wanted to, but it just couldn't quite do it (hair would start lifting but that was about it). The 18 didn't seem that much more windy, but after wiring it down and throwing 1kw more at it, it has gotten a lot more windy lol.

I plan on doing a bunch of testing tonight, hopefully will be able to get some more box rise results to add to my collection for my planned box rise thread. I'm planning on getting some video tonight too, I'm borrowing my roommate's GoPro Hero3 so I'm going to get some 240FPS video so I can do slowmo. Also will probably get some 720p @120hz too.

[Nate Dogg 51]

Nice thread! I just made a box for my Re se and I was thinking of staining it or varnishing it and came across this thread. Do you recommend Stain or Varnish? How do you apply it, Brush? Any helpful tips either?

[the_garynator]

stain works well, one thing i found was that if you dont sand it rather well after the stain dries, the resin doesnt adhere well. i'll post more about it, but I broke my hand so typing is a pain lol.

[the_garynator]

Last update to this build. I've since stripped everything out of the car because I bought a new winter car. Got big plans for the new car and I'll be posting a build thread for it soon.

got another 2 4" precision ports to see what 5 precision ports would do.

Port Baffle Complete and ready to be attached

Port Baffle test fitting

Ready to be screwed down

Assembled

Inside view

Taped up to prevent leaks

In car

Unfortunately I was unable to get any more gains with this setup on the meter. Based on the sealed at the dash results and other th‌ings, I pretty much decided to give up on the car as I believe that the car itself is and has been a big limiting factor (rusty and not holding pressure). Decided it was time to move onto bigger and better things.

Hope you enjoyed the build. Comments greatly appreciated!

[the_garynator]

Couple more pictures to post.

Most stuff removed

everything removed:

Interior back in:

I'll post a link to my new build thread in here once it's created.

[purplesyrup]

sweet build, lots of hard work and trial and error testing there, nice results toO!!!!!!

[the_garynator]

sweet build, lots of hard work and trial and error testing there, nice results toO!!!!!!

Thanks!

Link to my new build thread! www.stevemeadedesigns.com/board/topic/159860-the-roadmonster-build-roadmaster-wagon-build/