My setup is nearly identical to Jon's above, but I have the predecessor Greddy TI-C modified with a Helmholtz resonator to reduce drone. See Helmholtz resonator here within S2KI for details if interested. It reduced drone and seems like it's good for 1/2 db or so from the outside.

 

So, now for some results. First, a couple of pics to explain. First is my turn-down, which shows where I cut the OEM exhaust for the v-band.
[attachment=22644:turn down.jpg]
then, the new exhaust.
[attachment=22645:new exhaust.jpg]

I set up the sound meter on a tripod along side of a taxiway at the airport, quite a way from any buildings. It was 60 ft. from the center line I was driving. It is important to note that I live in southern Colorado, and the airport elevation is 7650 msl. That means the engine is only making about 75% power, so I presume the actual noise levels would be higher in San Diego for instance. Still the reading should be relative. I made 3 runs past the meter in each configuration, after a little practice so I could be in Vtec as I approached the meter, and at red-line rpm soon after I went by.

Again, I have a home made CAI, stock header, Berk HFC, stock resonator section to the v-band.

Turn-down 93.7 dB, 93.5 dB, 93.8 dB

Stock dual muffler system 82.1 dB, 81.4 dB, 82.4 dB

New exhaust system (Burn single stage) 87.3 dB, 88.0 dB, 89.1 dB

I am planning to make a turn down for the Burns muffler and test that, and also to do some road testing this week to see if it is tolerable on the street.

And, I am hoping to make it to the Colorado Tour event in a few weeks, and will get calibrated with whatever setup they might have.

Edit: I drove the car today in town and on the highway. I think it is perfectly livable...just a nice note when cruising on the highway, no drone at all. It is pretty quiet in town (quieter than a lot of the pickups and motorcycles), especially if it is driven gently. I can't imagine getting a ticket unless I was winding out to redline etc.

 

Nice work John. Thanks for the contribution. I was interested in using a Burns or Coast Fab muffler like this but chickened out before going to San Diego and went with the twin loop muffler to ensure it was quiet enough. I would guess that my setup is in the upper 80s range at sea level with humidity (higher density air).

 

John your exhaust looks good! I got the Toda header for $1100 because some guy brought it and then lost his job and needed to sell it. It came to me brand new still in the package. $1700 seems to high, you should be able to order one for $1400 or so.

this is how it came to me..


This is a dyno showing the difference between header and no header... (untuned, notice how much leaner it got)

As you can see not much gain without tuning. Besides leaning out alot.



I'm about to take the tip off my T1R 70R and weld on a Vband and make two tips, one a straight piece and the other a turn down. I was going to order the pieces from Burns but they seem way higher then what I can get a piece of stainless pipe off ebay or something. Any reason I should go with the burns pipe and vband over one from ebay or something? Also I was playing with a dryer vent at the last race and seemed quieter if the turn down was turned to the side alittle instead of straight at the ground. It seemed to echo off the ground when pointing straight down. Anyone else find this to be true? When testing the dryer vent my car went from 95 DB to 88-89 DB, which is quiet a drop!

 

Thanks Josh...From Evasive Motorsports right now, JsRacing header, $1575, Mugen $1670, Toda $1600. I am looking at PLM or Berk, but I won't do anything right away.

The Burns bends are pricey, and I see no reason to pay that much. I paid a little extra for 18 ga. rather than 16 ga. to save some weight, even that was probably wasted money. I order parts from Columbia River Mandrel Bending last night to make a turn down to slip on the muffler, using aluminum for that.

 

Alright, I finally have some useful data to add to this thread.

I ran my new setup at the Packwood NT. My setup is Header, 200-cell HFC, stock resonator, V-band, 2.5" all the way back to a burns 2-stage 2.5" muffer setup the same way Johnx's is set (the difference is that his goes from 2.5" to 3" after the resonator and he has 1-stage). At the packwood NT, I was blowing anywhere from 88 dB to 92.1 dB (the weather was changing and it was windy). Most readings were around 89-90 between my co-driver and myself.

Audibly it's WAY quieter than my B-stock style turn-down setup I had prior. It is very livable on street and I'm sure my neighbors appreciate it, but it still sounds sporty.

I need to get the setup tuned but if it's lean my VAFC can't add-fuel, but I think I might have stuffed up the top-end a bit. My butt Dyno should be considered unreliable at best.

Because I have the V-band, I might build a 2.5->3" setup like Johnx did so I can swap when I get to events.

EDIT: Oh yeah, weight. The whole new section from the V-band back (which is like 6" from the resonator) is 6.2 lbs.

 

did you use stainless piping?

 

Yes, 304 I believe. It's what the exhaust builder had. I'm not sure of the gauge, pretty sure it wasn't 20g.

 

3 inch... thats 76mm, I thought my T1R 70r was huge. Talk about zero back pressure...

 

Nice post. I assume from your post that by "stock resonator", you mean the stock piping is untouched from the cat flange to where the split was, and you put a v-band at the split like the B-stock turndown?