I got a warning at nationals last year at 97 dB with the similar cat back, but with the PLM header and HFC.

 

I did notice. I had the same cut off exhaust, but did this to lighten it and point the exhaust to the ground. The AP1s do read higher than the AP2s from what found. My setup at Nationals was a Berk header, HFC, and cut exhaust. I have local restrictions just like many others, so this will be the baseline. I have various ideas to quiet it down further.

Based on readings from our local S2000s, the cars with the exhaust exiting the rear (both sides) were usually around our limit (mid 90s) My CR with the cut exhaust sounded slightly louder, but the readings were consistently below 90db measured at 75'.

 

I think it can only help. It will be lighter, flow more/make more power, and help lean out the rich stock AP1 AFR.

 

In preparation for the San Diego Tour with its 93 dB sound limit, I made a new cat back exhaust. I purchased this cheap ass funny looking twin loop JDM ricer muffler on ebay and it turned out to work nicely. It's light and very quiet. Apparently it's a clone of a Mugen muffler. This plus two pre-bent 45 degree stainless tubes, a v-band added up to a $150 exhaust assuming a free OEM cat back to start with.



I'll have to get some better photos in the day light. The total weight of the cat back is 20.5 lbs including two rubber hangers, front half 11 lbs, rear half 9.5 lbs. The big four inch exit pipe had to be cut off in order to make it fit. The two straight through passes through the can make for a really light and quiet muffler. I think my wife will like it. I can actually listen to the radio now. Even going under a bridge it's really quiet with the intake the dominate sound. When I get the car tuned I'll consider getting a final pull with the muffler on to see if there is a power hit.





The v-band was moved rearward to avoid the axle flange. I plan to run it with the rear portion removed with a down turn for local events and nationals.





Under Construction








Here is what the inside looks like. Fiberglass insulation will not last forever.

 

Duuuude, that's awesome!! Thanks for sharing that!

 

nice work Rob! I'm guessing the Piping diameter on this is 63.5mm?

What type of welder are you using?
What type of wire?

 

Thanks. Yes, 2.5 inch tubing. Used a MIG welder with 0.025 steel wire.

 

If anyone is interested in this muffler it's also available from OBX. This version looks to be a closer replica of the Mugen version.

OBX Twin Loop Muffler 2.5" (63.5 mm)





Here's a source for the 45 deg 2.5" SS tube

Silicone Intakes - 2.5" 45 deg SS Pipe





2.5" V-band

2.5" v-band ebay

 

How was it welding stainless with the MIG? Was the .025 wire stainless or was it just standard wire like the L-56 Lincoln stuff?

Thanks,

Rob

 

The wire is mild steel, not stainless steel and it works just fine. Yes it's the regular Lincoln stuff. The settings were A for heat setting with a rate of 2.5. The welder is what would be equivalent to the WeldPak 140 HD which can be purchased at Home Depot.