Quiet side pipes

Tday · #1 (**permalink**) 03-16-2008, 06:45 PM

I had a set of side pipes built for my BDR...looking for street quiet and a different look than stainless steel stock pipes. So here's what I did.

I had a car chemistry set of disks put into the collector along with their stainless steel muffler packing, then a chambered muffler with a little more ss packing, and then a baffle extender into the elbow (so it doesn't trumpet with the expansion at the elbow). They were made by Tubular Auto in Rockland, MA---here's their website.

Tubular Automotive

The ss packing is really helpful since it keeps the pipes from ringing when you hit the accelerator from the exhaust packets hitting the disks. The ss packing diffuses the exhaust blasts from each cylindar, reducing the percussion. I then had them ceramic coated and made flat black...nice.

It sounds great...talking on the highway is easy (as any convertible), and it's not quite so tame sounding as undercar exhaust.

The guys at Tubular modified the primaries as well to create a tighter fit. They're fastened with bolts through two tabs. I'll post a sound file when I figure out how to make one tomorrow, but here are some pics. A picture of the primaries as modified but before re-ceramic coated. A picture of the end of the pipes with the fastening tab. Then on the car.

Tday · #2 (**permalink**) 03-18-2008, 04:16 PM

OK, here's a sound file of them at 4' done with a laptop. I'm sure you can't exactly tell the db levels, but it's a nice sound and plenty quiet without being invisible. The motor is a crate 351W. It's at idle and then up to 4200 rpm's. Let me know what you think.

Sound File of pipes

Open it in windows media player (or any player that will handle a wav file.)

uncltodd · #3 (**permalink**) 03-18-2008, 05:10 PM

Awesome mod. Did you ashcan the factory BDR pipes?

I wish I had access to that kind of machine work here for #139.

UT

Tday · #4 (**permalink**) 03-18-2008, 05:44 PM

I sold them to a fellow building a bdr cobra in canada. Apparently the car needs to be assembled up there and I think these pipes are part of his build. I think I got that right...or maybe they're a second set. Regardless---posting them here and on the BDR site got a bunch of inquiries.

Tom

Dangerous Doug · #5 (**permalink**) 03-18-2008, 05:45 PM

That has a nice, mellow tone to it. Nicely done.

h2oman · #6 (**permalink**) 03-18-2008, 06:13 PM

Sounds Great!

Looks Mean!

The black pipes always look good on a black car. Should still turn lots of heads, they'll just see you first now.

lineslinger · #7 (**permalink**) 03-18-2008, 09:40 PM

The internal baffling sounds substantial, that much baffling ends up restricting a lot of exhaust flow. Do you know how much HP you conceded with the internal "additives" from the modifications made?

The pipes match up with your car very well, I like the flat look over the shiny, looks good.

FST FOX · #8 (**permalink**) 03-18-2008, 09:51 PM

If I can ask what did the headers set you back? here in Tx they are looking to be around 1,000 for some bigger headers over stock

Tday · #9 (**permalink**) 03-19-2008, 05:19 AM

I've not dyno'd the car before or after, so I really don't know what I've lost. It feels like less than I thought though---around town and all that. The motor's a crate 351W and what I was thinking is that *now* I have a real need to look for something bigger...hahahaha. So end of drive season I'll look at what's next. These things are projects, right?

The headers were just a fix on the tips (except on #4 which was re-routed a bit since it touched the foot box). The stocks are not that well done by this guys standards---bent instead of rolled (?) so the turns are pinched in. So, I can't say what new would cost. I'll bet I could get some flow back had I done the whole header, but it was $125 to fix the ends...small $, so I did that.