Dual Exhaust! Check it Out...

MadBill · Post by **MadBill** » Sat Aug 23, 2003 10:20 am

OK, got some pix at last of my dual/cut out exhaust: Stainless oval Megs and a throttle valve* in the right side pipe for when I want to make quiet. Open, it sure out-decibeled the Borlas at today's Ontario meet in Oshawa... *to be cable-operated eventually

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MadBill · Post by **MadBill** » Sat Aug 23, 2003 10:21 am

here's how i hooked it up:

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MadBill · Post by **MadBill** » Sat Aug 23, 2003 10:23 am

And here's the throttle valve about 1/2 open. (it fits better than it looks from this angle, but I do need to clean up the cut out a bit.)

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Triton · Post by **Triton** » Sat Aug 23, 2003 10:27 am

That looks pretty good. Is your right side pipe louder than your left? I don't think that is something I would ever do, but I am curious to know.

MadBill · Post by **MadBill** » Sat Aug 23, 2003 10:31 am

I think 95% of the sound comes out the right side, but no one can tell when you're driving. It does seem a bit extreme to 'fiend' a near-new car, but I could always weld a patch over the pipe if necessary and I saved the cut out piece of the fascia, so I could bond it back in with a little filler if I needed to return it to stock.

NovaResource · Post by **NovaResource** » Sat Aug 23, 2003 10:44 am

Sweet.

millster · Post by **millster** » Sat Aug 23, 2003 11:28 am

Hmmm... I think I like it. For my personal needs, I'm thinking dual outlet muffler instead of the straight pipe. Any thoughts on that? I'm a little worried about backpressure. Think that would decrease it to the point that I would actually be hurting my performance? I know I stand to gain nothing from the duals except looks but that's what I want. My other question is, can you snap a photo straight on from the rear? I'm curious how the cut-out in the facia looks compared to the original opening. It looks like you did a wonderful job though. Very clean.

rubberman · Post by **rubberman** » Sat Aug 23, 2003 11:40 am

Hey Mad Bill we passed you coming out of Cobourg tonight could tell it was you by your huge meats!,I notice your car had a little more bark to it as you drove by.

ArcsVibe · Post by **ArcsVibe** » Sat Aug 23, 2003 11:44 am

Looks sweet man, nice job!If you don't mind me asking how much did it set you back?PS How was the meet?

MadBill · Post by **MadBill** » Sat Aug 23, 2003 12:35 pm

quote:Hmmm... I think I like it. For my personal needs, I'm thinking dual outlet muffler instead of the straight pipe. Any thoughts on that? I'm a little worried about backpressure. Think that would decrease it to the point that I would actually be hurting my performance? I know I stand to gain nothing from the duals except looks but that's what I want. My other question is, can you snap a photo straight on from the rear? I'm curious how the cut-out in the facia looks compared to the original opening. It looks like you did a wonderful job though. Very clean. Paired duals look really good too, Millster, but the backpressure is pretty well all in the muffler, so if it's just twin pipes on the stock muffler, it shouldn't change the BP.I don't subscribe to the "needs some backpressure" theory, but now that I have this system I can do back-to-back testing with and without the muffler to find out for sure. I also have a pressure tap just behind the first cat, so I will post psi readings also. It's a little dim, but here's a shot from the rear:

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rasermon · Post by **rasermon** » Sat Aug 23, 2003 12:38 pm

Looks good MadBill. Damn, those are some big meats!

MadBill · Post by **MadBill** » Sat Aug 23, 2003 12:44 pm

Quote>Hey Mad Bill we passed you coming out of Cobourg tonight could tell it was you by your huge meats!,I notice your car had a little more bark to it as you drove by. Hey, Rubberman!Sorry you couldn't make the meet! The Vibes were (briefly) outnumbered 9-8 by the Matrixes (Matrices?) and we could have used you. Great get together though, lots of scoping out mods and great discussions, plus a bit of a tour around the town..You weren't in a Vibe when you passed, were you? I didn't notice any familiar shapes (but I was trapped behind some slug in an Olds, and couldn't rip the exit fast enough to get any speed up the grade, so you likely blew by pretty fast... PS: Which LeMans-liveried Corvette is that in your avatar? Ron Fellows is a good friend of mine...

d_m_kolb · Post by **d_m_kolb** » Sat Aug 23, 2003 12:53 pm

I love the set up! Nice job.

millster · Post by **millster** » Sat Aug 23, 2003 12:58 pm

Ahh, thank you sir. That's exactly the angle I needed. Yes, I definitely like the look. So, my thought was to use some sort of a universal mount dual-outlet muffler, but maybe splitting the output of the factory muffler would be cheaper/easier? Though I wonder if that's possible? Well, I guess this is my project for Sunday. Climb under my car and see what I can find. Either way, good show Madbill! Looks good.

MadBill · Post by **MadBill** » Sat Aug 23, 2003 1:02 pm

quote:Looks sweet man, nice job!If you don't mind me asking how much did it set you back?PS How was the meet?Ha! You won't believe this, Arcs! The polished stainless Megs were $28 each, the guy at the Brafasco fasteners store couldn't be bothered writing up the 3 stainless bolts, 3 washers and 2 nuts, so they were free, the muffler shop gave me the 6" stub of 2-1/4" stainless pipe, and it cost me $30 to have the hole cut in the exhaust pipe and get them to weld it on. (Could have done it for free myself, but my gas welder likely would have distorted the pipe and messed up the fit of the throttle blade.)Total: $86. Effect: Priceless!

MadBill · Post by **MadBill** » Sat Aug 23, 2003 1:10 pm

quote:Ahh, thank you sir. That's exactly the angle I needed. Yes, I definitely like the look. So, my thought was to use some sort of a universal mount dual-outlet muffler, but maybe splitting the output of the factory muffler would be cheaper/easier? Though I wonder if that's possible? Well, I guess this is my project for Sunday. Climb under my car and see what I can find. Either way, good show Madbill! Looks good.Thanx millster!There are lots of different twin pipes that fit onto a single. The stock pipe is some metric size just under 2-1/4" (I had to use a sleeve to get a good fit with the 2-1/4" tip on the left pipe), so your could just cut the stock pipe ahead of the 3" tip and clamp one on. (Although I heated and bent the the pipe up a bit to get the tucked-in look.)Good luck!

MadBill · Post by **MadBill** » Sat Aug 23, 2003 1:13 pm

quote:Looks good MadBill. Damn, those are some big meats!Ya, I prolly need the supercharger just to overcome the added drag!

ArcsVibe · Post by **ArcsVibe** » Sat Aug 23, 2003 1:28 pm

86$ Canadian!?!!?!?!?!?Man that is worth every penny!Once again nice job!

AKLGT · Post by **AKLGT** » Sat Aug 23, 2003 2:59 pm

wow, madbill! that looks incredible. i want dual exhaust bad! actually, i was thinking about the set up for the PT Cruiser. possibly having it modified or something. but I like what you did there. keep us posted on the differences for the BP issue.

rubberman · Post by **rubberman** » Sat Aug 23, 2003 10:16 pm

I can't remember whos car it is,I thinks its Rons I got it from Motorsport.com.He's one of my favrites to

rubberman · Post by **rubberman** » Sat Aug 23, 2003 10:18 pm

Would a muffler off a F-body be made to fit(single muffler dual outlets)

rubberman · Post by **rubberman** » Sat Aug 23, 2003 10:20 pm

Yep that was us in the Abyss Vibe

savedbyzero · Post by **savedbyzero** » Sun Aug 24, 2003 6:11 am

Not a fan of the exhaust, but to each his own. congrats!

MadBill · Post by **MadBill** » Sun Aug 24, 2003 7:55 am

quote:86$ Canadian!?!!?!?!?!?Man that is worth every penny!Once again nice job!Well, the tips were actually US funds, but still pretty cheap altogether..

MadBill · Post by **MadBill** » Sun Aug 24, 2003 7:57 am

quote:Would a muffler off a F-body be made to fit(single muffler dual outlets)Likely. You could take some measurements and talk to say Flowmaster, Spintech, Walker, etc. I think you would find a match.

ArcsVibe · Post by **ArcsVibe** » Sun Aug 24, 2003 11:26 am

Still worth it! Once again very nice job!

MadBill · Post by **MadBill** » Sun Aug 24, 2003 8:42 pm

Sure, that could work silver, and would look great. Maybe an aftermarket muffler for a Sunfire, Grand Am or maybe even a Firebird would be close on dimensions and you'd just need to fabricate mounts to match the hangers on the car.For me however:1. I was too cheap to spring for a muffler.2. I wanted it to be LOUD when the valve was open.3. This way I knew the pipe spacing would be symmetrical.

MadBill · Post by **MadBill** » Mon Aug 25, 2003 6:02 am

Tech Report:I installed a pressure tap just downstream of the first cat on my base Vibe, and found that the exhaust backpressure reaches 4.0 psi @ the 6,400 RPM cut off. With my throttle valve dump open just upstream of the main muffler, BP drops to 2.2 psi, a 45% reduction. Obviously, the remaining pressure drop is distributed between the other cat and the resonator, and likely some small amount through the pipes, but my exhaust system would look like a piccolo if I put in enough taps for verification! Since the system looks pretty much the same on a GT and the exhaust flow is a lot higher, I suspect a 2ZZ would see more like 6 psi, so would gain more power than the base engine on a % basis from the addition of a good muffler.For my next act (since I don't have a G-Tech or similar device), I will average multiple WOT acceleration runs (likely in third gear) with the dump open vs. closed and time the intervals for each 1,000 RPM increment with my lap timer stop watch. This should tell me whether the reduced back pressure helps or hurts power at low and high RPM, as well as the overall effect.Watch for updates...

MadBill · Post by **MadBill** » Mon Aug 25, 2003 6:07 am

Man you are fast on the draw, silver! You should change your name to Quicksilver!

dcyco1 · Post by **dcyco1** » Mon Aug 25, 2003 8:50 am

How does the car sound with the cut oout open? Does it have a high or low pich to it, and does it sound like one of the coffe can exhaust? What did you use to cut out the passenger side bumper? Duals look but you are esessentially running a straight pipe when you have the cut out open. I want to eliminate the muffler and try a resonated monza tip out back. I did this on a previous car and it sounded louder but it was low&mellow, not high pitched and crackly. Chris

MadBill · Post by **MadBill** » Mon Aug 25, 2003 8:54 am

quote:....Duals look nice with the fat tires on the Vibe.. I am interested on what you are going to do next......Happens I am working on another little trick part. Look for it soon in "Wheels and Tires"... PS: Woo! I'm now a "senior member"! (as if it didn't show in my pic in "who are our...members?" thread...)

MadBill · Post by **MadBill** » Mon Aug 25, 2003 9:21 am

quote:How does the car sound with the cut oout open? Does it have a high or low pich to it, and does it sound like one of the coffe can exhaust? What did you use to cut out the passenger side bumper? Duals look but you are esessentially running a straight pipe when you have the cut out open. I want to eliminate the muffler and try a resonated monza tip out back. I did this on a previous car and it sounded louder but it was low&mellow, not high pitched and crackly. ChrisIt doesn't have that hollow sound that a giant tip muffler gives. It is a fair bit louder than say a Borla, and fairly high-pitched, but not crackly. I would like to try something like the Monza tip, i.e. a glass packing in the tip, to cut out some of the high frequencies and give a deeper tone, but I can partly close down the throttle blade and get a similar effect. (Keep in mind the two cats and the resonator provide some muffling.) If I can find someone to do a sound clip for me, I'll post it.I made a cardboard pattern of the left fascia cut out and traced it in the mirror image position, then used tin snips; it cut very easily. (and I saved the piece, JIC I wimp out at some later date...) (Wow! I'm also on the "Top 10 Posters" chart for the first time, right up there with Nova!)

dmitri · Post by **dmitri** » Tue Aug 26, 2003 2:31 am

Nice MadBill you been telling me about your project for like a month or two now lol. Looks good.

MadBill · Post by **MadBill** » Tue Aug 26, 2003 3:11 am

quote:Nice MadBill you been telling me about your project for like a month or two now lol. Looks good. Yeah, it's sort of a self-motivational approach: I'm kinda lazy, so if I blat on ad naseum about something I'm thinking of doing, it forces me to follow through, to avoid looking like a poseur

robdog · Post by **robdog** » Tue Aug 26, 2003 4:52 am

Got any sound clips? Be nice to hear a custom job for a change. Let us know. Thanks

MadBill · Post by **MadBill** » Tue Aug 26, 2003 6:02 am

Will do my best. I'll have to see if I can hunt up some recording equipment.

QUIKAG · Post by **QUIKAG** » Tue Aug 26, 2003 10:35 am

Just read through the thread. Nice work, MadBill! Let us know your findings on the acceleration runs and get some sound clips up soon! Looks great!

MadBill · Post by **MadBill** » Tue Aug 26, 2003 10:42 am

Always nice to strike a resonant chord with another appreciative Gearhead...

QUIKAG · Post by **QUIKAG** » Tue Aug 26, 2003 12:04 pm

I like your system in that you can 'turn off' the loud exhaust when you want to. Reminds me of the time I had a 2.5 inch custom exhaust with a straight dynomax flow-through muffler bolted onto my old '93 Honda Del Sol Si. I thought it sounded good initially, but soon realized it was VERY, VERY loud and obnoxious. I was 18 at the time and didn't know any better. It was '95 and the 'rice crowd' was really starting to grow. I liked to consider myself on the cutting edge then. haha.Anyway, your dual setup looks clean and is a rather ingenious setup, especially considering the cost.

Merzbow · Post by **Merzbow** » Wed Aug 27, 2003 8:50 am

HOLY COW, I'm impressed. I love it, so is there any way you could some how record the sound of it and post it on here??? like make a small video with a digital camera or something? I have only actually heard the engine of one Vibe and that was a Pontiac dealer demo I saw and it sounded like a Supra...you know, the low but loud groan? -=Paul=-

MadBill · Post by **MadBill** » Wed Aug 27, 2003 9:23 am

Thanx guys. I'll keep working on trying to get a recording.

AKLGT · Post by **AKLGT** » Wed Aug 27, 2003 9:24 am

yes, I completely agree there, Quikag. madbill, you've done a great job. quite creative and cost effective. i'd love to see if i could duplicate that!

MadBill · Post by **MadBill** » Wed Aug 27, 2003 9:43 am

If I can answer questions for anyone who wants to do something similar, ask away! Any muffler shop should be able to duplicate most of it quite simply; the only tricky bit was a lot of grinding and filing to get the throttle blade to seal tightly enough to not sound like a leaky exhaust. If you wanted to save some labour, you could just set the sound level to the desired level by drilling say a 1/2" hole in the original pipe where the right stub was welded on and then enlarging it until you got the sound you wanted. I have found that about "1/2 throttle" on my damper valve sounds pretty good but still civilized.

dmitri · Post by **dmitri** » Thu Aug 28, 2003 9:27 am

i posted 2 clips of my straight pipes a while ago ill find them for you.

dmitri · Post by **dmitri** » Thu Aug 28, 2003 9:30 am

ok got it. only bringing it up to like 4k and its kind of a bad recording but you get the idea.

Attached files PICT0181.wav (62.7 KB)

MadBill · Post by **MadBill** » Thu Aug 28, 2003 9:47 am

Yours seems to have a bit more 'bark' than mine, dmitri! Is it a GT?(Still trying to bum some gear to do my own clip...)

dmitri · Post by **dmitri** » Thu Aug 28, 2003 2:30 pm

yea i have a GT. I also have a CAI i dont know if you have one or not. i done a little inside engine work myself too that i keep secret

MadBill · Post by **MadBill** » Sun Aug 31, 2003 2:56 am

Here's a sound clip of my system with the exhaust throttle valve wide open. My borrowed laptop died before I got in a half-throttle run. I had the mike a bit too close; it doesn't sound so "wheezy" in real life. Apologies for the crappy shifts, I was distracted by the dying computer.(OK, what am I doing wrong? the file was "only" 1.26 Megs, and the post says it can be up to 3,000,000 bytes, but nothing's showing up!)

MadBill · Post by **MadBill** » Sun Aug 31, 2003 7:02 am

Unfortunately didn't have the charger...

roadrunner-r · Post by **roadrunner-r** » Sun Oct 26, 2003 9:56 am

Where can i find a valve like that? I been wanting to dual mine off too. I have a borla,and the resonator chopped,i think it will be loud. So i was thinking of useing a 1.5 pipe to quit it down.