posted on October 05, 2011 14:46
How to Build a Stainless Exhaust with Vibrant Performance
By Mike Kojima
A lot of times a pre made exhaust just wont do it. You might have a car that no one makes an exhaust for. You might want to make a big diameter turbo exhaust for a car that never came turbocharged. You might want to make a special exhaust for your own special requirements.
|The Protech mid pipe has this cool ball and socket that is compatable with the factory part on the 20V exhaust manifold. The stock 20V exhaust maniold outpowers most headers on the market but needs a 3" exhaust. The Protech part is 3" mandrel bent steel that is cermaic coated.
In our case we wanted to build an exhaust for a 92 Sentra SE-R. There really isn’t much aftermarket interest in this car any more and when there were commercially available exhausts, they were small diameter units for mild bolt on engines. We were bolting in a pretty healthy NA SR20VE engine into the car and a 2” or 2.25” system was not going to cut it.
|We used a Vibrant Streetpower muffler as our main muffler. It features all stainless steel constructionon and is ceramic coated black for stealth. It is a high quality unit and has about zero backpressure.
For a healthy NA motor with a lot of overlap, you need a big really low back pressure system. We wanted a 3” system and there wasn’t anything like this on the market. In addition. we wanted our big exhaust with super low backpressure to be both reasonably quiet and to not make excessive emissions. It’s a challenge to get an NA motor quiet with a large exhaust because there is no turbo to act as an effective silencer on its own but we were going to give it a shot.
|The Streetpower muffler has a straight through perforated core making it an absorption type muffler. No baffles or louvers to cause turbulence and back pressure here. The body is larger than typical round straight through mufflers for good silencing and is packed with stainless wool and fiberglass. It is very hard to make a large diameter. low backpressure exhaust quiet on an NA car because a turbo really makes the exhaust note quieter before the exhaust gas hits the exhaust system.
We were also running an OEM SR20VE 20V exhaust manifold in lieu of a header on our engine. The 20V manifold is known to make more power than most commercially available SR20 headers on the market, even on highly modified motors. It has large primaries and merged collectors in a long runner tri-y design where cylinders 1-4 are paired with 2-3 at the collector. The collector has a 3” in diameter exit, unusually large and it’s going to take a 3” exhaust to extract the maximum power from this manifold.
|Vibrant's race catalytic converter uses a low backpressure 100 cell metal core. The metal core is thinner than ceramic cores and has less frontal area for lower backpressure. The cat's stainless steel case is also profiled for good flow. We used this cat so we would not be a gross emitter. We also fabricated a test pipe for tuning and track use. This cat is not street legal on late model OBDII cars and may not be legal in all states.
Thursday, October 06, 2011 7:39 AM
Wow, very nice looking. What cat converter do you recommend on an SR20DET that needs to pass emissions? I'm guessing the Vibrant CC won't cut it?
Thursday, October 06, 2011 8:28 AM
That's a really clean 1 off exhaust install. I'd like to hear a sound clip of it.
Thursday, October 06, 2011 9:06 AM
8695 just run the stock cat to pass! Honestly project 200SX made 252 WHP and 219 WTQ through a stock cat and the car passed the tailpipe sniffer and scanner. The OEM Nissan's cats are not horrible designs that work great on mild builds. If you are so inclined you can simply use a test pipe in it's place that has rotating flanges and a bung for the O2 sensor. This is what we did for track purposes....
Thursday, October 06, 2011 10:08 AM
Yep, OEM cats are generally the best from an emissions standpoint. My SE-R gained 15whp (235whp to 250whp) on a T25 @ 12psi (IIRC, been YEARS) running a 2.5" test pipe in place of the stock cat. Not horrible, but meaningful. I ended up running an aftermarket one on the street to save my stock cat for emissions time.
If your cat's getting tired, George Peters taught me the restrictor plate trick: cut out a "flange" to match the stock setup out of 1/8" steel (for easier cutting, you could use 16g), except with a 1/2" hole in it instead of 2.5". Power sucks, and it sounds like an asthma-suffering harmonica player, but works. Usually need to cut back timing to the bottom of the threshold (13*) to cut back on NOx from the higher combustion temps. Don't floor it, btw. ;-p
Martin, did you re-coat your underbody? Looks CHERRY!
Thursday, October 06, 2011 10:35 AM
since the idea was a quiet N/A 3" exhaust can we get a video showing a SPL meter thru the rev range please,
Thursday, October 06, 2011 10:57 AM
I built my 3" exhaust with all of the components above.
The muffler is loud. You will need a resonator if you don't want to get the attention of the 5-oh.
The only thing that ISN'T top quality is those stainless steel hangers. The grade of stainless material that was used is low, resulting in unwanted oxidization.
Thursday, October 06, 2011 11:34 AM
Rockwood, that is a great idea! I just pulled my cat to replace my downpipe and it was starting to blow out. I've been fighting the sniffer since I bought my car (I even replaced the cat when I bought it) and I have been at my wits end trying to figure out how to get through the sniffer. Anyone else got any ideas to help me out? I've tried throwing a bit of rubbing alcohol in the gas and that helped.
Thursday, October 06, 2011 12:04 PM
The rest depend on your results. High NOx means too much timing or failing EGR (really high). High HC usually means bad O2 sensor, or the injector seals are dying/dead (if you've got side-feeds, that is), or some other rich mixture contributor. High HC and NOx is dead cat.
Thursday, October 06, 2011 1:40 PM
LOVE Ernie's welds! Does anyone know if Vibrant's resonators are based off frequency or purely decibel cancellation? Anyone else see why I'd be then wondering about the 2 resonators?
Thursday, October 06, 2011 1:55 PM
@SkullWorks - I'll try to post a sound clip next week.
For being a 3" exhaust on a N/A car - it's quiet! Thanks to the smaller cam on the VE, idle and partial throttle cruising has that pleasing low toned sound we're all looking for. This SE-R is my daily driver and I've put on a few thousand miles since the install and I'm very pleased. I've even driven by a few cops without a single look! But as good as all this quiet talk is, post 6,000rpm @ WOT = shit grinning good times!
@Rockwood = Hell no! That was the nice coating of 5w/30 I had done when I custom ventilated the block ;)
Thursday, October 06, 2011 3:07 PM
Damn! Couldn't have done a better job if you had tried! :)
Thursday, October 06, 2011 3:21 PM
Those resonators look nice, but I think they're too big to fit side-by-side on a car with dual exhaust.
Thursday, October 06, 2011 5:45 PM
Nice write up. I will be awaiting the sound clip also.
How is ground clearance, does anything hang lower than the crossmember? How much space between the resonators and the floor pan?
Thursday, October 06, 2011 8:46 PM
skullworks, do you happen to have a DB meter since your shop is close? Derbruce, these mufflers are absorption type, chambered mufflers are cancellation type. awd, the hangers are a lower grade of stainless so they are easier to bend, it is hard to find stainless hangers.
Thursday, October 06, 2011 9:31 PM
how do the Vibrant SS mufflers compare with the straight through magnaflow/flowmaster SS models in terms of sound/quality? Magnaflows and flowmasters are easy to get pretty cheaply online but i'm not sure about Vibrant.
Thursday, October 06, 2011 10:38 PM
Mike - Thanks for the downlow on the absorption info. I know you're jam packed this weekend and I'll be rooting for you guys!
Friday, October 07, 2011 12:14 AM
They sound like a Magnaflow but maybe silence a little better. Magnaflows work real well too. Flowmasters are dated designs and actually kill power a lot as well as silence poorly.
Friday, October 07, 2011 3:29 AM
I wish I knew someone who could fabricate an exhaust that nice locally! Comparing Flowmaster to anything is a bad idea....ebay mufflers sound better than Flowmasters, on the bright side they usually sound better than cherry bombs...especially on 4.6s.
Friday, October 07, 2011 8:32 AM
For a car with off the shelf performance exhausts available, roughly how much more would a custom exhaust like this cost?
Friday, October 07, 2011 11:13 AM
That is by far the most badass exhaust system for a SE-R ever. Dang Martin! I think that exhaust is worth more than the whole car! hahahaha :P
Saturday, October 08, 2011 12:43 AM
How did you fit 2 of those vibrant resonators under the B13? did you have to pound away at the tunnel? I know one will make it quiet but 2 and a cat must be really quiet.
Saturday, October 08, 2011 1:35 PM
Looks awesome! I need to make a mid-pipe for my Celica Alltrac, lol. My old B13 had a crappy muffler shop exhaust, which sounded decent, but didn't give it any extra power, ha ha.
Sunday, October 09, 2011 6:48 AM
Stainless Steel is the Best.
I hope I can make it to my BMW e34 540i 1994.
CAn you Help me with sugestions?
Tuesday, October 11, 2011 9:07 PM
This is close to my setup, same vibrant muffler with 1 resonator, test pipe and OBX header. Sounds really nice. I have an in car video and a video outside the car fe the rear sway bar on sr20-forum if anyone wnts to get a general idea on sound.
System looks awesom here, I used mild steel and me and a friend welded it up and are no pros haha.
Thursday, October 13, 2011 6:48 PM
Quick SS welding tips: 1. Try no to use solar flux on intake pipes. It tends to harden and flake off on the inside of the pipe if you don't clean it out.
2. The best coloring on a SS weld is a salmon / pinkish color. If it looks dull and not shiny, you put too much heat into the work piece.
3. The coloring on the SS is actually oxidation. If you want even better rust-less performance, use a wire brush to remove the coloring. It doesn't look as cool, but your weld will last longer.
Saturday, October 15, 2011 1:48 AM
Hey Martin, do you have a pic of your 20V header? The little bit I can see in the pic with the ceramic coating looks great! I've got a 20V header, and a secondary someone made for it, but it is NO WHERE nearly as nice as what you've got! Are you running the factory heat shield? Let me know if you've got that pic.. and hey to the old school SE-R guys out there..
Monday, October 17, 2011 8:02 AM
Whut up Tackleberry!
Monday, October 17, 2011 5:54 PM
Mike, sorry I forgot to check back on this thread, Yeah I have a SPL meter, you can bring the car by or let me know and I can bring it by.
Monday, October 17, 2011 7:51 PM
Monday, October 17, 2011 11:39 PM
I have a SPL meter, have had it for years..but I live in AZ..so that won't help much. :) Hey Rockster..
Saturday, November 05, 2011 4:55 PM
I was just on Vibrant's site, I've been looking for some 100cell metal cats for my VW R32 Turbo.. the ones on their site are 200cell. Is the 100 cell on you used different?
Thursday, November 10, 2011 8:03 AM
Grunt asked a great question that I didn't see an answer to.
Did you have to modify the exhaust tunnel in any way to make those ovals fit?
There is a discussion going on over at the SR20-Forum.com right now about those resonators and a lot of people aren't sure if they will fit very well without banging around in the tunnel. Maybe one of you guys would like to chime in over there?
Thursday, November 10, 2011 10:28 AM
Not my car, but I've been around it more than I'd like to be (sorry holmes), and I remember there were some initial rattling issues that were resolved pretty easily. I don't think they needed to break out any "tools of persuasion" to fix it, just shifting the parts a little...
Thursday, January 05, 2012 1:06 PM
Any chance there's a video of this exhaust someplace?
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