My Stealth Dual Exhaust

I finally couldn't stand it anymore and decided to open up my LGT exhaust. I also didn't want to fork over the big bucks on a high end system. So, after reading and re-reading many of the other posts, I decided to have a custom system done by a muffler shop.

 

I wanted a relatively quiet daily driver(especially after driving my WRX-see below)...nothing too loud or "visible" (audible") by the db police, but I also wanted the performance of a straight though exhaust.

 

I started with a GPMoto equal length header (sounds odd, but makes power). Then I added my TXS 4" DP and HFC from my '03 WRX.

 

Next, after deleting the resonator, I tried to run the stock mufflers...no good, with the EL header, it sounded like a bumble bee on steroids.

 

So, I went to Kenny's Muffler in Cypress, CA. Had them build a 3" catback:

12" resonator, then a "y" that splits to a 3" in/out Magnaflow straight thru muffler on the driver's side and a 3" NON-Muffled tailpipe with a 3" electric cutout inline on the passenger side.

 

For normal day to day driving, I keep the cutout closed and all of the exhaust runs thru the muffler and exits the driver's side tailpipe (like an STi). If I want some extra noise (power?), then all I do is hit the switch and open the cutout, and unmuffled exhaust flows from the passenger side too.

 

Sound is still mitigated by the HFC and the 12" resonator, but it does get quite a bit louder. I wanted to bypass the HFC and resonator, but there isn't enough room for 2-3" tubes to clear the rear suspension comfortably, so the "Y" is after the HFC and resonator.

 

On my WRX, I had a custom built 3" catless system with one 18" resonator, and 2x12" straight thru mufflers (looked almost stock, except for size)...the electric cutout had 8-1/4" holes drilled in the flapper valve and was placed in-line...when the cutout was in the flow position, it registered slightly over 110db at 4350 rpm. With the cutout in the closed position, it registered only 95 db at 4350rpm. But, power was severly limited. I only closed it when there was a chance of being heard by a cop. With the LGT, I didn't want to worry all the time, so I went the other way... loud(er) when I wanted it and semi-quiet normally with no power loss.

 

If I had used the stock header or a similar non-EL header, it would sound really awesome...the EL really kills the pulses. But, it runs great and sounds OK, so I'm done with it for a while. Visually, from the back, it all looks stock!

Awesome!

 

That's the type of exhaust setup I've been wanting to run for years, even before I knew electric cutoffs actually existed.

Did the muffler shop stock the cutoff or did you have to buy it seperately? I'm going to be getting a custom built setup as well (always do, much cheaper) and it would be pretty nice to go this route. Sometimes I really do want my car to be quiet (hauling around in-laws) and othertimes I want to hear it!

sound clips pls! :tia:

Very interesting set up! Do you plan to put your car on a dyno? Very curious to see how your exhaust performs open Vs closed.

thats pretty cool.. I like the cutout idea for the 2nd exhuast outlet.

wouldn't it make more sense to put the cutout at the 'y'? Also, why no mandrel bender?

With 3" pipe I would have thought it would not have enough clearance around the swaybar and/or ground clearance issues. Is that maganflow muffler tucked up underneath, or is it visible from the side?

 

I don't think with the 3" size pipe you have, the non mandrel bends aren't an issue.

 

I know you mentioned you didn't want to spend $$$ for a system, but with that piping,resonator, muffler, tips, & elec. cutout, I would have thought you equaled what a few exhausts are selling for?

 

Any other pics? Wouldn't mind hearing some audio clips too.

yea why is the cutout way at the end? it should be at the Y right? now all the exhaust flows back there and just gets stopped at the end by the cutout.

 

It would be great to hear soundclips.

 

Oh... and I have the GP Moto EL headers as well... with a PDE bellmouth DP and stock CBE. Exhaust sounds good, but hard to hear over the engine!

I don't think with the 3" size pipe you have, the non mandrel bends aren't an issue.

 

Agreed w/ brother edmundu - unless it's a big-power setup upstream, I also don't think that the non-mandrel bends are going to be an issue, given that the piping is 3" diameter.

 

I know you mentioned you didn't want to spend $$$ for a system, but with that piping,resonator, muffler, tips, & elec. cutout, I would have thought you equaled what a few exhausts are selling for?

 

Agreed. I know that for me, I ended up quite a bit above my budget for my system. Probably would have saved quite a few hundreds of dollars just going off-the-shelf with a complete system, but I know that getting the "sound" right was going to be problematic.

 

Looks good.

 

Add me to the list of guys who want to hear this thing.

 

As well as being curious as to what this setup would provide in terms of gains on the dyno. I know that brother team23jordan saw virtually no gains between an open and closed cut-out on his 3" diameter custom exhaust setup...wonder if this would be different.

While my new Stage I.V HTG Hog-Zaust system is very exciting to me, I would be interested in sound clips and what the cost was...

you have to see things right... Every Subaru boxer 4-cyl sounds weird.. the Equal length setups sound right

Thanks to all for your comments...let me clarify some issues, in no apparent order.

-No mandrel bends 1) cost, and 2) I really felt the curves weren't going to be too radical, 3) 3" tubing

-Y location...yes I wanted it closer to the DP, but the space issues of running two 3" tubes under the rear suspension was too tight. In my next system, I will try to address that, maybe with oval tubing.

-Cost was $400 and 2.5 hours...my real exhaust guy with the mandrel bender is two days and $????. I already had the cutout from my WRX system...It's from DMH, and it's bulletproof! >$200 - I know overall real cost is high, but I have something different and kind of trick.

-As for cutout location...I wanted to reduce heat load/exposure to the elements on the cutout motor, and the cavity for the stock muffler seemed like a clean location from an aesthetic standpoint too.

-From the rear and side, everything is hidden...tucked up nicely underneath the body. After I snapped the shot, I painted everything flat black to further hide anything that might standout. Car is lowered on Progress springs. To the uninitiated, it looks totally stock!

-EL header-what can I say? I've always liked the GPMoto header for power and I'm getting used to the sound. The car on AP stage 2 CA91 feels really strong.

-Butt Dyno likes the new muffler...hard to say with the cutout open if there is anymore power, but it gets LOUDER. The next local dyno day, I'll be there. Despite what some of my friends think, I'm on a severe budget and I have to rationalize every expenditure, so I need to find cheap dyno time in order for it to make sense.

 

I know there are many opinions and other/better ideas...this is my first pass at making one of my ideas a reality on the LGT. My WRX system was truly badass and sounded really sweet...perfect for a WRX. For the LGT, I had three different designs in mind, mainly for a quiet type system with low restriction and this was the easiest and most practical to do within my cost/time budget. Do I want mandrel bent tubing? Of course! Do I want the Y before the HFC, duh! Is there space for everthing I want...we'll see.

 

If I go for a bigger turbo (AVO450, FMIC, 3.5" APS DP), then V.2 will have to be built...until then, this will have to do.

 

I'll try to post pics and sound clips at a later date...I'm not too good at this posting stuff (too old and slow to learn), so please bear with me. For those local to SoCal, in the OC or Long Beach area, I'm always available to meet and demo!

 

-SRX

thanks for the info SRX.....creative thinking for sure. BTW - who's the chica in your avatar??

thanks for the info SRX.....creative thinking for sure. BTW - who's the chica in your avatar??

 

Thanks.

 

As for my avatar, her name is Jada and she's a model (former Miss Bikini Houston)...she works with me:icon_mrgr !

 

-SRX

Is it possible to put a large high flowing muffler before the Y-pipe? Would this help at all? Seems like it would be easier than using two mufflers, but don't know if it would be good / bad, or if it would even fit.

thanks for the info SRX.....creative thinking for sure.

 

Agreed! And definitely unique as well.

 

Looks well thought-out and absolutely honest. Bravo!

 

Agreed! And definitely unique as well.

 

Looks well thought-out and absolutely honest. Bravo!

 

 

Hey thanks for the kudos! I'm just trying to have fun! Like I tell my wife, buying parts and modding are cheaper than me having a girlfriend:lol: !

^

 

I'll definitely have to remember, as well as liberally employ, that line!

 

Like I said, this is great stuff, bro. Very creative, and it definitely looks like a good way to solve your stated set of problems. Again, bravo!

Is it possible to put a large high flowing muffler before the Y-pipe? Would this help at all? Seems like it would be easier than using two mufflers, but don't know if it would be good / bad, or if it would even fit.

 

This idea was one of my other plans...use a single-3" in/2-3" out Magnaflow (it should fit) instead of a "Y" with no cutout...or the same muffler with a cutout right after the HFC and a straight pipe outlet ending right after the axle...or some variation. The concern was space for 3-3" pipes!

 

The reason I have a resonator is to try to mitigate the EL header sound when coupled with the straight thru Magnaflow, versus a slightly more restrictive 2-chamber muffler, which would be more sound-friendly to the EL Header.

$400 for the piping and work? That's not too bad, I'd hope to have a similar cost at my local shop, but they have a mandral bender. I'm anticipating more like $500 for a 3" dual muffler setup, but I've never had to have them make a Y pipe before (or dual exhaust at all) so it's hard to anticipate the price... and if they recognize me, it will probably be cheaper. Last time I went in they gave me a pretty serious discount since I'm a (many time) repeat customer

$400 for the piping and work? That's not too bad, I'd hope to have a similar cost at my local shop, but they have a mandral bender. I'm anticipating more like $500 for a 3" dual muffler setup, but I've never had to have them make a Y pipe before (or dual exhaust at all) so it's hard to anticipate the price... and if they recognize me, it will probably be cheaper. Last time I went in they gave me a pretty serious discount since I'm a (many time) repeat customer

 

-Remember, it's only one muffler! It's basically a STi system with a twist. The muffler shop "Y" is a pretty simple deal...they do them all the time. Good luck!

I know, it's the mufflers I'm afraid of, Typically they charge about $150 a piece, so I figured $300 at least in mufflers alone.

 

Unless I can get myself an electric cutoff like that for cheap. I really do like your setup!

Is it possible to put a large high flowing muffler before the Y-pipe? Would this help at all? Seems like it would be easier than using two mufflers, but don't know if it would be good / bad, or if it would even fit.

 

 

ya i've been toying with the idea of placing a dynomax bullet on the midpipe and removing my 14827 magnaflows.... and tuck some nice tips under the bumper...

Awesome setup, is there anyway you could post up more pics of the underside and what it looks like when the car's on the ground?

Stay Tuned...I'll put it on the rack this weekend (time permitting) and take some more shots, as well as some on the street pics. Also, I will try to get some sound clips, both opened and closed.

I have a cheapie dB meter and I'll get some readings too.

 

 

I've been driving to/from work (mainly freeway) with the cutout OPEN for the past week:icon_mrgr. It's pretty loud, but if I back off, it gets pretty quiet. With it closed, it's really quiet at freeway speeds. I'm getting used to the EL header sound...still sounds like large displacement Civic when I'm on it.

 

-SRX