Dual exhaust on a 90 Legacy [Archive] - Subaru Legacy International

View Full Version : Dual exhaust on a 90 Legacy

=STAT!XXX=

09-02-2007, 11:02 AM

Just wanted to share some pics of the exhaust I put on my uggo wagon. It actually fit pretty well :)

http://www.thatsrightbitch.org/images/dx1.jpg

http://www.thatsrightbitch.org/images/dx2.jpg

http://www.thatsrightbitch.org/images/dx3.jpg

http://www.thatsrightbitch.org/images/dx4.jpg

ivwarrior

09-02-2007, 11:45 AM

OK, I gotta ask......WHY?

Reason

09-02-2007, 01:03 PM

Sound clip?

Sarra

09-02-2007, 06:01 PM

What kind of splitter did you use? Just a Y pipe?

Wiscon_Mark

09-03-2007, 10:20 AM

What kind of splitter did you use? Just a Y pipe?

He didn't. It's true dual exhaust.

I also have to ask why...

Sarra

09-03-2007, 07:14 PM

Your O2 sensors must hate you...

Huffer

09-03-2007, 08:20 PM

Those are some nasty welds.

Wiscon_Mark

09-04-2007, 11:09 AM

Yeah, I'm not so sure about the o2 sensor setup - Do you have both sensors on one line? Because if you start having cylinder problems on the other side, you might not know until it's too late.

Of course, having one on the left side and one on the right is even worse...

Sarra

09-05-2007, 05:14 AM

Maybe one exhaust for the front cylinders and another for the rear? I never thought dual exhaust on a 4 cylinder was a good idea from what I understand about exhaust systems. maybe on a 6 cylinder...

dodik

09-05-2007, 08:13 AM

pretty cool looking exhaust

Numbchux

09-05-2007, 03:32 PM

W00T!!!! that's awesome! https://sl-i.net/FORUM/images/imported/2007/09/bananadancegif-1.jpg

I HAVE to hear a sound clip! although I bet it could really use a pair of resonators. What mufflers did you use?

Maybe one exhaust for the front cylinders and another for the rear?

have you spent.....any....time under a subaru? ever? it doesn't work well on most 4-cyls because all 4 exhaust ports are right next to each other. well, subaru 4-cyls are not like most 4-cyls. one exhaust for each bank, just like a V6, V8, V10, etc.

also, 1990 legacy = OBD I = one 02 sensor.

my concern is back pressure. from my experience with EA-series Subaru motors, it's quite crucial to equalize the pulses from one bank to the other. I think you're setup could really benefit from a crossover. especially if you have an unequal length header before it (exhaust pulses would reach the x-over at different times).

I've been wanting to do this for a long time. ever since I saw this old picture from ultimate subaru:
https://sl-i.net/FORUM/images/imported/2007/09/duelexh-1.jpg

that's on an EA81, and obviously the "crossover" is not an ideal design, but that was my inspiration nonetheless.

my research and plotting continued, and I used a picture of a borla header, to photoshop this:
https://sl-i.net/FORUM/images/imported/2007/09/concept1-1.jpg

add a pair of resonators, and a pair of mufflers (maybe Thrush Glasspacks), and enjoy!

Sarra

09-06-2007, 02:39 AM

W00T!!!! that's awesome! https://sl-i.net/FORUM/images/imported/2007/09/bananadancegif-1.jpg

I HAVE to hear a sound clip! although I bet it could really use a pair of resonators. What mufflers did you use?

Maybe one exhaust for the front cylinders and another for the rear?

have you spent.....any....time under a subaru? ever? it doesn't work well on most 4-cyls because all 4 exhaust ports are right next to each other. well, subaru 4-cyls are not like most 4-cyls. one exhaust for each bank, just like a V6, V8, V10, etc.

also, 1990 legacy = OBD I = one 02 sensor.

my concern is back pressure. from my experience with EA-series Subaru motors, it's quite crucial to equalize the pulses from one bank to the other. I think you're setup could really benefit from a crossover. especially if you have an unequal length header before it (exhaust pulses would reach the x-over at different times).

I've been wanting to do this for a long time. ever since I saw this old picture from ultimate subaru:
[3mg]http://i26.photobucket.com/albums/c108/Numbchux/duelexh.jpg[/img]

that's on an EA81, and obviously the "crossover" is not an ideal design, but that was my inspiration nonetheless.

my research and plotting continued, and I used a picture of a borla header, to photoshop this:
[3mg]http://i26.photobucket.com/albums/c108/Numbchux/concept-1.jpg[/img]

add a pair of resonators, and a pair of mufflers (maybe Thrush Glasspacks), and enjoy!

LOL I know about the ODBI having a single O2. But, if you're doing a true dual exhaust, won't your single O2 sensor be getting half the signal it should? And what if you have an issue with one cylinder being hotter than the others? What would throw a code wouldn't... I could see it working if you put the sensor in an xover, but I don't see one...

The "Maybe front/rear exhausts" was a joke. Though, now I'm tempted to do it just for the ability to say I did... Hey, I have a car with an EA82... Eh, it's a turbo motor though.

Numbchux

09-06-2007, 01:50 PM

LOL I know about the ODBI having a single O2. But, if you're doing a true dual exhaust, won't your single O2 sensor be getting half the signal it should? And what if you have an issue with one cylinder being hotter than the others? What would throw a code wouldn't... I could see it working if you put the sensor in an xover, but I don't see one...

the 02 sensor measures the air/fuel ratio. if only 2 cylinders are feeding that tube, it'll have half the air, and half the fuel. meaning the ratio will remain unchanged.

don't know why one cylinder would be hotter than the others. but temperature won't effect anything, certainly won't throw a code.

and EA82ts make good boat anchors. total junk otherwise.

ivwarrior

09-06-2007, 10:30 PM

the 02 sensor measures the air/fuel ratio. if only 2 cylinders are feeding that tube, it'll have half the air, and half the fuel. meaning the ratio will remain unchanged.

don't know why one cylinder would be hotter than the others. but temperature won't effect anything, certainly won't throw a code.

and EA82ts make good boat anchors. total junk otherwise.

_IF_ all 4 cylinders are operating properly. If, however, one of the cylinders on the side not being monitored is misfiring, or is running lean, or whatever, you're not going to notice the problem in the O2 sensor readings and the ECM won't be able to attempt to adjust to correct for the problem.

Wiscon_Mark

09-07-2007, 12:06 AM

Numbchux

09-07-2007, 12:42 AM

Sarra

09-07-2007, 03:17 AM

_IF_ all 4 cylinders are operating properly. If, however, one of the cylinders on the side not being monitored is misfiring, or is running lean, or whatever, you're not going to notice the problem in the O2 sensor readings and the ECM won't be able to attempt to adjust to correct for the problem.

most definitely. but it won't cause problems. and it's a 22e.....they're tough, and cheap and easy to fix.

mine....will have the 02 in the xover.

That's the way V8 and V6 people do it with dual exhausts.

As for the EA82 being an awesome anchor, that it is. I'm gonna toss an EJ series 1.8 liter motor in and turbo it, a 2.2 liter engine and turbo it, or a TT 13B.

Jedi Taxi

09-07-2007, 08:47 AM

Sarra

09-08-2007, 02:17 AM

Reason

09-08-2007, 07:26 AM

be different, toss 20bTT motor in there, watch it fry the gear box back to hell. true dual bad ass-ness!

....and now you can get that awesome green pea taste with your meal!! MMMmmm, grenn peaness!!.....wait....thats not right..

If it gets a 13B or 20B, it's getting an STi 6 speed or RWD.

Noob question what is a 13B and 20B. And why would you put a tranny into a car that it's 4 times the value of the car??? :shock:

Jedi Taxi

09-08-2007, 09:52 AM

now for another small book that no one will read by jedi taxi

nah, dont worry about it reason, its a WANKEL thing. the 13b is a interesting accident in performance. i'll explain it, basicallt, due to a design inefficiency, in the rotor cycle, there is a small amount of time where the air and fuel coming in end up going straight to the exhaust ports without going throught the engine cycles. Now i know this sounds bad, but here is how crazy CRAZY people have turned it into an advantage. putting a turbo on it. when this happened, it forced more air through that small window of error turning it from a window of error into a window of oppertunity. Basically, with the boost being shoved down its throat, that small amount of pressurized air/ fuel is shoved through that window, when this happens you get an effect that is sooo much fun.

fresh air/fuel+flame from the exhaust already coming this way(all of which being directed directly to the exhaust port, to the turbo) = having a small jet engine to give you boost!

now how's that for a slice of fried gold?

running turbos that are nearly the size of the engine! AWESOME!!

anyways, that explains why these engines are kewl, but not what they are
-13b mazda rotory engine
-most common ones in the USA came in two forms, one a N/A 6 intake port 13b, the other a 4 port intake port turboed. most 13b guys get the N/A and turbo it because i has more intake port
-the 13b is a 1.3L rotary engine
-rotary engines are kewl because they weight very little, put out great power and use a greater amount of fuel. great racing engine.
-in other contries (CANADA) got varients that had the little 1.3L rotary engine that had twin turbos, and also a 2.0L variant that had 3 different rotars instead of the 1.3L's two rotors, even more power, after that, the 2.0L variant got twin turboed and was a performance king amongst any engine, and due to the technology of today, with the twin turbo variant rotaries, they nearly tuned out the flaw of sucking down sooo much gas.
-amongst the rotary guys, the new renesis engine is good as a daily driver engine because mazda designed out the old flaw that allowed the "JET ENGINE BLOWER"
-well, basically, in comparison to other N/A rotary engines, the renisis is the best with power, fuel economy, and weight.

Jedi Taxi

09-08-2007, 10:05 AM

oh, and for what its worth, he doesn't have to have a X pipe, he just das to weld in a pipe perpendicular to the two pipes to connect them together and put the O2 sensor in there. learn a trick from the fox body 5.0L guys, the H pipe. or he can just use a lambda variable ohm heated gas desnsity sensor off a desiel, it'll send the same type of signal to the computer. Still, i would cut off the shitty pipes, and at least put on some kewl pipe tips on there, just to show how bad ass that exhaust is.

I WANT A SOUUUND CLIIIP OF THIS!!!

(wet dream come true.)

this and some custom made ITB's set at a proper runner length would make a KILLER set up!

UGH! this makes me want to buy a BD legacy just so i could do that set up. BUT NOOO i have too many damn project and loo little money to do that right now! :(

first off, getting my shitty avenger/eclipse to stop leaking oil. i might just swap in a DOHC 2.4L just so that it wont be pissing oil when it drives. they did put out 150 hp and 167ft/lbs.

second, fixing up the porsche 944 i have.

Sarra

09-08-2007, 07:22 PM

I'd probably put a 13B in it, and either convert it to single turbo with the 6 port, or tune it. If I get one that's in good shape, I'll leave it alone, otherwise, it's getting ceramic rotors, housings, and apex seals.

The Rotary engines have an advantage over piston engines. You get more power per revolution, since the exhaust gasses are driven out of the rotating chamber before the chamber goes all the way around. It's like, a 1 1/3rd cycle engine instead of a 4 cycle.

What most likely will happen is, I'll get an STI block and gearbox for my Legacy, the NA motor and gearbox from my legacy will go in the Loyale, and I'll stick a supercharger on the Ej25D, after supporting mods. Complete rebuild with a supercharger.

AJM

09-08-2007, 08:59 PM

Rotaries have an advantage until you start talking about thing like realibility, gas mileage....and the fact thye sound like weed wackers on speed.

Sarra

09-09-2007, 01:34 AM

The NA rotaries actually are more reliable than you think. 12A and NA 13B motors tend to not need anything at all for a long time, and can last 300k miles. The turbo motors tend to have issues, blowing out seals and such. Ceramic rotors, housings, and seals eliminates that. This is going to be a fun car, not a daily driver.

grayguy

09-09-2007, 01:48 PM

We really need a sound clip of this exhaust!

And as far as RX-7's go, LS2 + 6spd tranny is definetly the way to go.

Sarra

09-09-2007, 06:11 PM

We really need a sound clip of this exhaust!

And as far as RX-7's go, LS2 + 6spd tranny is definetly the way to go.

I don't think I could fit an LS2 nor a 6 speed in my Loyale.

ivwarrior

09-09-2007, 07:23 PM

Anything possible with enough $$$ and fab skills. :grin:

StatGSR

09-09-2007, 09:35 PM

https://sl-i.net/FORUM/images/imported/2007/09/Motivator_Rotary-1.jpg

Jedi Taxi

09-09-2007, 10:15 PM

Yar... and Thar be a pic of a renisis motor thar..

too true about the weed whacker sound, also too true about the awesome reliablility of a N/A rotary. the part that i wrote about "the window of oppertunity" is awesome for power, and is also a great way to overwork (via heat cycles) the apex seals. other than that though, you have to run some serious boost (or lack of worth while oil managment) to bust more than an apex seal in the engine.

Sarra

09-10-2007, 01:33 AM

If I do an NA Rotary, then I'll make it silent. Cats, resonator, and mufflers. If it gets something more performancy, like an EJ20, 13B or 20B turbo, V6 turbo, V8, or anything more powerful than that, it's going to have straight pipes with cats, because I can't stand the smell of not having cats. It'll get a true dual exhaust, too.

I still want a sound clip of =STAT!XXX='s car. :p

=STAT!XXX=

09-14-2007, 12:23 AM

Wow lots of replies! The why is because I needed exhaust and thought I might as well do something interesting, and yeah it looks a bit like a$$, so does the rest of the car, so it fits in nicely :) I'll get a sound clip up ASAP! LOL

Numbchux

10-05-2007, 02:18 AM

I'll get a sound clip up ASAP! LOL

bump

SammyDaFish

10-25-2007, 02:31 PM

I dunno where all this talk of rotaries came from, but I wanna hear the sound clip of this thing too

oh, and those welds aren't bad at all for pipes that don't fit together well, I've made many a project out of spare/scrap pipes, trust me, you do what works. :)

SPR

10-25-2007, 04:07 PM

thats gotta be the worst exhaust system ive ever seen LOL no offence or anything haha. but i do wanna hear it. i at very least woulda put some better mufflers/tips on lol.

Numbchux

11-03-2007, 01:22 AM

thats gotta be the worst exhaust system ive ever seen LOL no offence or anything haha. but i do wanna hear it. i at very least woulda put some better mufflers/tips on lol.

yes, because what really matters in an exhaust system is what the tips look like :roll:

I'm not letting this thread die until a video/audio clip is posted!!

Jedi Taxi

11-04-2007, 07:37 PM

Tis a good thread. but i would like some thread in a different color. mabye a nice light red, but not pink. ( just a lame joke)

So even though its not the best design, i do think its pretty bad ass. I just wish we could get that sound clip. I'm not cretiquing or putting down the design, though if i were to do it, i would use borla's universal 5" round muffler, and place them farther upstream. Either that or two glass packs if you could find them for the small piping.

Numbchux

12-10-2007, 05:42 AM

time for another bump!!

Numbchux

03-13-2008, 07:29 AM

http://tekbone.homestead.com/files/bump.jpg

httrdd

11-06-2009, 05:15 PM

OHHH I guess I can bump this!

02_Legacy

11-08-2009, 09:41 PM

Can anyone see the pics in the first post? I can't but I want to see the set up so bad. LOL

4n70n1n0

11-10-2009, 11:00 PM

so someone else has gone and done it before me :-?

I want to do dual exhaust on a 1st gen just for the hell of it, but I would only do it cat back, I have a few ideas on how to accomplish such task :grin:

BUMP for sound clip and re-up of the old pics of the exhaust

:smt023