"TRUE" dual exhaust - Performance Forum

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"TRUE" dual exhaust
Saturday, December 03, 2005 10:45 AM
I have a 95 cavalier 2200. I like the look of dual exhaust, but Ive heard alot that its for looks, adds weight, sounds vary from ok to weak, etc.... My question is, is it totally crazy to have a "true" dual exhaust starting with the header?

U know, 2 down pipes, 2 cats, 2 catbacks.

I realize this would add alotta weight, but with a modified engine, say pushing 200hp would that make a considerable performance difference being "scavenging" would be more efficient due to less exhaust restriction ( 2 cylinders breathing out through 1 pipe instead of 4 cylinders breathing through 1 pipe ).

BTW, I hope I got this right, scavenging is when 1 cylinder finishes its exhaust stroke, the vacuum created by the exiting gases in that header sucks out the next cylinders exhaust gases resulting in a quicker clearing of the cylinder for the next stroke.

Lemme know what u guys think.

Re: "TRUE" dual exhaust
Saturday, December 03, 2005 11:59 AM
True dual exhaust would have headers, we only have a header, so you cant do it.

I guess if you wanted to spend alot of money tou could custom make your own manifold that only uses to exhuast ports and run that to a cat and so on, then repeat step for other two exhasut ports.



Re: "TRUE" dual exhaust
Saturday, December 03, 2005 12:57 PM
wonder how that would sound? I love the sound of a 6v with true duels






Re: "TRUE" dual exhaust
Saturday, December 03, 2005 1:12 PM
Yea, I was assumin people would no that part about the header, but what about one header at the cylinder head, and instead of all four pipes into 1 collector, 2 pipes - 1 collector, 2 pipes - 1 collector, so in essence a header with 2 collectors, but of course thats, like u said nasty, a custom fab.

But would this make a considerable difference in performance on a modified 4 cylinder? about 200hp?
Re: "TRUE" dual exhaust
Saturday, December 03, 2005 1:16 PM
In order to maintain adequate exhaust velocity, the exhaust pipes could only be like 1" in diameter
I don't believe you would get any gain over a proper 4-2-1 exhaust. Definately not enough to dismiss the effect of the added weight.



fortune cookie say:
better a delay than a disaster.
Re: "TRUE" dual exhaust
Saturday, December 03, 2005 1:40 PM
I concur with OHV Notec


Is it still speeding if the speedometer dosen't work???
Re: "TRUE" dual exhaust
Saturday, December 03, 2005 3:01 PM
I looked into this and talked to the place that built me an exhaust and they said it would work but not worth it... and they werent too sure if it would sound good or not... as i was just going to put a "Y" the the end of my header and have 2 pipes all the way back...


Its up to you i guess. it would bee kind of neet to see it done, and i kind of wish i would have done it but oh well...



The First Twin Charged jbody
blue car (R.I.P) - 240whp @7psi..
silver car - 305whp 315lbs.tq @15psi (91 Octane) or 420whp & 425lbs.TQ @20psi (94 octane+Alcohol Injection)
All dynos run on a Mustang dyno
Re: "TRUE" dual exhaust
Saturday, December 03, 2005 3:30 PM
Speaking of the dual exhaust, the 2003 Sunfire and 2004 Sunfires have a dual exhaust option. I haven't seen any 2005 Sunfires with dual pipes, only with one chrome tip. Did they do away with it?

Also, are there 2 small mufflers on the 2003-2004 Sunfires, or is there just one muffler with a split tip? I like the way it looks on the Sunfire, but wonder if that cross pipe will eventually rust out or is the exhaust pipe all stainless steel?

"...nevermind maneuvers lieutenant, just go straight at them!"
-Admiral Nelson at the Battle of Trafalgar

Re: "TRUE" dual exhaust
Saturday, December 03, 2005 11:54 PM
Blue Shark wrote:Speaking of the dual exhaust, the 2003 Sunfire and 2004 Sunfires have a dual exhaust option. I haven't seen any 2005 Sunfires with dual pipes, only with one chrome tip. Did they do away with it?

Also, are there 2 small mufflers on the 2003-2004 Sunfires, or is there just one muffler with a split tip? I like the way it looks on the Sunfire, but wonder if that cross pipe will eventually rust out or is the exhaust pipe all stainless steel?


I believe the 2005 has the option as well.

As far as how the duals are designed, there are 2 mufflers that are connected to a Y-Pipe which splits from the single piping coming from the catalytic converter. What you're talkinga bout with 1 muffler with split tips, people who have that on their j-body do it custom and it was immitated from Camaros (hence being called Camaro style dual exhaust).

Back to the original topic, even if someone did make a "true" dual exhaust by splitting the header, it would be pointless. Like OHV notec said, they would be very small each way and there wouldn't be enough velocity and more than likely you would lose lots of power from trying to attempt this. This is also why you don't see 4 cylinder cars with Twin Turbos, it's much more efficient to work with all 4 exhaust ports than splitting the ports (2 by 2) pushing exhaust out.



www.kronosperformance.com / 732-742-8837

Re: "TRUE" dual exhaust
Sunday, December 04, 2005 9:19 AM
dont know if you guys knew this or not..but the old quad engines some came with a "duel" header(had 2 collectors) and we all try to avoid it..i mean its a good concept and all but it sounds like crap and the gains are crap..at least from the ones ive seen


FACT : Statistics show that you are more likely to to be hit by lightning than to die street racing.


Re: "TRUE" dual exhaust
Sunday, December 04, 2005 9:29 AM
did not know that, are there any pics of that ??? but agreed not worth it




Re:
Sunday, December 04, 2005 9:42 AM
Quote:

I realize this would add alotta weight, but with a modified engine, say pushing 200hp would that make a considerable performance difference being "scavenging" would be more efficient due to less exhaust restriction ( 2 cylinders breathing out through 1 pipe instead of 4 cylinders breathing through 1 pipe ).


do you know how scavenging works? I don't think you do.. sorry to rain on your parade

The exhaust pulse in front helps pull the next exhaust pulse out of the car, etc etc

if you have the engine split into 2 cylinders its going to do a :
pulse - pause - pulse - pause
or even worse
pulse - pulse - pause - pause

It'll make scavenging not work anymore. In fact, the car will probably be choked up and lose performance if anything.

Its the same as having 3" pipe on a n/a car. There's this thing called exhaust gas velocity and its one of the key factors in good scavenging.

a well designed header will make more power everytime

V6s and V8s "true dual" works because they have two banks of exhaust ports (duh), but besides that, they have more cylinders. Which means that there is no pause in their exhaust pulses. Inline engines (especially 4 cylinders)are not meant to have 'true' dual exhaust.

And I'm not saying that as a derogitory statement, I'm saying it because there's only 4 cycles to the combustion process, and we only have 4 cylinders. So everytime there's 1 cycle going on, therefore there's only 1 pulse coming at a time. A split header design would work like crap because of that. Any pause in the exhaust pulse will literally take the exhaust flow to a stand still until the next cylinder fires.

So now instead of the exhaust pulling the next exhaust pulse out, one pulse goes into the pipe then waits for the next one to PUSH it out. It should cause a pretty substantial LOSS in performance

if you screw around with dumb crap like this, 200hp is a completely unrealistic goal especially with an OHV.

You can do 200hp without a doubt, but not with this exhaust system. There's a reason you don't hear about it much and why no one's done it. It doesn't work, and its rice.

plus, you'll be adding about 80lbs worth of piping to your car that has no place to mount to. Ground clearance will be drastically reduced, and I don't think you'll be able to find a place for the passenger side pipe to clear the rear exhaust.

It will be a mess under the car, it'll look and sound like crap, and it won't yield any performance.

Just get a regular cat back system or if you're looking for the dual look still get the magnaflow dual exhaust it splits with a y-pipe but gets the dual look.

I got it and it was pretty sweet for a while, but i'm tired of it I'm completely redoing my exhaust from front to rear





Re:
Sunday, December 04, 2005 9:51 AM
I love you TheFlyingSquirrel (PJ)




Re:
Sunday, December 04, 2005 9:53 AM






Re:
Sunday, December 04, 2005 2:57 PM
The dual Magnaflows sound awesome, but if and only if the engine is totally warmed up.
Re:
Monday, December 05, 2005 7:33 AM
Hey im new but ill tell you that the split dual exhaust wont be worth it my cuz has the twin exhaust not true and it sounds sweet off a 2.2 sunfire just dont forget to put your intake on it first or it will sound like a ricer
Re:
Monday, December 05, 2005 9:58 AM
Thanx guys, especially FlyingSquirrel, hey dont worry bout raining on me, a little water is refreshing and informative in this case! See, I knew about the "pulse" effect u spoke of (but I prolly couldve worded it better), but I DIDNT know about the exhaust velocity issue, nor did i take into account the "pause" that would occur from a split header.

Thanx for clearing that up. Glad that u guys answered.

OHV Notec, (hhuhuhuhh hhuhuhuhh, he said notec, hhuhuhuhh) u mentioned a 4-2-1 header, which from what I understand is better than a 4-1. The only thiing is I havent seen one for the 95 2200, only the 96 & up 2.4 twin cam.
Re:
Monday, December 05, 2005 10:16 AM
York sir wrote:OHV Notec, (hhuhuhuhh hhuhuhuhh, he said notec, hhuhuhuhh) u mentioned a 4-2-1 header, which from what I understand is better than a 4-1. The only thiing is I havent seen one for the 95 2200, only the 96 & up 2.4 twin cam.
Wow, all kinds of mistakes there...where to start...
First, background. Around here 90-97 LN2 = '2.2L' whereas 98-02 LN2 = '2200'
Therefore, there is no 2200 in 95. You'll confuse people if you go around referring to your engine like that
Second, there is no 'better' (as Event would gladly point out), only different. The 4-1 header may give you more hp, but move your powerband higher up. The 4-2-1 will give better midrange power (more useable on a daily driver in mosts' opinion).
Now, I believe the pacesetter sitting in my garage is a 4-2-1 (LN2 header), but I could be mistaken...(I've never used it and it's kind of crammed in a corner, so I can't picture it)
Also, headers can be interchanged between all years of LN2s with minimal drawbacks.



fortune cookie say:
better a delay than a disaster.
Re:
Monday, December 05, 2005 2:38 PM
LOL, this is funny, first lemme thank u for that OHV. I was referring to my engine as a 2.2l up until a post on here where someone told me in the suspension forum that if I said 2.2l, people would think I was talkin about the ecotec but hey, 2.2l is what it says in the haynes manual so thats what ima go wit.

This may be stretchin this post a bit, what is a 2.4L considered? LN(?) and is a 2.4l header interchangable w/ a 2.2l?
Re:
Monday, December 05, 2005 3:01 PM
2.4 is a LD9 i believe



Re:
Monday, December 05, 2005 4:37 PM
^^^^ Correct


1997 Sunfire
WAI
pacesetter header
Underdrive pulley = STILL SLOW.
50 shot of NX

Re:
Monday, December 05, 2005 4:39 PM
yeah, 2.4 is an LD9, ECO is an L61, and I'm sure someone else could tell you what the 2.3s were if you were interested. An eco is an ECO, although we now have to reference 2.2LECO/2.0LECO/2.4LECO. 99% of the people on this board will see 2.2L and think LN2, and that's the way it should be That guy must be all kinds of confused...good thing he's in the suspension forum
And no, the headers are not interchangeable, as the exhaust manifolds use different bolt spacings, port sizes, and they're on opposite sides of the engine



fortune cookie say:
better a delay than a disaster.
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