exhaust idea need help.

[spanky]

ive been thinking of doing a whole exhaust system header back. i already know how to weld(tig,mig,oxy asc) from colision class in school. i wanted to make a 4-2(y pipes) and run a dual exhaust. into two flex,res, and into two cans (super ricey sound). im not sure about cats b/c i work at a dealership and i can get inspection stickers w/o taking the emissions test. but i was wondering if i would need a resonator. because it's only two cylinders instead of 4. while runing the pipe to the back i'd have the pipes right next to eachother. also does anyone know where i can get a header flange for my engine a20 carb. thanx spanky

[A20A1]

I grinded down my A20 flange... all the 86-89 accords use the same exhaust flange.


It's not the best and could use some porting but I didn't mind using it since I didn't have to pay for a custom one.

Well if you want to reduce the ricey sound then get some resonators.
Without resonators and 2 pipes into 1 you may sound a lot more like a motor cycle.

What kind of specs do you plan for your header?
I used 1-5/8" primaries on mine.

What size pipes are you running to the mufflers?

WeirRacing can make a flange for you, and so can Stainlessworks



I would suggest having an "X" pipe connect the single pipes together then split them back up again.

Place the "X" pipe where you would normally merge a 4-2-1 header into a single pipe or possibly 66" from the exhaust ports.





I'm thinking it should broaden the powerband, help scavenging, and perhaps increase low end torque and throttle response.

I would pick an X-PIPE over an H-PIPE, an H-PIPE is changing the exhaust flow 90*.

Also linking the two pipes will reduce the noise of your exhaust system, if they are seperated you're more likely to hear the firing of the cylinders and it will give you a more motorcycle like sound. If thats what you want then don't add and X-pipe. Personally I would perfer to have a broader power band then a neat sounding exhaust.

Why would you do the X idea? Wouldnt that cause too much exhaust collision? Remember that having 2 cylinders going into 1 pipe will cause you to have low velocity, so for those (1,3 and 2,4) shouldnt be much bigger than 1.25" piping I think... Myabe 1.5 but thats pushing it

If the header primaries used are 1.625" then the secondaries should be the same or larger. I think max you should go is 1.75" after the "Y" "Y" which are technically the secondaries then connect the pipes to a "X" and from there 1.75" pipes to the mufflers.

Only problem I see is finding where to place the "X" and where to find one that is 1.75" in and out and 1.75" inlet mufflers.

If worse comes to worse you may have to make your own "X"
The design of many X-Pipes use 45* bends or 90* bends mated together in the middle.

The "X" pipes Magnaflow sells and most others I've seen only go down to 2.25"


There is no easy way around using duals, you'll be sacrificing a lot for the look you want. I'm trying to provide the best info I can to my knowledge so that your duals have the least negative impact... minus hanging a decoy muffler from the other half of the car.

Here is a flex joint
1.75" Stainless Flex Joint

Other options


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[FyreDaug]

Why would you do the X idea? Wouldnt that cause too much exhaust collision? Remember that having 2 cylinders going into 1 pipe will cause you to have low velocity, so for those (1,3 and 2,4) shouldnt be much bigger than 1.25" piping I think... Myabe 1.5 but thats pushing it

[88accordhatchdx]

I have an idea, how about you go high flow cat and 2.25" piping with a nice muffler and leave the duals to engines that can handle them.
Something like this would be good: https://www.3geez.com/showthread.php?t=37908

Sorry, don't mean to attack but I hate ricey duals, their such a waste of money.

[5spdaccordlxi]

ive been thinking of doing a whole exhaust system header back. i already know how to weld(tig,mig,oxy asc) from colision class in school. i wanted to make a 4-2(y pipes) and run a dual exhaust. into two flex,res, and into two cans (super ricey sound). im not sure about cats b/c i work at a dealership and i can get inspection stickers w/o taking the emissions test. but i was wondering if i would need a resonator. because it's only two cylinders instead of 4. while runing the pipe to the back i'd have the pipes right next to eachother. also does anyone know where i can get a header flange for my engine a20 carb. thanx spanky

you will have so much flow with this system that you wont even be able to operate the car without always diving at at least 4000rpm. I just have a headersback system without a cat or resonator and just a super turbo mufller with 2.25 piping and i cant even drive my car under 3000rpm. It sucks really bad. I'm putting my cat back on and a resonator. It also sounds like tertrible raspy riced angry hornet shit.

[A20A1]

I have an idea, how about you go high flow cat and 2.25" piping with a nice muffler and leave the duals to engines that can handle them.
Something like this would be good: https://www.3geez.com/showthread.php?t=37908

Sorry, don't mean to attack but I hate ricey duals, their such a waste of money.

Well if he's building the entire exhaust system on his own, I don't see any rice in that no matter what he chooses to do.
Sure it might not net the most gains over a single pipe system, but if you're going to go duals and do it the best way you can so you get the most out of the look and performance, then why not. There is no reason a smaller displacement motor can't handle duals, you just have to size the piping right.

[88accordhatchdx]

you will have so much flow with this system that you wont even be able to operate the car without always diving at at least 4000rpm. I just have a headersback system without a cat or resonator and just a super turbo mufller with 2.25 piping and i cant even drive my car under 3000rpm. It sucks really bad. I'm putting my cat back on and a resonator. It also sounds like tertrible raspy riced angry hornet shit.

My point exactly

[88accordhatchdx]

Well if he's building the entire exhaust system on his own, I don't see any rice in that no matter what he chooses to do.
Sure it might not net the most gains over a single pipe system, but if you're going to go duals and do it the best way you can so you get the most out of the look and performance, then why not. There is no reason a smaller displacement motor can't handle duals, you just have to size the piping right.

I mean he even he said "ricy mufflers" and "two cans", its great that hes doing the system himself that I applaud. And yes, smaller displacement engines can handle duals but would be bestest if the engine is built right so you don't have to worry so much about the piping.

[Acid X]

So does this mean that its bad for me to have 2.5" piping on my single pipe exhaust? It's not all the way back, but it goes from about half the cat-back pipe to the muffler, which is now a magnaflow.

[A20A1]

So does this mean that its bad for me to have 2.5" piping on my single pipe exhaust? It's not all the way back, but it goes from about half the cat-back pipe to the muffler, which is now a magnaflow.

You should read this and the posts above it.
https://www.3geez.com/showthread.php?p=537346#post537346

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[A20A1]

Someone had your idea... I know there were like two more with the idea as well.

4-2 Dual Exhaust 001 - MANGY

4-2 Dual Exhaust 002 - SABZ5150
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[Acid X]

Well that doesnt really answer my question. How can i figure out whether or not the piping size is good for the car or not?

[spanky]

i was thinking of going with a 1.5" pipe to a flex, High flow cat, 20"ressonator and then to the can(s). i might even just do the 4-2-1 and just have one can, im not sure.

[A20A1]

Well that doesnt really answer my question. How can i figure out whether or not the piping size is good for the car or not?

Well 2.25" is the optimum for Good Flow and Good Velocity for cars about 200 hp

• SINGLE PIPE EXHAUST SYSTEM 4-CYLINDER 1.5-2.5 liter
• -------------------------------------------------------
• 2.00" Low-Mid Range RPM N/A
• 2.25" Optimum Range RPM N/A
• 2.50" Mid-Upper Range RPM N/A / Supercharged / Nitrous Injected
• 2.75" Turbo / Supercharger
• 3.00" Turbo

[A20A1]

i was thinking of going with a 1.5" pipe to a flex, High flow cat, 20"ressonator and then to the can(s). i might even just do the 4-2-1 and just have one can, im not sure.

1.5 is good for duals, I wouldn't go any smaller then that for exhaust pipe.

So you'll build a header then split to duals or just build the header and go with single pipe?

Here is a 2.25" Build it yourself exhaust system kit
Stainless_works_kit
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[w00tw00t111]

This hasn't been said but I thought I would add it. Flowmaster makes a 1 in 2 out muffler why not use that? I mean you would have the optimum pipe set-up but then change it to 2 outlets at the very end to get the look youre wanting.

[spanky]

it's not that look im going for, i want the loud verberating noise and the cans to be sticking out of the back. i already have two mufflers i bought from ebay
http://cgi.ebay.com/ebaymotors/Unive...QQcmdZViewItem
and i think magnaflow make Oval mufflers instead of cans.(i could be wrong, i just dont fallow them)

[spanky]

k, i was just wonderin what a glasspack is,is it just another muffler? also today i went to a j/y and picked up a used header tomarrow im gonna cut the pipes off and get the flange down so i can weld the pipe when i get it from ups.

[A20A1]

Glass pack is a fiber material used to absorb sound... inside the resonator/muffler are tiny holes. Some use steel wool instead of the glass fiber. The packing material can burn out over time and the resonator/muffler will be less effective.

[w00tw00t111]

Hey a20 doesn't it amplify the sound? I remember talking to an old school hot rodder at church and he would bolt them on in the 60's b/c they would make is car loud like crazy!

[A20A1]

I suppose it could amplify sound. It depends on what and how you install it.

I know if exhaust resonates it gets louder (like passing a car with a muffler so your systems both resonate).
If you had dual pipes and didn't connect them they migh resonate with eachother and get louder... also if the tail pipe exists under the car instead of at the back of the car the sound would hit the car body and channel the sound in the car and that can make it sound louder.

You get absorbtion and maybe reflection if there are any reflective surfaces inside the tube but most Resonators are pure absorption. I believe expansion is the third element in altering exhaust tone and levels.


I have a relfection / absorption oval muffler, there are baffles inside that look more like waves on water on the floor and roof of the muffler. The waves mesh together at the side walls of the muffler. There is also many many holes in the waves.

[w00tw00t111]

I gotcha. So maybe what he meant was that he would remove every thing but throw in a glass pack to quiet a little bit but, it would stil be insanely loud.
BTW I like your new sig pic Looks pretty cool. Now you just need the real thing

[A20A1]

It's an old sig pic... I just decided to use it again.