Dual Exhaust Idea
- Thread starter Rennat
- Start date
if youre going to run a cat, id forgo the mufflers. a cat serves as quite an effective noise supression device.
perhaps a couple magnaflows would work as a straight thru muffler... better than bullets/resonators. if you do side exits, go for some resonated tips. they actually can make a difference.
perhaps a couple magnaflows would work as a straight thru muffler... better than bullets/resonators. if you do side exits, go for some resonated tips. they actually can make a difference.
cat. what? Just kidding. I'd make it true dual exhaust, so I'd need 2 of everything if I did put cats and mufflers in. That only place the exhaust would merge would be at the X directly after the first 2 collectors(cyl. 1-3 merge into one, 4-6 into the other) on the header, in hopes that the exhaust scavenging effect would work correctly.
I thought about making my own manifold, and have 3 cylinders merge into a 2.5'' pipe... but then i was like wait... thats a lot of work. haha.
and thank you for those pictures, it looks good.
Thats the other thing im worried about... is the room... but, i was just going to buy the mufflers and then start figuring it out, because its hard to measure without the real stuff...
And would a 3'' cat, and those 2 magnaflow mufflers be quiet enough on an N/A? I know i could always just add another muffler... but i would rather only do this once... Now i have to go and think some more about this... all these ideas just all rushing in my head... haha.
And do you scrape a lot with those dual pipes?
and thank you for those pictures, it looks good.
Thats the other thing im worried about... is the room... but, i was just going to buy the mufflers and then start figuring it out, because its hard to measure without the real stuff...
And would a 3'' cat, and those 2 magnaflow mufflers be quiet enough on an N/A? I know i could always just add another muffler... but i would rather only do this once... Now i have to go and think some more about this... all these ideas just all rushing in my head... haha.
And do you scrape a lot with those dual pipes?
If you are going to buy the parts first, just make sure you have the bill handy so you can return them if they arn't going to fit the way you want.
with the one magnaflow (3" in dual 3" out) i have and the 2 18" long vibrant resonators, my 1JZ is pretty quiet, but still sounds great.
i doubt you would be able to do a big muffler and resonators as long as mine if you had it exit before the rear wheels, but there is probably other options.
my system only really scrapes on the muffler. I knew this would happen before the system was fabbed up. This is why it has the little bash guard on the front of the muffler to stop it from getting hooked on things. with the flex section its nothing i worry about, and even though i am quite low it only really scrapes on large speed bumps.
If you are going 3" on an N/A with straight through mufflers it will still be a little on the loud side id guess, but how loud exactly and weather or not you can live with it i cannot say.
best i can do is give my opinion and wish ya luck. Besides if it's too loud on an N/A, just turbo your car
with the one magnaflow (3" in dual 3" out) i have and the 2 18" long vibrant resonators, my 1JZ is pretty quiet, but still sounds great.
i doubt you would be able to do a big muffler and resonators as long as mine if you had it exit before the rear wheels, but there is probably other options.
my system only really scrapes on the muffler. I knew this would happen before the system was fabbed up. This is why it has the little bash guard on the front of the muffler to stop it from getting hooked on things. with the flex section its nothing i worry about, and even though i am quite low it only really scrapes on large speed bumps.
If you are going 3" on an N/A with straight through mufflers it will still be a little on the loud side id guess, but how loud exactly and weather or not you can live with it i cannot say.
best i can do is give my opinion and wish ya luck. Besides if it's too loud on an N/A, just turbo your car
Im only doing 2.5'', no need for 3''.
So my cat, and the two magnaflows should be ok im guessing then....
And do you have a cat? it doesnt look like it... and i know that does a lot for sound... im debating on the cat, might just make a test pipe to replace when i want to try it out...
So my cat, and the two magnaflows should be ok im guessing then....
And do you have a cat? it doesnt look like it... and i know that does a lot for sound... im debating on the cat, might just make a test pipe to replace when i want to try it out...
Rennat said:
I thought about doing this... Since I have separate manifolds and downpipes for each turbo. My downpipes terminate right at the bottom of the transmission and I could run a dual exhaust back from there to whatever mufflers I felt like using.
if youre going to run a pair of mufflers, youll wanna do it in the driveshaft tunnel area, most likely after the tranny. it depends on how big of a diameter they are. id say, run the cat/test pipe right on the collector of the header. itll work the best and make the most room for the rest of the exhaust. so then youd wanna make a mid pipe after the cat, and feed it into a Y-pipe and try to stick the mufflers right to the Y pipe, If possible. that might not be possible since the outlets might be too close to eachother. in which case, youll need to make an pair of S bends out of four 45* bends and weld them up. if the S doesnt space apart far enough, you might have to add sections of straight tubing between the the 45* bends. run your mufflers of course and weld on your dumps or 90* bends for side exits.
if you want to run dumps, make sure youd ont weld them pointing straight down. rotate them so they point out to the sides of the car at about a 45* angle to the ground. this will reduce the amount of exhaust noise bouncing off the road and reverberating inside your car. ought to help reduce droning too. if you run side exits, youll have to add hangers to support the ends of the pipes. just weld them to the forward subframe brace plates. i spot welded hangers onto mine. still goin strong.
i almost never scrape unless im turning into an up-hill driveway too fast. if i turn at a normal speed, i dont scrape. i clear speed bumps and speed tables and whatnot. but im mostly at stock ride height. things will change when i lower it.
if you want to run dumps, make sure youd ont weld them pointing straight down. rotate them so they point out to the sides of the car at about a 45* angle to the ground. this will reduce the amount of exhaust noise bouncing off the road and reverberating inside your car. ought to help reduce droning too. if you run side exits, youll have to add hangers to support the ends of the pipes. just weld them to the forward subframe brace plates. i spot welded hangers onto mine. still goin strong.
i almost never scrape unless im turning into an up-hill driveway too fast. if i turn at a normal speed, i dont scrape. i clear speed bumps and speed tables and whatnot. but im mostly at stock ride height. things will change when i lower it.
I think im going to stick with my somewhat original idea of the 2 mufflers, with the turndown tips... and i guess i'll use that y-pipe... and a cat, and then the police can bug me, smog isnt due until 2009, so im good there, and hopefully its not too loud...
and i found all the pieces i need on ebay with free shipping!!! hahaha
and if i have to, i'll go to the muffler shop and have him bend me an s-bend... i dont need the minute difference of the mandrel vs. crush.
and i found all the pieces i need on ebay with free shipping!!! hahaha
and if i have to, i'll go to the muffler shop and have him bend me an s-bend... i dont need the minute difference of the mandrel vs. crush.
Rennat said:
what is this catalytic converter you speak of? :sarcasm:
not sure how you are going to run the two magnaflow's under the car, my vote would be for the way i think you have it planned: Magnaflow => vibrant super quiet resonator => ypipe => resonated tips
if all else fails throw more resonators at the problem!
flubyux2 said:i have no muffler on my car, thats just a Dr.Gas Y-pipe. i think its one of the best y-pipes ive ever seen and exactly what i wanted. for air flow systems like this, which have velocities UNDER the speed of sound, you want it to split via a round edge. having a sharp edge like a merge collector that has been reversed will create alot of turbulence. the round edges that my Y pipe has creates a high pressure wedge at the divider.
i would highly recommend against running dumps under the car. the resonance will be horrible and make driving the car a pain in the ears. it tends to be a big thing amongst mustang owners and LS1-equipped cars. my friends FD RX7 has an LS1 with Long tubes, bullets, an X pipe and dumps; its ridiculously loud inside. of course, my car is loud but only w/ the windows rolled down. it quiets down alot when i roll the windows up.
i think for the most efficient exhaust, id get a Y pipe like mine and run two individual mufflers. i dont beleive single in-dual out mufflers have a very efficient divider. i think your best bet is to have a straight-thru style muffler as long as its large enough to provide some semblance of sound suppression.
btw, if i do another MK3, ill be replicating the GpA exhaust... amongst other things
Louder is better, for me. I can handle the noise of the exhaust for long periods of time. As for the law, in my area, they have bigger fish to fry.
I changed from a 97Db 3" PITA noisy system to my duals that are 88Db and picked up 20ish rwhp but the HUGE improvement came in the midrange (430rwhp@4500) with everything happening 1000rpm earlier.
Keep in mind that IJ's not running a N/A.... a weak GE will have to work a bit harder to push the rapidly cooling/thickening exhaust out of the piping. The only reason why I imagine that a setup like this wouldn't cause a definite power loss is that right after you slow your exhaust gasses to the point that they would have a difficult time evacuating the system you increase the volume the system can accommodate.
Dumping the system under the car, one of the lowest pressure points may offer benefits while driving at a given velocity (see: scavenging). However, you also need to keep in mind that even in the case of small exhaust leaks enough toxic gas can enter the vehicle at highway speeds to render a driver unconscious during extended driving... make sure everything is well sealed (that means it needs to be MUCH tighter than it was new)! Headaches and drowsiness are the first things you'll want to watch out for.
Well, good luck with it, it'll at least look interesting.
Dumping the system under the car, one of the lowest pressure points may offer benefits while driving at a given velocity (see: scavenging). However, you also need to keep in mind that even in the case of small exhaust leaks enough toxic gas can enter the vehicle at highway speeds to render a driver unconscious during extended driving... make sure everything is well sealed (that means it needs to be MUCH tighter than it was new)! Headaches and drowsiness are the first things you'll want to watch out for.
Well, good luck with it, it'll at least look interesting.
CRE, i didnt quite understand that first paragraph... mind simplyfying it a little? haha.
I ran a somewhat open exhaust... i just left the gaskets off the cat... and they are so warped it sprays exhaust all over, and i loved the way it sounded... sometimes... haha. but i know what you mean by the gas smell... I dont mind it, and i know i wont pass out... thats also why i want the exhaust more towards the back, so that way its not bothering me...
I ran a somewhat open exhaust... i just left the gaskets off the cat... and they are so warped it sprays exhaust all over, and i loved the way it sounded... sometimes... haha. but i know what you mean by the gas smell... I dont mind it, and i know i wont pass out... thats also why i want the exhaust more towards the back, so that way its not bothering me...
The gas smell isn't the problem.... it's the thinner gasses which you don't smell that you have to worry about and they DO get in your car VERY easily. I tore my muffler off last winter, kept getting headaches and dizzy spells and some issues with fatigue.... I figured it was the noise. I didn't talk to my doctor about it until after I had already got my new exhaust installed, but he said it was far more likely CO poisoning. The guy at the muffler shop was the one who suggested i go to see my doctor right away, but I didn't go until a week later. Apparently it's rather common for people to get poisoned this way because they don't realize how the air flows and that CO separates from the rest of the gasses easily. So, put simply.... don't be an idiot. That shit goes through plywoodand drywall, you really think 20 year old floor drain plugs, dried weater stripping and access panel seals are going to keep it out?
Of course this will vary from one car to the next and also depending upon a TON of different factors, but why chance it? In my case my exhaust was exiting the piping further back than you suggest.
As for the first part.... you've got more reading to do. Sorry, but I don't have time to spell it all out right now.
Of course this will vary from one car to the next and also depending upon a TON of different factors, but why chance it? In my case my exhaust was exiting the piping further back than you suggest.
As for the first part.... you've got more reading to do. Sorry, but I don't have time to spell it all out right now.
I didnt know that about exhaust... i knew the stuff coming out was bad, and even worse if you didnt have a cat... Ill be sure to tell my friend about that though, his eclipse has a whole exhaust the size of an arm... it ends right after the oil pan...
And thats why i want the exhaust AT LEAST beyond the rear diff... but i'll go experiment and see.
I guess i'll go read up on exhaust flow and flow rates and such...
My GE isnt that weak... i mean i at least rebuilt it! haha.
And would a little dyno tuning help me out any?
I know later down the road i want to put some cams in it, just for some more overall power... and i know then i'll want to get them degreed, and dyno tuned for sure... but thats after christmas... (i plan to keep my N/A with the way gas prices are going here in CA)
And thats why i want the exhaust AT LEAST beyond the rear diff... but i'll go experiment and see.
I guess i'll go read up on exhaust flow and flow rates and such...
My GE isnt that weak... i mean i at least rebuilt it! haha.
And would a little dyno tuning help me out any?
I know later down the road i want to put some cams in it, just for some more overall power... and i know then i'll want to get them degreed, and dyno tuned for sure... but thats after christmas... (i plan to keep my N/A with the way gas prices are going here in CA)