Dual FD exhaust Pic request
10-27-09, 04:38 PM
#7
Well as she sits right now as a stripped down rolling chassis. So now is the time for me to be asking these questions. Wouldn't the fuel cell add noise to the interior, and have to be welded into the chassis? Guess I'll need pics of that too. 20B streetcar for those who want to know. Just going for something radically different.
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10-29-09, 01:32 AM
#15
what's broken this time
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10-29-09, 09:35 AM
#18
"Dual exhaust isn't good for anything except show. It's just extra weight, and extra space being taken up."
I don't agree. Two 2 1/2" pipes will flow more than one 3" pipe. Two pipes would allow two cats and two mufflers, reducing emissions, noise and back pressure.
I don't agree. Two 2 1/2" pipes will flow more than one 3" pipe. Two pipes would allow two cats and two mufflers, reducing emissions, noise and back pressure.
10-29-09, 09:46 AM
#19
Mike, I think you have proven my point on the weight and space issue. Regarding you're back pressure point, more back pressure is created by the muffler and cats than the diameter of the pipes. If pipe diameter was that big an issue, a single 4" pipe could be used.
10-29-09, 09:58 AM
#20
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Too large a diameter causes the flow to slow down which creates extra backpressure, there is an ideal exhaust diameter. Also, the T section that splits the exhaust needs to be propperly engineered or it will also create a lot of backpressure.
I'm not saying that it can't be done but I don't see any specific advantage to be gained.
Otherwise it's just a matter of opinion, personaly I think dual exhausts belong on cars with a lengthwise mounted V engine. Think musclecars and VQ powered Nissans.
I'm not saying that it can't be done but I don't see any specific advantage to be gained.
Otherwise it's just a matter of opinion, personaly I think dual exhausts belong on cars with a lengthwise mounted V engine. Think musclecars and VQ powered Nissans.
10-29-09, 10:10 AM
#21
"Regarding you're back pressure point, more back pressure is created by the muffler and cats than the diameter of the pipes. If pipe diameter was that big an issue, a single 4" pipe could be used. "
All true, but if you split the exhaust in two, each cat and muffler must handle half as much exhaust as a single pipe. I believe I've read posts here from guys who have 4" exhaust experience even more noise. I'd like my car to be quiet...think Porsche...but it seems that can't be done without sacrificing too much HP.
All true, but if you split the exhaust in two, each cat and muffler must handle half as much exhaust as a single pipe. I believe I've read posts here from guys who have 4" exhaust experience even more noise. I'd like my car to be quiet...think Porsche...but it seems that can't be done without sacrificing too much HP.
10-29-09, 10:38 AM
#23
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Part of that can be explained by the fact that performance isn't the only factor in a design, esthetics are also important.
Case in point: the Honda S2000, inline 4cylinder, but it has a dual exhaust because it just looks sportier and more symetrical. But most aftermarket exhausts for that car are single.
Case in point: the Honda S2000, inline 4cylinder, but it has a dual exhaust because it just looks sportier and more symetrical. But most aftermarket exhausts for that car are single.
10-29-09, 10:51 AM
#24
I'll throw this out. I have a single turbo FC and my friend whom I share a garage with has an FD with stock twins. Both are running straight pipes (no resonator or cat) back to a 3" Racing Beat catback (FD has dual tip). I know they're not the same setups, but my FC is noticeably quieter than the FD at idle and lower speeds. Up top it's hard to compare because I have an external wastegate rerouted into the downpipe (which changes the exhaust note) versus the stock twin setup on the FD.
I think the dual exhaust allows more noise suppression at a given level of flow, but you add additional weight. I ran the RB duals on my FC because the FC has dual exhaust from the factory and I think they don't look right with a single exhaust. It's still a 400+rwhp car so I'm not sweating the weight. I really like the look of the RB dual tip on the FD's though.
I think the dual exhaust allows more noise suppression at a given level of flow, but you add additional weight. I ran the RB duals on my FC because the FC has dual exhaust from the factory and I think they don't look right with a single exhaust. It's still a 400+rwhp car so I'm not sweating the weight. I really like the look of the RB dual tip on the FD's though.
10-29-09, 01:08 PM
#25
The only advantage is noise suppression and looks. Ignoring those 2 things, the amount of weight you add is not worth the gain unless a 4" exhaust isn't big enough for you? And even then if you can fit anything bigger then 4" under there, you could do the same at the muffler so I really don't see a point except for the 2 mentioned reasons. And if your setup is already radical enough to need that big of an exhaust, its probably some track/drag car, so why not just dump it out the side fender/door saving yourself that entire path and weight.
The exhaust theory where velocity will slow down does not matter on a turbo car. The bigger your pipe after the turbo the better in ALL power related cases.
thewird
The exhaust theory where velocity will slow down does not matter on a turbo car. The bigger your pipe after the turbo the better in ALL power related cases.
thewird