been searching for which exhaust system i want and have come across many that look and sound great. many options so it's going to be hard to choose. one thing that will help me decide is which exhaust produces more horse power, single or dual? i like the oem muffler look and the dual exhaust systems that have the mufflers that resemble the dual tipped sedan muffler. has anyone proven if dual exhaust produces more hp than single or vice versa?

i know on 4 cyl vehicles dual exhaust can actually decrease hp in some cases because the back pressure actually helps but, since i've got a v6 i'm wondering is dual exhaust mainly for forced induction on our cars? i'm just going na on my car so would dual exhaust hurt performance?

what size exhaust do most people run. i'm guessing 2.5" would be best for dual and 3" best for single. can someone fill me in on exhausts for G's.

 

There's nothing magic about dual exhaust. W/o specs, it can make more or less.

 

Depends on the setup.
Backpressure alone is always bad. However reducing backpressure by installing a larger cat-back system, will move the scavenging effect of the exhaust system to a higher RPM, this is why you often notice a reduction in power/torque at lower RPM if you just throw in a bigger system.

I feel a properly designed single exhaust system (inc. headers/extractors) will do better than a dual system because a single system can make better use of this scavenging effect.

 

No such thing as back pressure. High exhaust velocity pure and simple.

Both single and dual can take advanttage of scavanging. Single = Y pipe. Dual = x pipe

 

It's all about creating the best compromise between volume and exhaust velocity. The OEM exhaust piping on the first gen G/Z is ~2.5 (more like 2.46"). That's decent size for an OEM system on a 3.5 liter V6. Motordyne has extensively tested exhaust tubing sizes and layouts and I believe the best compromise for all out perfomance is a 3" single system. It does trade a fractional amount of low end power (below 2500rpms). IMO, I think 2.75" would be optimal for a DD that does some racing on the side.

The reality is there isn't a whole lot of power to be found in a catback exhaust. You're looking at legit 6 to 8whp and over half of that comes from the y-pipe. You can source an OEM HR y-pipe or buy the MD y-pipe which are both good for ~5whp.

 

Dave, I think Tony found that using Y primaries at 2.5" and dumping them into a 3" single yielded the best combo of low end and top end power.

 

2.5" Y-pipe into a 3" dual produced the most (like the TDX). But it's probably only like a 1-2 hp difference from a 3" single.

 

Depends on the setup and amount of exhaust gases traveling through.. Yes at a point duals create more power but can also reduce back pressure too much if you use a too large of a diameter.

 

Way to many variables to offer up a blanket statement such as "duals are better than single"

I do like the look of two stainless tips, but HATE seeing exposed cans.

 

Yeah, I'm not a fan of exposed cans either. If you've noticed, more and more cars are coming out now with the mufflers being hidden. The 370z and I believe (g37 coupe also) changed the rear to only show tips. Much cleaner look.

 

i like the idea of the dual exhaust going into the one oem looking muffler. just wasn't sure if i should go dual or stay single. also, dunno if i wanna get hfc's first or the rest of my exhaust. only have the ichiba Y pipe now.

 

I believe the magnaflow system is dual while retaining the Oem look at the muffler.

 

yea there's the magnaflow and a few other brands i've seen. wondering which sounds the best.

 

I have kinetix hfc's and a magnaflow dual (x pipe) that dumps into one muffler. Fairly stock looking too. I love the sound, more like a 350z/g coupe than a sedan. I would definately recommend x pipe over y.