2climbbig

Here is a picture of my last mustang...

zhuskers1

UPDATE -I just finished a 3 hour road trip. All driving 65 to 75MPH. My gas mileage was 21.9 MPG. Prior to installing venturi to my dual exhaust system yielded between 17 to 18 MPG on the highway.

RedneckJeep

Yeah. Me. I've been at it over thirty years. But they ain't havin the old school argument, so I just shut up about it.

RA070424

Hypothetically, if you increased backpressure, would that move the torque curve even lower?

What's the best way to get dual exhaust with losing backpressure?

JPop

I would be old school as well.

The primary difference from those days is that bigger was better for the exhaust systems and it was hard to get anyone to bend 3" pipe. Not that 3" pipe would have been beneficial, but we saw big improvements with 2.5" pipe that was good up to around 500hp. If we would have been able to find someone to bend the bigger pipe we would have been up against the same things we are up against today, reduced exhaust velocity and less cylinder scavenging.

With my Chevelle I went from a 2.5" exhaust to a 3" and the results were an increase in mph and a drop in ET for a 1/4 mile. After a great deal of time trying to tune for the increase in exhaust size I just couldn't get very far with 60' times nor ET. The eventual solution was just increasing the engine power with higher ratio rockers and a beefier cam. Along the way I found out just how much was already figured out with exhaust flow by the 70s, just that I was operating under the guise that bigger was better.

As for headers of unequal length there are some great advantages to them. Tubes of different lengths will produce peak performance at different rpm ranges, whereas equal length tubes produce more power at a specified rpm. Lots of short circle track racers will run unequal length headers because they have a broad range of rpm they need to make power with. That's certainly not the same as drag racing or other motor sports where you aren't lifting much or hitting the brakes.

SnakeskinJeep

So what you guys are saying is for maximum power benefits you should get a single exit exhaust?

zhuskers1

If your preference is a dual system, get a dual system.......I would just plan on spending and extra $24 with Borla to get a Venturi and have it installed when you have your dual system installed.

zhuskers1

That is one awesome looking mustang!

JPop

2.5" single exhaust,

1.75" dual exhaust or something that is going to increase exhaust gas velocity with any larger exits.

2climbbig

I am not as familiar with the new chip sets, but I would call those companies and ask them if their chips can take advantage of the reduced back preasure. If the answer is yes... then get the dual exhausts. If the answer is then just get the flow master or other nice muffler.

If you really want dual exhausts, then Jpop is right... go with the 1.75.

As for my mustang...Thanks! I really hated selling her but she went to a good home