How many have "dual exhaust" on theirs?

[johnboneske]

I dont disagree, Sometimes you need back pressure, it's amazing how many people open up their cars/trucks, and loose power. I dont think my truck is hurting, since the cats are still on it and it is a Single in/Dual out system.

 

[Canadian Expy]

I have true duals 2.5" S.S. headers back to 2 new magna flow cats then dual in dual out magna muffler with chrome tips. i like the sound and still think the back pressure is there. I don't feel I lost power.

 

[Lightnig]

are you asking about dual exhausts or dual exits?

IMHO, it's an aesthetic only thing to have dual exit (single pipe split into a dual) so have never bothered myself.

I am planning to be upgrading to a full dual once I get energetic and actually go buy a new welder...

 

[hwy73]

are you asking about dual exhausts or dual exits?

IMHO, it's an aesthetic only thing to have dual exit (single pipe split into a dual) so have never bothered myself.I am planning to be upgrading to a full dual once I get energetic and actually go buy a new welder...

Agreed. Aesthetic and maybe psychological. Although with tailpipes exiting to each side, exhaust sound is projected to each side of the vehicle.

 

[GAINMOB]

so I was home in Michigan and they wanted $400 for 40 series duals...single in dual out...might as well get it here

 

[Thermo]

i have done a lot of research into what works for our trucks. If you are looking at a true dual setup (ie, dual pipes all the way from the motor till it exits), then you want to stop at 2.5" pipes. Yes, you can go bigger and net more power, but it is also at the cost of low end torque. This is where you have to decide how much time you spend at say 2,000 RPM in relation to 4,000 RPM. Also keep in mind that depending on how many cats your truck came with (some came with 2, others with 4) and also the series muffler you are running (very restrictive, semi restrictive, free flowing), this can also affect how much power you are going to get out. So, a simple straight forward "this is the ideal setup" is not realistic.

Now, with all that being said, I have a true dual setup on Nukie which is a 2.5" pipe setup, no cross over pipe, running into a Flowmaster 70 series DI/DO muffler. By no means is it one of those systems that will catch your attention due to the rumble it makes. But then, I built the exhaust system around making maximum low end torque. The way that I use my truck, I need that 1,500 RPM grunt, not the 5,000 RPM scream. But to each their own.

Please keep in mind that when you supercharging/turboing a motor, a lot of the exhaust stuff that I mentioned goes out the window as you now have other factors playing into it.

 

[GAINMOB]

thx thermo...I want that rumble and I don't think I go past 3k rpm and that's hitting the gas...im more reserved and trying to be seen and heard with my bass at times...but I want to be heard when I pull off at a stop sign or light...so im saving up $500 to do 40 series with cat back duals...i'll attack again when I get the supercharger...last thing for truck so that's years down the road unless I will a lawsuit or lottery

 

[toms89]

Velocity is what your looking for!!! Not back pressure to maintain low end torque.

Exhaust needs to be properly sized to maintain velocity. Too large and the velocity will drop which reduces the scavanging effect. This also allows the exhaust gasses to cool more and slow which then become more dense and harder to expel.

The higher the velocity and heat you can maintain in the exhaust without increasing back pressure the more power and torque you will make. The volume of the exhaust changes with rpms obviously so it is a compromise.

If you do a quick search online you can find recommended diameters of exhaust depending on your hp level. Stock expys should fall between 2.25 -2.5" for dual exhaust or 3" for single.

Now if you have significant cam overlap between intake and exhaust valve timing a small amount of back pressure can help prevent prevent the fuel mix from getting sucked right out the exhaust at low rpms. But this overlap is rare on any production vehicle because it is not emissions friendly. And its a non-issue with a stock expy.

 

[BakerEdition]

can you get a tail pipe on the left side of the a Gen-1 with out having to move the spare to another location?

 

[hwy73]

Yes.