4 into 2 exhaust

[geno58]

Has any one ever put a 4 into 2 exhaust out the back? In other words, taken the two pipe down pipe and cut the collector off, and ran two pipes and two mufflers out the back. Just curious, if there was any gains in performance, and how it might sound.

[So Cal Mark]

you would lose scavenging effect by running two pipes to the rear

[fiat218]

you would lose scavenging effect by running two pipes to the rear

What does that mean?

[So Cal Mark]

it means less power and torque

[fiat218]

it means less power and torque

Ok thanks

[RRoller123]

I think it has something to do with the pressure waves that build up in the exhaust (and intake too) that help the flow of air through. Think of a "slinky" spring toy, with a low pressure wave at the time when the cylinder gets purged. The same reason why a car with a muffler that has fallen off has so little power and just limps along. I think this is it anyway. Someone with way more knowledge than I can comment.

[fiat218]

so what is being said ,meaning you can not split the pipes and have dual exhaust versus single ?
only because there only one manifold ,

[Tobi]

Your cylinders discharge in the order 1342. If you use two exhaust it is going to be 1 4 and 3 2 and "where" is the air coming from to fill the gap that now is in between (1 and 4) and (3 and 2) to give it a flow?!

[BEEK]

the previous exhaust pulse actually created a vacuum behind it, which helps pull the next pulse out of the engine (scavenging effect) then when the 2 pipes come into 1 larger pipe the same event occurs. lengths and diameters will change the characteristics of the torque and hp curve , it could also kill power if done wrong

[carl]

If the real issue is to have a dual exhaust look at the back of the car, have a splitter installed after the single pipe hops over the axle. This is the way most cars on the road effect a "dual exhaust" look.

carl

[geno58]

No, its not the look, I like to DIY, and I like to have what no one else or very few people have.
Or perhaps that unique sound. But if there is no benifit or would hurt performance, then no interest.
There are other vehicles out there that use 4into2 headers, so my mind gets to working.

[131]

No, its not the look, I like to DIY, and I like to have what no one else or very few people have.

Do it, and supercharge it, then scavenging is less of an issue. You'll also have something that no one else has.

[geno58]

Now that sounds like a plan, LOL.