Project KiMaFo Thunda...

[BigElCat]

custom Festiva exhaust in the works.

I'll start with a short back story.

I pulled Festus out of the JY about 4 years ago. It needed quite a bit of work, but ran really well. The exhaust system from the cat back was hanging off, so I just removed it.

I drove for about a month with the cat dumping into the exhaust tunnel. It was loud, with an awful tone. I had a muffler shop put a custom 2" pipe from the cat out the back in the stock location. This exhaust pipe cut my performance down considerably. The power reduction is not just 'in my head', I can feel the difference in the seat of my pants. I was hoping for a speed boost, and I was seriously disappointed.

My project is a side exhaust. The prototype outlet will go here.

[BigElCat]

I'm thinking that I might be able to eliminate almost all the back pressure from behind the cat.

It is a 7" by 1" rectangle.

[BigElCat]

Here's some pics of the transition.

I work for a place that does pnuematic conveyance; industrial air flow.

We would call this part a "round to rectangular 90 degree offset transition".

[BigElCat]

This is looking down the 2" OD tube, as the exhaust flow will hit the diverter.
The front diverter spoon protrudes and occupies a guesstimated 3% of the cross sectional area of the 2" tube, the second spoon enters into about 17% of the exhaust flow and is partially shielded by the first spoon.



The back wall will catch most of the exhaust flow, and cause it to back up toward the diverter spoons. This is because the exhaust flow doesn't want to change direction until it forced to by the on-coming flow.

[Grey Vw]

Those curves:eeeeeek:

[BigElCat]

But look at the area volume increase, instant low pressure area. I'm more worried about the decrease in velocity, and pushing a large volume of gas.

It may turn out to be an automotive Albatross. If so, I'll 'Face palm Kitty' and keep up my Hillbilly Banter. Or pull a Dickmeyer, and disappear.:p I was really into his B3. He should have just posted the dyno figures.

I hope he comes back, at least to tell me to kiss off. (I'm just playing)

[Powerstiva]

How is this exaust working for you? And would I maybe be able to get one?