• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Fiesta ST Forum and Fiesta ST community dedicated to Fiesta ST owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the Fiesta ST Forum today!


Beastwood's quarter-wave resonator calculator (google docs)

Clint Beastwood

2000 Post Club
Messages
2,599
Likes
2,344
Location
Laguna beach
#1
Feel free to check it out and hit me back here with questions/comments. My use-case for this was my FiST and a V8 audi; I have not tested extensively with every car/exhaust combination, so I am not sure how something like a v8 with true duals and an x-pipe would be calculated (pulses per rpm -> frequency), but if you get the frequency via a spectrum analyzer the rest of the sheet works fine. Please copy the calculator to your own google drive and use it that way. As it always needs to be said, I am not responsible for your use of this tool, it's just the reference I have been using for myself and as there are a ton of environmental variables you need to pay close attention when utilizing it.

https://docs.google.com/spreadsheets/d/1lDwwrAibQa-cqZWlNG-Y04wATCq5bGZLWIsL7phyHBo/edit?usp=sharing
 


RubenZZZ

1000 Post Club
Messages
1,436
Likes
915
Location
El Monte
#3
Could this be used to figure out how to lose the drone associated with running dumped, 2-chamber Flomasters?

I love the sound but hate the drone at cruise speed...

Sent from my LGLS992 using Tapatalk
 


OP
Clint Beastwood

Clint Beastwood

2000 Post Club
Messages
2,599
Likes
2,344
Location
Laguna beach
Thread Starter #4
Could this be used to figure out how to lose the drone associated with running dumped, 2-chamber Flomasters?

I love the sound but hate the drone at cruise speed...

Sent from my LGLS992 using Tapatalk
Absolutely, thats exactly what it's for :)

Figuring out the length of the required chamber isn't too hard, on all the Fiesta's I've seen it winds up being 3200 rpm or 106.67hz - what's hard is figuring out where to fit nearly 32" of pipe. I think your flowmaster has a rear muffler, so you're going to have to find an exhaust shop willing to get creative. The only way I was able to fit the piping was not having a rear muffler.
 


RubenZZZ

1000 Post Club
Messages
1,436
Likes
915
Location
El Monte
#5
Absolutely, thats exactly what it's for :)

Figuring out the length of the required chamber isn't too hard, on all the Fiesta's I've seen it winds up being 3200 rpm or 106.67hz - what's hard is figuring out where to fit nearly 32" of pipe. I think your flowmaster has a rear muffler, so you're going to have to find an exhaust shop willing to get creative. The only way I was able to fit the piping was not having a rear muffler.
I'm thinking of using this for my Chevelle. It drones like a mofo.

Sent from my LGLS992 using Tapatalk
 




Top