Gernby

FWIW, I believe that a stock block F2XC needs throttles that are 50mm or smaller (or 52mm oval), unless you have some exotic curved runners to clear the hood and brake stuff.

I don't know if I've posted this before, but below is a dyno plot showing my '08 S2000 compared to my '13 Civic Si. Both have stock blocks, stock injectors, similar exhaust systems, and similar ITB's, but the K24 in the civic has the crappy exhaust manifold cast into the head, and does NOT have VTEC on the ehxaust cam. In stock form, the Civic Si makes significantly less than 200 WHP. However, the ITB's on my S2000 are 52mm oval, but they are 45 mm on my Civic.

s2sik

A very elementary way (or in this case, middle school way) of trying to explain the correlation between length and width that trumpets have, is to go back to a 8th grade science project. There was a project where you would tape together the openings of two 2-liter soda bottles (after an amount of water was placed into one bottle) to simulate tornado type effects. You would twirl the bottles X amount of times, until you created the swirling tornado effect that would funnel the water into the other end of the empty bottle. In this case, if you cut open one end of the 2 litter bottle (the base end), and did the same experiment, and logged how many twirls it took before you were able to create the tornado effect; then, continued to cut down the opening length of the bottle (trumpet length in this example), proceeded to log etc, you would see that the shorter the length of the bottle, the less efficient it was to create the same effect (needing more swirls before you got the tornado effect). So the idea then with ITB trumpets, is to find the right balance/efficiency between length and width for your specific application.

Gernby

I don't really get your point with this...

A better correlation is a pipe organ. The resonance of a pipe is determined by its length and diameter, which is why a pipe organ has so many pipes with different combinations of varying length and diameter.

s2000ellier

Gernby why does the torque drop so much?

Gernby

If you are asking why midrange torque would drop by going with a larger diameter setup, that is because the resonant frequency of a pipe increases as diameter increases. However, the resonant frequency goes DOWN as length increases.

s2sik

It stemmed from my consideration to the demographic that is on a car forum. A simple experiment that was commonly found in schools for some, versus pipe organs? I am not well versed in pipe organs, and I don't know many that are. My example is how length and width of a funnel can/will impact speed and velocity.

herecomesboost

Yes
[/quote]
Awesome! Was wondering who snagged those. What numbers are you shooting for?

MB

I've gone for the Toda ITBs. Hopefully they will arrive this week I've ordered it with the mesh and filters but I intend to run a large plenum and air feed like the J's Racing one.

I want to make the FPR and fuel hoses as tidy as possible as a lot of the setups ive seen look a bit messy.

It's a shame there isn't a hard pipe option, like using a U fitting on the return of the fuel rail and then a hard pipe running under the ITBs. Also looked at Radium's fuel rail as it uses the OEM regulator which is a nice touch. But I'd rather stick to the Toda rail.

https://www.radiumauto.com/Fuel-Rail...0-05-P362.aspx

flanders

Not sure how well the Reverie "plenums" would fit the Todas but might be worth checking out.
These for example
Air box http://www.reverie.ltd.uk/product_li...A%20AIRB%204CZ
Back plates http://www.reverie.ltd.uk/product_li...A%20AIRB%20ACZ

MB

I've gone for the J's Racing one. It's bigger than the Toda one which I think will be a good thing on my engine