Homemade Throttlebodies On MA61!!

[StanS]

Jen
The machining is beautiful. How did you make the bellmouth's? The power gain that you're getting is from effectively increasing the tp area by a factor of 6 if your using the same size tp as stock. Even doubling the tp area from stock should give you a good gain. The length of the tubes should be increased if you want max power for two reasons. First with such short tubes the resonances (that induce extra air into the cylinder as the intake valve starts to open) will probably start at too high an RPM. Secondly, and probably more importantly, the VE is the highest when you have a longer column of air. When the intake valve opens the air in the column (tube) starts to accelerate and fill the cylinder. Somewhere in the middle of the stroke the column air reaches maximum velocity. Near the end of the stroke the piston is slowing down to a crawl while the air column has momentum which keeps filling the cylinder, thus raising the charge pressure (and mass) in the cylinder. A short air column has less momentum and will fill the cylinder less. If your going to run at the stock RPM range then the tubes should be about as long as the stock intake manifold (runners). Since your putting so much effort in (and doing such beautiful work) I suggest that you start
with a better theoretical underpinning (i.e. longer tubes). Good luck on whatever you do.

[Dave A.]

Keep up the excellent work, Jen! Depending on what cams and valve timing you're planning to dial in, those ITB's should howl at the moon with relative ease. The air horn length combined with the port length should achieve some good airflow velocity as long as the diameter of the throttle plates are approx. the same as the port diameter. There's a whole slew of 4AGE engines running ITB's that are making plenty of HP with essentially the same type of setup as yours.

What static CR are you shooting for?

[Jens Lyn]

Now the project is a little bit closer to the finish line than before :-)!
All the ITB are now ready for mount on the flange!
And i think it looks pretty nice :-)!

Here is an pic update!

















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More pic will come next week!
See ya

[ViPeR_NiPPleX]

thats awesome, with a capital OMFG!

just makes me want to do all that to my 5m-ge

[NashMan]

nice

[Dave A.]

Very nice!!

[Tire Shredder]

oh my god that's amazing jen! we're all awaiting your results anxiously! so much talk it's good to see somebody able to do what they have planned.

I want some for a 7mge!

[Jens Lyn]

Here is the latest pic of my project.....I like it :-)







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Kind regards jens pedersen!

[Solo1Supra]

Awesome work Jens.

[rsdeo]

Great work. Please keep us posted with many pics.

One of the reasons I wanted a small machine shop in the garage... laithe, milling machine, plainer, etc.