Flat Slide throttle body

[Josip]

Hi all!

Do you know is anyone tried to build this and use on formula student car, and would it have any impact on performance?

As I know it should give better response and some more power because TB is wide open with no shaft in the middle.

Thanks!

[Francis Gagné]

We had that in 2008, 2010, and 2011.

First design was small and pretty light. Worked well at first, then weared up, started leaking, and was stucking up. Redesign for 2011, did not leaked, slided very well, was huge and heavy. Took way too much time to design and build.

As for the feel, the power response compared to the pedal movement was a bit weird. In 2012 we bought the AT Power TB with shaftless blade and the integrated restrictor. We saw no difference on peak power on the dyno, the feel was much better, it is reliable, relatively lightweight, doesn't cost much. Plus it took zero time to design, and had a TPS.

If you really want to know how much difference a flat slide throttle body would make on the dyno just remove your TB and put some flat sheet in front of the restrictor entrance.

You can see the 2011 throttle for yourself here but not very well : http://sphotos-f.ak.fbcdn.net/...481786_6337202_n.jpg (http://sphotos-f.ak.fbcdn.net/hphotos-ak-ash3/227266_212100455481786_6337202_n.jpg)

[Owen Thomas]

As I know it should give better response and some more power because TB is wide open with no shaft in the middle.

Be careful making that assumption. If you look up some k-values for both types of valves ("gate" and "butterfly"), it will give you a ballpark for the relative flow resistance each type has. It's true, gate or slide valves have less resistance when wide open (~4times), but keep in mind that the limiting factor for airflow is not the throttle body, it is the restrictor.

On another note, while the rate of change in cross-sectional area during opening is not very linear with a butterfly valve (steadily increasing), it is not any better with a gate (increase-decrease). Unfortunately this is still not the best way to compare response, since gas dynamics are a bit loony. The k-value can again be used here, or your own testing.

I would definitely start looking into some empirical data regarding flow resistance before putting too much of your resources into this project. Or consider how much actual gain you would get from the design.