Why does my FI bike have a choke plate? TE449/511

[robertaccio]

I like this rotating throttle valve design..only venturi open flow no butterfly plates making the airflow weird and blocking the port.
http://www.r1dean.com/shopping/index.php?main_page=product_info&products_id=3

 

[Dangermouse449]

I disagree about the air flow meter. While a MAF system is accurate, they are also expensive, cumbersome, and possibly restrictive. A speed-density system (MAP/TPS and RPM) is much simpler and easier to implement.

TPS works fine as a load metric, it's just not as nice as MAP because it's very nonlinear, so the map/curve shapes can be funky, and therefore require more tuning time on the back end.

You are right about the MAF being more cumbersome & dearer, I wasn't suggesting they should have fitted one, just that they are quicker to log changes of throttle opening.
And yes, you get a much better 3D map for fueling/timing using the MAP rather than a TPS.
A TPS-only system is a 'best guess' of the actual load on the engine, just knowing the throttle is open to 'x' position doesn't tell it how much air is coming in.
So yeah, more dyno time to trim up the maps.

 

[Dangermouse449]

I like this rotating throttle valve design..only venturi open flow no butterfly plates making the airflow weird and blocking the port.
http://www.r1dean.com/shopping/index.php?main_page=product_info&products_id=3

Nice looking product, if a little dear =)

 

[huskylove]

Wow, that throttle body is "genius"...


I want one! Lets send them a te511 throttle body to reverse engineer

 

[Kyle Tarry]

You are right about the MAF being more cumbersome & dearer, I wasn't suggesting they should have fitted one, just that they are quicker to log changes of throttle opening.

That really depends on where the MAF is located. On many MAF cars, the MAF is out at the air filter, so the air pulse has to travel all the way from the filter to the valve, which takes time. MAP is measured right at the manifold (essentially at the valve), so it's near instantaneous. In this case, the MAP/TPS system is much quicker to respond.

 

[Tinken]

I like this rotating throttle valve design..only venturi open flow no butterfly plates making the airflow weird and blocking the port.
http://www.r1dean.com/shopping/index.php?main_page=product_info&products_id=3

It's a ball valve.

This is a noloss 40mm. $800.00