ca s'applique sur un D-series, 30 secondes de recherche, donc si tu boost un B, un H ou un K, 70mm est ben en masse:
Larger throttle bodies on most D-series turbo setups that aren't really silly are just a mind-game. A stock 56mm throttle body flows more than enough air at reasonable velocities to support about 320HP (not WHP). Larger throttle bodies mostly don't effect power, they do effect feel of the engine. Supposedly the "better throttle response" is simply from the fact that with the greater CSA but normally unaltered opening angle (with respect to the throttle position) allows more air to flow sooner. You can get the same effect from opening the throttle pedal faster with a smaller throttle body. You also loose precision throttle modulation with too large a TB.
The biggest thing that most guys don't seem to understand (and I'm still struggling to have more than just a cursory understanding) is the relationship between plenum volume and throttle body sizing. Boost complicates this some, but the relationships are generally the same as with NA engines.
For boosted engines, there isn't much reason to go bigger than a stock 60mm TB on smaller engines like the D, unless you were building a max effort drag race only engine. 60mm is large enough to support over 500HP (though if you were going for more than that, going larger wouldn't hurt).
Bottom line is that on a D, the TB size isn't really much of an issue and certainly not much of a hindrance on spool time.
D-series.org.
