I also posted this in the smallblock forum - wasn't sure where to go for the best response. Anybody got an idea what the CFM's of my stock EFI system is? The manifolds and throttle body are from a '90 E-350 351W and the MAF sensor was in the mass air kit - probably '89-ish Mustang. Everybody knows how many CFM's their carb can flow and make use of this info, but I haven't seen any references to EFI beyond just using bigger throttle bodies and MAF sensors or even going to aftermarket manifolds. Nobody ever really states at what point the engine has to have more, so I'm trying to convert this so I can decide whether or not my stock parts will move enough air to feed the engine in it's new configuration. It sure is fun to buy cool new parts and dream about how much power they're going to make, but it's rough on the wallet, too! Hate to do that if it won't get me anything.

 

'Rage,

I thoroughly checked two different books books I have on Ford EFI (one of which is exceedingly detailed) as well as one book on hopping up sbf's and not one word about how air the system can flow or even the various sizes of throttle bodies etc.

With regard to getting flow rates on the throttle bodies in particular, I think you'll have to go to someone that sells them - like Ford-SVO or Saleen.

Maybe the folks that offer aftermarket EFI intake manifolds have flow rates for the stock manifolds (since they like to brag about more air their manifolds will flow versus stock).

Anyway, I gave it a good hour and came up blank....

Later,