Weber 48IDF vs IDA
 

What is the difference in term of performance between Weber 48IDF and 48IDA? Their sizes seem the same and can set up with same sizes of venturi, jet, etc. but how come the price difference between the two is quite big. Would it be worthwhile to use 48IDA for road racing application? Or 48IDF would do the same?

Tim

Hello-

If you have the same size venturis and butterflies in each, then the difference in flow is negligible. Now, include the manifolds into the picture and you have _IDF_ winning, not IDA. IDA bore spacing is 120mm; IDF is 90mm. The intake port spacing of T4 is ~88mm, and T1 is ~50mm. So, IDFs will allow for better manifolds for both T1 and T4 than IDA. Plus, parts cost and availability of IDF is far better, AND they fit into engine bays a lot easier.

The only advantage (IMHO) of IDA is that you can bore them out to bigger than 48mm butterflies. If you don't plan to do this, then get IDF.

Take care,

Thanks a lot! You save me over 400 bucks.

Best regards from Hong Kong
Tim