Weber IDF's 44 or 48 ?

[Jean-Paul Reckinger]

Hello everybody,
I'm actually thinking of mocking up my 302 engine and the Weber IDF's just look so fine,
on the market there are 44 and 48 kits,can anyone give me advice which to choose and why?
Regards JP

 

[Terry Oxandale]

My understanding is this decision is more about what you want to do with the car. The larger the throttle opening, the less vacuum response at the venturi for a fixed volume of air flow. Comparable to placing a big honkin Holley 950 on your engine when a 650 would give better throttle response for nearly all your needs except WOT at the racetrack. Some of this can be adjusted with different throat rings, but that is again a compromise. For daily driving, and fun, probably the 44 would allow a better response, the 48 better upper RPM performance at the sacrifice of "driveablity" (however you define that term).

 

[Jean-Paul Reckinger]

the car will be mainly for road use,as it is a 30year old GTD to be rebuild,so 44's than

 

[Mike Pass]

I have just cleaned and rebuilt a set of quad 44IDFs for one of our members here in NW UK. The engine is a 302 stroked to 347. It runs very well as it was set up on the dyno at EDA. Also very loud on the megaphones!
Cheers
Mike

 

[Jean-Paul Reckinger]

Thanks Mike,can you recommend someone (shop/carb specialists) who to buy from in the UK or mainland Europe?