Larger chokes (venturies) on my Webers? Options

[Eddie914]

I have removed the Weber 40IDC 3A carbs for a rebuild.

They currently have 32mm venturies.

Will larger venturies give more top end power?

The engine is 2.7 from a '77 911. Internals (P/Cs, compression ratio, Cams) are unknown. Bursch Headers with megaphones (with removable baffles).

The car is 90% track. Weighs less than 2100lbs.


Thanks

Eddie

[campbellcj]

I could be wrong (it happens every few years (IMG:style_emoticons/default/cool_shades.gif) ) but IMHO 32's may be significantly too small for a 2.7. I have 32's on my 2.2S and its Webers are set up to factory (carbed) 2.0S specs. My car had larger chokes, 34mm IIRC or maybe 36's, previously and it had a nasty tendancy to bog at lower revs and break up (cavitation?) at high revs.

I hate to mention this but in this particular case you may be well-advised to search the Pelican 911BBS for "2.7 jetting" as I know this has been discussed before. There are tons of Weber-equipped 2.7RS clones running around, both street and track.

Also, you may want to contact Richard at PMO. He can provide jetting advice based on your specific application and can also supply any parts you may need.