Good question. My understanding is that the engine must be stock compression, therefore cutting the manifold would not be required. Manifolds need to be shortened on 5/1600 and 1-2/1600 engines due to flycutting for compression. I don't know how this plays out on the Class 9 manifold modification rules. I'm still building my car. I'd like to hear what the veteran 9 guys have to say.
I could be wrong, but with the intake cut it also allows for the removal of the manifold while leaving the altenator, stand, and fan shroud in place, if the occasion should ever arise. Can anyone confirm this? I might be mistaken......
I too have seen manifolds cut on 9 cars, and spiced together with tubing. Here is a quote from the 2000 SCORE rule book on class 9. under the topic "Carburetor" "Intake manifold must be stock VW, No chemical milling of manifold or carburetors." that's it... Does this mean that manifolds can not be cut? or must they remain in the stock VW configuration? Also class 9 engines run a reduced compression ratio of 7.5 to 1 - down form a stock 9 to 1. also the Combustion chamber volume must be no smaller than 42cc. This is accomplished by adding shims to the barrels at either the case side or in the heads. This actually increases the space between the heads which is why the stock manifold always fits so lousy! Rob Stapp #975