Ok here are some of the differences:

SU's work well with a moderately tuned engine and they are more tolerant then some of the higher performance carbs............CV carbs are more user friendly in that you can be pretty far off on the jetting and it will still run with out severe symptoms. In other words the car can be uber rich and due to they way CV carbs work it won't flood out if you slap the gas peddle to the floor They do use up the oil in the dash puts at a slow rate but it's a 30 second check and all of a minute to put more oil in, The big down side of SU's is flow........................2 throats vs 4.

By contrast when your running DCOE carbs you need to do more set up on the front end to get them running well, the webers may need some tuning from time to time to keep them perfect................SU's are not any better in this respect it's just you notice with Webers.

People say the same things about Flat Slide carbs that have a bog at low RPM's......it's just the way they are.......not true, sized and tuned properly they work very well at any RPM.

With all that said I do like the SU's in a motor tuned like the GX engine is..............part of it has to due with packaging for LHD cars.


Tom