Posted 14 March 2013 - 10:41 AM
Please define your critera of "best", or is that what you want us to do ??
Also the engine spec you've listed is more like Trackday/sprint/semi-race spec rather than fast road (In my opinion obviously !!)
For me a webber is not the right carb for a mini used on the road, ever. It has advantages for a race car, particularly where you can cut the bulkhead and run a proper 5 inch manifold, filter and bell-mouths/ram stacks. In the confined space of a standard mini the manifold is so short and so compromised to negate the possible flow advantage, and is perhaps why so many people find them tricky to set up at part throttle. There are three or four separate "tuning" components in the webber, all of which need to be set up correctly by your dyno or tuning "expert" : the choke, the emussion tube and jet, all of which can be changed, and thats without getting into "progression drillings" in the main body of the carb.............. The usual reports are that the webber is fine at wide open throttle, but bugger all good anywhere else. Don't get me wrong, they can be made to work and very effectively, but for me they are just not worth the effort.
So that leaves us with SU's, either single or twins.
If you want to have the "Cooper S" look, already have a pair of inch and a halfs or inch and three-quarters and mainfold to suit then there is a lot to having a set of twins. The Maniflow steel manifold is the best for twins, but pricy. The downsides are that you have to balance them up properly, and you have to buy two needles, two springs and two filters at a time. Twin SU's don't go "off tune" or "out of balance" anything like as often as the nay-sayers may tell you, providing they were set up properly in the first place.
Finally the single HIF44/HIF6. The advantages of this are your likely to have one as they were fitted to all Cooper/MG Metros as standard. They can flow enough air for all but the highest state of tune. You only have one needle, spring and filter to buy and no balancing required. The plethora of alloy manifolds available (including the standard Cooper/Metro one you are also likely to have knocking about in the shed) are all pretty good, there are some better than others but unless you're interested in splitting the infinative I wouldn't worry too much.
So for me the choice is : Do I really want or already have twin SU's ?? IF yes happy days, if not stick with the single SU.
How many times I can vote lol !!
