Hey guys,

just a small question on what size su i should upgrade to? I have a new fully rebuilt 1100cc 40tho over, all standard except for LCB excractors and a 2" exhaust. Currently it only has a 1 1/4 inch su on it. I was thinking of fitting a 1 3/4 su, not to sure if that will be to large for a fairly standard 1100, and how much it will effect fuel economy? It is my daily driver and dont want it to guzzel fuel.

cheers.

I would put on a 1.5" HS/HIF SU. You don't really need the extra size of a 1.75" SU, and it would most likely be more expensive anyway. Using an aftermarket manifold (Mini Spares water heated manifold is good) and a good air filter, it should go pretty well. And then if you want a 1.75" SU later, you can still use the manifold.

I would suggest a 47' SU (A HIF 95)
SEROIUSLY
but that would be overkill:
I ran a 1.75 for a few years on a 1100 it was pretty good. gave a good bottom end that was pretty linear with power/revs I thought is was a nice combo.
of course the 1.5 will give less fuel consumption but you only live once and if mini's don't use the last of the fuel I'm sure some V8 will drink it all

SLAP ON A 1.75 when it's in tune it should run really well

_________________
-doing a Degree in Mechanical Engineering,
and a few conversions:
13B Extend in a 1600
4EFTE in a mini ute (all slowly)

I agree - slap on the HIF44 - properly needled and jetted its a very economical carby.
The beauty of the SU carby design is that the engine only sucks what air fuel mixture it needs. Other carbies may run out of breath at times but a HIF44 will provide what you need all the way through the range.

Graham Russell tells the story of a mildy warm 998 on the engione dyno with a HIF44 and the bell chamber is all the way to the top and the engine is using all it can suck.

I Also Agreee HIF44

Mine has provine to be as good as a Dellotor on a Dyno with very similar Spec's
Scout UK Ebay for a manfold and you can also find Combernation
Get it Dyno for the rite Needle and your laughing

If you have a little more money see how the head is also

_________________
Stop Licking the Dog...I Don't Care Who Started It