Nah bin it. I've got a bored out SPS so put a bigger radiator on to cope better, but found i actually have to tape parts of it off to keep the temp up most of the time in UK! Be surprised how much air goes through one one these things at track pace. Just don't leave it ticking over unattended, and make sure you're battery's strong enough to cope with turning it on and off while waiting for scruntineering/noise tests.
As above, the fan doesn't do anything above about 40mph, also watch it if you put it on a rolling road some of the fans they stick in front do naff all.
When I bought my R it had no fans (they were in a box of bits it came with). I have since put one of them back on just for piece of mind and for those times when waiting for noise tests etc. Considering that it weighs approximately cock-all, I reckon I can live with the drop in performance.
I have one with and one without and to be honest it makes no difference. The fan rarely gets used but if I was worried about saving such a small amount of weight I'd just make sure I take a s#it before a race :biggrin:. If its on there then leave it, if it's not then I wouldn't make the effort to put it on.