Re: How much octane?
Got a response from the Weber guys the other day. They said:
"Unfortunately higher grade fuel would not hlep unless the engine is re-mapped to take advantage of the higher octane. I am not aware of anyone doing that kind of performance work to date.
The only easy change is a less restrictive exhaust system. You can gain about four horsepower by doing that. I think Redline is close to offering this. You may also want to use a larger two stage air intake filtration from Donaldson or Fleetguard. The original one is a just a bit restrictive.
An expensive option is to change to a turbo charged engine. Redline is just finalizing a factory coversion that is quite unique so it all fits. The base engine has pistons swapped (lower compression), high temp exhaust valves, and they reconfigure our turbo to be upside down so it will fit in with special brackets and swap to the turbo intake manifold and single TB and new single exhaust.
You might want to contact them to see if they are willing to convert used buggies, or do it through someone else like Wasteland Performance (normally does Ranger and Rzr conversions) or Watcon.com (Weber Aftermarket Dealer Distributor in Washington)."
I have followed up with a question about needing to re-tune the computer if you do an exhaust swap because there is no O2 sensor. I believe, like in a Rhino, if you swap out for a free flowing exhaust and intake, you need to update the computer to take advantage so you don't run lean and burn stuff up. No O2 sensor to adjust the fuel curves, etc. More to come........