Lightened Flywheel

[cannondalemaine]

Just curious if anyone has ever lightened up a flywheel for hp gains? What were the results you got if any? Also has anyone on the site tried vp u4.4 fuel, just curious if it is living up to the hp gain hype? Thanks alot.

[cannondale27]

Never lightened a flywheel. Yes VP U4.4 was just tried last monday. It works great in any quad that you can't adjust the ignition timing on. I believe on my motor which had ignition timing tuned it was only worth 1/2hp compared to Turbo Blue/Pump gas mix same day optimized tunes for both gasses. Now its not a gas test but I have never seen a 450 stock motor YFZ with cam mod and FCI intake put out 50hp. Most with his mods make 48hp. This one did using U4.4. I figure he got 2-3hp out of the gas. Will it be kind to your fuel system? Time will tell but the old U4 ate everything up bad. So if you aren't comfortable with tuning your ignition and you are willing to risk fuel system damage unless drained everytime I would say it is worth it.