Wondering if anyone has experimented with advancing the timing of their corolla. Mine is 4afe, I advanced a little bit and got a strange sound at higher rpms almost like crinkling plastic. I know your supposed to switch to higher octane to stop knocking but i didnt get a knock. The distributor has 2 lower locking bolts. I rotated it clockwise a couple of milimeters, this is all it would go.
Be very careful messing with your timing. Firstly, you should have a timing light, a tach, and a manual. You can do serious engine damage. Gasoline is intended to burn, not explode. Correctly adjusted timing begins the burning process before the piston reaches the top of the compression stroke and is measured in degrees. As the RPMs increase the timing needs to advance more, to allow adequate time whereas the piston is moving faster. If you inadvertantly retard this, you cause the fuel/air mix to "detonate" as a result of heat and pressure. You can burn holes in pistons, damage connecting rods and bearings etc. If you advance it too much, you don't get peak power at the right time in the cycle. Best to set it to factory specs and leave it there and use the octane rating Toyota recommends for that vehicle.