Timing kits..........

and once again everyone is getting mechanical timing and ignition timing completely mixed up here... time for a little education folks.

1. ignition or electronic timing is the timing of the spark in direct relation (however different) to the mechanical timing of the car. timing a spark a 0 degrees TDC will cause the spark to ignite just as the piston reaches its highest point and just before it begins its journey back down the cylinder to the bottom. by retarding or advancing the timing (mind you this is only making an adjustment of when this thing sparks by the milliseconds) you can effect performance a little gaining a few horsepower. The comment about rotate the distributor doesnt apply in the 1ZZ motors as there is *NO* distributor in these model engines. The entire timing system is 100% electronically controlled by the ECU. The only way to modify this is to attach a piggy back system (eManage) to the ECU and retard/advance the timing post ECU signal in between the ECU and the coil packs.

2. mechanical timing (or the timing of your pistons, cams/valves, etc) is used to make sure the exhaust valves are open on exhaust strokes of the pistons and the intake valves are open on intake strokes of the pistons. Now, by changing the timing of these, you can change when air is allowed into the combustion chamber and/or allow exhaust to escape sooner or later based on what you're trying to do. this can provide *some* gains based on how you tune your head to react to crank timing. For instance, if the intake stroke on a motor begins half a second before the valves open and closes half a second before the stroke is finished, in theory you can change the timing of your intake opening to be exactly on time or just before the intake stroke begins. in some cases this can allow more air into the combustion chamber and give you more power when the spark ignites the fuel/air mixture. changing this is beneficial especially on forced induction as it allows for maximum flow rate into combustion chamber. this can also be accomplished by installing a different cam as well as that can change the duration and the timing of the intake/exhaust valve control as well. the latter however can give you better gains as it can modify how far your valves open as well.

Now, in addition to item #2 this is why vvt-i and vvt-li engines get more horsepower than the non-vvti motors. at certain rpm's and conditions (throttle position, etc) the timing of the intake valves is changed to allow more air into the combustion chamber as well as the ignition timing is advanced slightly to increase the yield on the combustion. This gives you the extra few hp difference between the two models of engine. in the case of the vvti-li motors, lift is added which causes even more air to be drawn in and thus you get even more gains. there is nothing mystical about vvti/li as it is just automating methods that motors have been tuned with since the days of the muscle cars... it's just now electronically controlled and can change based on conditions to help yield better performance without sacraficing economic benefits of the motors basic tuning.

anytime...

yeah, 350 is pretty good for a complete timing rebuild kit however... toyota wants an arm and a leg for that stuff - however i think if you use 1sttoyotaparts.com you can order almost all the oem parts for that price or lower... if i get time today i'll go price it all out.

what about it?

eManage