hks cams, lightweight pulleys Options

[barmyhawkins]

hi all i have a celica st205 gt4 wrc 1994. do hks or kent cams make much difference to pulling power etc. also is it worth getting lightweight pulleys, flywheel etc. have people done this and is it worth the expense and time. many thanks

[Rusty]

Camshafts

Never heard of kent cams before? After checking out their website, they don't actually make cams for the 3S, only the 4A-GE Corolla & MR2 (AW11) 1.6L There are a lot of other great camshaft brands not just hks, kelford cams have a high reputation.
My strong opinion is that unless you swap over to the 3S-GE mild upgrade cams or have upgraded the turbo there is no point in getting bigger cams, you just up the boost with a boost controller. If you do go for aftermarket camshafts, vernier pulleys or cam gears are a must for tuning & getting the most out of them.

Lightweight pulleys from Wikipedia

An underdrive pulley refers to an aftermarket crankshaft or accessory pulley (a/c, alternator, power steering, water pump, etc.) designed to turn at a slower speed than stock. To Underdrive means to slow the rate of rotation in a system. Underdrive is achieved by either making the crank/main (drive) pulley smaller or the accessory (driven) pulley larger than the stock pulleys.

Underdrive pulleys increase engine output by reducing the draw of the engines accessories by slowing them down and reducing the HP they use. Horsepower gains from underdrive pulleys can vary but improvement of up to 10-15 hp at the wheels have been seen.

Poorly designed underdrive pulleys can cause severe side effects from not spinning the alternator, power steering, and/or air conditioning fast enough. These lead to low alternator voltage, weak/no power steering assist, and weak/no air conditioning effectiveness, especially at idle/low rpm. The most commonly seen result is lighting may dim, or the stereo may cut out. Too much underdrive for a race car is not much of a concern due to the high rpm's they run at, but for daily driven vehicles it can lead to a dead battery if too much time is spend at idle or low/rpm.

In addition changing the original crankshaft pulley can have negative effects if the replacement pulley is not manufactured properly. A crankshaft or accessory pulley not machined or balanced properly can cause severe damage leading to thousands of dollars in repairs. It is highly recommended only reputable brand be used.

Since the 3S is balanced from the pulleys you need to balance the engine internals.


I've just bought a Jun lightweight flywheel to install myself