Before we d'able into advancing your cam timing we must first edjumacate ones knowledge of what he/she knows/doesn't know about cams.
Camshafts are the bumpy sticks that reside in your cylinder head, opening and closing the valves. The cams affect how the air flows in and out of the engine.
FAQ
Q: Can I install adj. cam gears on my stock cams?
A: Installing adj. cam gears on a stock 3S-G is futile.
Q: Can I put adj. cam gears in my stock motor?
A: See above.
Q: When should I install adj. cam gears?
A: Adj. cam gears - and cams for that matter should be installed after all other mods have been performed ie. CAI, headers/DP, cat-back, AFM mod/FPR, coil, plugs, wires, etc.
Q: Does cam timing affect ignition timing?
A: Yes. Ignition timing is mandated by the dizzy and it usually runs off the intake cam. So changing the cam timing directly affects the ignition timing. Ignition timing should be re-set after each change in can timing.
Q: How do I change my ignition timing?
A: If you dont know how to do this or haven't done it by now you shouldn't even be here. There are countless posts, threads, articals regarding this very procedure. Here are a few good articals on how to do just this...
http://www.toyotacelicaonline.com/timing.htm
http://howto.henryvo.com/timing.html
Q: Do I have to install adj. cam gears when I put in aftermarket cams?
A: One thing to also keep in mind is adj. cam gears should be installed before cams and cams should be one of the last upgrades to be performed on a motor.
Note:Sometimes installing cams might nessessitate the need for a head re&re with larger valves, larger port openings, porting of the bowls, head decking, lifter conversion.....but cam upgrades is a whole other topic in itself.
Theory
Usually adv. the intake cam a few degrees will yeild a few hidden HP and retarding the exh. cam may and may not yeild a bit more. Most cars respone well by just adv. the intake cam a few degrees and leaving the exhaust cam alone.
A few precations to take into account when adv/retarding cam timing:
-use only premium gas
-dialing/degree'n in cams using adj. cam gears CAN only be done safely on a dyno
-the dizzy runs off one of the cams, so when dialing in cams the ignitin timing should be reset after a change has been made
-do not tolerate any detonation
Procedure
OK so you got all the mods done to you motor that can be done and your ready for adj. cam gears...apart from the obvious while your in there you might as well go ahead and change that timing belt & idler pulley at the least. If you want you can change the water pump, oil pump, cam seals and front main seal as preventative maintence.
Ok so you got all your parts and your ready for installation, you get all your new goodies installed and your good to go right? Wrong. Dialing in cams is best done using a timing wheel and a dial indicator...however most of us dont have these tools, thats ok cause all you really need is to get them dialed in as close as possible to get you to the dyno so the professionals can dial them in correctly.
Camshafts/cam gears should be set at 0 degress or what ever the manufacture recommends, so check your BGB or Haynes manual.
Ok so you got it all installed and you safely made it to the dyno without any problems. When degree'n cams you should adv/retard in 2 degree increments, continue until you see the power drop off and back off a tad and set it. Remember to re-set your igniton timing between changes. Try to shoot for the best performance instead of peak HP. Power under the curve is better suited to keep the gains in a more useable power band, across the rpm range opposed to the high end. A gain of 4-6hp from 2500-5500rpm is better than 10hp from 5800-6200rpm and will get you down the track faster.
Happy tuning.
Till next time, same TN time same TN channel.
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