adjustable cam gears and dyno

[mistercrow]

hello guys.

Earlyer this year i have completed my tune, but we didnt play with the cam gears as time wasnt on our side. this week i have available time and am thinking of putting the car on the dyno again to adjust my cam gears to develop more lower end response.

my tuner isnt in town right now but i still have access to a dyno and i am wondering if i play with the exaust cam gear if i will need to retune the car, since the cam sensor is on exaust cam?

i know intake isnt too much of a problem, but i dont want to play with exaust cam gear if its going to create problems without a tune.

[mistercrow]

just a FYI, i went on the dyno, the car got 25 whp and 52 wheel torque by moving the intake cam gear 2 teeth in advance timing, no need to touch cas. if you play with exaust wheel, i got no gain, but you will need to reajust your cas to initial timing (i was at 20 btdc, had to make sure i was still there)

[240zdan]

2 teeth or two degrees? Can you post a pic of the dyno?

[Pldovr]

Probably 2 marks, and 4 degrees.

The secret is, as you advance the intake, the turbo spools faster, and you pick up bottom end. At some point, you will start to lose top end, then you decide at what ppint you accept the compromise.

The exhaust makes little difference, unless you go to extremes. I just watched my tuner do an SR20. It has intake vtec type thing, I think he said 20 degrees advance. Gained something like 70 lb ft at the bottom, tapering off, and at about 5500 the output was equal, and much less above, so the switch over was set at 5400. Cool stuff.

[240zdan]

I've advanced my intake cam timing 4 degrees and love how the engine responds under full load. I would almost wish for a bit less spool at partial throttle, but I think some quick ecu tuning will fix that. I didn't notice much of a drop in topend, the dyno may show otherwise but I only rev to 7k rpm anyways.