dialing adjustable cam gears

[gezed]

this has been discussed a lot on the Australia forums, and it seems that the general consensus is to retard exhaust and advance intake to get more overlap

anyone with adjustable cam gears mind sharing their adjustments and the differences(if any) it made?

[frankiman]

you'll need to do it directly on the dyno to get it just right, or else you might set it terribly wrong and not know about it

[Skym]

This should help with setting up cams -

http://www.kelford.co.nz/sole-purpose-of-degreeing-your-cam

I remember something along the lines of that it said somewhere on that website that more overlap for turbo, less for NA cams. But can't find it again.

Also read this (what the adjustments to camgears do to powerband, etc) -

http://www.tomei-p.co.jp/_2003web-catalogue/e092_adjust-p.html

[evilgtr]

I had my cam's degreed at the speed shop on the specifications that Tomei provided to the tuner in a phone conversation. GTR-DAD had his cam's degreed as well to the direct specs from Tomei and the results were huge ! By adjusting the intake exhaust gears essentially aren't you just playing with where your power band will be ?

[Voodoo_ChildR32]

Basically it's adjusting the cam timing. Like mentioned above, if done properly good gains will be had. Adjust incorrectly and you could be replacing a head.

[GTR-Dad]

Manufacturer specs are a great place to start.
Mine were off 3 degrees on the intake and 10 degrees on the exhaust. (Not sure which direction, but I think the exhaust was opening early based on a big fart of black smoke when I turned up the boost)
Set them to Jun specs and and picked up over 100 (yes, one hundred) AWHP.
d

[gezed]

^ lol no way, thats amazing

in general i hear people getting up to 20-30whp gains from correct cam gear dialing

Also had a good read about the tomei cams, I got type A's i guess they are already optimized so theres no need to plan with the timing?

[GTR-Dad]

Don't assume they're right just because they're set to 'zero'. Milled decks change the center distance of the cam pulleys and therefore the timing. Dial the cams as you rotate through the full crank rotation to get a direct measure of when they're fully open.

These ones were pretty far out! Don't expect this result every time you try this at home. ;_)

[Skym]

Tomei cams are like copies of stock cams but with more aggressive specs (lift, duration) hence why they work with stock camgears. They are similar to welding on lobes (to get more lift), regrinding weld, base circle of lobes (to get more duration) to more aggressive specs, but Tomei did it the proper way by making them from new blanks.

Cam manufacture can regrind the base circle of lobes on stock cams for more hp (I think affects duration, similar to what can be done with adjusting camgears) without affecting cam longevity -

http://www.kelford.co.nz/regrinds

[evilgtr]

Thanks Dan, I didn't want to quote any power gains in the event they werent accurate. The gains are substantial when this procedure is done correctly. It is possible to degree cams when they are in the car as well

[Super_Dude]

Like gtrdad said, a lot of things can change cam timing. You need to use your cam gears and find the actual lobe centers and from there you can adjust them on the dyno.

There is no way of telling the amount of power to gained by doing this because they can be way out to lunch or almost perfect.

Mine were dialed at +4 intake -1 exhaust and it made considerably more power under the curve. Im not saying these are right for anyone else, you have to find what works for your setup. Im just giving am example.

[Dragon Humper]

As has been already stated, EVERY engine is different and a multitude of things will make your cam timing way off even though they are set to zero on the cam gears. You should set the centerlines to spec and then play with it from there to get the power delievery you want.



Jon.

[cobrAA]

is there a way to dial the cam without beeing on the dyno ( dyno time is expensive) ?

[knate]

sure! just guess and hope its working better!

[evilgtr]

Theres a great article in the most recent modified magazine showing in detail step by step how to degree cam'w with the engine in the car. They actually printed off a degree wheel and scaled it to size to use for there application. They go into detail about the importance of this and how to do it yourself with only a few simple and inexpensive tools.