JWT adjustable cam gears

[timg20t]

Hey guys,

Would it be worth my while to get JWT adjustable cam gears? And if some what are the best settings for these example. Like 2 degrees advanced for intake and 2 degrees retarded on the exhaust. Also I have heard of people using two different sized cams for the exhaust and the intake is that a worth it as well. I was thinking of mix matching the S3's i have now and getting one S4 along with the cam gears. If its a good idea would I have strong enough top end set up. I think I have the HKS valve springs and the cowler titanium retainers along with the valve stoppers.:cool::eek::rolleyes::confused:

These things are cool!!!!

[Jason@JGY]

They are worth it IF you use them to make more power. That is easily said and often not done.

I feel that they are best purchased ONLY if you are willing to have the car dyno tuned. True, you can read on the internet about where it is best to set your gears and probably be ok, but all motors are different.......and for you, your motor is a built motor and has different components than others and all of this adds to the issue that "X and Y" for this motor may not be best for you. Even if you had an unattractive cousin that had the same built motor that you had with the same car mods, nothing is ever the same. Even simple things like ignition timing......you might have 15.2 and he might have 15.3

2 things I want to add:

1. Safety.....the JWT gears are the best. They have different dowel pins and holes that you set the gears with.....the Greddy's don't. This means that in theory, the Greddy's might be able to move slightly with enough force. Would that ever happen.........I don't know, but I have thought about it
2. The Greddy's are infinitely adjustable and the JWT's are not. This could prove to be better for dyno tuning where 1.4 degrees gives you more power than 2.

Now........you decide which ones you want.

[timg20t]

What about the staggered cam sizes?

[bruce240]

What about the staggered cam sizes?

Well it depends on where you want your power band to hit at, and at what level of power you experience when it hits.

I could be somewhat wrong.... no expert here! But, What I have heard is staggered cams have a wider power band feel, so you wont feel the power as much at a certain rpm, since it has a wider band, whereas same profile cams have a more narrow area, so you could tune for a more specific rpm, like more mid range, or more top end, depending on what you want out of your setup!


BTW; I have staggered cams, Greddy 256IN 264EX stage I!

[Jason@JGY]

Hate to burst your bubble.......but when I put your motor together.....you had HKS cam

[bruce240]

Hate to burst your bubble.......but when I put your motor together.....you had HKS cam


your right, my bad...hehe :D

I got them from you also! :)

[timg20t]

If I were to get staggared cams the exhaust cam should be the one thats bigger. I thought it would make sense that the bigger cam be the intake seeing we have turbo. Or is it that the air can exit faster with quickere spool exiting more freely out of the exhaust?

[bruce240]

If I were to get staggared cams the exhaust cam should be the one thats bigger. I thought it would make sense that the bigger cam be the intake seeing we have turbo. Or is it that the air can exit faster with quickere spool exiting more freely out of the exhaust?


Ya, having a turbo motor, you have higher temps, so you want the intake air coming in slower, and moving the exhaust out faster to help keep your internal charge temps down lower, and you don't have to have staggered cams to do this with, you could have adj cam gears to do it, like set your intake gear at 2-, and exhaust at 2+

[GregG20ConwayDubFace]

Team, I say adjustable (slide/lock) cam sprockets like Stillen's really are only good for dyno tuning due to the problem if the sliders loose lock and slide a degree or more? Plus you have to experiment with these to find your power band.

Pre-set cam sprockets like JWT with permanent set marker holes are best because head damage is less likely* also the preset holes marks and based upon your cams, injector size, & amount of boost if all are JWT sold items then can pretty much tell you how much power you will make at certain points on the sprocket.

I only suggest advance the intake 1 and retard the exhaust 1 and this way you'll be safe.

*Also please note, when you play with these spockets (adjusting them 2 or more holes) you endanger the valves due to the fact that they are staying open longer and can be hit by the piston then adding a cam with more lift & duration that a JWT S3 (for example) or mixing and matching cams S3 intake, S4 exhaust my and both sprockets set at the 2nd notch. . .

I advise you first to assemble the head, then have the valve depth measured. Next have your pistons flycut to play it safe based on the measurements of the valves fully extended downward.

However the sr20vet cams also employ this type of working platform (exhaust cam and intake cam) have different lobe sizes but I cannot recall which is which but I have the stuff.

-Me

[Jason@JGY]

I agree with Greg on all this and add some more info.

1. Install the stuff how you want and turn the crank by hand slowly. This is a simple way of seeing if the valves will hit the pistons........Yes, due to rotational mass and heat, in theory they could not touch, and then when running they could.....but this is better than nothing.

2. I sugges that it is not worth dismantling a motor to cut your pistons to miss the valves. If you do this, might as well change all the bearings and rings. Heck, might as well change the pistons while you are at it and the rods. I would not advance the cams far enough to make the valves hit the pistons. If it works before you take it apart, it's always a risk to take it apart and something happen.