Depends on your goals. I have them because I wanted to do all I could to get a flatter torque curve (more torque at lower RPM). they allow me to tweak exhaust and Intake valve timing independent of each other. While I achieved only a modest HP increase with them (~15HP), I did get a flatter torque curve lower in the RPM range that I was looking for for Road Racing. I ended up at 3 degrees Retard on the exhaust side and 1 degree of advance on the intake side. Where you end up will be completely unique for your car with your set-up and your goals.

I would also highly recommend that you go with a dyno if you want to get the absolute most from cam gears. You can use the butt meter, but this can sometime send you down the rabbit hole!

The following tech article (that I found on this site) does a good job of covering the basics.

"http://my.prostreetonline.com/forums...php?t-117.html

or for the lazy or slow computer owners (like myself)

This article assumes that you have a clear understanding of what cam gears are and that you have at least one of them installed. Keep in mind that your modifications (turbo, fuel setup, etc.) might yield different results for your application. Use the explanation below to experiment with your cam gear settings but we HIGHLY advise not exceeding 5 degrees in either direction, advance or retard. As with all of our tech tips and how tos, You should have a certified mechanic working on your car, or if you wish to do yourself, Pro Street Industries is not responsible for the modifications you perform on your own vehicle.

On the 4g63 DOHC engine you can dial-in intake and exhaust timing independently of each other to regulate overlap. As you'll start to see as you make changes, combined with the use of a chassis dyno (highly recommended) you can fine-tune your cam's entire operation by advancing or retarding its action, squeezing as much horsepower and torque from your state-of-tune as possible.

It's important to note that adjustable cam gears have no direct effect on the duration and lift of the valves, that's the job of the camshaft lobes (profile) as dictated by the cam manufacturer.

*TIP - Always make sure your cam gears are tightened correctly to combat cam gear slippage. Slippage refers to the bolts that hold your cam gear to the settings you desire loosening up and allowing the cam timing to advance or retard fully often with catastrophic results. DO NOT LET THIS HAPPEN TO YOU. And not to state the obvious, but... make sure your car is in tip-top working order before you adjust your cam gears.

Generally, advancing a cam gear opens a valve sooner, and closes it sooner... retarding the cam gear, opens the valve later, and closes it later... since all you've done is "move" the fixed event.

Advancing Intake and Exhaust : This will provide the car with more bottom end power, and will decrease top end. Advancing both cam gears will move overlap earlier but will not increase it.

Retarding Intake and Exhaust : This will increase the cars top end, but will decrease low end. Retarding both cam gears will move the overlap later and but will not change the amount of overlap.

Advance Exhaust Only : This will help the cars top end, and it reduces overlap.

Retard Exhaust only : This will help the cars mid range power, very useful for cars with big turbos / big cams. By increasing overlap, It decreases lag significantly. Doing this will bring the boost on all at once. Very common DSM modification.

Advance Intake only : This will increase overlap and helps the cars bottom end and mid range power. This mod will bring the turbo on all at once, although isnt a very common mod for DSMS.


There is a ton of info on this topic if you need more, both here and all over the net."


Best of luck to ya!


PE

If I am just looking for 350 to 400 whp on 272 cams, think its necessary to have the cam gears or just leave them stockers?

I guess it depends i plan on making that much on stock, like he said just depends on if that extra 15 means anything to you.

It's not so much the extra HP that you get with cam gears it's the ability to further tune where you torque is (low-mid or high RPM). They are not really a very good HP/$ investment in my opinion, but if you are trying to get that last bit of control over where that horsepower resides in the RPM range then they are nice to have. My 2 cents

PE

Yea, see that's what I'm wondering. If they are worth the cash. I know cams will help me a lot. I don't see a ton of people with the adjustable gears, so I guess it isn't THAT big of a deal.

Ill save you a long post and answer your question quickly.
They arent necessary at all.

Here's an interesting link on this topic that is drawn out in black and white for the beginners - even though it's not DSM related ... but you get the idea..

Cam gear tuning basics - Team Integra

... and read the prelimenary topic of the "powerband" to really get the idea before you plunge into the adjustable cam world in this link above.

-DSM

With a skilled tuner and a few dyno pulls an engine's torque curve can be moved up or down the RPM range by adjusting cam gears.

Without the dyno tuning aftermarket cam gears are just bling that can slip out of adjustment and introduce your valves to the pistons.