I did some searching around and didnt find anything on how to tune cams soo,

This was taking from prostreetonline.com

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.


So here is where my questions start, for top end would it be better to retard both intake and exhaust or advance exhaust? Im on a stock 8 turbo if that plays a factor.

 

Stock cams?

 

BC 280s

 

really? Noone cares about tuning there cams?

 

Throw it on a dyno and start playing with the gears for best results. IMO cam gear power isn't worth the time you will spend on the dyno tuning them.

 

It is on BC280's. They aren't zero'd using factory settings.

But ya easiest thing is throw them on the dyno.

The more complicated approach is using a degree and finding their centerline, although I don't know how to do it myself.

 

Cam tuning is very complicated, there are infinite combinations you can come out with. You have a very good description. What you must remember is the head, manifolds, turbo etc will all effect how the intake and exhaust gas will flow, and how and where you can make power.

There is no magic formula for every setup and can take a very long time to tune and optimize

 

degree your cams. dont tune them.

 

Let a pro do it just my 2 cents

 

So my plan is to start at 0,0 and retard from the to -4,-4. I dont have a dyno, but will compare the runs with evoscan and vdr.

 

So we know these combos:

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.

But what about the others:

Retard Exhaust cam, Advanced Intake cam?

Advanced Exhaust cam, retard intake cam?

Retard exhuast and intake but exhaust more?

retard exhuast and intake but intake more?

advance exhuast and intake but exhaust more?

advance exhaust and intake but intake more?

If we get a good base of all the combos it would make for a nice sticky. As there must be others that would like to tune there cams/cam gears but there isnt enough info on the subject.

 

Good idea, just run your result's through vdr and see where ya end up with.

I would do at least 3 pulls for each setting. GL

 

bump

 

with my kelford 272's with FP red, we went from 0,0 to +5,0 and picked up 500rpm spool, but at the loss at top end power. We needed 2psi more boost to keep the same top end power. we then advanced the exhaust to +3 to keep the idle quality good (ish). advancing the exhaust didn't really have any effect on the power/spool

my 2c

 

Ahh don't listen to this ****in loser.