Exhaust Cam Gear

[Dean_HR31]

Hey guys so that u know this is the car that i am talking about so that ur aware

of what the cam gear would do for me..

http://www.skylinesaustralia.com/forums/in...howtopic=168432

I've been advised by my tuner, that it woudlnt be a bad idea to get an exhaust cam gear,

since i may pick up some tourqe in the power and possibly even up top power...

Just want to know the main purpose of these, what u can do with em, why they help out & how much.

Thanks!

Edited May 17, 2007 by Dean_HR31

[MANWHORE]

yeh, they're good.

[Dean_HR31]

I hope u can type 45++ words per minute cos that would've taken u a long time to write!

[BAMR33]

Do a search there's alotalota info about them.

[BAMR33]

http://www.skylinesaustralia.com/forums/in...;hl=ex+cam+gear

Particularly good comparo

[Dean_HR31]

thanks mate!

[Dean_HR31]

hmmm had a read.. still not what i want to know... That is all about who has em, whether they made power gains

& which brands are better...

I want to know HOW & WHY they help? What exactly do tuners DO with them...???

thanks guys

[Birnie]

hmmm had a read.. still not what i want to know... That is all about who has em, whether they made power gains

& which brands are better...

I want to know HOW & WHY they help? What exactly do tuners DO with them...???

thanks guys

The 1st post of that link pretty much answers all your questions in that 1st paragraph.

Who - the guy who posted

Whether they made poer gains - look at the graph !

Which brand though, i don't think it matters too much, there was a group buy on Arospeed ones not long ago, i picked up 1 for $80.

Once they are set in position, they don't really do anything, as long as they can hold that same pos they're ok.

How and Why, just look at one and it sorta makes sense. it allows you to make adjustments on the position of the cam shaft forwards or back a certain degree. ie, letting axhaust gas out earlier or later during the revolution of the stroke.

What do tuners do, undo the bolts on the cam, turn it fraction, do it back up. And as these are common cars, they would already know the optimum settings. Possibly a retune afterwards.

[WRRR]

hmmm had a read.. still not what i want to know... That is all about who has em, whether they made power gains

& which brands are better...

I want to know HOW & WHY they help? What exactly do tuners DO with them...???

thanks guys

Adjustable cam gears give you additional adjustment points that can help you get the most out of your engine setup and tune.

Non adj cams are normally dialled in at zero in terms of timing. Adjustable cam gears allow you to advance and retard the cam timing (when and where the cam opens and closes the valves in relation to the crankshaft rotation) infinitely (more or less). To alter the cam timing without adjustable cams you are limited to moving the cam gear +/- 1 tooth which is coase and may alter the timing too far and lose any advantage.

Adjustments in cam timing can allow you to bring desirable characteristics into your tune. ie advancing exh timing often brings in a stronger top end. Retarding inlet timing on a small cam will often bring out a bit more low/mid range torque. But it all depends on the engine, camshaft profiles and what you want to achieve.

Let your tuner be the guide.

[MANWHORE]

From memory, 1 timing belt tooth works out to be something like 7 degrees or something like that. Way too muhc to be of any use. that's where the adjustible cam gear comes into play

The reason why I was brief, is because these questions are asked fairly often. Material has been covered much better in those threads that anyone would CARE to answer in here, since they've already answered it a few times. You'd get a better result by having a read - there's heaps of info

[WazR32GTSt]

exhaust cam gear's gaims, in my experience, can be summed up as:

- boost on significantly earlier

- more power/torque down low

- a little top end lost (i lost 3rwkw up top but gained up to 25rwkw in the midrange with exhaust cam on already existing tomei poncams)

[BAMR33]

hmmm had a read.. still not what i want to know... That is all about who has em, whether they made power gains

& which brands are better...

I want to know HOW & WHY they help? What exactly do tuners DO with them...???

thanks guys

How? They allow more gases to be pushed out faster without the restriction of the ex valves starting to close.

Why? Because, most people with an adj cam gear also have a big flowing exhaust which reduces back pressure reversing into the combustion chamber while the valves are still partially open. so this therefore this allows you to retard the ex cam more without the spent gases causing detonation and poor burn.

[(B1) MR_fanny]

i dunno if this is any help but i got mine tuned with a hks one at 11psi exhaust, 34smic, intake and lightened flywheel and i got 199kw which was a shock considering it was pretty much stock before. obviously in shootout mode so id take 10kw off but still a surprising figure imo i was expecting 168kw. picked up alot more torque mid range so the car is very responsive to drive. smells like its running rich and on idle it misses now and then dunno if thats to do with the exhaust cam though.