HKS Cam Gears

[adam 32]

just a few questions on these adjustable cam gears

a) whats a good price for them

B) should you use buy both inlet and exhaust?

c) do they confuse any ECU's?

d) whats involved in setting them up and tuning them?

e) under what situation are they recommended ie for a heavily tuned vehicle, to reduce lag, increase tuneability??

thanks

adam

[skyline33]

I have one wanting 220 for it

[adam 32]

you can get 1 for $185 from nengun

[GTS-t VSPEC]

Adam,

Wait till it's landed, it becomes more than the $185.

See'ya:burnout:

[adam 32]

ok forget aout price, i want to know what they do, how you install them and under what circumstances they are beneficial. exhaust side only... thanks

[GTS-t VSPEC]

Adam,

They cause the cam overlap to change, meaning the cylinder fill is different.

Most R33's use the exhaust cam gear only, as the inlet gear removes the variable cam timing, but I don't think RB20's have NVCS.

Easy to install, rev210 did his in under 1 hour.

See'ya:burnout:

[adam 32]

what sort of gains? under what situation is the gear most suited to? can it reduce lag?

[GTS-t VSPEC]

Usually about 5kW per cam gear on stock cams, more if you have aftermarket cams.

If can reduce lag, but most people use it for top-end power, which reduces power down low.

You can dial in the gears for top-end power or mid-range torque.

See'ya:burnout:

[adam 32]

ah k, maybe not what im looking for

im trying to increase the flow in the head on the exhaust side to help spool-up and according to the head guy there isnt a whole heap to be gained from port n polish ie money vs effect

[GTS-t VSPEC]

Port matching and knife edging is all you need on the head.

Ceramic coat the exhaust manifold.

See'ya:burnout:

[adam 32]

ceramic coating aint gunah reduce spool times. cmon paul, think!

[GTS-t VSPEC]

Adam,

Read the other thread, they managed to make it spool up quicker, but usually comes at a cost.

See'ya:burnout:

[GTS-t VSPEC]

Adam,

Yes it does:p

Change plenum design.

See'ya:burnout:

[adam 32]

nah im looking for a cheaper option, prefereably to do with the head/cams/cam gears as its all off the car at the moment

[GTS-t VSPEC]

Adam,

Cam gears are the only cheap option, the other thread said they managed to get better spool up.

See'ya:burnout:

[adam 32]

hmm seem a little expensive for what they do. maybe im just expecting too much. ill just put it all together as is

[Sydneykid]

Hi adam 32, by changing the overlap/separation on the inlet and exhaust camshafts you can most definitely improve the responsiveness of the engine.

However it is a lot easier to set them up for maximum horsepower, we simply run the car up on the dyno and determine where in the RPM band it currently makes its max horsepower. We then work through the combinations of advance on the inlet and retard on the exhaust until we achieve the highest reading at the predetermined rpm. We may move up a down a little in the rpm range just to make sure the adjustments have not altered the maximum power rpm point. Generally speaking there will be little if any adjustments required in the fuel and ignition maps. This process normally nets a 10 to 15 bhp increase at that rpm, but sometimes we loose as much as 10 bhp in the lower rpm positions.

Setting the cam timing up for best responsiveness is a lot more difficult as you are tuning through a range of rpm not just a single point. The way we do it is to tune as above but at the maximum torque rpm. Depending on the boots rise, we are aiming to increase the torque for at least 1,000 to 1,500 rpm around that point. We find that in order to get a good increase we need to change the ignition and fuel maps. Typically we will get a 20 bhp increase at that rpm, but loose up to 10 bhp at the maximum horsepower rpm.

Once we finish on the dyno, a road (better is track) test to confirm we have achieved not only a torque increase but a response increase as well. Our experience has been that if we have to make large changes in the ignition and fuel maps we will get a big improvement in response. Conversely if we only make very tiny adjustments, the response improvement is not as great.

Hope that helps.

[adam 32]

thanks, it turns out this isnt really what im after. top end is fine on my car and makes big power. but due to the large turbo it lacks driveability, ive downsiezed the exhaust wheel from a 2.24" to a 2" but without the desired effect. i want full boost by 3500rpm, maybe with a turbo that big im dreamin

[Sydneykid]

Hi adam32 again, anything that increase the temperature of the exhaust gas improves turbine rpm. So if you ceramic coat the inside on the combustion chambers, valve heads, piston tops and exhaust ports you reduce the temperature loss into the head and ultimately water jacket. The car runs lower water and oil temperature but higher exhaust gas temperature.

Higher temperature = more energy, more energy = higher turbine rpm, higher turbine rpm = more boost at lower engine rpm.

I can't give you real world example on a Skyline as we have always tended to do other things at the same time as we are ceramic coating. But I can tell you that in the targa Lotus we noticed a 10 degree decrease in the water temperature, a 7 degree decrease in the oil temperature and a 30 degree increase in the exhaust gas temperature. Turbo boost reached 1 bar 250 rpm earlier in the rev range.

It is certainly something we do regularly on the team cars, and our personal RB31/RB26 hybrid is having it done as I write this.

Hope that helps.

[adam 32]

how much would it cost to ceramic coat the exhaust manifold only?