HKS Cam Gears

[GTS-t VSPEC]

See Adam, the smart man agrees with me. I have contact details of a guy here in Perth, but it isn't cheap, nothing good is.

See'ya:burnout:

[Sydneykid]

Hi adam 32 once again, I can guarantee you that if you adjust your camshaft timing, port the head (mildly) and do the ceramic coating you will achieve more boost at lower rpm.

By changing to an equal length, more free flowing exhaust manifold of smaller diameter you will also achieve a similar improvement. You may also be able to achieve an improvement by turbine outlet pipe changes and wastegate diameter increases.

The main problem is that this was not the question you asked when you started this post, you asked about camshaft pulleys and response.

If you want further advice it will help greatly if you post the turbo and relevant engine specs.

Hope that helps

[b2barker]

Or you could thermowrap cheaper and uglier. There is a thread in here somewhere about pricing ceramic coating and thermowrap. Rev210 wraps his doesn't he, or was that the dump pipe?

[Sydneykid]

Hi guys, I'm not too keen on wrapping a cast exhaust manifold, it easily exceeds its design temperaure. Wrapping is OK on stainless pipework, but ceramic coating the inside of the cast manifold is a good solution.

Hope that clarifies.

[Sydneykid]

Something is wrong, I agreed with GTS-t VSPEC, quick call the doctor.

[GTS-t VSPEC]

Sydneykid,

Just make sure it doens't happen again:p

Adam has an HKS manifold already, so I think that a mild porting and ceramic coating would be beneficial.

See'ya:burnout:

[rev210]

adam if you want less time to spool (the revs will remain the same but you will get there quicker) then a light flywheel and pulleys (also reduced ratio). An easy and cheap way to speed the exhaust gas on it's way is to thermal wrap the dump pipe.

I'd say the cam pulleys are worth the $$, at least all you need is the 1 exhaust pulley to sharpen up the turbo end of things.

[adam 32]

ive got a lightened flywheel already...

but you think the cam gear on the exhaust side is worth it?

[rev210]

yep the exhaust side most benificial.

The intercooler pipe from turbo to intercooler benifits from thermal wrap as well, keeps it nice and hot.

[adam 32]

im not too keen on the thermal wrap, if i were going to change the piping id probably HPC them. reason being that ive got BOV and small hoses coming off most of the intake pipes which makes it hard to wrap them properly

[rev210]

yes ceramic coating is quite good for those fiddly areas that tape doesn't do as easy.

Having said that the turbo to intercooler pipe doesn't have much on it at all and it just saves a few $$$ before you go and get the ceramic stuff. $100 worth of thermal tape will probably do your dump pipe and the intercooler pipe.

[dojobi]

Adam, I'm almost certain that you can get the result you want with the cam gears. Mine is set up to be exactly the opposite of what you want. ie dead bottom end, and high top end. I am considering having it retuned to fix the bottom end the way you want it.

If you want to see a dyno sheet where the cam gear is set for top end I've got one at www.ozemail.com.au/~caddies

The file is MIC33Rdyno.jpg or something like that.

This was done with 2 deg retard on the ex gear. Above or below that it made it drop up top and rise down low (or the whole power curve dropped). I don't know why everyone says 4 deg retard on the ex gear, as I tried that initially and it certainly wasn't pretty.

BTW The dip in the curve at the bottom is due to the cam gear. It used to be straight until the gear was adjusted.

[Sydneykid]

Hi MIC33R, you asked "I don't know why everyone says 4 deg retard on the ex gear".

Are you talking 4 degrees of camshaft rotation? Or 4 degrees of crankshaft rotation?

The camshafts rotates at half crankshaft speed, so 4 degrees of crankshaft rotation = 2 degrees of camshaft rotation.

Generally speaking the markings on the adjustable pulleys are camshaft degrees.

When I discuss adjusting camshaft timing I normally refer to degrees of crankshaft rotation. This is so that ignition timing, injector timing and camshaft timing can be referenced against each other as they all refer to crankshaft rotation. I don't know whether the other guys do that, but that's the way I do it.

So 4 degrees of crankshaft = 2 degrees on camshaft pulley markings, which I suspect is what you have found to be best for high end power.

Hope that makes sense.

[dojobi]

Ahh, makes total sense. If that's the case, then add me to the list of people who say 4 degrees is the optimal setting for a better top end. This was tested over a fair few dyno pulls too.

I'm still going to adjust mine to give me a better mid range as I don't like the hole in the power down low.

[rev210]

I've just reset my exhaust cam gear to 1.5 deg retard (3 crank deg). The mid range improvement is awesome over the previous 2 deg (4 crank) setting. Now I have serious 'leaning out' at as low as 3400rpm that requires me to 'add' fuel on the S-afc, the factory fuel curve can't supply enough!