I won't let it go will I.....................

I'd be interested to see the result's of someone fitting cam's to their engine and seeing what the difference was power wise before and after, and the cost of such a stunt.

Simon from XFT might be able to answer that very question.

The usual principles apply to turbo cars as for n/a cars

I.e

1.longer duration/overlap for lumpier idle and for a lot more power at higher revs, to allow more air to flow.

2. more cam lift to flow more air, but more cam wear and pressure on valve springs.

Turbo cams used to have less overlap than na cams, for better emissions, and with turbo pressure meant you did not need as much inlet duration to get the air into the cylinders, and better drivability at lower revs, to compensate for the lower compression of turbo cars. Variable cam timing means that is no longer a major issue, and even more so if the tuner knows how to vary the exhaust and inlet independently.

Over 20 years ago I played with a Group C racing cam in my Pulsar ET. Power increase was incredible, drivability pathetic under 2500 revs…. those days are over.

My car is now running very little extra in terms of lift and extra duration, and that is providing for a 7500 revs limit, and retaining pretty good idle at a bit higher than standard.

Factory cams seem to be pretty good up to 500rwkw, and before you get to this power level you need to change quite a few components, including turbo & exhaust manifold.

The hydraulic lifters seem to work OK as well, and my car has been used for evaluation of solid and hydraulic lifters.

Note:

1: no-one is going to reveal their cam specs

2: rarely do you do a cam change only (someone doing R&D should)

3: don’t expect the same results as someone else if you have different other components…. I.e benefits quoted may not apply to you

I’d expect aftermarket cams to have very subtle changes, and probably not a lot of bang for buck, assuming that good drivability is retained.

Brian

Are there any benefits to fitting vernier gears for cam phasing as they tend to do for the jap cars. I had them fitted to my GT-4 way back and it allowed the tuner a lot of scope for optimising power without changing cams. Cam timing was easily altered and made quite a difference picking up, upto 20rwkW on a car only making 150rwkW at all four wheels.

on my car I have atomic cams and the power difference is negligable with the stock turbo running out of puff before they are in their happy zone. the intake and exhaust note on the other hand are magic and in that respect has won a lot of fans.

hope this helps

performance aside the sound is worth every penny

MmmMm....

Ok.

I ran cams in mine and I ran cams out of mine. Same motor with nothimg changed but the cams.

I did dyno testing and boost testing between the 2. I did low down power testing ect ect.

I came up with this.

I wouldnt bother in anything that isnt making HUGE power.

Ive done 3 with cams and find them pretty easy to tune with cams but still would preffer not to use them. Once I change my turbo at a later date to achive more power Im considering trying some more, but they wont be as big as the ones I currently have sitting under my bench.(Same as youngys and DAZZA's have)

Ill try some smaller. Also if I had a choice between cams and oil pump gears the gears would win HANDS DOWN, for what 650 bucks or so you have invested in your thousands of dollars worth of engine.

OK OK OK Rapid F6 and SIMON!!!!

I am not going to buy cams - but OIL PUMP GEARS INSTEAD!!

Where can I get these billet ones for $650???

Thanks for all the great feedback everyone - good to have a technical discussion with no Tuner stooging for once.

From me