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Just add my 2 cents, the earlier model RB25's (R33) come with hydraulic lifters and the major japanese tuning shops only make cam profiles up to ~264 degrees duration with off the shelf type items for those lifters.

Late model Rb25's (R34 and some lucky R33's) come with solid lifters standard and can run the more aggresive profiles. This includes higher lift and more duration.

Some shops offer bolt in hydro to solid conversion kits - it's not a terribly hard thing to do. Or you can knock off an R34 head. You only need to machine the head if you are chasing more than ~10 mil of lift.. something which most off-the-shelf cams for the RB25 don't have. Also, just because you can't find a specific cam from some honky manufacturer doesn't mean you can't get it.

Bu5ter's car has some wickedly large cams in it, sounds like a rotary at cold idle. There are quite a few cars going around that are meant to have more than 500hp with "only" 264 cams.

Machining the head is not very hard. There isn't much to clear. I have 10mm of lift and there isn't too much to take off. An engine shop would charge SFA to die grind it out. Mahcining the head has nothing to do with duration, just lift.

Converting to solid doesn't give you more lift. Identical profiles for solid and hydraulic show approximately half a millimeter more lift on the solid cam. This is clearance take up which is done by the ramps on the lobe.

i have already an achieveable 450hp atw, so jus looking for complimenting camshafts to enhance it to at least 500hp. Suggestions so far are HKS 256/264 and Tomei 264/264, but has anybody actually achieved this hp with those cams? or are these theoretical statements? We're talking top dollar so i have to be certain what i buy. And not much time, engine is out and ready for cams....

for traction im currently running 11 inch wide street tyres

thanks for the input guys...

Say what....

"Late model Rb25's (R34 and some lucky R33's) come with solid lifters standard"

How come our 1999 model R34GTT has hydraulic cam followers? Have we been jipped?

Hi GT 1, I haven't seen a 50 rwhp increase from just changing to 264 degree camshafts, maybe 35 at best. Bit of port matching and tidying up around the valve guides will get you the extra 20 or so.

Our cams in a customers RB30/25 went from 430hp atw to 570 from putting our cams in.

Goes to show that Aussie Engineers aren't so dumb eh? You don't always have to go to Japan to get parts for your cars. Bad for the economy.

The Japs tend to overdo a lot of things when they shouldn't...

Sorry to say Sydneykid, but I actually bought your solids off an anonymous warfie. He claims since the new RAWS reg's went into place everyone there is going broke and actually have to work to make some money. :)

Here's another R34 RB25 thing... the rods are identical to RB26 ones. Not the same part number, but identical in every other way.

Lukevl

So you are telling me, you changed NOTHING else?! Not the AF ratios, not the Ignition timing, intercooler, spark plugs, boost level, etc... and you got an extra 140RWHP?!

Right, Here is the deal. I will pay you personally, $10 for every additional horsepower these camshafts produce in our RB31DET over 40rwhp. Plus, of course, I will pay for the camshafts themselves.

So, if your claim is true, you stand to make $1000.

PM me when your ready. The catch is, if it only makes 40rwhp, I get the camshafts for free.

Ready when you are, Inbox is cleared.

You don't have to be a complete knob-shine. Obviously the Autronic was retuned. How the hell do you expect to install new camshafts and not alter timing? Are you running a back-yard hick shed labelled 'Tuning House' or what?

Note to all: DO NOT INSTALL NEW CAMSHAFTS WITHOUT RE-TUNING YOUR CAR! IT DEFEATS THE PURPOSE OF PUTTING THEM IN THERE IN THE FIRST PLACE.

P.S> My understanding is that the boost and cooler were kept the same.

Originally posted by lukevl

Our cams in a customers RB30/25 went from 430hp atw to 570 from putting our cams in.

I was only repeating what you said. Maybe the truth is the car was reeeeally badly tuned, before hand, and picked up 110rwhp from a decent tune and 30rwhp from the camshafts.

Obviously I was allowing for the performance increase from tuning (for the camshafts) in the 140rwhp. No extra boost of couse, that would be cheating.

The offer STILL stands, PM me when you're ready.

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