What Cam Lift And Duration Would You Reccomend?

[BADR33]

hey guys. im hopfully going to be able to get a hold of another set of cams soon so i can send them off to a cam shop to get regound.

what lift and duration are you guys using?

basicly the specs of the engine is:

rb30 block with 25de pistons and 25vvt head.

10.4:1 compression.

custom headers, 2.5" exhuast

wasted spark ingnition.

soon to be fitted:

2x xf throttle bodys and intake pipes or new airbox.

plug in link ecu

also if i do end up taking the head off is there anything else you would reccomend?

at the moment im about 125rwkw

my aim is 150kw+ peak power at about 6500+ if possible.

cheers

[Eug]

the standard cams can only be mildy regrounded.

standard:

240º and 7.8mm lift (from memory, don't quote me on that)

and from what i read somewhere on here ages back, you can get them reground to:

inlet: 255º and 8.2mm lift

exhaust: 258º and 8.2mm lift

if you do take the head off, maybe see if you can:

- deck the block or head a little to bump up compression

- port and polish

- cam gears

- extrude honing??

- thinner head gasket

- also check for piston vs. valve clearance.

stock cams are 240 degrees duration with 7. 8 mm lift

[SKiT_R31]

Ive got pretty much the same setup to you, with twin standard throttlebody's and a surecam reground cam with 255 degrees duration and 8.2 mm lift, and adjustable cam gears, with UNTUNED SAFC2, had it on the dyno yesturday, got 150.9RWKW on dr drifts dyno.

my power peaked at about ~ 5500-5800rpm and dropped nearly 10kw by ~ 6500rpm (all guesstimates as rpm was not shown)

Though i think this may be due to an exhaust restriction (only got a 2.25" cat in it with press bent 2.5" exhaust, to be fixed very soon) and it was a bit rich up top (about 12.5:1 the reading was - there was plenty of black smoke after 5000rpm) gonna be tuned as soon as i get the exhaust redone/heat wrapped and hopefully new extractors.

Edited February 20, 2007 by SKiT_R31

[BADR33]

oh true. hmm sweet as..

i guess i will needa have a good think about this..

i need to decide between that regrind or somthing like tomi poncams but at double the price i think ill go with regrinds....

[SKiT_R31]

oh true. hmm sweet as..

i guess i will needa have a good think about this..

i need to decide between that regrind or somthing like tomi poncams but at double the price i think ill go with regrinds....

worked out my dyno graph the other night (translated kph to rpm) peak power was exactly 6000rpm, peak torque exactly 5000rpm, it held its power for about ~ 300rpm, then from there it lost about ~8rwkw to limiter (set at 6800rpm).

so i was off by about 300rpm in my guesstimation

i reckon with a few things and a good tune hopefully it should hold its power to limiter