Rb26 Cam Choice

[rev210]

Thanx thats what I had thought from what I have been reading on here, will they be a bit laggier or much if a muchness if tuned right (assuming you may have done this at some time so might know), a bit new to TURBO cars so not so sure I suspect tuned right they may even help eliminate some lag due to better/more flow cylinder filling etc. Is that a possibility or have I missed the mark completely

They are not laggy at all. They reduce lag over the factory cams significantly and increase power everywhere.

[Faid]

I use the poncams on my daily driven setup, with a T04Z running 23 psi of boost and 1000cc squirters. the poncams are 260 dur and 9.15 mm lift. using tomei lifters and jun valvesprings. manley custom Gen II 0.5mm oversize valves and ratainers. when i didnt dail in my cams, the car was sluggish to come onto boost, but after expert advice by SK the cams were dailed in and i was actually amazed at how much it allowed me to push the ignition. the car came to full song 400rpm earlier and acually from a roling start it would light up all 4rs through the 1st, 2nd and it would chirp the 3rd. the cams made big big differance, the power increased to 467awkw. on the drag engine im building atm i will be eploying 1mm oversize valves, and jun 280 deg 11.35mm lift cams, to push the T51 SPL BB turbo. all the bits in the head will be jun exept the valves. for the street i dont recomend bigger then 260 on both in and ex.

[noone]

They are not laggy at all. They reduce lag over the factory cams significantly and increase power everywhere.

Thanks mate that confirms what I had suspected, cams I ordered wont make it to me before the dyno time I have booked so will be able to post good before and after cam type dyno sheets for all to see.

Would have liked to put em straight in though with all the other bolt-ons and powerfc but just isnt going to happen.

[overpowered]

why do people not reccomend 272/280 cams for the street? i have them and they dont cause any drivability issues at all so whats the downside besides maybe abit of lag, but plenty of top end power?

[ike]

does anyone know the standard r33 rb26dett cam lift and duration

cheers

[Sydneykid]

why do people not reccomend 272/280 cams for the street? i have them and they dont cause any drivability issues at all so whats the downside besides maybe abit of lag, but plenty of top end power?

Fuel ecomomy

Emmissions, nasty

Noise, a legal 92 db with 248's is not going to be legal wiht 272's

Soft idle problem (and just up from idle) with air con, electrical and power steering loads

Plug fouling

Clutch wear, in fact the full drive train, as you have to use higher rpm to get up the torque curve

Extra capacity does overcome some of those, for example an RB20 is really weak with 272/280‘s but an RB30 with the same cams is strong at idle and just above. High (static) compression ratio also helps as the extra overlap lowers the (dynamic) compression ratio anyway.

cheers

[STATUS]

they do look like an interesting bolt on don't they and to run the cams surgested would make one nasty rb26

far out im diggin from the past but those tomei turbs are big, bigger than the T618Z's ive used in the past... even the T618Z's needed big big cams to work effectively... like 280 big and as far as lift goes they were big enough to require relieving the cam tunnels (common i know but still)

anyone used them? they are bigger than TD06's but low mounted.

[blk180]

Dam T618Z are bigger then TD06s Trent. What size TD06 was that up against.

[Ryosuke Takahashi]

Hi I'm looking at purchasing the JUN stage one camshaft kit from greenline.jp , (272/272 9.7mm lift) the kit says it includes valve springs, is this all that I need to fit the camshafts??

No retainers etc needed?

Cheers

[rev210]

I'd go grab some new bolts, retainers if the motor is going to be seeing big rpm regularly and the usual gasket kit. Oh and you might need a few shims once you measure it all up.

[ronnydotk]

does anyone know the standard r33 rb26dett cam lift and duration

cheers

from my R32 GTR manual

Intake:

valve opens 7deg BTDC, closes 53deg BBDC

Exhaust:

valve opens 63deg BBDC, closes 7deg BTDC

does that make sense?

lift is not stated, just clearances

Edited April 9, 2007 by ronnydotk

[Ryosuke Takahashi]

some new bolts??

Yeah I think I will definately need to shim the head cylinder.

Thanks.

[rev210]

the bolts that hold the cam bearings, they aren't designed for re-use and can break during or even after install. Plenty of people re-use them and of those a small number suffer broken cams and or bolts and if really unlucky a buggered motor.

[ike]

from my R32 GTR manual

Intake:

valve opens 7deg BTDC, closes 53deg BBDC

Exhaust:

valve opens 63deg BBDC, closes 7deg BTDC

does that make sense?

lift is not stated, just clearances

Thats good I can work the rest out thanks but maybe the inlet closes 53deg ABDC ??? making it 240 duration against 236 for the exhaust dunno.

Edited April 10, 2007 by ike