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Hey all,

I've just got my hands on a copy of dyno2000 (looking for 2003 if anyone has it)

and i'm trying to find the stats to simulate an rb25det and other skyline types. so far i've found the bore and stroke (thanks to meggala's site) but thats pretty much all.

These are the variables with the ones i know filled in.

25det

Cylinders 6

Bore 86mm

Stroke 71.7mm

cyl vol 416.49cc

Total vol 2498.95cc

4 valves per cylinder

Intake valves 2

Exhaust valves 2

intake diameter : unknown

ext diameter : unknown

Compression ratio : 9.something??

Induction flow : approx?? cfm

Stock turbo flow : cfm

Pressure ratio : ??

surge flow : ??

And a whole pile of cam stuff i have no idea how to figure out or even explain.

I've tried searching for the above and really cant find much.

Any assistance would be useful, and others might find the info of value aswell.

look forward to hearing your replies.

cheers

M

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I have this program too. Putting all of the below stats into it showed a graph which was very similar to what Nissan shows as factory output of the RB26DETT in an R32 GTR:

RB26DETT

Bore: 86.0mm

Stroke: 73.7mm

Intake Valve: 34.5mm

Exhaust Valve: 30.0mm

Compression ratio: 8.5

Lifter: Solid

Cam Specs @ seat to seat

Int Lift @ Valve: 8.58mm

Exh Lift @ Valve: 8.28mm

Intake Valve Open (BTDC): 7.0 degrees

Intake Valve Close (ABDC): 53.0 degrees

Exhaust Valve Open (BBDC): 63.0 degrees

Exhaust Valve Close (BTDC): 7.0 degrees

with the above specs, all the other data will be automatically calculated by Dyno2000, like cylinder cc volume, total cc volume, combustion cc volume, and camshaft specs like Lobe centres, valve overlap, int & exh duration. It's all maths... very interesting program once you start playing around with the turbo specs, although it is hard to find data on the CFM flowrates of certain turbos unless you went to the trouble of going to a turbo specialist and flowbench each and every turbo... Have fun, but use it as a GUIDE only... I have the save file of the above specs i gave you if you want it.

Cheers,

Zen.

RB26DETT ex valve closes 7BTDC (there's 0 overlap). Although it actually depends which RB26DETT you are dealing with. Zensoku quoted for the R32 version.

For the R33 (R33 N1):

In opens 7BTDC (7BTDC), closes 53ABDC (53ABDC)

Ex opens 63BBDC (58BBDC), closes 7BTDC (2BTDC)

R34 (and R34 N1):

In opens 3BTDC, closes 57ABDC

Ex opens 59BBDC, closes 3BTDC

RB25DET also depends which RB25:

R33:

In opens @TDC, closes 60ABDC

Ex opens 57BBDC, closes 3ATDC

R34:

In opens 1ATDC, closes 57ABDC

Ex opens 51BBDC, closes 1ATDC

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