Rb20 Mix Cams

[falkhen]

Im some what new to RB even though have owned one for some time.

what i have.

Stock RB20DET, with FMIC, Cam gears.

I got some cam gears and i wanted to show them off, like an idiot i took the cam cover off and put the CAS on back on after a while this cause the Cam CAS tooth to break... this made very difficult to get the alignment correct.

one of my friends had a pair tomie cams in wich the intake side was broken during installtion.

i bought the exhuast side in hopes of some performance gains and fixing my CAS alignment problem.

what i did to install this cam.

mechnically aligned the crank at TDC (using the Rod in cylinder method)

aligned the cams at the perspective timing marks.

In\cam is stock RB20DET cam

Ex\cam is Tomie 256° duration cam

i checked the timing over and over its good electrionic wise..

my conclusion is that mechnical time is off but where?

i notice that the Tomie cam is 115° lobe center as the stock cam is 120° could i be 5° off mechanicly?

what it feels like is the timing is way off the the to the left if you would have set the timing on the RB backwards. in my case i check this server times i also noted that the CAS was all the way over in order to get 15°+ TDC

and im from the US,

Seattle , WA

cheers

[blind_elk]

Some timing lights give an incorrect reading using the "timing loop". Check ignition timing by inserting a spark plug lead between coil and spark plug on #1.

I have a spreadsheet (at home) with all the physical characteristics of the standard cams - I'll have a look tonight and see what effect moving 1 LCA by 5deg will have on overlap, etc.

[falkhen]

i would be most greatful.

I found another problem... I went back over the car checking for any leaks and the stock hardpipe that goes into the intakemanifold one of the hose clamps was loose...

the car ran much better but still the problem persists

[blind_elk]

Ok, stock RB20DET exhaust (LCA = 120, duration = 240):

Opens 60 BBDC, closes TDC. This gives 5 degrees overlap with the inlet. Lobe Separation = 117.5

Using a Tomei with LCA = 115, duration = 256:

Opens 63 BBDC, closes 13 ATDC. Gives 18 deg overlap with inlet. Lobe Separation = 115.

AFAIK, turbos don't like a lot of overlap. I'm going to suggest retarding the exhaust cam 10 degrees, but an expert in these matters is free to shoot me down.

[falkhen]

I will take a look at this weekend as i have no time during the work week.

[falkhen]

exhuast set at -10° no good, its even more gutless then before.

car ran better with the cams set at 0°

duh!! double post... sorry about that can't be help.