Jump to content
SAU Community

Recommended Posts

got some cam gears for my 32 and i'm just checking that when installing them ready for tuning its best just to set them both to zero?

EDIT: I've just finished installing my adjustable cam gears and now the cars idle is extremely rough and eventually stalls, my ignition timing on my power fc is on about 20? Don't have a timing light so can't check it that way!

Anyone got any ideas what it could be? I made sure the harmonic balancer lines were at tdc aswell as having both the cam gears at 0 (figured i'd let my tuner play around with whats best)

PLEASE HELP!!!!

Edited by mr_rbman
Link to comment
https://www.sau.com.au/forums/topic/137751-installing-cam-gears/
Share on other sites

got some cam gears for my 32 and i'm just checking that when installing them ready for tuning its best just to set them both to zero?

Set them both to zero and dial them in on the dyno when you take it in for a tune.

If it's a 20, the inlet will most likely stay at zero and the exhaust will probably be changed to 2 degrees retarded but leave it up to the tuner to set it properly.

Definitely some tweaking to do ash.

Drop Andrew a line and see what he set his up at.

All though he was running RB20DET cams which run a 240duration 7.8mm lift exh cam vs the rb25de's 232duration 7.3mm.

I'll try to dig up the R32 RB25DE and RB20DET cam centerlines to get you started.

Ok got the centerlines...

R32 RB25DE

Inlet: 240dur 7.8mm lift, Centerline: 112degree's

Exh.: 232dur 7.3mm lift, Centerline: 118degree's (I think)

IVO: 8, IVC: 52, EVO: 54, EVO: -2

In/Exh lobe relationship (LCA): 115degree's

Overlap: 6degree's

RB20DET

Inlet: 240dur 7.8mm lift, Centerline: 115degree's

Exh.: 240dur 7.8mm lift, Centerline: 120degree's

IVO: 5, IVC: 55, EVO: 60, EVC: 0

In/Exh. labe relationship (LCA): 117.5degree's

Overlap: 5degree's

Should give you a good head start in where to begin fiddling. :ban:

Also note the tomei web site lists very very slightly(LCA) different specs for the cams. I'll believe the engine manual.

Where to start with the 3ltr... No idea :wave:

post-382-1160403623.jpg

as said leave it at zero for the dyno operator to change...

on my rb20det i made more power everywhere with +3 inlet and -5 exhaust settings (do a search i wrote it all in a thread somewhere)

it basically shifted the power curve left so that at the same rpm i was making about 10% more power.. :(

as said leave it at zero for the dyno operator to change...

on my rb20det i made more power everywhere with +3 inlet and -5 exhaust settings (do a search i wrote it all in a thread somewhere)

it basically shifted the power curve left so that at the same rpm i was making about 10% more power.. :)

cheers, i tried looking for that thread as i remember it but i dunno what i do when i search but i never seem to find what i wanna look for!

Cubes, thanks for that but isn't that referring to camshafts rather than cam gears? I think i'll let Shaun just fiddle with it on the dyno, as long as i have it setup safe to drive for a while i'll be happy!

cheers, i tried looking for that thread as i remember it but i dunno what i do when i search but i never seem to find what i wanna look for!

Cubes, thanks for that but isn't that referring to camshafts rather than cam gears? I think i'll let Shaun just fiddle with it on the dyno, as long as i have it setup safe to drive for a while i'll be happy!

The cam gears is what setup the centerlines... For example 0 on the rb25de inlet cam is a centerline of 112degree's. Move the cam gear -5 or +5 and it changes the cams centerline accordingly.

So there's 3degree's difference between the std positioning of the rb25de and rb20det inlet cam.

Sky30 ran a heap of overlap to bring the turbo on sooner and pick up mid range power; from memory top end power was sacrificed by ~10rwkw but he picked up something like 20-30rwkw through the mid. He will be able to clear up the exact power increases. I can't remember exactly but those numbers do ring a bell. :)

The cam gears is what setup the centerlines... For example 0 on the rb25de inlet cam is a centerline of 112degree's. Move the cam gear -5 or +5 and it changes the cams centerline accordingly.

So there's 3degree's difference between the std positioning of the rb25de and rb20det inlet cam.

Sky30 ran a heap of overlap to bring the turbo on sooner and pick up mid range power; from memory top end power was sacrificed by ~10rwkw but he picked up something like 20-30rwkw through the mid. He will be able to clear up the exact power increases. I can't remember exactly but those numbers do ring a bell. :P

ahhh, i understand now, takes me a couple of reads to understand things but i get there! I'll msg andrew!

3lit3,

By retarding the exh. cam by 2 degree's what sort of gains do you see? Mid to high rpm with no noticable loss from the low end?

Mainly just a jump in mid range. No loss down low but I am using a GT2876 with a 0.86 rear so it really has nothing down low anyway.

I'd say start again.

Rip out the radiator, harmonic balancer and cam belt covers.

Throw it on to TDC and check the cam timing is all lined up.

By leaving the harmonic balancer on and trying to line everything up its possible for the belt to be slightly off the lower drive gear (simply because there's no tension on it and you can't see it), as a result when you spin the motor over it jumps a tooth or two and the cam timing is thrown out.

If you remember back to when you first got the motor in the car, I checked and reset (as it was out a tooth) the cam timing; I pulled off the balancer as it wasn't worth the hassle of the lower drive gear being out a tooth or two.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Here is the mess that I made. That filler there was successful in filling dents in that area. But in the middle area. I can feel dents. And I've gone ocer it multiple times with filler. And the filler is no longer there because i accidently sanded it away. I've chased my tail on this job but this is something else lol. So I'm gonna attempt filler one more time and if it doesn't work I'll just high fill primer the door and see where the issues are because guidecoat is of no use atm.
    • Ok, so I think I sort of figured out where I went wrong. So I definitely overthinked it, and I over sanded, which is probably a large part of the problem. to fix it, I ended up tapping some spots that were likely to be high, made them low, filled them in, and I tackled small sections at a time, and it feels a lot better.    I think what confused me as well is you have the bare metal, and some spots darker and some are lighter, and when I run my finger across it, it' would feel like it's a low spot, but I think it's just a transition in different texture from metal to body filler.    When your finger's sliding on the body filler, and crosses over to the bare metal, going back and forth, it feels like it's a low spot. So I kept putting filler there and sanding, but I think it was just a transition in texture, nothing to do with the low or high spot. But the panel's feels a lot better, and I'm just going to end up priming it, and then I'll block it after with guide coat.   Ended up wasting just about all of my filler on this damn door lol  
    • -10 is plenty for running to an oil cooler. When you look at oil feeds, like power steering feeds, they're much smaller, and then just a larger hose size to move volume in less pressure. No need for -12. Even on the race cars, like Duncans, and endurance cars, most of them are all running -10 and everything works perfectly fine, temps are under control, and there's no restrictions.
    • Update: O2 sensor in my downpipe turned out to be faulty when I plugged in to the Haltech software. Was getting a "open circuit" warning. Tons of carbon buildup on it, probably from when I was running rich for a while before getting it corrected. Replaced with new unit and test drove again. The shuffle still happens, albeit far less now. I am not able to replicate it as reliably and it no longer happens at the same RPM levels as before. The only time I was able to hear it was in 5th going uphill and another time in 5th where there was no noticeable incline but applying more throttle first sped it up and then cleared it. Then once in 4th when I slightly lifted the throttle going over a bump but cleared right after. My understanding is that with the O2 sensor out, the ECU relies entirely on the MAP tune and isn't able to make its small adjustments based on the sensors reading. All in all, a big improvement, though not the silver bullet. Will try validating the actuators are set up correctly, and potentially setting up shop time to tune the boost controller on closed loop rather than the open loop it is set to now. Think if it's set up on closed loop to take the O2 reading, that should deal with these last bits. Will try to update again as I go. 
    • More so GReddy oil relocation kits, sandwich plates, etc. all use 10AN fittings. And same, I've only used 10AN and my car sees track work (circuit, doing laps, not 10 sec squirt business).
×
×
  • Create New...