Jump to content
SAU Community

Recommended Posts

If you buy Jap cams for the RB25VVT they will have a conservative inlet so it can run with the VVT. Buy cams to suit a non-VVT Rb25 or RB20 that way your HKS gears (I assume they are the same- 4 bolts and a pin) will bolt on and you will have no VVT.

I have used the Tomei Poncams (256 for RB25DET and 260 for RB25DET Neo) in a few engines and they work very well. I have tried an adjustable exhaust camshaft pulley on 2 of them and found no improvement. They appear to be very well timed standard.:cheers:

Gary thats good info that has been repeated alot around here i have noticed, BUT

does the inlet cam have 4 bolts + locating pin or does i just have 1 big bolt to hold the VVT gear on?

What sort of cams would be suitable in an RB30DET situation.. Limited to 8.5mm lift due to rb25det head?

Reason why i have concerns with the Tomei cams is that they are made to work with the VVT, so therefore you would still bolt the stock cam gear on thus would have the incorrect bolt pattern for my HKS RB cam gear...

Gary thats good info that has been repeated alot around here i have noticed, BUT

does the inlet cam have 4 bolts + locating pin or does i just have 1 big bolt to hold the VVT gear on?

What sort of cams would be suitable in an RB30DET situation.. Limited to 8.5mm lift due to rb25det head?

Reason why i have concerns with the Tomei cams is that they are made to work with the VVT, so therefore you would still bolt the stock cam gear on thus would have the incorrect bolt pattern for my HKS RB cam gear...

I am certainly not the only one that has found that the RB25DET Tomei Poncams don't need adj pulleys, Croydons have reported the same on a few cars as well.

The standard internals RB30 is not a big rever, so it doesn't really need big duration cams. The 256's should work VERY well. The 8.5 mm lift is not "limited by the RB25 head", I have used the Jun 256/9.3 mm in an RB25, but the valve springs needed to be changed.

As for camshaft selection, it was suggested to me that the RB20DET 256/8.5mm camshafts would work OK in an RB25DET cylinder head with adjustable camshaft pulleys. I have not personally tested this though, but the source is reputable.

Hope that is of some help:cheers:

Gradenko: I'd be interested to know how they managed to put that cam gear on the inlet cam!

Does anyone know anyone with Tomei Poncams installed in an RB25DET head? I want to know what the profile is on the front of the cam to hold the cam gear on... Is it 4 bolts and a locating pin, or is it the same as stock with a single bolt??

  • 2 years later...

just checked my tome poncams 260 for my neo. the inlet has one bolt.....dat suxs coz i got a set of tomei adj cam gears to go aswell!!! Anyway of still installing it???? And if it could be done then the hud on the stock inlet could be removed?

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

    • So, now all you need to do is connect the 2 or 3x 12v feeds into the unit to permanent 12v, ACC 12V and IGN 12V that you can find in the spot behind the stereo, and the earth, and then it will switch on with the car.
    • Yes then it will turn on but I want the car features to work  
    • My thought is if you were just moving it forward and the upstream geometry remained the same, then no difference at all. But because the current one has the filter direct into the AFM inlet, you effectively have the best chance of a completely symmetric air flow profile upstream, and in, the AFM, whilst the aftermarket inlet thingo has a (small, to be sure) bend between the filter and the AFM. That would bias the flow to the outside of the bend (downstream of the bend) which might well reduce the size of the signal seen by the AFM, for the same total flow rate. Having said that: If you're proposing to make your inlet look like a hybrid of your existing one and the aftermarket one, such that there is no bend where the filter is clamped on... then I say it will be just fine. If there is going to be such a bend, then, if you can align the insertion of the AFM blade such that it is at right angles to the plane of the bend, then there is a better than even chance that the centreline velocity where the blade is will remain more or less the same, and the velocity will just be a little faster to the outside of that, and just a little slower to the inside. **This is not professional investment advice and you should consult a suitably qualified ouija board, tea leaves or the intestines of a goat for more accurate prognostication.
    • Hi Tao, Thanks for your reply.  It's been a while and I managed to get the valve stem seals replaced with the head on the car.  Unfortunately this didn't solve my issue, the car still smokes a lot after idling (to be honest during idle you can see a bit of blue smoke from the exhaust), same after deceleration. I will try disconnecting the valve cover breathers, do I leave the PCV valve in? By engine oil drain pipe, do you mean the turbo oil drain?
    • What about if you just give it direct 12v and earth?
×
×
  • Create New...