Jump to content
SAU Community

Recommended Posts

On 5/17/2022 at 8:40 PM, The Mafia said:

Okay, so changed the valve springs and the VCT works as it should now (nice and responsive at idle). 

125psi springs were just too heavy for it. 

I have heard that when people have put heavier springs in the Barra those have stopped working too. 

Currently running HKS springs. 

I recommend lighter springs 90psi would be pushing it. 75psi or below will be my safe estimation.

(Please bear in mind your RPM targets, cam selections, etc). It's a careful balancing act. 

This is actually the first time I've ever heard of this. 

On 19/5/2022 at 9:45 AM, Dose Pipe Sutututu said:

Then you face another problem with valve lift when big boost/rpm are introduced

Spose it has to be application specific.

Youre not going to run 140 lb springs on a basic setup that runs twins and will rev to 8000 rpm and you’re not going to run 50 lb things on an 8 second thing that spins to the moon with turbos the size of a small planet.

FWIW in my pleb motor shit box, I have 80 lb springs in there, I suspect any softer it would valve lift with the boost it sees.

I can't imagine @The Mafia's setup being anywhere near pleb level.

Talking about valve springs in these terms is problematic. Valve spring pressures are measured at the seat, and on the nose of the cam (max cam lift). Two different springs with the same seat pressure don't necessarily have the same pressure on the nose, and vice versa. Like spring rate vs wheel rate when discussing suspension = apples vs oranges

There are so many factors to valve float, seat pressure is barely half the story. Heavy springs will generally help with valve float but they are not always the best way to skin that particular cat and always cost power.

  • Like 2
On 19/05/2022 at 12:40 PM, Komdotkom said:

Talking about valve springs in these terms is problematic. Valve spring pressures are measured at the seat, and on the nose of the cam (max cam lift). Two different springs with the same seat pressure don't necessarily have the same pressure on the nose, and vice versa. Like spring rate vs wheel rate when discussing suspension = apples vs oranges

There are so many factors to valve float, seat pressure is barely half the story. Heavy springs will generally help with valve float but they are not always the best way to skin that particular cat and always cost power.

Very fair points as well, I suppose this is why talking to an engine builder with decades of RB experience helps.

I pretty much just took guidance from whatever Alex at Birrong Automotive recommended.

On 19/05/2022 at 9:59 AM, Dose Pipe Sutututu said:

FWIW in my pleb motor shit box, I have 80 lb springs in there, I suspect any softer it would valve lift with the boost it sees.

I can't imagine @The Mafia's setup being anywhere near pleb level.

haha details. What engine / cams / turbo / boost / power are you running? 

On 20/05/2022 at 10:12 AM, The Mafia said:

haha details. What engine / cams / turbo / boost / power are you running? 

Pleb setup lol.. just a 2.5L with cheapie forged parts (CP Pistons, Manley H beams), 264/272 9.6mm w/ VCT retained, planned 2bar, GTX3576R Gen2 with divided 1.01, Sinco TS manifold.

Need to book a dyno to tune it when I have time.

  • 3 weeks later...
  • 1 month later...

HKS suggest upgrading the valve springs for the Vcam Step 2 or step pro kits.

anyone know what the seat pressure of the HKS springs are? I can't find any info.

I've got kelford beehives at 105lb seat so it would be interesting to know if this rules out Vcam for me.

On 27/07/2022 at 11:37 PM, burn4005 said:

HKS suggest upgrading the valve springs for the Vcam Step 2 or step pro kits.

anyone know what the seat pressure of the HKS springs are? I can't find any info.

I've got kelford beehives at 105lb seat so it would be interesting to know if this rules out Vcam for me.

Hey mate

HKS springs have a 55psi seat pressure. We measured them ourselves when installing them. 

Your 105lb Kelford Springs will be too heavy. Vcam won't work until over 3000rpm.

JUN springs are 65psi and I recommend those. I would have used them now that I have the HKS springs. 

This is just a guess too - but I think about 75psi would be the limit for a Vcam. 

The Vcam was worth it though. Car had about 1000rpm more usable powerband down low. comes on boost a lot more savage now too, and that is with the BW EFR 8374. I just installed a 8474 so I'm keen to see how that performs. 

 

  • Like 4
On 7/27/2022 at 3:37 PM, burn4005 said:

HKS suggest upgrading the valve springs for the Vcam Step 2 or step pro kits.

anyone know what the seat pressure of the HKS springs are? I can't find any info.

I've got kelford beehives at 105lb seat so it would be interesting to know if this rules out Vcam for me.

Funny I ask that to HKS last week, they said 55

  • 3 weeks later...

This is the purest form of Skylines Australia. Proper data straight into the SAU encyclopaedia. 

I wish I knew this when I installed mine. Could have saved a lot of time and $$ and used heavier springs. 
 

Thanks so much for the information. 

  • Like 1

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

    • From there, it is really just test and assemble. Plug the adapter cables from the unit into the back of the screen, then the other side to the car harness. Don't forget all the other plugs too! Run the cables behind the unit and screw it back into place (4 screws) and you should now have 3 cables to run from the top screen to the android unit. I ran them along the DS of the other AV units in the gap between their backets and the console, and used some corrugated tubing on the sharp edges of the bracket so the wires were safe. Plug the centre console and lower screen in temporarily and turn the car to ACC, the AV should fire up as normal. Hold the back button for 3 sec and Android should appear on the top screen. You need to set the input to Aux for audio (more on that later). I put the unit under the AC duct in the centre console, with the wifi antenna on top of the AC duct near the shifter, the bluetooth antenna on the AC duct under the centre console The GPS unit on top of the DS to AC duct; they all seem to work OK there are are out of the way. Neat cable routing is a pain. For the drive recorder I mounted it near the rear view mirror and run the cable in the headlining, across the a pillar and then down the inside of the a pillar seal to the DS lower dash. From there it goes across and to one USB input for the unit. The second USB input is attached to the ECUtec OBD dongle and the 3rd goes to the USB bulkhead connected I added in the centre console. This is how the centre console looks "tidied" up Note I didn't install the provided speaker, didn't use the 2.5mm IPod in line or the piggyback loom for the Ipod or change any DIP switches; they seem to only be required if you need to use the Ipod input rather than the AUX input. That's it, install done, I'll follow up with a separate post on how the unit works, but in summary it retains all factory functions and inputs (so I still use my phone to the car for calls), reverse still works like factory etc.
    • Place the new daughterboard in the case and mount it using the 3 small black rivets provided, and reconnect the 3 factory ribbon cables to the new board Then, use the 3 piggyback cables from the daughterboard into the factory board on top (there are stand offs in the case to keep them apart. and remember to reconnect the antenna and rear cover fan wires. 1 screw to hold the motherboard in place. Before closing the case, make a hole in the sticker covering a hole in the case and run the cable for the android unit into the plug there. The video forgot this step, so did I, so will you probably. Then redo the 4 screws on back, 2 each top and bottom, 3 each side and put the 2 brackets back on.....all ready to go and not that tricky really.      
    • Onto the android unit. You need to remove the top screen because there is a daughterboard to put inside the case. Each side vent pops out from clips; start at the bottom and carefully remove upwards (use a trim remover tool to avoid breaking anything). Then the lower screen and controls come out, 4 screws, a couple of clips (including 3 flimsy ones at the top) and 3 plugs on the rear. Then the upper screen, 4 screws and a bunch of plugs and she is out. From there, remove the mounting brackets (2 screws each), 4 screws on the rear, 2 screws top and bottom and 3 screws holding in the small plates on each side. When you remove the back cover (tight fit), watch out for the power cable for the fan, I removed it so I could put the back aside. The mainboard is held in by 1 screw in the middle, 1 aerial at the top and 3 ribbon cables. If you've ever done any laptop stuff the ribbon cables are OK to work with, just pop up the retainer and they slide out. If you are not familiar just grab a 12 year old from an iphone factory, they will know how it works The case should now look like this:
    • Switching the console was tricky. First there were 6 screws to remove, and also the little adapter loom and its screws had to come out. Also don't forget to remove the 2 screws holding the central locking receiver. Then there are 4 clips on either side....these were very tight in this case and needed careful persuading with a long flat screw driver....some force required but not enough to break them...this was probably the fiddliest part of the whole job. In my case I needed both the wiring loom and the central locking receiver module to swap across to the new one. That was it for the console, so "assembly is the reverse of disassembly"
    • But first....while I was there, I also swapped across the centre console box for the other style where the AV inputs don't intrude into the (very limited !) space.  Part# was 96926-4GA0A, 284H3-4GA0B, 284H3-4GA0A. (I've already swapped the top 12v socket for a USB bulkhead in this pic, it fit the hole without modification:) Comparison of the 2: Basically to do the console you need to remove the DS and PS side console trim (they slide up and back, held in by clips only) Then remove the back half of the console top trim with the cupholders, pops up, all clips again but be careful at the front as it is pretty flimsy. Then slide the shifter boot down, remove the spring clip, loose it forever somewhere in the car the pull the shift knob off. Remove the tiny plastic piece on DS near "P" and use something thin and long (most screwdrivers won't fit) to push down the interlock and put the shifter down in D for space. There is one screw at the front, then the shifter surround and ashtray lift up. There are 3 or 4 plugs underneath and it is off. Next is the rear cover of the centre console; you need to open the console lid, pop off the trim covering the lid hinge and undo the 2rd screw from the driver's side (the rest all need to come out later so you can do them all now and remove the lid) Then the rear cover unclips (6 clips), start at the top with a trim tool pulling backwards. Once it is off there are 2 screws facing rearwards to remove (need a short phillips for these) and you are done with the rear of the console. There are 4 plugs at the A/V box to unclip Then there are 2 screws at the front of the console, and 2 clips (pull up and back) and the console will come out.
×
×
  • Create New...