83 replies to this topic

[2LV8ETR]

Wolf3D v5 ECU, Z32 AFM's.

With the Wolf you won't need the AFM's.

Heres something, what injectors, cams and cams gears does everyone recommend? Ive herd HKS cam gears are bad for slipping. I don't want that happening. JUN/Tomei?

Nismo or Sard injectors. Sard's will most likely need a spacer, but that's neither here nor there. Depending of course what fuel rail you'll be using.
Cams - Jun Stage 2R $$$$$$ (comes with gears), Tomei or HKS in second place. Also lift & duration will vary depending on power figures.
I've too heard of HKS cam gears slipping. Then again, a lot of people are using them with excellent results. Nitto's are supposed to be good but pricey.

BTW the jumping on the HP figure i reckon was because it was jumping on the dyno but i could be wrong.

Not my opinon. I reckon the wastegates were cracking open. I believe the Le Mans turbos you have to put on come with heavier springs. That's why big power turbos use an external gate.

[NA_Goodness]

I've never heard of HKS cam gears slipping. We've discovered Phil has some on his GTR, and no issues there.
Poncams are good, and I've heard good things about HKS cams too.

[Hanaldo]

Not my opinon. I reckon the wastegates were cracking open. I believe the Le Mans turbos you have to put on come with heavier springs. That's why big power turbos use an external gate.

That's sort of what I thought, but the bouncing on the power curve was only in the higher rpm, if you compare it to the boost curve the boost curve is relatively smooth? Surely if it were the wastegates causing the problem then the boost would be bouncing as well?

[2LV8ETR]

Have a look at the power curve. It begins to dip, then rise multiple times. When it dips, it's because the wastegate cracks, allowing the exhaust through which decreases the boost, which is where the loss of power occurs. If you look at the boost curve, you'll also notice the flutter at the same time that the power declines. The boost only has to taper off momentarily to eccentuate the loss of power at the wheels. This is why there's such a dramatic wobble in power compared to the small flutter in the boost line.
The car wasn't skipping on the rollers so that rules out that thought. If it was slipping and breaking traction, there would be a dip in the curve, not a wobble. It would be like laying a burnout on the street, instant loss of traction, not axle tramp.

[Hanaldo]

Ahh yes, true, I didn't really pay much attention to the little dip in the boost. Is that noticeable when you're driving? I imagine not, my boost tapers off but I don't feel it at all...

[V8EATER]

That's sort of what I thought, but the bouncing on the power curve was only in the higher rpm, if you compare it to the boost curve the boost curve is relatively smooth? Surely if it were the wastegates causing the problem then the boost would be bouncing as well?

Thats what i would of thought.

Full boost was at 95kmph. It does a couple of little hops (Spikes) at 100 - 110kmph, then stays stable all the way thru with 13psi. If it was cracking the waist gate fluttering it at the 160 to 180kmph range (shown on the power curve), then the boost curve should show that too. Well it doesnt, so that makes no sense Al.

The first run shown in Red, shows it all bouncy. When i watched the video of the first run, he shuts the car off afterwards and made some adjustments to the dyno. The second run (Blue line) shows it being a lot better run without it jumping as much. They must of changed something to stop it from happening. Adjusted roller postion or something.

Who knows...

[2LV8ETR]

Makes perfect sense. The hp loss per wave is only between 5-8hp. You won't feel that at 280hp. The boost falters at the same time as the hp.
Take note of the first run (red). The boost falters more here than with the second run. The hp on the first run is all over the place compared to the second run where boost falters less.
At the end where the power tapers off, you'll see the boost dip as well.
Like I said, the car was not skipping on the rollers. It definitely would not lose and gain traction as quick as shown on the chart either.
If one, or both of the actuator springs were lazy, it would crack open the gate which causes a loss of exhaust flow through the turbine, which in turn decreases boost, which decreases power. The actuator can only hold so much force before the pressure in the turbine outweighs the spring tension.
The same can be said for BOVs and bypass valves. If there's too much manifold pressure for the spring to sustain, it would crack open and release the boost, which would cause a loss in power.
But if the actuator spring was lazy, yes it would be a contributing factor.
Regardless, I stand my ground.

[2LV8ETR]

Look what I just found in my inbox: http://www.skylinesa...re-t337672.html

[Tiddy]

Cant go past jun cams + oversized valves, sodium filled maybe.
maybe go a dry sump?
computer with a MAP sensor would be better than AFM. Probably easier to tune and also more accurate

[Char]

Ah yeh true, could well have been...

Cams and cam gears = Tomei ftw! Tomei pon cams are awesome

Tomei pon cams are shit, i sold some about a year ago. stuff all lift 256 duration, basically same as stock. + they are only for rb25.
u can go pro cams or hks (if u can find them) but for rb25s u need solid lifters etc

for rb26 or even rb25 id just walk into a machine shop get the stock ones chopped or get custom ones

[Hanaldo]

they are only for rb25.

Tomei disagrees http://www.tomei-p.c...0_cam_RB26.html

You can get different lift and duration specs? Anywhere from 250 degrees to 290 degrees, and lift anywhere from 9.15mm to 11.50mm.

[V8EATER]

JUN cams sound like the go for sure after seeing that link from Allen.

Sodium filled??? Whats that Callum?

[Tiddy]

JUN!

[NA_Goodness]

Hollow valves with sodium beads in them. The beads draw heat out of the valve then dissapate it somewhere (Cant remember now ) but they're definately the go where possible. Many new cars have them now, I know CX7's and Mazda 3 MPS's all run sodium filled valves

[Hanaldo]

JUN cams sound like the go for sure after seeing that link from Allen.

If you look at the link again, the verdict is that the camshaft was not installed properly, which lead to the snappage. Can't expect it to last if you don't install it right

[2LV8ETR]

The valves are hollow and contain sodium which melts during engine operation. The valve action causes the sodium to circulate, removing heat from the head. The heat travels up the valve stem and is transferred to the cylinder head where the heat is carried away by the cooling channels.

[V8EATER]

Hmm interesting, sodium filled valves. The more i read and find out info, the more i like JUN as a cam solution.

With the ecu, im thinking of changing my mind to either a ViPEC V44/V88, a MoTeC M600/M800 (expensive), or a Microtech LT12s. Theres more support for the products and tuners can tune them easier compared to the wolf3d ecu from what ive been told.

[Tiddy]

definately m800 gold box! wideband lambda and data logging.

[NA_Goodness]

ViPec ftw

[Tiddy]

motec sticker alone gains u 20hp!