Power Ceiling Gt3076R

[R32Abuser]

Haven't paid a cent yet...But I'll be making sure Im not incurring extra charges for the timing to be done right. Considering the motor was to be "blueprinted" and timed correctly to start with is argument enough.

Problem with taking it back and taking it to Shaun, I would void all "warranty" I had (if any)...Something that isn't worth the risk at such a late stage in the game...

[Dale FZ1]

If you get GTR re-grinds, definitely get adjustable cam gears. The user Dale_FZ1 has gone down this road with some great success.

I used the 805C grind, same as Cubes and after consulting with him well in advance of the build. That spec has proved very effective although I still don't feel that the cam timing has yet been optimised either. It seemed that the biggest issue with a 30DET running stock type cams was for the torque to fall away quickly after 6000rpm, and I simply wanted a wider operating rpm range than that. Peak torque from 3400-6900 suggests Cubes got it right back when he recommended the Tighe grind, and I honestly believe that my 0.87 GT3037 Pro S turbine spec is not letting the engine breathe to the potential that the cams are capable of. Either a 1.06 GT30 or a GT35 would probably see it keep making useable torque for another 500+ rpm, but I haven't spent the $$ on replacement rotating bits and just wasn't interested in spinning it that hard. In short, what I have worked, similar to Cubes.

I have played with cam timing a bit, and even a few degrees via adjustable gears brings noticeable change in torque delivery. Remember this is a hybrid so there will be some benefit (and satisfaction) of ending up with the sort of delivery that suits you (eg. beefier bottom end or extending the top end). Mine is making 410+ rwhp but importantly it runs strong to 7000, delivers down low and is driveable. I reckon it has a bit more via cam timing changes and we might chase those 10-15 horses before next year's sprint series starts. But currently all parts are working together, within spec.

I can tell you that my setup is very hungry for ignition timing, and seems very knock resistant as though scavenging is very effective.

Sorry to break it to you man, but they are very very hard to get right,

My opinion is learn how to do it yourself...try different things, turn the motor over 10 times before checking the timing again before putting it back together, its going to be a long haul but if you put your mind to it eventually you will "fluke" the sweet spot and watch your engine come alive.

As above, yes things are hard to get "right". I noticed someone had posted comment suggesting setting it up via a dial indicator. This is only correct if you are running a solid lifter setup, because unless there is oil pressure in the hydraulic lifters (meaning the motor is running), then the cam lobe is not acting directly on the valve. There is excess clearance. Simple as that. Degreeing an engine on the bench is entirely practical provided you know the cam spec, and the valve train is solid (meaning a known clearance).

As Guilt Toy says, it is a long haul of trialing to get things in the happiest position. Setting it up with drive belt covers removed and budgeting for enough dyno time to trial a few variations on cam timing will get you there, with the longest time waster being to remove the CAS, adjust the exhasut cam gear and then re-set your base igntion timing before going again. Realistically there is about 6-7 dyno pulls but a fair amount of go-slow while you make the adjustments on that exhaust gear. Then it's an overlay of the best runs on inlet + exhaust, and hopefully a final run to validate your particular settings.

[GTSBoy]

There are tricks to pack out hydraulic lifters so you can degree them with a dial indicator.

[Dale FZ1]

Would you post up an overlay of torque v boost (and rpm on the X axis). It would help to visualise what things look like.

[R32Abuser]

I'll see if I can get a printout tomorrow...if I manage to get away from work early

Using standard cam gears, then how do you get the timing spot on? If using the standard timing marks is simply not working to get the motor happy, then what do you do besides actually measuring the rise and fall of the valve/hydraulic lifter assembly?

[DVS JEZ]

Use adjustable gears and trial an error testing to set it up

[Guilt-Toy]

This issue brings back bad memories, got laughed at on dyno comps because i couldnt get more then 400hp, when i had a 500whp setup.. it was a very long haul for me and i have avoided pulling my timing belt off untill this week, and today it all started again! 4 years+ and 3 countries later and soo many dyno runs and drag races and drifting i have now opted for a smaller turbocharger with Tomei pro cam 270 (hydo types)

I have 2 x tomei cam wheels also, so today when we put the timing belt on it was not exactly spot on, but I have a dyno here at the shop i can use as long as i want with helpers so i am hoping its going to be a breeze to get this engine going the way it should again with some cam dialing.

Get cam gears and work with it. you will not remove that smile from your face for weeks once you get it setup right, I swear my car gained 80hp, from run to run and after i tuned everything it was about 100+ hp gains just from getting the timing right.

The time i had issues I had a cam gear on the exhaust and the stock vct gear on intake, i got the setup exactly right the cam gear was set to 0. now i can play with both cams so lets see what happens. Il keep you posted.

Here is a pic of my 270's installed and everything ready for the big long RB30DET timing belt mission, but its worth it in the long run pic was taken today.

[R32Abuser]

Use adjustable gears and trial an error testing to set it up

I was afraid you'd say that

[R32Abuser]

UPDATE!!!

Ok so Tomei 256/8.5 IN&EX cams + adjustable gears were put in.

Car was timed using DIAL GUAGES. Builder said that he had to run 7-8 deg advanced on the intake side and 6 deg on the exhaust side from "zero" when the dial guages displayed that the cams were in the right position ("zero'd" as you would with a standard type setup).

Car was chucked on the dyno...From what I was told in conversation, the ignition timing was measured with a gun so that the ignition timing on the computer could be verified. For some reason the timing was 10 degrees out (advanced from memory). I have no idea why this was the case as the computer was not touched since last time the thing was on the dyno. So the timing was reset in the computer.

Few runs were conducted. Timing was played with up to around 8-10 times on both the exhaust side and intake side. But the thing still wouldn't make more power than about 250RWKW. Much lower than you would expect with the cams + turbo + motor setup.

They took it off the dyno for lunch. Cooled down, then ran it again...Made about 5RWKW more.

So all up it finished with about 255.5RWKW at an A/R of about 11.5-11.8.

See dyno graph below.

Edited October 7, 2011 by R32Abuser

[zebra]

255kw at what boost?

[Dale FZ1]

Would you post up an overlay of torque v boost (and rpm on the X axis). It would help to visualise what things look like.

Second request please.

[R32Abuser]

Sorry 18psi. Apparently it was reasonably flat across the board.

[R32Abuser]

Second request please.

Don't have a boost graph. Will be getting some of these graphs off the tuner when possible.

[Rolls]

With estimated RPM using these specs:

diff ratio 4.343 tyres are 235/45/17 on the rears. Rims 17 X 9

RPM =36.026*(speed in kph) -0.927

http://www.kabamus.c...rage/gears.html

Torque figure must be huge for that power that early in the rev range, looks like it is choking up top, either it isn't holding 18psi flat (can you run more boost?), some sort of intake/exhaust restriction, possibly a mild intake leak (unlikely)? I suggested he pressure tests the intake for a leak, checks pressure differential over the IC and gets a heat probe in the exhaust to narrow it down. You guys got any other ideas?

Regardless look awesome to drive! tyre shredding torque bye bye license haha

Edited October 7, 2011 by Rolls

[zebra]

valve float?

did the tuner take it past 6k rpm...with cams and a built motor I would be inclined to go towards 8000

[Rolls]

Apparently its a reco'd head, usually valve float makes weird dips all over the shop, hypergear had a few dyno runs showing it, generally makes it really obvious.

[zebra]

ther are enough dips in that curve + 18psi to make me concerned about it....really should be ~300rwks at that boost

[R32Abuser]

Reco'd head and uprated valve springs. Can't remember spring stifness though.

We have been talking bout the lifters being overly noisy. Like one has failed etc.

[R32Abuser]

Dips I've been told are like that on every car that is dyno'd at Morpowa.

[zebra]

yeah thats a possibility...still hydrauli lifters?

might be pumping up and that will kill the top end.