Mik

I no speak-a de engrish...

I would have said something...but everyone is stealing my thunder

Bump

Yep...that was possible me... So...tell me more about this old road you talk about

Rev210, I said that it is impossible to accelerate faster without increasing power…yes. BUT…we are talking about real power put down to the ground at any point in time. In theory, when you lighten something that the engine needs to accelerate in the torsional plane, you are wasting less energy, so can put more power to the ground. IE. This will be picked up on a dyno. I wasn’t saying that the lighter prop shaft won’t have an effect. I was just saying that it won’t be anywhere near as much as that of a flywheel because it’s moment of inertia is so much smaller. I know the tailshaft is hollow, but assuming a radius of 30mm, then you could assume the average mass is 30mm from the axis (will actually be a bit less due the thickness of the material used). Now, Assuming a flywheel has a radius of 150mm, you could reasonable assume that the average mass is 100mm from the axis (I think this is exactly what it is, but I don’t have time to look for the formula, and it’s been years since I did it). Of course, if you lighten the car, it will accelerate faster too. But the affects of lightened pullies on this are negligible. To be generous, say you can save 5kg. On a 1500Kg car, this 1/3 of a percent. It is the energy required to accelerate these items rotationally that makes the difference. I didn’t disagree with you at all. Lightening things that accelerate in the linear plane will make them faster. And lightening things that accelerate in the torsional plane will make them accelerate faster by an even bigger degree. My point was that this power ‘increase’ will be able to be measure by a dyno.

It's a manual too!

Are you sure the clutch isn't an R33 one?

You are contradicting yourself there...just a little though. Yes, lightening things that turn, reduces inertia in the torsional axis, and you say that this won't lead to an increase in horsepower, which it won't as everyone knows, you can't create energy. You say that the car will accelerate faster...which it will, but it is impossible for the car to accelerate faster without having more power. Accerlerating something that turns requires a certain amount of torque, for a certain amount of time (A certain amount of power) Just like accellerating something in the linear plane requires a certain amount of force for a certain amount of time. When rotating parts are lighter, less torque is needed for less time to accelerate to the same RPM. (IE less power). So, you are consuming less power to accelerate rotating parts, you have more energy in a given second (power) to use to accelerate the car in the linear plane. IE, you are putting more power down to the road OR the dyno. So...the power 'gain' should be able to be measured on the dyno. Looking at it anohter way...if you think about how a dyno works, it lets the engine accelerate in RPM a certain number of RPM per second. The dyno then measures how much torque it needs to hold the engine at this rate of acceleration. Power is then calculated. So, if the car is going to accelerate faster, the increase in power will show on the dyno. Also, a lightweight carbon prop shaft that saves say 10kg, will make no where near as much difference as a lightened flywheel that saves 5kg. The reason is the steel prop shaft's moment of inertia is much lower than that of a the flywheel. IE. The average mass of the prop shaft is much closer to the axis of rotation than it is for the flywheel. The lower the moment of inertia, the less torque is needed per second to accelerate the mass to a given RPM. I can’t remember the exact relationship, but it would be a square law. I could dig it out a of an old physics textbook if I could be bothered. You can test this by rolling a ball bearing, a shot put and a steel pipe down a hill. All else being equal, the ball bearing and the shot put should reach the bottom at the same time. The pipe should arrive last, because it has the highest moment of inertia, meaning more energy is wasted accelerating the pipe in the torsional axis.

Do you have a web link?

Item: NISMO 600cc injectors - To suit RB26 (purple) Location: Sydney, but will post Item Condition: Brand new in box Item Condition: $790 Contact Details: PM, email msimotas@hotmail.com, or call 0419 126 206

Haha...I was going to post something along those lines, but you beat me to it. Strange how he doesn't put his name to his gear anymore...

I think Auto Gallery yokohama just do a double syncro conversion. They also upgrade gearsets...but I'm pretty sure they use OS Giken gear sets. One think with the Giken gearset is that 1st is so damn tall. It would be a pain for hill starts and driving up driveways, especially in a heavy R33/R34/Stag with biggish cams.

Yep...they are. Only thing is, they are a butt pain if you want to fit mines cam baffles.

The required shims are different sizes, even on a new engine. That's the whole point of using shims! The clearances depend on the length of the valve, thickness of the lifter and mostly how far into the head the valve seats. Most head reconditioners don't order shims, they just grind the back of the valve to open the clearances back up after they have dround the vlaves and cut the seats.

You thought wrong Paul. What I am saying is that it is fairly common knowledge that dynologs read lower than dyno dynamics. (And dyno packs read even higher again). Ask anyone that works on diesels (lots of them use mainline dynos) Also, a 300kw Gen III commodore makes 180-190 rwkw...they make over 200 on Dyno Dynamics. One interesting thing is that the torque reading that the dynologs give is surprisingly accurate. A mate of mine has put his GT2 and GT3 on his dyno and the torque reading was almost exactly what Porsche quote. It was a similar story with his Galardo too. Out of interest Paul, how much torque did the GTR make at autosalson? But in the end...who cares, the dyno is only a tuning tool...Buster has the right idea. Something very perculiar is happening if the GTR made the same power in AWD as it did in 2wd...it is physically impossible!!

Yep...it was slightly warmer in Syd than the gong...only a degree or 2. Yep..I agree

I didn't say you didn't...but I think Cabin must have a 'special' version of the Dynolog software. I know of a wrx that made 20% more power on CRD's dyno in the afternoon than it made on a Dynolog in the morning. There were no changes in between. Had the same tank of juice and all. All the other dynologs I've seen read very similarly (comparing the same cars on different days)

Nope...I can walk much faster

Where?..which dynos? Anytime I have seen the same car go on a dynolog and then a dynamics, the dynamics always reads about 10-15% higher.

pfft...my pulsar will do better than that!! I walked it in about 5mins last night

Good for peeling tyres off rims trying though.

The reason they want you to remove the front axel tube is to ream out the little hiles that let oil drain back into the rear of the sump from the front.

Can't remember if the Exige had tape on it, there were two ornage ones there, but Jason's is the one with 'RPM' number plates. He had to retire because it lost the harmonic balancer doing a burnout before the quater mile run. He will be back this year, but I have a feeling he will bring his GT2 this year. The silver rexy is actually pretty quick, he had a few issues though too...broke the exhaust manifold. He finished the round, but couldn't make much boost.

Very nice...no wasn't competing. Was their with a couple of other competitors. Damo (silver WRX hatch) and Jason (orange Exige)

Russell...is your GTR the one from Dutton last year with the big PPG stickers on it?