PST Carbon Fiber Drive Shaft Installed

[civicdrivr]

Its hard to tell from the pics, but how close is it to the exhaust?

[msile]

Originally Posted by civicdrivr

Its hard to tell from the pics, but how close is it to the exhaust?

Far away. Same as stock..

[tonystewart]

Driveshaft $1,100 ... But the pool table in the photograph is Priceless$

[msile]

Originally Posted by tonystewart

Driveshaft $1,100 ... But the pool table in the photograph is Priceless$

Busted! I wanted good lighting

[F3dzo]

Is it me or do you have a lift in your garage...

[msile]

Originally Posted by F3dzo

Is it me or do you have a lift in your garage...

I tried, but the garage doors were in the way. I would have to modify it. Too much hassle.

[phillip]

Originally Posted by RallySport Direct

Glad you are enjoying the shaft as well, we are loving ours!

Giggity

[jadewbj]

Never thought it was that easy to swap out. Very nice.

[Auto-Hauss]

Any max torque numbers you can putt through it? With shop already putting 380+ wtq through a stock block when they start to build them it could end up being around 600. I drift and twisting aluminum shafts is pretty common once you start getting into the higher horse power in that type of environment.

[msile]

Originally Posted by ExiledLakai

Any max torque numbers you can putt through it? With shop already putting 380+ wtq through a stock block when they start to build them it could end up being around 600. I drift and twisting aluminum shafts is pretty common once you start getting into the higher horse power in that type of environment.

From RallySport's Thread:

The shafts are rated at over 2700lbf/tq, in other words you have to do something crazy to break it!
PST has drag cars running in the 6 second 1/4 mile using the same shaft designs.

Cool thing about carbon fiber shafts..they twist a certain degree while staying in the elastic region of the sheer stress, meaning they take up shock and spring back to original shape.
One thing that simply blew me away was that the weak point on these shafts....the metal yokes on the end, and not the carbon. If you ever manage to break the yoke, well PST can make you a billet unit for you monster when that time comes

[Auto-Hauss]

2700 will do... haha One other good thing about the flex would be the shock savings on the half shafts. Even though I want shock going through the drive train in certain situations the flex would theoretically help prevent the half shafts from snapping at higher horse power loads and increased tire size. pretty neat.

[RallySport Direct]

If we have enough interest for a AT unit we can get those made as well

As for Aluminum vs Carbon, this is a write up I did going over both of them. This was done on our 2011 Sti shop car as the test mule but the exact same concepts apply.

http://theattack.rallysportdirect.co...shaft-overview

If you guys have any questions dont hesitate to let us know

Kirill
RallySportDirect.com

[RossGA]

Originally Posted by serialk11r

After the differential gear ratio reduction is taken into account, the effective moment of inertia decrease is pretty small compared to wheels. Of course, wheels can only be made so light, but their effective "moment radius" is still larger.

Absolutely true, but there is more to the physics of spinning an object and the energy involved than just the moment of inertia. Total RPM will represent an energy investment, and the higher the RPM, the higher the investment.

Gear ratios and weight savings on spinning objects do come into account, and that is one of the reasons why the best place to remove rotating mass is on the crank...it is the fastest spinning object in the power train minus the alt. The wheels my be the best spot to improve overall weight savings in the rotating objects category; but pulling 1lb off a crank that can spin 7K RPM equates to several pounds at the wheels that spin tremendously slower. So yes, the gear ratio in the rear diff will have an impact here.

So I am not disagreeing, just adding to your argument that RPM will also play a factor. Taking 10lbs off the driveline that spins 4x faster than the wheels will be as effective as removing several pounds from the wheels. Think of it this way, spin the driveline the same speed as the wheels....and increase it's diameter by 4. And redo the math. They both will offer an excellent improvement to responsiveness; and the difference of which is superior may not be as clear as it first appears.

[msile]

Originally Posted by RossGA

Absolutely true, but there is more to the physics of spinning an object and the energy involved than just the moment of inertia. Total RPM will represent an energy investment, and the higher the RPM, the higher the investment.

Gear ratios and weight savings on spinning objects do come into account, and that is one of the reasons why the best place to remove rotating mass is on the crank...it is the fastest spinning object in the power train minus the alt. The wheels my be the best spot to improve overall weight savings in the rotating objects category; but pulling 1lb off a crank that can spin 7K RPM equates to several pounds at the wheels that spin tremendously slower. So yes, the gear ratio in the rear diff will have an impact here.

So I am not disagreeing, just adding to your argument that RPM will also play a factor. Taking 10lbs off the driveline that spins 4x faster than the wheels will be as effective as removing several pounds from the wheels. Think of it this way, spin the driveline the same speed as the wheels....and increase it's diameter by 4. And redo the math. They both will offer an excellent improvement to responsiveness; and the difference of which is superior may not be as clear as it first appears.

Good write up. It is as you said. I have lighter wheels, crank pulley and shaft. The combo feels very good.