off season pondering pinion angle

[Don Fardie]

Originally Posted by Chris Hill

Awsome video! Now put a strobe light on it and see what happens.

Not sure I could do that without triggering some Flashbacks!!!!!

[gmonde]

Originally Posted by Don Fardie

Hi Larry,
I ended using a Go-Pro camera to record what was happening and found I had too much Pinion Angle. As you can see in the video going down the track I was running a negative angle, so I removed 2 deg. Also at launch it was really never going past 0 or postive degrees.
When using the Go-Pro editing software you can slow it way down and zero in on any area of concern within the lens area.

don :great footage !! are the springs caltracs also ??? is this before removing 2 degrees
gmonde

[Dave Gantz]

Don, you have the right idea, imo. I've always heard all of the different angles for different suspensions. I've always wondered how anyone really knew what it looked like under there to recommend a given angle. I wouldn't know how to put whatever camera under a car to see it working (not to mention I'm hardly ever at a track anymore), but it would be interesting to test a large sample of cars and see if these recommended angles are working.

[Jeff Lee]

What is it that measures shock travel and records it on the data logger? Whatever that thingamajig is called, you need to fabricate one for the nose of the differential and actually measure the movement from the base angle. You could build a mechanical apparatus not using a data logger.
I know a guy that was video'ing the movement with a strobe light on his BBC SS car back in the '80's. I don't remember if it was a 4-link or ladder bar car. But as I recall, it was difficult or impossible to keep the pinion angle below zero with shocks and chassis tuning that would enable the car to launch correctly. This was a National record holding car.

[Tom Goldman]

Performance Trends' 4 Link software has a very good pinion angle program. altho limited to 4 link and ladder suspensions.
it allows you to input all the relevant driveline angles and it will put it into animated motion and allow anaylisis of the changes thru the suspension travel.
Not a 100% susbstitute for on track experiments, but it does give some insite into the possible pinion angle changes a given setup will yeild.

[Don Fardie]

Originally Posted by gmonde

don :great footage !! are the springs caltracs also ??? is this before removing 2 degrees
gmonde

Yes they are the Caltracs Split mono springs and this video was before I removed the 2 degrees. When having the car scaled this past spring at Victory Racecraft the first thing they noticed was the pinion angle and suggested removing some. That's what made me hook the camera up for that shot.