Join Date: Feb 2002
Location: N.W. Washington
Re: 4-link angles
There is no simple answer whatsoever. You need to figure out what the instant center needs to be as well as pinion angle for you particular set up and it really needs to be scaled as well.
But the basic of basic answers is, the bottom bar should be roughly paralell to the ground, car fully loaded with you in it, and the top bar should be higher in the back than in the front, and if you drew an imaginary line paralell to the bottom bar straight out front, and the top bar straight out front, the point they intersect is your instant center, where this point is based on your car will affect how it hits the tires.
My recomendation is get a good book on chassis from Alston or Bickle and read up, they are not simple but once you get a feel for them they work great on the track. If racing is not an issue close will be good for a start, but the best bet is get it close to where you think it should be (always with the driver and fully loaded car) and test at the track to get it right making small changes at a time or you will endlessly chase your tail.
Be aware that with a high powered car the 4 link will do crazy stuff not just on launch but down the track it will steer the car if the bars are wrong, so take it easy.
Good luck with it and do your homework!
1968 rs with an old school 354" SB2.2 pump gas motor.
Repetition does not transform a lie into a truth.
Franklin D. Roosevelt