|12-09-2018 06:12 PM|
Every thing has a center of gravity. Good handling super cars have the CG close to the middle of the vehicle. Equal load on each wheel is the goal. By moving your fuel tank behind the rear end, you're moving the CG rearward. Pick Up trucks are notoriously front heavy or CG is far forward of center of the vehicle. This is why batteries are moved to the trunk, engines and transmissions are moved rear ward, etc. Look at exotic Super Cars. They spend millions of dollars to get the CG in the middle of the car and as low as possible for exceptional handling.
Drag race cars shoot for about 60 or 70% weight on the rear wheels for good launch. Weight transfer out of the hole and down force from spoilers and aerodynamics are also huge factors in getting down the track quickly. I know you're not building a Super Car or Drag Car, but why not do the best you can with what you have.
|12-09-2018 02:37 PM|
" Or put the fuel tank behind the rear end. Better weight distribution that way. "
One reason I am putting it where I did is for weight distribution... my thinking is that the further to the rear the more centrifugal force to throw to spin under heavy cornering. Not correct here? Also I don't care for the bed level tank access that I see with rear mounted tanks.
|12-09-2018 02:30 PM|
" If the point is right there at the back of the fuel tank/crossmember that we can see in the picture, the driveshaft at that point is only going to move about 1/2 or a little less of that 4-1/2" axle travel, so I think you'd be good?? "
The 4 1/2" travel is based on the angle from center axel to transmission and the clearance that I have at the point directly under the bracket. Actual clearance at that point is more like 1 1/2".
|12-09-2018 01:34 PM|
|'48 Austin||First, you will need rubber snubbers mounted to the bottom of the frame to limit bottom out travel. Never limit the travel with the shocks unless they are designed for that purpose, like coil overs or front Mustang II shocks. Once you have the snubbers in place, take the U bolts off the rear leaf springs and let the frame down on rear end until the snubbers are holding up the frame. With the pinion angle close to the final setting, check drive shaft clearance between fuel tank and brackets. Realize the snubbers will compress even further in a driving/bottom out situation. Or put the fuel tank behind the rear end. Better weight distribution that way.|
|12-09-2018 01:27 PM|
Have you also accounted for how far the weight of the bed is going to make things settle after it is installed??
If the point is right there at the back of the fuel tank/crossmember that we can see in the picture, the driveshaft at that point is only going to move about 1/2 or a little less of that 4-1/2" axle travel, so I think you'd be good??
Or is the new bracket not in that picture??
|12-09-2018 10:54 AM|
axel travel question
I just installed a fuel tank bracket and am wondering if I need to re-adjust my thinking here. Once completed, the drive shaft may come in contact with the cross bracket I just I just welded into place if both wheels move upward together more than 4-1/2 inches. This is a street driven hotrod so I don't think this will be a problem (the spring itself would have to flex to above the front pivot point to get there) but thought I would run it by you guys to get your opinions.
I can, of course, grind the welds and re-think my design but would rather not if there is no reason to... but would rather do it now than after I have a bent drive shaft in the future.
What are your thoughts on this?