Need some Suspension Advice Please....

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70Dart499

70Dart499

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I have been running into a problem with my Dart bouncing during the first 60' of a run. The suspension will load up as soon as I hit the throttle, but it almost immediately unloads and bounces three or four times before it hooks up again, and goes.. I have adjusted the pinion angle, and added a pinion snubber, and that has helped the car hook, but now I have this bouncing issue. I have the pinion angle set at -5*, and I have the pinion snubber set at about 1/2" below the floor. Someone suggested I put the snubber up where it is closer to the body, and that will help, but does anyone else have any other suggestions on what to try in order to eiliminate this issue? Thanks For the Help.
 
What's the rear suspension? SS springs, Calvert etc. Weight, trans, tire, air press, etc.

Can be a couple things. If SS springs don't move the snubber closer. Make sure no bind in anything in the rear. If you have adjustable rear shocks tighten the extension, and/or make sure they are not overextending. It sounds like the car is "porpousing".

Also do you have 4-5" of free travel in the front end with no bind etc?

Hopefully a place to start.
 
something like this??

[ame="http://www.youtube.com/watch?v=bie5_lBrFQk&list=UU2UfycLWJQRo0DnRrnW3KxQ&index=8&feature=plcp"]SS And AFX Mr. Norms SS Hemi Dart #1 - YouTube[/ame]

we went from SS springs to Calverts with a little better launch...

cranked up the rear shocks and that helped alot...

make sure you are getting enough front end lift... like 5"...

i set the lower bump stop 1/2" from bottoming out and take the upper out and see what happens...

also how are you launching it? foot brake, 2 step? launch rpm?
 
70Dart499 said:
I have been running into a problem with my Dart bouncing during the first 60' of a run. The suspension will load up as soon as I hit the throttle, but it almost immediately unloads and bounces three or four times before it hooks up again, and goes.. I have adjusted the pinion angle, and added a pinion snubber, and that has helped the car hook, but now I have this bouncing issue. I have the pinion angle set at -5*, and I have the pinion snubber set at about 1/2" below the floor. Someone suggested I put the snubber up where it is closer to the body, and that will help, but does anyone else have any other suggestions on what to try in order to eiliminate this issue? Thanks For the Help.
Click to expand...

put longer shocks on the rear, imperial shocks will work.
bob
 
It's a super stock spring car with a comp. Eng. 3 ways. In the rear that are set on 50/50. They were on the car before I bought it, so I don't know what length they are. What shocks does everyone recommend if I do change them.
 
Are the rears the 2730 or 2735 number. 2735 is slightly longer.

What shocks to buy will depend on how much you are going to race it. If only 5-10 times a year stay with the CE's or more preferrable the rancho adjustables.

If your racing all the time adjustability will be very important to consistency and getting the most out of your car. If so consider DA's like strange or afco. But price goes from 1-200 a pair to 500 plus.

Still make sure your fronts moving freely.
 
First thing I would do is chip down the starting line RPM to 3000, then slowly increase the RPM each launch until it spins the tires and that is your leave RPM window. I launch my Dart at 3200 and anything over 4000 it spins the tires.

ClintGravesPhoto025-1.jpg
 
I had the same problem.
Clamped the springs in 2 places on the front segment and 1 clamp on the rear segment.Moved the snubber away from the body. It stiffens the springs, slows down the axle rotation and keeps the snubber from the loading and unloading.
 
805moparkid said:
something like this??

SS And AFX Mr. Norms SS Hemi Dart #1 - YouTube

we went from SS springs to Calverts with a little better launch...

cranked up the rear shocks and that helped alot...

make sure you are getting enough front end lift... like 5"...

i set the lower bump stop 1/2" from bottoming out and take the upper out and see what happens...

also how are you launching it? foot brake, 2 step? launch rpm?
Click to expand...

Yes, but not nearly as bad. Launching on the footbrake about 2000-2500 RPM. What did you set your rear shocks at??
 
805moparkid said:
something like this??

SS And AFX Mr. Norms SS Hemi Dart #1 - YouTube

we went from SS springs to Calverts with a little better launch...

cranked up the rear shocks and that helped alot...

make sure you are getting enough front end lift... like 5"...

i set the lower bump stop 1/2" from bottoming out and take the upper out and see what happens...

also how are you launching it? foot brake, 2 step? launch rpm?
Click to expand...
Watching the video you need to learn how to do a burnout. Where was the smoke? Here let my wife show you how to burnout.:burnout::D
[ame="http://youtu.be/fAP_2rxz_GA"]302 Found[/ame]
 
Let us know what you find out.

Btw, is this a new problem or has the car worked ok until the most recent outing? 50/50 for a rear setting is ok. Stiffer, like 7-8 on a rancho also a good place to start.

The spring clamping is also a good recommendation so you can change the spring frequency. Adding a little weight to the front will do the same.

Good luck.
 
Aren't burnouts tire dependent. Do a big smoker with a drag radial and they sometimes get greasy.

Put as much air pressure in the tire where it 60's the best.

If it's porpoising, IMO, you likely need a better shock package.

The front end has a BIG effect on what the rear does.

IMO, throw the snubber in the trash... it's a band aid for a bad set of SS springs. When I ran SS springs NONE of my cars ever had one, it's not needed if the front/rear segments are set up properly. It can actually cause more problems than it's intended to solve.
 
ironside said:
Let us know what you find out.

Btw, is this a new problem or has the car worked ok until the most recent outing? 50/50 for a rear setting is ok. Stiffer, like 7-8 on a rancho also a good place to start.

The spring clamping is also a good recommendation so you can change the spring frequency. Adding a little weight to the front will do the same.

Good luck.
Click to expand...

Its not really a new problem, its just that I have just now gotten the car where it will hook at the hit of the throttle, before it was just spinning the tires on the hit. Now that I have got it hooking, I have this bouncing issue. I'm going to clamp the front springs, and make sure the shocks are a set 50/50, and head to the track and see how it does.
 
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