Rear suspension tuning for a 2wd truck

oldestof11

oldestof11

Drag racer
Joined
Jul 17, 2007
Messages
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What should I look at doing for getting a better weight transfer and hooking with my Ext cab LONG Bed Cummins?

My plan is getting some QA1 62 series shocks, adding some 150lbs coil over springs, taking all but the main leaf out of the pack, and adding a traction bar from the pumpkin to a cross member under the bed.

Then adding some softer taller springs to the front and running stock shocks right now as they are less than a year old.
 
No one? Well, I guess I will use this as my build experience.

I have been reading a lot on Yellowbullet about leaf spring suspension tuning. However, I cannot find anything about an antiwrap bar or tractions bars. Lots of slapper and Caltracs.

So it looks like some shocks are going to be ordered and just going to see how 2 leaf springs do on my truck.
 
iv been told to take one leaf out at time until it starts getting ttraction, a caltrac set up would work great! But id start there, thats how im doing it
 
You decide? Or find more information? i too am interested but what i posted is about all I know
 
oldestof11 said:
No one? Well, I guess I will use this as my build experience.

I have been reading a lot on Yellowbullet about leaf spring suspension tuning. However, I cannot find anything about an antiwrap bar or tractions bars. Lots of slapper and Caltracs.

So it looks like some shocks are going to be ordered and just going to see how 2 leaf springs do on my truck.
Click to expand...

If you're serious about drag racing, get a good double adjustable shock (threaded for future coilover). Next step would be something similar for the front. Don't just order what looks good in a magazine, call afco, qa1, etc and see what they say. You'll need to provide them with front and rear weights, shock length, etc for them to give you accurate information. Ultimately, you'll end up with a 4 link or ladder bar rear, and coil overs at every corner.

Give us some more information about your truck and your goals for it.
 
It is staying VE. Shooting for 400hp on fuel, 500 on spray.

It will be a DD/weekend warrior. If I can get it to hook on Toyo Proxes, I want to go that direction.

I am not looking to do a 4 link setup. I am wondering if this type of bar would prevent axle wrap if it had a shackle on the front mount. I would modify it a little to make it fit under the bed.

wp_20140822_10_10_10_pro-jpg.960029


I am not looking to spend $1000 in shocks. This is more of a budget build and with only having at max 500hp, I do not need an exotic setup either. From reading Yellowbullet, leaf springs work on trucks, just need good shocks and some sort of antiwrap bar, be it slappers or Caltracs. These are also vehicles that run 8's, way faster than I plan on going.
 
Shocks control wheel dampening, don't get so stuck on shocks as being your key...

Trucks have a suspension to do work, suspend their weight plus another trucks weight.
This is why many DD use 4x4 to leave, can't have a truck and race car unless you're willing to sacrifice in one area.
.
Yellow bullet is cars, car leaf design is TOTALLY different, what works in my car that is leaf sprung and runs singe digits isn't working in your truck, and my car has no additional add on help, just the leafs, no caltrac, no ladder, no nothing but leafs carefully played with to work.

Removing your leafs is not the right direction, understanding leaf spings and making it work without all the nonsense is where it'll shine.
Some shackle designs in trucks are designed to carry weight not plant tires, another issue to deal with.
.
 
In your opinion, at what HP would things get jumpy/squirly when leaving the line?
I'm doing something similar on my 1st gen and wondering if it'll even put out enough power for rear end concerns.
 
oldestof11 said:
It is staying VE. Shooting for 400hp on fuel, 500 on spray.

It will be a DD/weekend warrior. If I can get it to hook on Toyo Proxes, I want to go that direction.

I am not looking to do a 4 link setup. I am wondering if this type of bar would prevent axle wrap if it had a shackle on the front mount. I would modify it a little to make it fit under the bed.

wp_20140822_10_10_10_pro-jpg.960029


I am not looking to spend $1000 in shocks. This is more of a budget build and with only having at max 500hp, I do not need an exotic setup either. From reading Yellowbullet, leaf springs work on trucks, just need good shocks and some sort of antiwrap bar, be it slappers or Caltracs. These are also vehicles that run 8's, way faster than I plan on going.
Click to expand...

Sure it would. That's similar to what 90's F bodies come with stock.
 
Supershafts said:
Shocks control wheel dampening, don't get so stuck on shocks as being your key...

Trucks have a suspension to do work, suspend their weight plus another trucks weight.
This is why many DD use 4x4 to leave, can't have a truck and race car unless you're willing to sacrifice in one area.
.
Yellow bullet is cars, car leaf design is TOTALLY different, what works in my car that is leaf sprung and runs singe digits isn't working in your truck, and my car has no additional add on help, just the leafs, no caltrac, no ladder, no nothing but leafs carefully played with to work.

Removing your leafs is not the right direction, understanding leaf spings and making it work without all the nonsense is where it'll shine.
Some shackle designs in trucks are designed to carry weight not plant tires, another issue to deal with.
.
Click to expand...
You're also assuming I'll be using it as a truck. I use it one occasionally. If I need more capacity, I'll look into an over the leaf airbag setup.
TheBigNasty said:
Sure it would. That's similar to what 90's F bodies come with stock.
Click to expand...
Now that you say it, yes it does!
 
I love my proxes. They hook really well and I can build 20 lbs of boost before they start spinning. Give a chirp with lock up at 35 - 45 mph and then it takes off.
 
Remember the more movement (distance) you have, the longer your weight transfer will take. The longer you spend tranfering, equals the less time you are planting your 'shoes' to the pavement adequately and beating your opponent. Now if you think about it in another view, as your weight transfers you can imagine a continuing change happening until your point has been reached to 'plant' your weight to lay a good contact patch with the tire and grip well enough. There is more room for hitting your target or not with soft spring rates. Look at gasser cars, solid front axle etc. Good luck.
 
If you change to comp style you'll be able to make changes and tune the springs to work for you. however you may have to get involved in changing mounting points.

Say if you go to comp style , if the rear spring eye goes to the same plane or lower you'll need to either lower the front spring eye, or mount the frame mount for the rear shackle higher. (which you may want to make one end somewhat adjustable, say have 3 positions each one around .75" apart)
The angle of the spring front to rear is as important as a 4 links geometry, plays a similar role.
Then you'll want to remove all clamps at the rear section of the spring, you'll want to add more and tighter clamps to the front section.
Making the front or rear of the spring have adjustment up or down is helpful to make changes for harder or softer launching.
.
You may want to watch some dirt drag racers using leafs.
The leaf can work as well for racing as the link style.

.
 
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