I have a fullsize 1988 f150. I am running 4.30 gears and stock suppension. I cant get my truck to give a hard launch and make the rear squat like i want it to. When it bangs the gears it feels like the rearend raises and it spins the tires. My dad and i are planning on pulling out the bottom helper leafspring. If anyone has any info on what to do or any other modifications let me know, any help is greatly appreciated.

 

I think that for a couple hundred bucks you can get a bladder made by Stylin Concepts...$119 to be exact...and you can add up to 300 lbs. to the back of your truck without the water slopping around because the bladder is made with several compartments to minimize the water movement.... when empty it weighs next to nothing, but when full, 300lbs to hook up them tires boy!...

here's the link...http://www.stylinconcepts.com/part.a.../categoryid/25

Good luck..._motes

 

leafsprings = spring "wrap"= traction bars for traction

...zap!

 

heres the thing i am trying to minimize weight not add more, i need to minimize weight and get the rearend as soft as possible, also when i run my traction bars the way the axel and leafsprings are in order to get the front of the tration bars to be a 1/2" from the springs the bak of the tration bars have to be way away from the from the springs. From what i know about cars and traction bars you ant have the tration bar on just the axel housing and front of the springs, this stiffens the whole suspension and dosnt let the back squat down and bite. Is their anyone that makes a drag racing leaf spring kit for an 88 f150, or do i need to keep taking leafs out until i get the suspension as soft as possible without being dangerous?

 

The back end doesn't have to squat to get a good launch. You only need weight transfer. It's that weight transfer that causes the back end to squat and hook up, not the other way around. The same amount of weight transfer will occur whether you run a hard spring or a soft spring. It's the acceleration force generated by the tires around the center of mass of the vehicle that causes the weight transfer. If you're having a problem hooking up at launch, 300-500 lbs over the drive wheels will add weight, but will also add that weight directly over the drive wheels, which *should* help it hook up.

The traction bars aren't there to help the back end squat or bite, they're there to prevent axle wrap.

The advice is sound. More weight transfer to the drive wheels can be accomplished by adding more weight over the drive wheels. Sounds counter-intuitive, but it's true.

-Joe

 

Thanks GIJoeCam...i thought i knew what i was talking about..._motes

 

Yes...Joe is correct in the answer to your question and he gave some other good info as well. The question he answered was in regards to getting better traction off the line.

HOWEVER, i'm going to say while his way would certainly provide better traction, there is NO WAY i can advise someone to add more weight when drag racing. We all know it's F=ma. So if considering the whole picture, the advice is not sound.

If you want to get better traction i'd start with a set of traction bars for your application. These are either in the form of the cheapies (if long enough) for $30 or so...or a set of slide-a-links or cal-tracs (better). The primary purpose of these is to prevent axle wrap, as posted above.....a weak leaf will wrap like into an "S" shape when launching....if that spring unloads you will get rearend hopping, resulting in spinning. The traction bars prevent the rearend from hopping. You don't want a soft leaf...you want a stiff leaf with cal-trac bars. Adjustable shocks (front and rear) will also help to dial in the suspension better.

What are you current 60' times? Stick or auto? Vehicle weight?

 

The overall equation for the vehicle of F=MA only works if you're power-limited. If you're traction'limited, you've got a whole other set of variables to overcome before you can worry about the overall vehicle weight. Ideally, if traction is the issue, (and I'm assuming it is since the original poster mentioned needing it to squat or plant on launch) you would readjust the existing weight on the vehicle to get more of the weight over the rear wheels on launch. Shift too much weight too far to the rear, and you get a wheel stand.

Being that he has a pickup (I assume), there isn't going to be an easy way to shift the weight bias further to the rear by removing weight from the front. He might be able to shave a few pounds by removing interior components, or even the hood, but neither will significantly shift the weight distribution on launch.

The only other option to get a better rearward weight bias would be to ADD weight to the rear end, and that bladder is the perfect way to do it.

Even if you soften the springs to the point that the rear end is on the bump-stops off the line, there's still no guarantees that'll help the launch significantly. One could always artificially plant the rear end with a couple of fat buddies. Load the bed full of a bunch of portley racing fans, then crawl underneath and use a heavy-duty ratchet strap to wrench the rear axle down to the bump-stops. It's not good for the springs, but will help the weight transfer ever-so-slightly.

When you're trying to get a good launch, it's all about the weight transfer. That's because, the more weight you transfer to the rear, the more the normal force increases on the rear tires. The more normal force you generate, the more traction force there is available to accelerate the car. Once you are able to transfer all the weight onto the rear wheels at launch(i.e. wheel-stand), then you are no longer traction limited, and yes, by removing weight from the vehicle, you will be faster down the strip.

No more rambling... shutting up now.

-Joe

 

Why not put a nice set of drag radials on it? They should stick pretty good.

I think traction bars and Radials would be the way to go. \

Ive also heard its easier to launch a longer wheel base truck, even tho that typically means more race weight.
-Patrick

 

I have experienced the 'weight transfer' theory or lack thereof.
My F150 doesn't lift on hard acceleration to any degree I notice.
My BMW is 51/49 Front to Rear. The Germans even put the battery in the trunk.
The front raises several inches when I dump the clutch.
I dunno, maybe my shocks are shot.

 

I totally agree with the above comments accept the bladder for the bed. I am planning on taking out my bench seat and putting in two fiberglass bucket, and moving my battery to the bed on the right side. My 60' times are 2.34, it is and automatic with a transco shift kit and the clutches have been doubled up between the 1st and 2nd gears. It weighs 4,360lbs. I am also thinking about running a light weight wheel in the front and getting some hoosier slicks. I think i will pull the bottom leaf out and run my traction bars until i get money for some cal-tracs.

 

If money werent an issue, you could look into putting a 4 link rear end into it too. With air ride, you can change the characteristics of the launch very easily.
-Patrick

 

You don't want the rear end to squat on the launch. You want it to raise slightly, mashing the rear tires into the track. Weigh transfer is the key, and properly working leaf springs. The front part of the leaf should be quite stiff, and the back can be softer, The stiff front end takes the force from the launch, and instead of axle wrap, it uses that force to raise the truck, and force the tires into the track. Measure up the length of your leafs, and see if there is a Chrysler Super Stock spring available in that length. Or go to your local spring shop. Many larger cities have them. Talk to a chassis shop.

Also, soft on the rebound, firm on the compression for front shocks. Maybe as much as 90/10 rate will allow for maximum weight transfer.

I drag raced many years ago in Pro Stock, and had a touring Pro live behind me. He was a chassis wizard.

 

So does anyone knolw where i an find 90/10 front and rear shocks for a fullsize 88.

 

Correct me if I'm wrong, but wasn't soft on the rebound and hard on compression to prevent bottoming out the front suspension when it settled immediately after the launch? It allows the front wheels to drop quickly when the nose comes up and keep the front wheels in contact with the asphalt.

As for where to find 'em, nobody will make them off the shelf for an F-150. Koni will build you whatever damping rates you want, but they won't be cheap. (probably on the order of $1000 each) Additionally, there will be no significant gain at the track. It's not the shocks that are his problem.