I think it's time to get going on this

I should be ready to go by St. Paul. It's over at the neighbors getting shiny new paint job right now. I'm getting the engine, and some of the other stuff done as I can in the mean time. You coming up and hanging out with us in Sturgis this year?

How did you go about chosing an initial coil spring rate for your rear suspension?

Initial spring rate is determined by the weight of the vehicle. My truck is close to 4000lbs and the tech guy said that I would be close with a 200lb/in spring.

How much weight do you have on the back tires? Are you close to 50/50 weight distribution?

I have no idea on weight bias yet. I still have to get it all put together. If I were to guess, it will be more like low 40's on the rear and high 50's front. I hope to have it all together next week some time and get another weight check and find out where it's at.

schmitty wrote:Initial spring rate is determined by the weight of the vehicle. My truck is close to 4000lbs and the tech guy said that I would be close with a 200lb/in spring.

my guess is thats to heavy i almost bet u end up with 150lbs on the rear. eric

^^Agreed. With the amount of weight you are removing by cutting your frame, skinning the bed down, and removing the heavy leaf springs, that alone will drop your weight a bunch. If you've done similar with the cab and front clip, I bet you'll be around the 3500lb range. I run 110lb springs in my coilovers and that's with full bed floor. Granted I have to run the monoleaf to keep me in class rules, but they are there for looks and axle location. They really don't do squat for the suspension.

You may be needing to look at a way to add weight back to the rear so you can get the needed traction to get on top. All the suspension setup in the world will do nothing if the rear is too light to plant all that power to the ground.

I weighed the truck, minus engine and myself and it was about 2800 and change, and by the time I add the engine, and all of the necessary stuff, and my fat self, it will be around that 4k area. According to Uncle Charlies engine weights, the complete engine will be around 750, fuel system, electrical, cooling system, it will be close to 259# more and my fat butt will bring it close to that 4k area. All of the info I'm getting on chassis stuff says that is going to need the 200lb/in springs.

Meh, calculations smalculations. Get it done and show us what it does!

Knowing how Denny's truck ran with the same combo, I'm guessing it'll run like a bat out of Hades.

schmitty I had 225 lb springs in the back of my truck had a 40 percent rear weight ratio on a 4480 lb truck(with me in drivers seat), I think you will be pretty close but may have to tweek the springs after you run it and see what happens.

Sooooo, what would some characteristics of too low vs. too high of a spring rate on the coils be?

If the springs are too low, there will be a lot of compression and possibly bottoming out on the shock. Too high of a spring rate, and the rear will be bouncy, and not able to flex to fit the track and maintain traction.

We need pics of the new look of the truck

schmitty wrote:If the springs are too low, there will be a lot of compression and possibly bottoming out on the shock. Too high of a spring rate, and the rear will be bouncy, and not able to flex to fit the track and maintain traction.

I've been mud racing for a long time and all my experiences. Is u want the rear springs almost to be coil bound?? And after lookin at the truck pics again I think your going to need little more weight behind the rear end?

Well it's hotter than the hubs of Hades here, but the project must go on. I let my inner Thndrchkn out yesterday, and hacked the heck out of the front end on the truck. I found out that the oil pan on this engine, and the factory TTB crossmember would not cohabitate. I bought a 76 F150 chassis a while back and decided it was time for a straight axle upgrade.



I was surprised at how easily this came apart and went back together. All of this was done in a short afternoon and was not complicated at all. The old style radius arms fit into the frame brackets on this pickup with minimal effort. I reused the radius arm bushings from the TTB on the straight axle radius arms, and the fit was almost perfect. The straight axle radius arms are about 7" longer than the TTB arms and this pushed the front axle out in front of the engine and will help with the weight bias a bunch. With the big wide open frame it was a cinch to set the engine/trans/TC in all in one piece.

I am going to convert to full hydraulic steering with the components off of an old combine, and will be running a set of coil overs in the front.

Really like the progress Rob! I should have got you to work on my truck; you really get stuff done!!

David Willingham wrote:Really like the progress Rob! I should have got you to work on my truck; you really get stuff done!!

My father in law and crew chief neighbor helped out quite a lot on this so far. The front end swap wasn't as bad as I imagined, especially when I just went all in with the gas axe torch and stripped it out. You are more than welcome to bring that truck of yours over any time, it would be a privelege to work on it. I'm keeping an eye peeled on that EFI injection you have on yours. I'm very intersted in how it comes together.

It's looking good Rob.
Are you going to do some pasture tnt when it's together??

f250mike wrote:It's looking good Rob.
Are you going to do some pasture tnt when it's together??

nice work Rob!