Project Wheels Up

[Vader's Fury]

It would, but only for the half of the spring that is behind the axle. The front half of the spring is still rigid mounted so it causes a lot of energy to be trapped in the spring, which once it releases, is causing you to loose traction.

 

[Vader's Fury]

Another visual aid.

In this picture the spring on top is in normal ride position when the truck is sitting still. The lower picture is once the spring is compressed, or in your case when you launch the truck and going down the track under power.

Pay attention to the rear shackle on the spring and how different it is angled between the 2 pictures. This is the motion that your bar is preventing from happening. So all the energy that would normally make the spring move like that is getting trapped in the spring with nowhere to go.

The release of that energy is what is causing you to break traction and making the truck hop/spin the tires.

 

[Hotrodtractor]

Vader has it.

Now if you want to really get this thing lined out - get it on a set of corner scales and figure out the CG location - combine that with some measurements off the truck and you can setup or monoleaf and traction bar setup so it mimics a 4 link in setup by having your instantaneous center exactly where you need it.

I would also venture to say your monoleaf with the angle iron is also flexing more than you think. Removing that angle and adding in some spring leaves that are cut short just after the axle and combined with a healthy spring clamp will help stabilize that aspect of the setup as well.

Again - a GOOD side shot that is taken relatively square to the truck (and preferably of the entire truck, but high enough quality to clearly make out all the mounting points of the rear suspension).

Or we could do this the hard way and decide upon a common reference point and measure all the mounting locations off of it and build a diagram.

 

[STROKIN N STYLE]

Sent from the Sea

 

[Hotrodtractor]

Engineers rule the world.

 

[STROKIN N STYLE]

I like that one lol

Sent from the Sea

 

[vanderchevy18]

Vader has it.

Now if you want to really get this thing lined out - get it on a set of corner scales and figure out the CG location - combine that with some measurements off the truck and you can setup or monoleaf and traction bar setup so it mimics a 4 link in setup by having your instantaneous center exactly where you need it.

I would also venture to say your monoleaf with the angle iron is also flexing more than you think. Removing that angle and adding in some spring leaves that are cut short just after the axle and combined with a healthy spring clamp will help stabilize that aspect of the setup as well.

Again - a GOOD side shot that is taken relatively square to the truck (and preferably of the entire truck, but high enough quality to clearly make out all the mounting points of the rear suspension).

Or we could do this the hard way and decide upon a common reference point and measure all the mounting locations off of it and build a diagram.

It does have an extra short leaf up front. It's rather thick as well.

I'll see about getting it on some scales. Not sure where to get a hold of them though.

I'll get some pictures when I get a chance. I can also get some measurements if that helps more.

 

[Hotrodtractor]

It does have an extra short leaf up front. It's rather thick as well.

I'll see about getting it on some scales. Not sure where to get a hold of them though.

I'll get some pictures when I get a chance. I can also get some measurements if that helps more.

http://www.how-to-build-hotrods.com/center-of-gravity.html

Except ignore their CG height approximation and figure it out by taking the same weight readings as above - except by elevating one end of the vehicle by placing the wheels on blocks of a known height (say 8-12") - make sure you subtract the weight of the blocks.

 

[Vader's Fury]

Good link. I want to try that with my Excursion and see where it is.

 

[JoeDaddy]

Any of your local circle track guys will have scales.
I'm going to go against the grain here and say....don't change a thing about that chassis. The capability you've displayed would suggest to me you start a tube chassis.
If.....you are set on a truck chassis.....? Lets start with a better chassis. Something without I-beams, something with rack and pinion steering, and A-arms or struts..? Might I suggest a 1st gen Dakota..?

 

[Hotrodtractor]

I'm going to go against the grain here and say....don't change a thing about that chassis. The capability you've displayed would suggest to me you start a tube chassis.

IMHO this is terrible advice. There has not been one single clean pass with this truck. It is in its current condition not very consistent either. To run in the class its CURRENTLY racing in he needs to be high 9s/low 10s and still won't be the fastest of the fast in the class (9.523 is the current class record). A full tube chassis will put you looking at the 7 second range in the NHRDA.

 

[vanderchevy18]

IMHO this is terrible advice. There has not been one single clean pass with this truck. It is in its current condition not very consistent either. To run in the class its CURRENTLY racing in he needs to be high 9s/low 10s and still won't be the fastest of the fast in the class (9.523 is the current class record). A full tube chassis will put you looking at the 7 second range in the NHRDA.

I do agree with Jason on this one. I want to stay Super Street. That means no 4 link, back half, or tube chassis. Now that being said, you can't exactly make fun of the chassis quite yet. I have only made 2 runs with nitrous down here where the turbo lights. Once I added the nitrous the suspension would load hard enough to make the passes. I have gotten faster every time I run. Not fast then slow then fast. I don't think I have enough time in it to say it's inconsistent yet. I mean, come on. A 10.87 and on another pass a 1.54 60' all from a haggard leaf spring suspension under an old ass truck that's all sheet metal. That's absolutely incredible if you ask me. Especially seeing as how I built it and I know absolutely nothing about building a drag racing chassis. Give me a little more time with this setup. I'll find the center of gravity and instant center. Then maybe I'll try to swap around the track bar. Most importantly though I'm going to add a rear spoiler to give it some down force at speed. Maybe eventually I will build a tube chassis drag racer. But that truck/car will be a 6.4. This has been build solely with super street in mind. I'm keeping it that way.

 

[vanderchevy18]

Well here's an interesting plot twist. The wife decided to back the race truck off the trailer for me since it's fixing to rain. (Even though I had it covered with a tarp and told her not to.) Well the trailer wasn't hooked up. No big deal right? Trailer pops up, back it off easy, trailer comes back down, no biggy. Well apparently they came back down too quick. The trailer smacked the bottom of the radiator and busted it..... So if anybody has a suggestion on where to look for a good light custom radiator, let me know. :fustrate:

 

[vanderchevy18]

You know, if I was really good at this whole competition thing, I would just get someone to sponsor me a new radiator, intercooler, and one of them new fangled BD air cut off dealies. I'm just about tired of paying for stupid **** like this.

 

[Spatel23]

Would you even be able to attend enough events for a sponsor to consider it ?

They usually require a certain # of events, and its not easy to make it to all of them.

 

[vanderchevy18]

I didn't invest in a hauler and enclosed trailer with living quarters for nothing. That's the whole point.

 

[bigrpowr]

nobody sponsors $hit these days anyway.

 

[Cutting-Edge Diesel]

True story lol

 

[vanderchevy18]

Unless you're a little sleezeball that enters into DPC with a 6.7....

 

[JoeDaddy]

I have several small radiators.

And my advice was to not waste anymore time on that overweight tractor frame. It served 1 purpose. Get into a 12.0 class with a stock suspension. That page has turned.
Run what you brung or start a new chapter.