CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.

The Shop Truck

1971 Chevy C20 with a custom flat bed.
I enjoy watching this thread for 2 reasons.

One, because it's awesome :thumb:

Two, which I'm somewhat ashamed of, is your finding all the weak points I'm going to find eventually. Some I've already had similar happen lol.

Trying to make hippos into race trucks is an interesting road :haha:
 
I've been going to buy one of these.

Amazon.com: CGOLDENWALL Digital Crane Scale 4400lb Industrial Hanging Scale Handheld Hoist Scale kg lb Switchable 2000kg Wild Game Scale for Farms, Hunting and Livestock : Office Products https://share.google/IsJhx3xIhtDhbMbAj

Then just use my gantry to lift and end.
Plus it'd be useful for other stuff around here.
 
I knew about preloading the sway bar, but what does preloading the upper link do? I can also move the crane as @imiceman44 suggested.

A similar thing, if you shorten one of the upper links with a little preload, it can set it up so that it pulls one side harder on the launch to help it go straight. This only works with custom parallel 4 links for drag racing (parallel when viewed from the top, not the side).

Single, there's a lot that isn't optimal about this truck and most of that is because I want to keep it 8 lug. That severely limits my choices, in fact I've found exactly 1 wheel that will work for me on the street and 1 that works for beadlocks. If you can find me someone that can make me a custom 8 lug double beadlock with the width and positive offset I need that will also fit over the big silverado brakes, let me know.

Your rear axle does limit you quite a bit. There are a few companies that do beadlock conversins, perhaps you can have your wheel converted to a double beadlock. It might save your tires.




So you're only looking at top speed for these numbers? If that's the case then yes I can do that, but if we're talking ET I'm not consistent enough to compare those yet.

Ideally you would look at both, but you can get very very close by tuning the engine for MPH and then tuning the chassis for 60 ft and ET. It would certainly get you closer to the right tune, it already did, but there could be more.

I agree. I'm not trying to make the truck as fast as it can possibly be, I'm trying to make it as fast as I can with the parts I have on it currently. I think the real answer is to keep the setup I have, but slow down the launch until it goes down reliably. If I ever do a drag and drive event that has actual competition, I'd probably shoot for the 10.5 index or a DYO in the low 10s.

Slowing down the launch is only one answer, you can also tune the suspension and tires so it will hook. First time I sprayed the nitrous it blew the tires off. Happened several times but as I got the shocks dialed closer it hooked, slowly picked the front wheels 6" and held them there to around the 60 ft mark. Then it set down so gentle you could barely feel it. Whereas if I would of just cranked the shocks I might of stood it on the rear bumper and broke stuff.

Unfortunately I had a gout flare up as soon as we got home (too much partying, not enough water), so I'm not sure I'll be able to get the truck ready for Friday, but I'm not giving up hope yet. If it clears up quickly I could get the diff inspected and back together, preload the sway bar, and move the crane. I'll also probably bump the tire pressure up to the max (30psi).

bummer, get well soon.
 
A similar thing, if you shorten one of the upper links with a little preload, it can set it up so that it pulls one side harder on the launch to help it go straight. This only works with custom parallel 4 links for drag racing (parallel when viewed from the top, not the side).
My 4 link is a parallel 4 link with a watt's link to keep it centered. Which link would I shorten/lengthen to get the desired effect and how much?
Your rear axle does limit you quite a bit. There are a few companies that do beadlock conversins, perhaps you can have your wheel converted to a double beadlock. It might save your tires.


That's an excellent option, I wonder if they do other peoples wheels. Also, the wheel I'm running is the Battle Born Sierra Forged Beadlock Race Spec. They are designed to be able to run a small tire inside the main offroad tire that acts as both a run flat and an inner beadlock. I didn't get the wheels drilled and tapped for the second shraeder valve, but I could do that myself. I have heard that they are a pain in the butt to get mounted though.
Adding the second beadlock would make the wheel effectively wider, which would be good since I'm running a 10.5 on an 8.5" wide wheel.
Ideally you would look at both, but you can get very very close by tuning the engine for MPH and then tuning the chassis for 60 ft and ET. It would certainly get you closer to the right tune, it already did, but there could be more.
(y)
Slowing down the launch is only one answer, you can also tune the suspension and tires so it will hook. First time I sprayed the nitrous it blew the tires off. Happened several times but as I got the shocks dialed closer it hooked, slowly picked the front wheels 6" and held them there to around the 60 ft mark. Then it set down so gentle you could barely feel it. Whereas if I would of just cranked the shocks I might of stood it on the rear bumper and broke stuff.
Exactly, it will be a combination of things that I do to make it reliably launch in a variety of traction conditions. One of the Firebird staff has pretty much talked me into competing in their shutdown showdown no prep/no time events. That's definitely something I was wanting to try out.
bummer, get well soon.
Thanks
 
My 4 link is a parallel 4 link with a watt's link to keep it centered. Which link would I shorten/lengthen to get the desired effect and how much?

You would shorten or lengthen the upper right arm. But I don't think I would add any preload to that yet. That tuning mostly helps the vehicle go straight while fighting body roll, I think this is also because of roll steer. And usually they put preload in that bar when they don't have an antiroll bar, but you can use both.

That's an excellent option, I wonder if they do other peoples wheels. Also, the wheel I'm running is the Battle Born Sierra Forged Beadlock Race Spec. They are designed to be able to run a small tire inside the main offroad tire that acts as both a run flat and an inner beadlock. I didn't get the wheels drilled and tapped for the second shraeder valve, but I could do that myself. I have heard that they are a pain in the butt to get mounted though.
Adding the second beadlock would make the wheel effectively wider, which would be good since I'm running a 10.5 on an 8.5" wide wheel.

Yes, MacFab specializes in beadlock conversions of other wheels, and RC Comp does them, but they also make wheels. Your limit might be the wheel width. RC comp was the only company I found that would build me a 15x9 double beadlock wheel. All the other companies wanted at least a 15x10 to do double beadlock, which I have stock wheel wells and I couldn't fit as it widens the cross section of the same tire. Most people want a wider wheel because a wider wheel on the same tire gives you a bigger contact patch and more traction.


(y)

Exactly, it will be a combination of things that I do to make it reliably launch in a variety of traction conditions. One of the Firebird staff has pretty much talked me into competing in their shutdown showdown no prep/no time events. That's definitely something I was wanting to try out.

Careful with the no prep stuff, I won't go down a non prepped track for safety reasons, especially with drag radials, radials need a prepped track.


 
After doing a bit of research, tire liners are common with drag racing too. I may talk to Battle Born and figure out which liners I need for my wheels. That would be the easiest option (other than mounting/dismounting).
 
Apparently it needs BFG liners that are only available to their factory teams. So much for that idea.
 
Top Bottom