DR10 1967 Mustang no prep build

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I have been playing with the front steering linkage. It still has just a little bit of bump steer. I have the links level and the chassis is just nose down a fraction. I don’t even know if that is good.
I think the angle of the steering blocks from the DR10 kit are doing something strange with the zero caster bulkhead. Seems odd and probably steers just fine. But when you move the chassis up and down. The wheels move in and out just a little.
Can you make a video of what you are talking about?
 
That is just bump steer. Your front suspension shouldn't be moving that much anyway. Bump steer isn't going to be too detrimental on a drag car since it will mostly only see flat surfaces.

You will want a bit of droop in the front suspension so the front wheels can try to stay planted as the weight transfers to the rear. Kinda like the old Lakewood lift shocks. They had a piston in them that let them extend easy, but were hard to compress. You could usually tell when cars were running them by the way the cars launched. When they left the line their front end would lift, then slowly return to normal ride height as they went down the track.

It would be cool if someone introduced a shock piston in RC that worked that way. It would require check valves in the pistons. I may eventually try to print some.
 
Didn’t thy call those 90/10 shocks?

It’s not to bad now . With the flat block it was probably no drivable.
 
I set the tow with just enough tow in at rest to be pretty much zero tow at full
Compression.
That way it’s steering straight on deceleration and from rest to full compression the bump steer is very minimal.
Now I want to get rid of the servo saver.
 
I set the tow with just enough tow in at rest to be pretty much zero tow at full
Compression.
That way it’s steering straight on deceleration and from rest to full compression the bump steer is very minimal.
Now I want to get rid of the servo saver.
You don't need a servo saver on a drag car really. I mean if you crash, it would be good to have. But the body will absorb most of the blow anyway. I don't run servo savers on any of my buggies, and they are open wheeled.
 
The linkage is so strange on this thing I had use the stock servo saver just to get it together. I have a metal one coming in a week or so.
 
I made a new steering linkage. This eliminates the ball and cup links at the servo and the servo saver. That eliminated 30 percent of the slop in the steering linkage.
I’m still playing with the steering links angle so I will cut that to the proper length when I know it’s right.

This is the servo I’m using . It was a good servo back in the days for airplanes.
 

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I went to the local hobby shop for 10 Guage wire and they have a drag slash so I lifted the body and immediately knew what my problem was.
Wen I changed to the zero degree bulkhead it changed the angle of the tie rod and upper control arm.
They need to be parallel.
I removed the inner control arm mounts and used rock crawler links to move the upper control are down.
No more bump steer. And much less slop in the suspension now.
 

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I replaced the steering tie rod ends with rock crawler ball link ends. The tie rods with the left hand thread still work but now they are nice and tight.

I centered my sub trim and steering servo trim to zero and adjusted everything so when I roll it across the ground the car goes straight. I am running about two degrees of toe in and one degree of negative camber and zero caster or very little I have not measured it yet.

I made up the 10AWG wiring from the motor to the monster X with 6.5mm bullet connectors. It looks massive.
 

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This is getting fun.
So I got rid of the bump steer by lowering the inner position of the upper control arms.

Before when I pushed down on the suspension the front of the tire moved out. Now it does not move in and out. But the tire does not move straight up and down. It kinda swings through an arc. I’m going to experiment with different camber settings and see what happens. I looked up some diagrams about suspension geometry.
 
This is getting fun.
So I got rid of the bump steer by lowering the inner position of the upper control arms.

Before when I pushed down on the suspension the front of the tire moved out. Now it does not move in and out. But the tire does not move straight up and down. It kinda swings through an arc. I’m going to experiment with different camber settings and see what happens. I looked up some diagrams about suspension geometry.
Play with some spacers on the upper link.

Actually, looking at the geometry, you won't be able to dial out any camber that is added with suspension travel. The upper arm is traveling at a different radius. So it is always going to add negative camber as the arm travels upward. But camber isn't going to hurt anything. Don't worry sbout it, because almost sll cars are setup this way.
Screenshot_20211227-171230_Chrome.jpg
 
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Yes it’s going to be there. Just have to set it up so when it’s under power the tire has the most contact possible.
Same with the caster and toe.

I think the original set up had 15 deg of caster.
I want maybe 4 deg so let’s see what I come up with tonight. It’s fun to see some changes and what it takes to make the changes. Should get my 4 mm bullet connectors for the battery and some different bell cranks to experiment with
 
Yes it’s going to be there. Just have to set it up so when it’s under power the tire has the most contact possible.
Same with the caster and toe.

I think the original set up had 15 deg of caster.
I want maybe 4 deg so let’s see what I come up with tonight. It’s fun to see some changes and what it takes to make the changes. Should get my 4 mm bullet connectors for the battery and some different bell cranks to experiment with
Actually, having very little contact on the front tires is best to lower rolling resistance. Typically, in drag racing, you air the front tires up as much as possible to lower the contact patch.
 
For what it's worth, here is image of the 2006 R1E bracket racing truck. TRX Rustler with cut down bandit wheels with an o-ring in the wheel groove made for the bead. No steering issues.

This was a full-prep car. Don't know what present day no-prep rules are regarding front wheels. 'AC'
 

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I was thinking it was a toss up between the rolling resistance and control. Since I have ZERO rc drag racing experience I can only guess.

I finished the electronics.

Up front is the castle B-link.
Then a Futaba S9351 servo. The recever is a five Chanel Spektrum with a 6 volt glitch buster.
The battery is from my short corse truck with a 100C 2 cell. I’ll get a proper 150c drag pack later.
Next is a Castle Monster X wired with 10AWG wiring. Out back I have the Trinity 3.5T Hole shot Drag master motor.

And finally a 6 volt LED taillight.

I changed the camber to -2 deg. And set the toe to -1 deg. Probably change the rear toe to -1 also.

The movement is so much better than it was that I’m just going to have to run it and see what happens.

 

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For what it's worth, here is image of the 2006 R1E bracket racing truck. TRX Rustler with cut down bandit wheels with an o-ring in the wheel groove made for the bead. No steering issues.

This was a full-prep car. Don't know what present day no-prep rules are regarding front wheels. 'AC'

Most no-prep clubs don't allow the o-ring tires for some reason, not exactly sure why (probably lemming mentality, lol).
 
I wish I could use O rings for front tires. I have some super cool o ring wheels for pylon racing airplanes. Super smooth with bearings inside.
 
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