Offroad big block thing built from junk

[Denny]

Looks great! A couple of suggestions though. Go with a full floor of at least 1/8” steel. Running over a branch and having it pop up and spear you through the chest would kind of suck. A roll bar and 5 pt. harness might be kind of fun to have also. Seeing how it is kind of tall.

 

[Bigblockguy]

A removable roll bar and removable full cage with a 5 point are in it's future, as is a diamond plate aluminum floor pan. I had a major screw up that I realized yesterday with the steering. Basically I had reverse ackerman and to fix it I'm gonna need to run narrower front wheels to allow me to move the arms to the outside of the kingpins. You live and learn I guess. Those 22x11s weren't fun to try and turn at a stop anyway.

 

[Denny]

Power steering?

 

[Bigblockguy]

Power steering?

Nope. But who really needs to steer at a stop anyway. I'm gonna get some new 20x7x8s so I can change the direction of the brackets. And relegate the ones I have now for rear spares. I was gonna put knobbies all around anyway, and wouldn't ya know? The 4pack with smaller fronts is almost 50$ cheaper.

 

[madprofessor]

Why change wheels and tires to get proper Ackermann? You've got leading arm spindles right now, and it's true that the kingpin bolts are way too close to the tires to get that kind of angle on the spindle arms the way I know how to do it. Why not just alter the steering linkage plan to make it a trailing arm setup? On a trailing arm setup the spindle arms angle inward of the kingpin bolt, on the leading arm setup you've got they have to angle outward toward the tires, and there's no room to do that.
BTW: The only way I know how to set Ackermann is with a straight line drawn (a string pulled tight) from the center of the rear axle in a path that crosses over the kingpin bolt and over the tierod connecting bolt. Crazy angled deal you've got going there, interested to see if you have a way to set Ackermann without crossing over the kingpin bolt. I'm great with math, but rapidly losing my spatial grasp, transpose things all the time.

 

[Bigblockguy]

Why change wheels and tires to get proper Ackermann? You've got leading arm spindles right now, and it's true that the kingpin bolts are way too close to the tires to get that kind of angle on the spindle arms the way I know how to do it. Why not just alter the steering linkage plan to make it a trailing arm setup? On a trailing arm setup the spindle arms angle inward of the kingpin bolt, on the leading arm setup you've got they have to angle outward toward the tires, and there's no room to do that.
BTW: The only way I know how to set Ackermann is with a straight line drawn (a string pulled tight) from the center of the rear axle in a path that crosses over the kingpin bolt and over the tierod connecting bolt. Crazy angled deal you've got going there, interested to see if you have a way to set Ackermann without crossing over the kingpin bolt. I'm great with math, but rapidly losing my spatial grasp, transpose things all the time.

Just saw this now. Im no expert, but one guy on youtube showed how to get proper ackerman with forward facing arms. Basically you use the measurements of your rearward triangle in front. The crazy angled things i have are to clear the frame, and using the forward facing triangle method (that didnt work), i put my holes in line with what shouldve been correct. I cant make rear facing arms on that frame without chopping out the frame supports near the back of the tire, so im stuck using forward facing ones. Using a tire and rim thats narrower would allow my to get rid of the crazy angled things, put on arms that face straight or outward. Even if its not perfect ackerman, itll be better than reverse ackerman.

 

[redflash]

ackerman.... shmakerman... just drive it as fast as you can !

Da Flash says.....

 

[Bigblockguy]

ackerman.... shmakerman... just drive it as fast as you can !

Da Flash says.....

Lol. With wheels that dont turn correctly all itll ever do is go fast and straight. Fine for a dragster, not so much for my intended use.

 

[Bigblockguy]

Not a big update but i fabbed up some tie rods just so i could take it for a spin. Handling is very twitchy due to tie rods being so close to the spindles, but i can take my hands off the wheel and it still tracks straight. Projects largely on hold bc ive got a trip coming up, but after that i can finish this portion up and get started on a cage for it.

 

[Denny]

Is the steering twitchy or just very responsive? See what I did there!
Make sure all the chevrons face the same way as the tires on the rear.

 

[Bigblockguy]

Is the steering twitchy or just very responsive? See what I did there!
Make sure all the chevrons face the same way as the tires on the rear.

 

[Bigblockguy]

I know the front left is backwards. I didnt mount them lol. All 4 tires are junk and dont hold air for more than a quick ride. Im going with narrower rims and tires in the front so i can rework the steering and putting knobbies all around.

 

[Denny]

Those tires don’t look bad! Just put tubes in them.

 

[Bigblockguy]

Those tires don’t look bad! Just put tubes in them.

They look good bc theyre wet in that pic. I was literally able to SEE air coming out of the front ones. I may keep the rear ones as spares

 

[Bigblockguy]

Small update. Took it out yesterday to see how fast i could get it to go. Without pushing an ungoverned motor with no tach, i hit 35, using the app on my phone. Im hoping with upgraded intske, exhaust and upgraded internals to hit 45-50 and hopefully get the front end to lift on launch.

 

[Functional Artist]

hopefully get the front end to lift on launch.

Well, that's a whole lot of (really nice ) heavy duty kart ta try-n-get the front end to lift on a launch

Here is my little !ARRIBA!
She can easily lift the front wheels
...with only (2) 1,000W motors (~3HP total)

 

[madprofessor]

That Arriba looks like hilarious fun. I still say it needs wheelie bars, since my extreme antics would flip it over backwards on a speed bump or something immediately. I split a Bell helmet in half once on my first dirt bike, you can't rely solely on your safety equipment.

 

[Bigblockguy]

T

Well, that's a whole lot of (really nice ) heavy duty kart ta try-n-get the front end to lift on a launch

Here is my little !ARRIBA!
She can easily lift the front wheels
...with only (2) 1,000W motors (~3HP total)

Thanks. That little electric cart looks like fun. And electric motors are straight torque monsters. Mines not THAT heavy. I can lift the front end w one hand. And its got torque. Im thinking when i upgrade the intake and exhaust i should prob get better throttle response and get torque to earth a lot faster.

 

[Bigblockguy]

Been a while since i did an update. I added a rear roll cage, mcp braking system, bought 4 new rims, reworked the steering with straight tie rod arms and im now waiting on the new knobby tires

 

[Bigblockguy]

All the big stuff is finally finished and took it out for a shakedown run yesterday. Got it up to 33. Still need stiffer springs in the front and to finish the removeable front cage, but at 30mph it doesnt seem to care if its on or off road. The pics dont do it justice, those rear tires are huge.