Class 2 Gspeed build

[Iowa crawler]

Got the Treal vintage bead lock wheels. This truck may not do it all be it is getting to be my favorite real quick

 

[Iowa crawler]

I do like this wheel. No sold on the center hubs.
This is what I was after. A scale truck I can take anywhere and have fun. Plus I can run it next April at the scale nationals.

 

[Iowa crawler]

I removed the portals to try out the straight axles. As I was doing that I get an early delivery notification for the brass portal boxes. That’s because I don’t need them early.

The reason I don’t like the portals are mainly the gear ratio. I mean one rotation of the drive shaft moves the portal wheel about 45 degrees. One rotation of the straight axles is about double. I normally run a 10 tooth pinion and went to a 15 tooth pinion just to make it OK. On rocks sometimes you need to spin the tires or hop and that was not happening here. Maybe a different rig they will be great.
Then there’s is all the noise. I pulled them apart and greased everything with Molly. They had nice grease in them. I suspect they will break in and quiet down.

Then there is the weight. 300 grams plus I need to brass up the front axle to get the weight distribution.
3/4 of a pound on a five pound rig makes a difference on a rock side . And with a hard body the lower center of gravity is a good thing.

And to put the final nail in my portal dreams. Toyota Hilex pickup trucks don’t have portal axles. So from a scale truck point of view they are wrong.

 

[Iowa crawler]

I don’t mean to bash portals at all. I think it’s just the parts combination that made them not fit. I think the AR45 straight axle might be the perfect thing but for now I like this set up. It did all 16 climbs in my yard and with a 13 tooth pinion it kicks up a rooster tail of leaves racing across the yard. Even handles ok in the turns. Rock crawlers are not meant for speed that’s for sure.

But with great power comes great responsibility. And when you send it things might not end the way you like.

Haha no big deal just the first “CRACK” sound I've heard. No big deal. Just snapped a glue joint. A little reinforcement won’t hurt.

 

[Iowa crawler]

I am still thinking about the KYX portals.
It must be a different ratio trans for the scx10iii and Capra. I took the KYX portals apart and they have the exact same ratio as the stock SCX10iii axles with an 8/30 diff and 12/23 reduction.
But with my trans it only had a top speed around four MPH.
I found a set of gears to change the portals to 15/20. That’s like 69 bucks to do both axles so I’ll wait.

 

[Iowa crawler]

I got the proper springs in today and they are perfect. The resting position is about half travel.
That is the final piece of the puzzle. I’m calling this done.

So now I have to put it on the trailer and hit some comps. Of course I have to build a trailer and a tow vehicle. Haha.

 

[WickedFog]

Gorgeous truck man!

 

[Iowa crawler]

I like that I can just use it and even bash it or go rock crawling . Front cab is less than 20 bucks if I total it. But I really just want to drive it. And try not to total it . But I know I can do a better job on the next one. I’m curious how styrene holds up.

Just a quick video with the new springs.

 

[Iowa crawler]

I had a problem using the vanquish rod ends on my cheater rig but now that this is finished I had to replace all the crappy metal ends I built it with.
So now it solid as a rock. With no play

 

[Iowa crawler]

I just had to put in an interior. It just looked bad with a big hole and wires and stuff.

But I did not want a full plastic heave one with a figure. To much weight. So I cut up an old Lexan crawler body and now I have a nice set of red leather seats. Perfect fit after very careful cutting and hot glue.

 

[Xraycer]

Excellent build thread!

That rig is awesome?

 

[Iowa crawler]

I got the Class 2 truck out today for a trail run. What a blast. 2:45 minutes on two battery packs. No break downs and no hand of god flip overs. I just blasted around the trails. I got stuck in a root and used my winch to pull off of it. Other than that it was pure fun.

The second video is a deer trail. I have climbed it many times.
With the leaves you can’t see the trail. It made it up and down. I don’t know why I turned off the camera on the decent. It was cool .

Deer trail hill climb.

 

[Doom!]

Glad it's living up to expectations!

 

[WickedFog]

Very cool. Love this build man!

 

[Iowa crawler]

I’m having trouble getting my head around portals.
I built this rig with the intention of using AR45s . The offset diff and portals give extra clearance.
I used a forward motor mount with this so the engine is under the right side and the driveshaft is running beside the motor. And goes straight to the diff from the transfer case. Excellent driveline set up.

The problem is the truck was slow. With a 10 tooth pinion it was stupid. With a 13 tooth it was drivable. But off the rocks was just a slow walk. And zero wheel speed for hopping across a gap or something.

The trans has 30% overdrive to the front.
I swapped back to the AR44s and as you can see from the video the truck is a blast to drive.
All these axles use the stock 8x30 ring and pinion with a 56 tooth spur on the trans.

They have overdrive gears for the portals.
15/20
Should I swap the front and rear portal gears for overdrive gears. I have the split overdrive in the trans. Or swap the spur with a 54 from the 56?
Or will this still be to slow for trail driving?

 

[Xraycer]

I wish I could help, but this is just too technical for me.

 

[Iowa crawler]

Ya me too

I don’t want to buy a bunch of parts and begin a science experiment. I am hoping someone has been down this rabbit hole already.

I want to like portals. But so far I like straight axles.
I’m thinking I should get the AR45 straight axle conversion kit for this. But the 44s work great.

 

[Doom!]

@Iowa crawler You just made my brain hurt! maybe that's why I mostly have RTR's.

 

[Iowa crawler]

Here is the problem. I don’t want to buy Capra axles and have the same problem with my G shot. I bought a front AR45 and two rear AR45 portal because I was thinking about a portal rear with straight front. But the gearing issue made my head hurt. I have been scouring the web and am just more confused.

Axle diff gears 8/30 = 3.75:1

Ring and pinion O.D. 8/27 = 3.38:1

Portal gears 12/23 = 1.92:1

TGH O.D. portal gears 15/20 = 1.33:1

Hot Racing O.D. Portal gears 13/22 = 1.69:1

Total axle ratio 7.2:1

TGH Portal overdriven axle ratio 5:1

H.R. Portal overdriven axle ratio 6.35:1

Ring and pinion overdriven axle ratio 6.48:1

Both (TGH) overdriven axle ratio 4.49:1

Both (H.R.) overdriven axle ratio 5.71:1



TGH portal OD percentage 36%

HR portal OD percentage 13%

Ring and pinion OD percentage 10.5%

Both (TGH) OD percentage 46%

Both (HR) OD percentage 23%

TGH OD front, ring and pinion OD rear total OD percentage 26%

HR OD front, ring and pinion OD rear total OD percentage 2%

TGH OD front HR OD rear total OD percentage 24%



Internal transmission gears 30/54 = 1.8:1

Ratio before pinion selection 12.96:1

Spur 34t pinion 17t = 2:1 total= 25.92:1

34/16= 2.13;1 = 27.6:1

34/15= 2.27 = 29.42:1

34/14 = 2.43:1 = 31.49:1

34/13= 2.62:1 = 33.96:1

34/12= 2.83:1 = 36.59:1

34/11 = 3.09:1 = 40.05:1

34/10 = 3.4:1 = 44.06:1

34/9= 3.78:1 = 48.99:1



Final drive ratios are based on stock axle gearing
I don’t want to buy another set of portals.

I see the other rigs like the Capra and they are not super slow with portals. But a lot of portals vehicles have two speed transmissions.

It cost 80 buck for enough gears to change the portal ratio. A small spur and big pinion cost 20 but it might be jumpy or drive poorly on the rocks.

 

[Iowa crawler]

I found a face book post and a u tube video about adding overdrive to the front and rear of portals when swapping from straight axles to portals on Axial based vehicles. So against my wishes I’m going to do some experiments with this class 2 truck.
Figure out how fast it can cover a given distance in my back yard.

Then tear it down and put the portals in figure out the pan hard and steering links. Then do it again.

Then by that time the portal gears should be here. And I can speed test it with the new gears.
I just ordered 15/20 portal gears for the front and rear.

After that I will make my decisions about the G-Shot axles.

Snowing this weekend so it’s a good time to spend in the shop.