Build Thread Beer’s Kyosho Nitro USA-1 Improvement Build

[Beer_Goggles_RC]

I’m starting this thread to share the improvements that I will making to my USA-1.

I’ve owned this RC since late 2023. It was purchased new on Amain as part of a sale and if I remember correctly was only ~$400.

This has certainly been what I think is the coolest RC I’ve ever owned, and possibly ever will own. The solid axles make this thing handle and jump like a real monster truck. And of course, all real monster trucks need an ENGINE!

Overall from the factory this is a very good truck. There’s just a few improvements I’d like to make.

 

[WickedFog]

I’m starting this thread to share the improvements that I will making to my USA-1.

View attachment 199330

I’ve owned this RC since late 2023. It was purchased new on Amain as part of a sale and if I remember correctly was only ~$400.

This has certainly been what I think is the coolest RC I’ve ever owned, and possibly ever will own. The solid axles make this thing handle and jump like a real monster truck. And of course, all real monster trucks need an ENGINE!

Overall from the factory this is a very good truck. There’s just a few improvements I’d like to make.

We have a nitro Mad Crusher. Very cool trucks.

 

[Beer_Goggles_RC]

We have a nitro Mad Crusher. Very cool trucks.

Thought about selling my left nut for This Giga Crusher but I guess my wife still wants more kids lol

 

[WickedFog]

Thought about selling my left nut for This Giga Crusher but I guess my wife still wants more kids lol

Yeah, that Giga is a rarity. But I think you got one of the best monster trucks there is. So many RC's out there are called monster trucks these days. But 95% of them aren't even close to being a true monster truck. They're just truggies with big tires. And it bugs the hell out of me the industry has come to know RC's such as a Kraton as a monster truck... pffft!

 

[Littlemotor]

I’m starting this thread to share the improvements that I will making to my USA-1.

View attachment 199330

I’ve owned this RC since late 2023. It was purchased new on Amain as part of a sale and if I remember correctly was only ~$400.

This has certainly been what I think is the coolest RC I’ve ever owned, and possibly ever will own. The solid axles make this thing handle and jump like a real monster truck. And of course, all real monster trucks need an ENGINE!

Overall from the factory this is a very good truck. There’s just a few improvements I’d like to make.

HELL

DAMMIT

YES.

 

[Tunedfrog]

Always been one of the coolest MTs I've seen.
@WickedFog kyosho Mad Crusher is another one.

 

[Lostinthewoods86]

Now I need to add another truck to my wish list

 

[Beer_Goggles_RC]

Now I need to add another truck to my wish list

You wouuld not be disappointed! The ke25sp2 is an awesome engine in this truck. But swapping out the throttle servo is a MUST. Lots of reports of runaways

 

[Beer_Goggles_RC]

Mod #1 - Suspension

Parts required for this upgrade:
2x sets of Kraton 6s rear shocks - ARA330622
2x sets of Tekno 95mm 3.96 Springs - TKR6080
1x Set of Arrma 6s Shock Standoff - AR330482
4x Arrma Shock Cap Protector 6S AR330492
4x Arrma 3x28mm Cap Head Hex Screw AR723328
4x Nylon Nut 3mm AR715001
1x Set of Arrma 6s Composite Ball Set - AR330483
1x Kyosho Rear Shock Stay - MA076BK
1x Kyosho Strut Bar - MA077 (or some allthread and a sleeve)
TLR 25wt Shock Oil

My first upgrade for this vehicle will be the suspension. Monster truck suspension is unique as with the vehicle being solid axle with XXL tires, quite a bit of the weight is unable to be dampened by the shocks, and instead is cushioned by the tires.

The USA-1 is a great truck with lots of great design execution, ..except for the suspension.. The shocks that come with the truck are at best OK. The bodies and caps are plastic, and the shock cap bladders leak. The front shocks are at a pretty laid down angle, I’m not sure why they were engineered this way but the more they are laid down they are compressed slower as the suspension travels and the shock has to travel less. What travel the truck does have (about 2”) is relatively stiff.

To replace these stock shocks I used 2 sets of rear shocks from the Kraton 6s.

Given the nature of truggy suspension, the Kraton 6s springs are relatively stiff for this application. Tekno springs fit Arrma shocks relatively well so I opted for the lightest 95mm spring they have. I could’ve gotten a softer shorter spring and ran the shock collar down, but figured these springs should do just fine. I also swapped out the shock oil with the lightest stuff I had on the shelf, TLR 25wt. I’m not sure what comes in the Arrma shocks from the factory, but the 25wt made them much more plush.

I added another kyosho rear shock stay to the front to alleviate the harsh angle that the front shocks are laying at. This required drilling a hole in the chassis and using a few spacer washers to mount it. Take extra caution with your hole placement so both shock stays mount at the same angle. I also custom fabbed a strut bar as the stock bar (MA077) was out of stock. This custom strut bar was made using #8 allthread with a sleeve slid over it.

Using the 6s Arrma shock standoffs and composite balls, I was able to mount the Arrma shocks.

You can see at the bottom of the shock I used an extra nut to space them away from the axle as they would rub without it.

Overall I’m relatively pleased with how this turned out. The truck sits higher and has almost twice as much suspension travel now. I also prefer the look of these shocks and that the front shocks are no longer laid down.

I haven’t had the chance to bash it yet, but the good ole drop from waist height suspension test has proved that this is a better setup.

In the future I will likely opt for some softer springs and asses the shock pistons as I would prefer a bit more plushness.

 

[majin]

man i wanna see this thing run stuff over