^^^ That is quite a collection you have there ^^^
The first machine I ever owned was the Original Duratrax Street Force GP. It's a vintage machine now that's hard to find parts for.
This ugly thing took me most of my younger adult life to get it to where it would go straight with a big honking motor. As a kid I always thought bigger was better. In some ways, I guess I still do but I learned that you have to get the power to weight ratio correct and balance the power. I put this huge motor on thinking that I was going to rule the roost when I raced my friend. All it would do was doughnuts. Couldn't get it to go straight to save my a$$. I learned that power is only part of the equation
Fast forward many years. A few years ago, I made it my mission to fiddle with the gearing and differential slippage, clutch settings, etc..until I could get the power under control and make it as fast as I could. It's still about what you would imagine when you nail it. It's like trying to control an estes model rocket engine. You have to fight the steering wheel the whole time. I don't run it much because with this huge ars motor it breaks too many vintage hard to get parts and I can't keep my finger out of the throttle when it get it out...lol.
Here are a few speed runs 2 years ago when I last got it out. It has a two speed transmission and an 18 OS engine but due to the torque of the motor, it pretty much just hops into 2nd when you nail it..lol
https://www.youtube.com/watch?v=7p6nP93EyAY&feature=youtu.be