Originally Posted by Slash'em1

Its a good day fellas! I just got my kit today and hopfully will be starting the build tonight. Has any thought about using RMP ballcups? I never had a issue with them on my B44. I'm thinking I should just get new ones before I start the build. I just want to make sure I get something that will work.

Originally Posted by Cpt.America

Im not sure they will work with the larger metric ball studs.

Originally Posted by Cpt.America

Definitly

Me too.. My car had TONS of steering last night, even with the locked in rear-end


Motor config first, as you have to have that set when building the car. Choose this based on whether you like a darty car, or a more planted car, and from how much traction you track has in general. If your track has a LOT of traction, tire spin might not be an issue, and 3 gear might feel better. If you fight rear tire spin as I do, RM4 might be a better way.

Originally Posted by Jmuck69

I was thinking since it's very simple to flip the motor around that it can be done at the track to help tune. My home track is high grip so the 3 gear is the way to go but another track I go to in the area is low to med grip so the 4 gear might be the ticket.

Originally Posted by Cpt.America

Very simple? If you say so.... You'd have to rebuild the rear-end, and rewire the entire car.... That may be simple , but not something I like to do over and over.

Originally Posted by Jonny5

I have yet to try it, but when I wired Cush's car I tried to make the motor wires so that they would reach to the other side so we can flip the motor if desired. It helps that we have a Speed Passion motor in it with bullet plugs that just slide off, but I'm confident it can be done. All you would need to do is rebalance the car if you have added weight as the motor would sit just off to the other side.

Originally Posted by Cpt.America

In a 3 gear config, the motor spins backwards. When the motor spins backwards, it makes the car attached to it spin the opposite direction, which is forward. forward rotation of the chassis means more pressure on the front tires, and less on the rear

In a 4 gear config, the opposite happens. The motor spins forward, which makes the chassis rotate backwards, which means less pressure on the front tires, and more on the rear tires.

So in both configs the car squats on-throttle, but there is a slight pressure bias towards the front tires in 3 gear, and a slight bias towards the rear tires with the 4 gear.

Originally Posted by Jonny5

I have yet to try it, but when I wired Cush's car I tried to make the motor wires so that they would reach to the other side so we can flip the motor if desired. It helps that we have a Speed Passion motor in it with bullet plugs that just slide off, but I'm confident it can be done. All you would need to do is rebalance the car if you have added weight as the motor would sit just off to the other side.

Originally Posted by Jmuck69

maybe not, the motor looks to be centered in the chassis.

Originally Posted by Cpt.America

The topic was actually RM4.

It doens't really help in the scheme of communication to say things like "better grip". you have to define what type of grip you are trying to qualify and quantify. In this scenerio, we are talking about Rear tire straight line grip, on-throttle. It's important to qualify that. The motor hanging out the end of an RM car ads leverage to the weight that sits on the back tires. Motor placement is going to have a larger affect on which tires are receiving weight than which direction the motor is spinning.

On an extreme grip track, like astroturf, Rear tirespin is never an issue, and forward (rear tire on throttle) grip is always abundant... so a mid motor car, will excel. This is because a mid motor car is better balanced front and back, so it will be better in the corners. But on a dirt track, where forward traction is limited, the forward traction that is missing from the mid motor car will keep you from being able to get hard on the gas. Tire spin will keep your lap times up. The rear motor car, with more weight leverage over the rear axle, will have better forward grip.

Originally Posted by JayBuc

Got all that..good break down by the way! Thanks! but that is where the 4 gear plays into this. As stated before...4 gear setup would help you maintain that back tire pressure even with a mid-motor configuration right?

Originally Posted by Glowster21

Guys, any of you running the actual kit 6 hole pistons? I want to try those and also close up some holes on the 2nd set of 6 holes it comes with, any particular pattern I should close off to go from 6 to 4 holes?