Body Inset for DFW

How necessary is it to trim an inset of 1/16"-3/32" for the DFW? The purpose of it is to allow the DFW to rub the rail and to keep the back wheel on the same side off the rail, but if the rear wheels are canted out then would they not be able to reach the rail if the car runs straight?

Thanks in advance.

 

The car will run better with the rears centered over the rail

 

3 degrees on the rears, 5 on the front does produce an offset. But I think you will want your rears centered between the rails with your front just off the rail. You will need to narrow the front to accomplish that.

 

I end up trimming both sides, with the end goal of keeping the rears centered and front tight on the rail. If you have a track, it helps to let it roll from just slightly up the hill to see how your car is centering. My opinion is that a front being tight on the rail is especially helpful on scout cars as the tracks tend to be rough and bounce around more thru track transitions.

 

So, you’re saying that you run the front looser for league racing?

 

One thing you have to be careful with on Scout cars when making the car sit tight on the rail, the person staging the car for the race may not realize what is going on, and you may end up with one of the front wheels riding down between the center rails.

 

Didn't say that. All things equal i would guess you'd pick up way more speed keeping a car tight on a rough track than a perfect one.

 

That's a very good point. Which is why I stage for our pack.

 

Got it, thanks!

 

Center the rears, add your bent axle & take the 1/16 or whatever.
Leave the non dom side alone. Relief for a bouncy Scout track & in line for aero ?
If the cars wiggles on a league track it's over anyway

 

Me too!

 

Thanks for all of the input. I'm still not understanding why the 1/16" on the DFW side is necessary to take off if the rears are canted out 3 degrees. Seems like the cant would take the rears away from the center rail. Any inset on the front would just be insurance in case the car starts with a bad stage and the rear wheels hit before the steer kicks in. Is that wrong?

Anyway, I'm not resistant to taking the 1/16" off the front, I did that last year, just trying to understand the interplay between all of the variables. I'm also trying to keep the build as simple as possible because I'm trying to have my son do more and more of the build as he gets old enough to handle tools and do more precise work.

 

You take the 1/16th (or so) off so the car will go down the track straight. If you don't, it will be slightly crooked, resulting in more friction, robbing speed.

 

Ahh...makes sense. I appreciate it!