Jrxt Racer Lipo Battery Placement Help

[RCveteran]

In order to run the same battery I run in my 22 I want to remount in my XT racer. Curious from people with more racing experience which you would choose and why. The battery is so light it probably matters less than old days but not sure.

[jwscab]

if you are completely happy with the existing chassis dynamics, my suggestion would be to install a standard pack and locate the CG of the chassis(fully loaded, all gear installed, including motor). Use a ruler on edge clamped in a vise and set the truck across it. mark it off somehow and then remove that pack and install your new one loosely. adjust until the CG is the same. then fix the battery in that location the best that you can.

all other things being equal, you will have the same CG as before, but you will just be lighter. You would potentially need to change your shock/spring rate for the new weight.

if you are racing under sanctioned rules and you are now underweight, you can add weight back directly under the battery, or equally fore and aft to end up at the race weight and cg. alternatively, now you can add weight to better adjust your chassis dynamics.

[RCveteran]

You know the way you described it seems so easy and I have never done that all these years. My serious racing days are long gone and these days with the track over an hour I tend to just go on a day off when I can maximize lap time on an open practice day. I can run many battery packs through this way.

I was running a 5000MAH NIMH 6 cell in it, not sure if I was "totally" happy, but it seemed pretty well planted for a vintage truck on a modern track. I was running the tires you see but sauced. I was playing with the Losi AVC though and it really fools me into thinking I can set up a car better than I can.

[RCveteran]

Using that method its somewhere between pic 4 and 5. Or vertically down middle about an inch in front of rear battery box.

I can't help but think though if you could go back in the day with these smaller batteries moving wieght forward might have been likely, Much like current kick to go mid engine in 2wd. The rear is usually the looser end.

All things equal would a bit more weight bias to front be better? I suppose ideally you would move it to suit each track, but I cant keep drilling for battery boxes over and over.

[jwscab]

I would make a thin battery tray you could drill to your hearts content for battery location, like .062" fiberglass. Since you will be underweight anyway. make it fit the pack, then drill a series of holes so you can adjust the location every 1/4" or something.

I would say its really track dependent where you want that weight as you mentioned. some cars need more weight up front, some need it for rear traction.

[RCveteran]

Good thinking. I could even drill the holes in chassis such that I could move these hold downs back and forth together.