Finally - some TESTING
We had a 60 degree day yesterday (sadly, today it's 60, but raining). I got the car fired up, and started working on the tune. Took a while to get things right, now that it's using the tiny little 2.5 oz tank instead of the massive tank in a Mad Crusher. Once I had that running decently, I tested the trans brake. It had NO chance to hold that big block. I anticipated that though, and designed a brake adaptor that would allow me to set up a dual disc system.
Since it's a good bit longer than the stock adapter, it needs to be held in in another way besides an e-clip. The one that HR sells uses a (very, very) tiny set screw. IMO, that's no bueno. I added little tabs that use the disc itself to keep it in place.
This worked perfectly, and I had dual brakes! Wow did they have a lot more stopping power.
I have two pad types - the CF pad I put on the inside, as it worked better with those tabs. The other disc is a little sloppier and I was worried it might somehow allow the adaptor to squeeze through, though probably not, but I wanted to be sure. Nothing worse that losing brakes at 80 mph! You can also see that I have the aluminum (hard to find) brake lever. This is a *must* upgrade, as the plastic one notoriously flexes.
Gave the trans brake a test, and it was perfect. It held with a solid 12% idle bump, which seemed pretty close to the way a 1:1 drag car does - didn't see any flames coming out of the exhaust like a 1:1 though (lol). Gave it a test 60 ft run, and oh my lord. That thing shot out like a rocket, wheels up, on the bar, until I let off. Did a couple more because it was just so much fun! Then I notice my brakes weren't functioning. The bolts holding the pad had backed out (I had doused them liberally with Loctite the night before, but clearly it wasn't working well). Luckily I had thread tape in my truck toolbox, so I wrapped the bolts up, and put them in, re-adjusted, and did some more 60 ft tests. I also popped the chute out, and it worked perfectly. Didn't seem to lift the car any, so I think I have it set correctly. I'll have to work up to seeing how that works on a full test. As it was, I didn't want to run any 120 ft tests this day, I didn't fully trust a lot of stuff yet. I did notice that it was shifting into second pretty early, so at the advice of a friend, I set the shift point as far out as it could, but I might actually move it back some as that seemed a little too much, it was winding pretty high in first.
I did a few more launch tests, just mesmerized by how this thing just leaps off the line. Then the car wouldn't move. Rut row. I had visions of my previous transmission detonating the gears and snapping the shafts. Sure enough, it all seemed to be bound up. Closer inspection revealed that the brake discs were jammed against the bolts, and that the adapter I printed was trashed.
Instantly I realized that I had printed this out hollow. Doh! I really thought I had the infill at 100%, but when I got home, I saw it was 25%. Whoops. Looks like slamming on the brakes at 40 mph was enough to crush it. In reality though, with these powerful brakes, it probably saved my transmission. Bringing it to a dead stop from 20k or more rpm, I'm starting to think *that* is what demolished my transmission the last time. Phew - glad I figured that out before trashing another one. Meanwhile, I printed out a handful more of them, but solid. I also re-programmed my brake rates and curve so that it won't lock up when hitting them (I think my instinct is to always just slam them).
I went back out, tested another dozen or so 60ft launches, did a little more tuning, and tweaked some settings on the brakes, got it where it felt good to hit hard, and a more gradual slowdown without locking up. The KE25 definitely was a big power increase over the OS .21 tm, and I will work on the launches and shift point some more if the weather is good this week, and then I'll start on the full 132 foot passes. Sorry, I didn't take video - I always find that to be a chore, but I'll get some soon, and some data to post.
I also found time this weekend to make some travel cases for my cars out of old military ammo boxes.
I think this is the most badass RC I've seen, inside and out. At this point I don't know how it could get any cooler but you keep surprising me. 
Saturday was nice, but I decided without the steel gears it was a better idea to forgo any RC stuff and go out on a date with the wife 
