Help me do 40+

[Stevothehoe]

How much are we talking here? Took a shot in the dark with 5 on turbo.....
Any suggestion on a good combo of boost/turbo?
Thanks again for the input and tips.

[RC10th]

Start small and go up, if you got 2 mph out of 5 degrees of turbo try 5* boost and see. Turbo is probably a little easier on the gearbox then boost but a little boost shouldn't really hurt either.

If you get the itch for speed keep going up till you break something then back off a touch. Not sure what the hobbyking tops out at but the max combined timing hobbywing will add is 64* from memory.

[kandkhobby13]

At those temperatures on the electronics, you definitely could gear up a few teeth 22t-25t should keep you in a safe temp range and get you over 40mph.

[Stevothehoe]

OK now I'm trippin. Not going to repost duplicate pics, but you can see my programmer recorded a max RPM of 33,670 when my GPS logged 35mph.
Yesterday GPS got me at 37mph after I added 5° turbo timing. Buuuuutttt.....my programmer shows that my 37mph pass max RPM was 32,378.
Make it make sense lol.
Timing, gearing, rpm, traction, slipper, pinion.....how did 1300 less rpm gain 2mph via a timing adjustment..

[TRX-1-3]

[RC10th]

Go big !!

[juicedcoupe]

Timing, gearing, rpm, traction, slipper, pinion.....how did 1300 less rpm gain 2mph via a timing adjustment..

Could be traction, diff slippage, tires ballooning, or just simple deviation with the electronics.

Let's be honest, we are talking about hobby grade (probably Chinese made) electronics, not NASA instruments.

[Stevothehoe]

Well it's official. The 40th hit 40. Bumped the turbo timing to 7° and added only 3° boost timing. The electronics are still new to me so baby steps. Damn near 36,000 RPM. Still drives like a dream. Smooth as silk. (Not pictured: 108° motor temp)
Thanks for the tips and comments and for playing along with me!

[Stevothehoe]

*not electronics related but prolly not worth a new thread.

Buuut my right rear wheel was wobbling and i thought maybe the nut was loose. Nope....Anyone have any idea why my right rear wheel bearing would just disintegrate? I was always under the impression that bearings were an 'upgrade' from stock bushings. I'm pretty sure they were installed correctly. Left rear feels a little loose but I haven't pulled it apart yet. Possibly defective? Cornering or braking too hard at these speeds?
Should I be worried about the bearings in the tranny next? Going to put the stock bushings in and see what happens.
I used an ACER RACING bearing kit from a-main for what it's worth.

[RC10th]

The bearings in the rear hubs aren't particularly robust. When you assemble it make sure there is just a little bit of end play (in/out) which will help with their longevity. Unfortunately the bearings will still require frequent cleaning and oiling if you want them to last.

[Stevothehoe]

How is play adjustable? Seems they just push in, put the spring, dogbone, shims and pin in and done.

[Frankentruck]

Because of their smaller roller sizing, the bearings for 1/4" rear axles are not as durable as the bearings for the later 3/16" rear axles. Also, bearings being run that hard probably need frequent re-lubrication to keep them cool-ish for high speed runs.

Bronze bushings wear out too. They aren't perfect. They lose the oil in them, they lose material due to rub and get to be a sloppier fit. They also eventually wear grooves in the steel axles and ruin the axles. They aren't perfect, just different wear to keep track of.

[JosephS]

*not electronics related but prolly not worth a new thread.

Buuut my right rear wheel was wobbling and i thought maybe the nut was loose. Nope....Anyone have any idea why my right rear wheel bearing would just disintegrate? I was always under the impression that bearings were an 'upgrade' from stock bushings. I'm pretty sure they were installed correctly. Left rear feels a little loose but I haven't pulled it apart yet. Possibly defective? Cornering or braking too hard at these speeds?
Should I be worried about the bearings in the tranny next? Going to put the stock bushings in and see what happens.
I used an ACER RACING bearing kit from a-main for what it's worth.

You might want to write acer and see if they will just send you a replacement. 40 mph isn't exactly top end for a modern rc.The bearings should have survived.

[RC10th]

Any pre load/side load without a crush sleeve will drastically reduce their life.

Try without the conical washer and see if there is a bit of end float. If so flatten the washer or use a 1/4" pan car axle shim so when the wheel is tight there is the slightest bit of play. Also when everything gets hot it will expand slightly.

Edit, if the 40th uses 1/4" shims remove one or more until perfect

[Stevothehoe]

Thanks for the tips guys. Ran fine with the bushings for now. Set the timing back to zero and still hitting 37. Which is plenty. I just wanted to see 40 just to say I did.
That being said, I'm hearing some noise now at low speed just puttering around. And also feeling some slop and kind of skipping if I grab a rear tire and turn it. I'm feeling like the transmission is next to go. Maybe I'm just scared of what I've read and heard about stock trans vs stealth. I have ZERO knowledge of the stealth thing. The last car I built was my original in the 80's. If I want to keep running this hard, should I post up elsewhere since it might turn to be less electronics related? or spend hours searching for tips? or keep the conversation rolling here?
Don't want to start redundant threads or spend hours searching.
Thanks again from an old fart that just wants to go fast.