Why am I slow?

[kazuaki]

Sorry for the title...lol

I'm a bit disappointed right now and looking for some guidance. I've been working on a top speed setup for my 1/16 Mini E-Revo for the past few weeks. I made the initial speed runs today and am less than impressed and very confused. Please review my setup and let me know if anything is way off base or any theories you may have for my lack of speed.

1/16 E-Revo
Stock diffs and tranny
EZRun 60A esc
Neu 1112/2D motor (3250kv rated)
ESC timing 15 degrees (this is the EZRUN default, not sure if that is best)
Custom motor mount (see below)
ParkBEC 6v
Ko Propo ex-5 UR radio/receiver
HS-5085MG servo
45t spur gear
Various pinion gears (35, 39, 43, 47)
2 - Hyperion G3 VX packs (2S, 1800mah) in series
HPI Super Nitro belted slicks and rims (measured 9.5" circ., 3.0" diam.)

So, as you can see, I made my own motor mount and tranny plate. The stock setup would not allow for any more than a 35t pinion and the Neu 1112 contacted the rear shock mount. So, I made this setup in my garage. This si the first time I've tried somethign like this. I don't have a mill or anything cool like that, just a drill press and hand tools, so be nice Anyway, this setup can fit the largest pinion gear I can find (47t) with room to spare and the motor clears the shock mount.

I made a bunch of runs today and seemed to hit somewhat of a wall in the mid-60's (MPH). I ran everything from 35/45 gearing up to the big 47/45 gearing. Each run was between 62-66 MPH. Now, I never got a prolonged full throttle run, I usually came up to speed and was maybe just touching full throttle for a split second, if at all. Regardless, I expected to be running much faster. Additionally, I can't figure why my gearing changes had no noticeable effect on speed. I must have made 30 runs easily and they were all about the same. Normally, I would think this means the motor is just unable to push the truck any faster, but others have gone much faster on "lesser" motors. I expected this Neu would have enough power that it would be the last of my issues. Temps never got super hot. The motor was usually around 120-140, hitting 155 once after a long string of runs. The ESC never got above about 130 or so. I recalibrated the ESC once to make sure it was seeing full throttle from the radio. I also have a ziptie pulling the rockers together so that the suspension rests just above bottom.

BTW, for those that have not been following the mini revo. There are already a few folks that have recorded 81-82 MPH runs. One even managed it with a stock esc/motor on 4S, although he knows he is on borrowed time. I've spent lots of time on BrianG's tope speed calculator and see no reason why I am not going faster.

I have plans to hit a longer road tomorrow to see if I can get full throttle for a few seconds straight, but I'm not expected much of a change. This has been fairly disappointing for the money and time invested. I feel like I'm using the right parts, but maybe I missed something. Maybe my driving is an issue, just not sure. So tell me guys, what do you think?

Pics of my setup...Thanks!

[_paralyzed_]

poor schooling? inbred parents?

[simplechamp]

Did you run your setup through BrianG's speed calc to get an estimate of what to expect speed-wise? Sorry I can't be more helpful, awesome Mini Revo though.

[OZ-RUSTLER]

Originally Posted by _paralyzed_

poor schooling? inbred parents?

Sorry. Nice ride you got there.

[kazuaki]

Originally Posted by simplechamp

Did you run your setup through BrianG's speed calc to get an estimate of what to expect speed-wise? Sorry I can't be more helpful, awesome Mini Revo though.

Yeah, and it should be a bunch faster.

[kazuaki]

Originally Posted by _paralyzed_

poor schooling? inbred parents?

My parents are only 2nd cousins, so I should be all good...

[_paralyzed_]

you said you only touched full throttle for like a second. did you run out of room? I'm thinking since your pushing the limits of what the r/c is physically capable of your spool up and top speed are probably similar and you just need a place where you can really open her up and let her fly.

BTW: it's awesome you joked with me and didn't get your tighty whities in a bunch over my first comment. A+ motor mount and ride. I like you already!

[littlegiant]

Have you tried better tyres? Tyres with more grip? How about using a lid with more aerodynamics? Maybe the Mamba max will push it further?

[phatmonk]

Either way that is a great lookin setup.

[TexasSP]

I would adjust the timing back to zero and see what you get. I have a feeling it could be causing and issue. The tires would be my next choice. Maybe see about some foams.

Check your suspension settings. It's difficult to tell from the pictures, but it looks as though you are running front toe-out which is going to scrub a bunch of speed off straight away.

Sweet looking truck though, 66mph is still hella fast!

[kazuaki]

_paralyzed_, you'll have to do much worse than that to get me upset

I'm going to try a longer road today. The previous runs were on my street in front of my house, which is a long straight road, but it's got cars parked on the side and just not that wide.

[kazuaki]

I'll also try 0 timing today. Like I said, the ESC came defaulted to 15 degrees and I read on the Neu site that my motor should be 0-10 degrees. So, I will run 0 degrees this morning, on a much longer wider road. As for tires, I thought I was doing the right thing by getting belted slicks. They definitely don't seem to balloon. As for pushing the limits of what the car is capable of, based on other peoples efforts that is not true. I'm not even close to where I should be. I seriously expected 20MPH more than I'm getting.

I'm seriously wondering about the ESC now. IF I am able to hold it wide open today and it doesn't go a bunch faster, then I wonder if I'm hitting some current limit on the ESC or something.

[whitrzac]

Originally Posted by kazuaki

I'll also try 0 timing today. Like I said, the ESC came defaulted to 15 degrees and I read on the Neu site that my motor should be 0-10 degrees. So, I will run 0 degrees this morning, on a much longer wider road. As for tires, I thought I was doing the right thing by getting belted slicks. They definitely don't seem to balloon. As for pushing the limits of what the car is capable of, based on other peoples efforts that is not true. I'm not even close to where I should be. I seriously expected 20MPH more than I'm getting.

I'm seriously wondering about the ESC now. IF I am able to hold it wide open today and it doesn't go a bunch faster, then I wonder if I'm hitting some current limit on the ESC or something.

it might be a RPM limit like on the traxxas escs...

ever think about wind drag??... and terminal vlocity

[kazuaki]

Originally Posted by whitrzac

ever think about wind drag??... and terminal vlocity

Not when others are doing 80 mph. Let's not forget, these little trucks will do an honest 50 mph stock, with 2 nimh packs.