MPH Challenge

[Redvegasgt]

[QUOTE=Snook Man;5312492]One thing I’ve learned over the years is, custom builds are never done...There is always something that you are going too, or want to change.

Ah men! 10 years ago I pulled the mild street engine out of my El Camino to freshen it up and make a few small changes. 2yrs later it went back into a 12 point caged, tubbed track car making 870hp before the bottle. My wife told me this would happen this is why I'm making a very conscious effort to keep my Maxx stock! Won't last forever though

[JoshB99]

any updates?

[revoman78]

updates or at least a post of some sort

[Snook Man]

Nothing new to update. Waiting until spring time to unleash the beast.

[Redsawacs]

I have to say, I'm slightly bothered by the perfection of your build.....we're suppose to be novice RC'rs!!

Now, get out there and make it look home made! Kidding!

Thats a very nice and quite precise looking build - Thank you for allowing us to share in your fun over the past few months...cant wait to see the end results.

"Red"

[emaxx3903]

New year update snook?

[Tev364]

Been gone a while but now I'm back any updates?

[Rcracing6575]

interesting. Like to see how that works.

[Rcracing6575]

I though I would be better to use a proven speed trans like the jato over a monster truck trans. What am I missing, someone explain? Just looked at a video of jato doing 93mph.

[Wildman4910]

I though I would be better to use a proven speed trans like the jato over a monster truck trans. What am I missing, someone explain? Just looked at a video of jato doing 93mph.

Custom 3 speed trany.

[Tony187240]

Any new updates for this Monster?

[Snook Man]

Yup...It’s all polished up with new electronics waiting for good weather and some free time to run it.
I'm thinking somewhere around mid April until it see's any run time.

[Tonda]

Yup...It’s all polished up with new electronics waiting for good weather and some free time to run it.
I'm thinking somewhere around mid April until it see's any run time.

it's may now, must be time soon¿?

[Snook Man]

I’m having big failure issues with the transmissions in this and the SMaxx build. I have a bunch of parts/gears ready to rework the tranny a little differently. Hope to run them both at full speed Memorial Day weekend.

[mike-susieq1]

I had a feeling the gears would delay just a little but those are not too bad to get right. I found the hardest thing in your build was the wind resistance issues.

[Nitronaught]

Oh man it's getting closer..... It's always something Snook, you know the drill.

I really am looking forward to seeing these guys run!!!

[Wolfslash16]

Man, would you just run it already? I been watching this for 8+ months!

[Snook Man]

It's always something Snook, you know the drill.

Don’t I know it…
Here are a few issues I’ve run into.

It’s not so much a gear issue any longer, the gears that were failing I swapped out with Tekno pinion gear and they are holding up well. I’m having problems with the primary OWB mostly along with a couple broken primary shafts.
I have smoked 5 OWB’s, 3 used that were in good condition and 2 new within a few short runs in 3rd gear.
Seems the stock OWB just can’t handle the rpm’s the primary shaft is turning with the gear ratio I’m running and the 3 speed and it heats up and almost welds itself to the primary shaft which causes havoc. Broken shafts, pins, and gears.

Imagine a stock 2.5 clutch bell/spur gear ratio of 20T/70T = 3.5:1, running a ratio close to that, the 3 speed works just fine without any issues at all. But when you start to increase the rpm’s of the primary shaft things start to happen.
In the SMaxx which I’m using to do all the testing for now I’m running 18T/28T cb/sg = 1.55:1, more than double lower the ratio of 20T/70T. That means the primary shaft is turning a lot faster and the OWB has to free spin much faster to allow 1st gear to free spin in 2nd & 3rd gears. In 2nd gear its holding up ok but once it hits 3rd the primary shaft rpm’s increase yet again and the bearing just heats up and fails rather quickly.

This twin build I’m running 18T/22T cb/sg with a ratio of 1.22:1, even fast rpm’s of the primary shaft. The HP of those two engines pushing that ratio and the OWB doesn’t stand a chance.

I went as far as making a test stand with an electric motor spinning the spur gear with no load on the transmission just to diagnose just what was going on.
I tried new stock primary shafts with new out of the pack OWB and even custom diameter primary shafts reduced in size at the OWB thinking the tolerance was too tight between the primary and the OWB but each time the OWB started heating up in 3rd gear and it would slowly start to grip the primary shaft slowing it down and causing even more friction and heat to the point that if I continued to run it, it would completely lock the owb to the shaft and either break something in the transmission or stall the electric motor.

My fix to the issue is to slow the speed of the primary shaft back to a more reasonable rpm and increase the ratio of the primary forward gear and the output gear to make up the difference. Unfortunately the lowest ratio between the forward primary and output I can run with the 3 speed is the stock 28T primary and 26T output. 28T being the largest diameter gear I can use in the altered position on the primary shaft due to the 3rd gear clutch hub pushing the forward output back farther on the shaft.

Removal of 3rd gear and running just a 2 speed allows a lot more possibilities for ratios between the primary forward and output gears. For every tooth you increase or decrease on the primary forward gear you must do the opposite on the output gear. Starting at the stock tooth count of 28T primary & 26T output you can change the ratio to any of these using electric motor pinion gears that anchor to the primary and output shaft with a grub screw.

28T/26T – Stock 0.92:1 ratio
29T/25T - 0.86:1
30T/24T - 0.8:1
31T/23T - 0.74:1
32T/22T - 0.68:1
33T/21T - 0.63:1
34T/20T - 0.58:1

The only pinion gear that I haven’t been able to get/find is the 33T pinion in a 5mm bore and that’s the ratio I wanted to run. If anyone knows of that gear please LMK.
So for now I’ll be testing 2 speed transmissions, 1 with the 0.68:1 and 1 with the 0.58:1 primary/output ratios.

The SMaxx is able to handle the tall ratio with the 2 speed well since it is pretty lightweight and it’s tested well with good speed. This twin weighs approx 3.5lbs more than the SMaxx, running both engines at the same time shouldn’t be too much of a strain on the engine clutches but I’m worried I may overheat an engine clutch when trying to run 1 at a time for tuning so I may need to tune with a different transmission with a higher ratio and then just swap in the lower ratio transmission for the speed runs which would be easier than changing the clutch bells/and spur gear ratio.

Work in progress…

[NitroTrout]

This probably sounds outlandish but if you could air cool the inside of that transmission
case with something similar to the forced air ducts that cool a race cars brakes,
it might keep things from melting?

[fuzzum111]

So from what I am gathering, if I pay snookman to 3 speed-a-fy my stock 2.5 black tranny, there is a chance I'll burn the whole thing down once I hit and try to sustain 3rd gear?

I am running standard 70t/20t so that is an interesting problem.

Still want him to do it later this year :3

[johnzillia54]

I have to say, I'm slightly bothered by the perfection of your build.....we're suppose to be novice RC'rs!!

Now, get out there and make it look home made! Kidding!

Thats a very nice and quite precise looking build - Thank you for allowing us to share in your fun over the past few months...cant wait to see the end results.

"Red"

What?!?!?!?!? Haha

[Hugoboss]

A-mazing looking forward for the final run!!
Good luck!

[riley n]

did you beat the eletrics butt? by how much

[wvaughn7]

riley from your post it doesn't seem you have read the entire thread. He actually hasn't finished it yet, but he is getting close. I recommend dedicating some time to read through from start to finish if you enjoy the nitro rc world the least bit, it is purely amazing the skill and craftsmanship shown in the build.

[Tankdg]

riley from your post it doesn't seem you have read the entire thread. He actually hasn't finished it yet, but he is getting close. I recommend dedicating some time to read through from start to finish if you enjoy the nitro rc world the least bit, it is purely amazing the skill and craftsmanship shown in the build.

I second the motion.

[2010450x]

Any new updates to the trans issue?

[danielhawkins]

Anymore updates. I read through this whole thread a few wks ago and it simply blew me away.
Awesome build you have got going here snook man. Hope you can fix your tranny problems.

[Snook Man]

Tranny problems cured with a 2 speed and overdrive gearing.
108-MPH achieved early last summer with potential for more, got bored with it and put it away in a sealed tote for now. Off-road bug has bitten me again.

[revoman78]

So you broke the 100mph mark nice!!!!!!!

[Wolfslash16]

Sweet! So you won the bet?

[danielhawkins]

Tranny problems cured with a 2 speed and overdrive gearing.
108-MPH achieved early last summer with potential for more, got bored with it and put it away in a sealed tote for now. Off-road bug has bitten me again.

That is excellent
Wow that is v fast indeed. Is that what you call very fast for a Nitro? I mean it took a fair bit to achieve that. Well at least you beat your goal and as wolfslash said did you win the bet?

[Nitronaught]

Tranny problems cured with a 2 speed and overdrive gearing.
108-MPH achieved early last summer with potential for more, got bored with it and put it away in a sealed tote for now. Off-road bug has bitten me again.

Overdrive..... How in the world did you shoehorn an overdrive setup into the tranny? Sure hope to see some runs when things warm up this year...... I always love your builds and projects....

Congrats on breaking 100 mph !!!

[PopeyePulls]

Awesome!!t, what gearing snook. (Inside and outside) I wanna try this.

[Snook Man]

Internal gearing was stock 1st & 2nd gear ratios on the input and primary gear sets. Primary forward output 34T (XO1 pinion) turning a 20T pinion on the output shaft.

20T clutch bells and 22T spur, and a looooooong runup and slooooow down smooth surface to get there.

Good luck Popeye, hang on tight.

[PopeyePulls]

Ok is that with trans u had in the twin with the overdrive unit for the spur? Or just a regular mod 1 spur

[Nitronaught]

Any plans for a few runs this season Snook?

[Redvegasgt]

Alright Snook, you're being a tease here! How bout some video of the beast

[Tonda]

Bringing this back from the dead to see some video!

[mxaustin]

I think were all still waiting on your vids snook!!!

[Nitronaught]

I think were all still waiting on your vids snook!!!

Bet he needs someone to vids while he wrangles a TMAXX over 100 mph...

It has to be a handful.