Rear Only Portal Axle & Overdrive Calculations - VS4-10 Pro

I wanted to install a portal axle into the rear of my VS4-10 Pro. While this may sound odd, hear me out first. Plus I get into how you calculate overdrive percentages.
Portal Rear Axle: bit.ly/2klyt0o
Portal Overdrive Gears: bit.ly/2lV7qcq
AR44 6-Hole Overdrive Gears: bit.ly/2kltDjI
F9 Servo On Axle Mount: bit.ly/2m2WGcd
Percentage Difference Calculator: bit.ly/2ky5Qgr
VS4-10 Pro Available for purchase here:
Clear: bit.ly/2ZxxPvv
Black: bit.ly/2KqlOof
See it in action here - Autism Awareness Crawl 2019 - Event Vlog • Autism Awareness Crawl...

[@Chibs_Creationz]

Josh these are the videos u do I love the most I may not understand it 100% or be doing the same build but it's awesome to learn new things and watch you geek out with the numbers, math and physics of it all that's when you're on your wheel house keep these types of videos coming bro 🤘🤓

[@montesamapping]

The best technical specification about overdrive ! Really clear and full of interesting information about an apparently strange upgrade, that is became significant after your analysis ! Really a good job !

[@bigmiketamayo2668]

I dig your technical videos, takes me back to when you first started and would voice details of the details. My mother always tells me “The Devil is in the details.”

[@ReadySetRC]

I love these kind of videos! I'm a Computer Science guy, I loved the equations! Really trying to incorporate overdrive more in my kits. Thank you for taking the time to explain in such thorough detail.

[@spankymcfarland8360]

I watched the whole thing, it was actually very informative, and helpful! So many KZbin videos just skim across the technical info and it sucks!

[@stanandstansfriend6019]

This video was perfect timing I'm in the middle of building a custom rig right now and I was trying to figure out the gear ratios thanks a lot Josh for all your help.👍

[@moe282]

This is still my favorite video you ever posted; loved the math discussion and have referred many to it over the years.

[@DavidRamirez-eo1nf]

I love videos like this man, I didn't know how to calculate overdrive properly before this. Knowledge is power!

[@andyrichey1192]

That's awesome Josh, I love learning new things !! Appreciate you sharing, I love my VS4-10 Pro. Went together so smooth, while I was watching your live build video, really appreciate that !! Painted mine all-black, turned out awesome !! Just waiting on the LEDs what a great product, always logged vanquish Products. Again appreciate you sharing this video Love learning new stuff about the hobby until the next one

[@VanOrdCustoms]

Great job on the video Josh. Loving the new background. Very professional.

[@RubyS.1]

Definitely a video to add to my stuff I may use. Honestly I watch this channel for the tech.

[@matthealy563]

thanks for the video Josh, I would like to see more videos like this if possible.

[@Stickies72]

Professor Josh's class is now in session. Great Video, as an engineer myself I love when folks start using the maths!!!! 👍👍👍👍👍

[@RTmadnesstoo]

Good job, Josh ! I liked the 'chalk board' that you pulled out. I'm impressed that you took on that task. it reminded me of my algebra teacher using gear ratios and torque curves to explain transmission design and shift points. Excellent !

[@leestewart5424]

Very cool always looking for improvement in performance and trying different ideas to see what works the best Great video

[@lawrenceshields8791]

Please do more tech videos like this! I love listening and learning this detaild tech. Thank you

[@michaelburton831]

Nicely done Josh. I would say it was actually refreshing to see a video that is so technical. I thought you did a good job to keep it simple and interesting. I come from the full size world of wheeling, so for me all of this really connects me. Also Josh, i think this is what sets your channel apart from others because you do keep it technical. Im pretty sure the simple non technical people are watching RC Girl. Shes cool too but she is really for the entry level person

[@renobob7781]

I made it Josh, great video its good to know the science, physics and logistics plus the benefits of what we do with our tiny trucks. Keep on bringing it to us. 🤠🇺🇸☝️

[@Warwick3511]

I find these to be interesting, to understand the why and how to do something and how it works.

[@smokin0137]

Thanks Josh. I loved it. You have great knowledge.

[@johnsdad092009]

Thanks I enjoyed it and now I understand gear ratios much more.

[@brulecr1]

Thanks for the video. I was considering this now I can run some numbers see if its doable on my rig

[@vmaxmercer]

I like the video...I did know how to calculate gear ratios....key word did...I petty much completely forgot over the years...now I know again...Great video.

[@ericshepherd5788]

Awesome video Josh, it's not your basic math, this will help extremely so I can figure out the od in the comp killer build now thanks.

[@michaelhoyle2665]

Really cool to do your own engineering. I liked the video. Lot of good gear ratio info.

[@J4me5De1t0nniu5]

Enjoyed the tech stuff being I’m doing comps and love the insight

[@redline6871]

Did this to my trx4. Definitely some overdrive in that rig.

[@distortedbalance]

Thanks for being super technical, math doesn't scare me at all. I learned a lot from this video

[@bryanmatheis2194]

Very outside the box Josh, it was fun to listen too and I was very curious how you were able to get this to work when I 1st came across seeing you run this at that Autism crawl event! Thanks for explaining it in detail.

[@williamammon4899]

I made it, but I did get lost. Lol awesome truck. Keep up the awesomeness.

[@justinranum7351]

Absolutely freakin awesome vid man! This is the kinda video that keeps me coming back. I'm also a religious SNU watcher and am really only interested in watching YOUR videos on newly released rigs as you take the time to show us the guts... not the revel over the box art. I feel that so many channels are sadly afraid to pursue the math/science at the risk of boring some viewers. Thank you for filling that void and keeping balance in the universe. Now to keep my own balance... time to watch Mr Talbot beat an Xmax like it owes him money! Mmmmm... an evening of math and carnage... a perfect balance. Thank you.

[@MarcoLemmetti]

Great video. Keep ‘em coming.

[@rcbloke1766]

Love the information thank you I’ll put it to use 👍👍

[@johnroberts1.6rc82]

I would actually like more of these engineering videos!

[@Realman1981]

Looking good RC!!👍👍👍

[@WestDesertShooter]

Under drive the front as well. This was an interesting video thanks for nerding out on this!

[@HarleyDesignsInc]

I don’t think they make an underdrive gear set yet, only overdrive which is the opposite of what I need. But maybe it will be available in the future.

[@neiljones8284]

Ring gears.would be too big, right??? Or a pinion thatd had to be too small to work right???

[@scottoblander9419]

very helpful josh

[@MechAnism820]

Thank you for the explanation.

[@otakumoto2136]

I'm doing it!!! Awesome project!!

[@ajosepi1976]

I watched all the way through. I ignored the math because I have no need for it, but if I ever do, now I can re watch this to get the math I need. Good video.

[@stratobungle]

Really interesting stuff! I'm glad you released this video - got very intrigued when I first heard about you building a rear-portal-only rig. After watching your Enduro video with the Vanquish chassis swap, I started thinking about a build myself with the VS410 chassis, Enduro tranny, and SSD axles and was even considering swapping the rear for the SSD portal axle because I heard SBG mention you were running something similar. Then, I heard of the Capra coming out and decided to sit it out and wait to see what it includes. I still have the parts (except the portal axle) sitting around - at some point I'll be assembling them in some sort of combination. I hope you don't mind, Harley, that I included an embed of this video in a new thread over at rccrawler.com to increase discussion of the use of portals, overdrive, reversed transmissions, and flipped ring and pinions for more performance...

[@brookmiller2427]

So your saying my sweet ar44 front trx4 rear idea is probably going to not work based on the axles having different FDRs. Well looks like a VS410 pro is the only option then. Loved the video and the techy info. Reminds me of my 1:1 days👍

[@CasperRc81]

I have an ar44 in the rear do to the different cut in gears my front ax10 housing is flipped upside down drilling new truss holes.

[@billcox87]

Loved the vid brother, VERY HELPFUL!! thanx;)

[@michaellenheiser3157]

Got it....I like this idea / option.

[@roberth5370]

I watched the entire video These are the vids i need... anyone can unbox an rtr...... but who's gonna help with all my mad scientist creations if not u..... thanks and keep emm coming

[@richardfleming9243]

This look to have fun with. Great info. The F9 portal cost is nothing for Performance.

[@tomandrews5392]

Great tech information...keep it up..

[@robbryan3044]

Great video...although, I've got another suggestion for you (and, if you do, I'm certain a LOT of people would be interested in a "how to" video): 4-wheel steering VS4-10. Obviously, a duplicate of the included front axle couldn't be used for the rear, due to the offset pumpkin, but maybe the VSP07850?

[@brianwalls4733]

This is awesome

[@gonemadd8522]

Learning is Fundamental!

[@carolina.lb27]

Love that truck‼️‼️‼️

[@HarleyDesignsInc]

Thanks for entertaining my wife 😂

[@vipxj1]

I'm confused, lol. Good explanation on how you achieved the gearing.

[@douglasparnell3224]

I don’t know if I will ever use this info but it is always cool to see what others are doing . Thanks , the rc hold/shelve looks good. Do you have a video of it? Like to build something to hold my rc’s better.

[@HarleyDesignsInc]

The shelves in the back are from IKEA and called the Lack. I reinforced them a little but that’s all. Nothing fancy!

[@brentrobinson3274]

Math class 101 is fine for me as long as its vehicle related hard data is always great to have but rarely dished out great job

[@trialpsycho_rc]

Great help thx

[@rctrucktalk1149]

Don't enjoy math for maths sake, but when it is applicable math I am all over that, thanks for the insight, now I am going to start my own database of gearing stats.

[@MrBulldog917]

I did watch all the way through but it made my brain hert

[@roor512]

Did you run the stock links in the rear with the portals? Or did you have to also get new links? Love the videos and SNU Thanks you

[@chavez4lsuable]

Makes perfect sense to me but I have been in the offroad 1:1 world for 20 years so ratio calcs are fun to me. I have a Capra and I thought the inside of its 3rd member had an area specifically "carved" out for the ring gear to slide into...now I need to break it down again and see if the ring gear can be flipped to the other side. I would need to swap my transmission out though...Capra trans is geared too high.

[@israelcardona5170]

If I had the money I would definitely tackle something like this.

[@CasperRc81]

Ya my new bright tj build with a terrible 11.24” wheelbase and 7lb rig I need all the help I can. So I run an overdrive front ax10 metal housing with the hd overdrive gear 2:53-1 and flipping the housing upside down do to the different cut in gears. The rear I choose an ar44 that is 3:75-1 out of my 1.9 wraith making my difference according to your calculator 38.85%. It’s extreme but man it’s so detailed in picking a line. With 4.19 hyrax and 80mm shocks to save pinion angles. I need to loose weight in the rear with such a short wheel base and wanted ground clearance which compared to an OG ax 10 it feels like there is a portal in the rear. Also I made a custom forward trans mount plate milled out of aluminum. And my tcase is another ax10 trans laid down side ways. My forward diff gear drives the tcase slipper clutch shaft giving me crazy gear reduction. I run a castle slate 2850kv micro x 54/11 on 3s and still only achieve 5mph. 😂 your builds are always awesome and has inspired me greatly thx you.

[@ryanp.8807]

Still more fun than geometry yesterday

[@HarleyDesignsInc]

I loved geometry! My favorite class I ever took 😁

[@scalebuildersguild]

I think I'll just put a portal on the front too and be done with it. ;)

[@themountain59]

awesome video..even when its older . My question is would one of the now easily available budget reverse gearboxes make it possible to put a portal to my budget truck ? A transmission like that is around 40bucks only .

[@HarleyDesignsInc]

I’m not aware of the trans you’re talking about but if it has a reversed rotation from front to rear than yes.

[@Gorealawarfare]

66.6 percent! Its the devil overdrive!

[@indybama80]

Still a bit confused lol. May have to watch it a few more times to catch on lol.

[@yotatech04]

Great video, I've always liked math so it wasn't too much in my opinion.

[@Mr450pro]

I hate math. But you did a good job of explaining how to calculate over drive 😉👌🏻 Did Vanquish release higher over drive gears or is it only the 6.5% in stock?

[@Legoman585]

Cool video, I can't seam to find the calculator

[@davidbanaszak562]

Great Marketing Video.. so when does Vanquish start to manufacture the items you just prototyped??? Obviously now that you produced it other people are going to want it also..

[@dtpcustomsrc4851]

My head hurts... but... I learned something. Thank you sir.

[@seanhanley947]

Professor Harley. I thought it was fun.

[@Cooncified]

Who builds all your personal rigs?

[@00godlovesus]

Does it come in the kit;)

[@donaldsneffe]

Christmas Time? Oh, no... it is your car-tree ;-)

[@Chiefs_Estrella_de_Mar]

Easy to follow explanation.. but I love math. I’m taking it you have some prototype gears I’d like to get my paws on...

[@jahmenrcbuildingasone4254]

I cant find the video of your VS10 with back portal only I thought i was going to be in the description below?

[@HarleyDesignsInc]

Whoops, I’ll add it. You can see it in the ASD vlog.

[@S5UPERCHARGED]

I'm trying to get around 20% overdrive in my scx10ii with ar44 axles. I have the 27t 8t overdrive gears in the front but it's only around 10%. Is there a way to get closer to 20% with out going this route with portals?

[@HarleyDesignsInc]

Yes, pick up the Vanquish Underdrive AR44 gear set for the rear axle.

[@koens4433]

Could you use an underdrive ring and pinion in the front

[@HarleyDesignsInc]

Yes. But they weren’t available at the time I made this video.

[@RUSERIOUS76]

Could you have taken a under drive gear set in the front and get down to your desired ratio?

[@HarleyDesignsInc]

I don’t think I’ve seen an under drive gear set yet, only overdrive.

[@tommy1504]

Awesome truck, all maths aside

[@GrimJerr]

I went with the Ultra, but I have been noticing a lot more Pros, and I was wondering why. I always thought for a crawler Portal axles were the best you could get for crawling. Rear Portal only makes sense to do if that's why you would go with the Pro, unmodified why would the Pro be a preference for a crawler ? Just wondering, already have my Ultra.

[@HarleyDesignsInc]

It fully a personal opinion between having more clearance at the axle or a lower center of gravity. The Pro also has a little more steering (51 degrees vs 47). And then it comes down to if you like the look of a portal or straight axle better.

[@jasonsmith8443]

im new to asking questions online like this. so please bare with me. i'm debating on purchasing a 410 pro or ultra. my problem is i watched you video on the rear portal install on the pro and that is the way i would like to go if possible. i know this video is old, but has there been any new ways you've discovered to reverse the gears in the rear so i can run portals. i would be a little nervous with all the grinding personally. i would really like to go this route if at all possible. any help would be appreciated. Thanks, Jason

[@HarleyDesignsInc]

There had been someone who made a 3D printed transfer case adapter to do it as a bolt on option. I don’t have his name though! You could post in the VS4-10 Facebook page to try and have someone post it up.

[@jasonsmith8443]

Harley Designs ok. Thank you for your response. It’s appreciated.

[@oldreliable303]

My jeep has a rear portle, and a ttb in the front.

[@HarleyDesignsInc]

Jeep with a TTB, that’s an interesting one.

[@oldreliable303]

@@HarleyDesignsInc kzbin.info/www/bejne/bKi9gYqdntOqfa8 Im not sure why i build it...

[@rc-ingaroundamerica8792]

Alright, I might be stupid here, but wouldn't putting a set of under drive gears in the front help to reduce that percentage as well, interesting build, but like you said not sure if that's something I'd want to tackle, liking the new house studio

[@HarleyDesignsInc]

I don’t believe they make underdrive gears yet, only overdrive, which is the opposite of what I need. Hopefully soon it will be an option though.

[@rc-ingaroundamerica8792]

@@HarleyDesignsInc I wasn't sure if they did or didn't, but just a thought

[@WoodedCivilian]

I think a lot of people will be watching this video 50 times to learn that math lol.

[@DavidRamirez-eo1nf]

I know I'll watch it a few times lol

[@TheLMMLAX9]

how did you get the 8.71:1 for the rear

[@HarleyDesignsInc]

It’s explained around 11:00

[@robertrosson1990]

To build a very capable rig,math is a very important tool to help with the driveline to work at its best performance level.Why bother building a rig to be at its peak performance if you don't understand gear ratios.Its a must know how in my oipion.Thats for sharing.Yes it almost felt like I was back it school for a minute.L.O.L.But still great info.

[@travkas6862]

66.6% !!!

[@808grapplemonkey]

How does it work having an overdrive trans and OD gears at your portals?

[@HarleyDesignsInc]

I work thru all the math in this video.

[@808grapplemonkey]

@@HarleyDesignsInc thank you man. I actually watched this vid 2x and copied the formulas from it... and I was braining so hard that I failed to see I was answering my own question using it.

[@GrimJerr]

More Math Teacher !

[@mojaveadv7135]

Thanks, for the lesson. Trying to figure out what my F9 portals with a Senduro transmission gearing combinations are.

[@josbarhorst6574]

Did you just say the VFD transmission is stuck with overdrive? That would not be good for a truck of this caliber... or me...

[@Wildwes1981]

What kind of tires are u runing on your vs4

[@HarleyDesignsInc]

Proline Krawlers in G8 compound.

[@Wildwes1981]

Ty

[@chess135]

just wow. but i loved it. wats up all bla bla ratio the end. you are awesome.harley goes 50% portal 2019. 2022 goes 100% portals :)

[@HarleyDesignsInc]

Maybe I’ll go 75% first...

[@RTmadnesstoo]

@@HarleyDesignsInc on a 6x6.

[@vlozity]

i am a visual type of person, a graphic designer by trade and not an engineer! hehehe you have the truck in front of you... why not show us the insides of this build?

[@chaplinnone1274]

Huh?

[@stevesrandomadventures9066]

I don't really enjoy math too much but I did enjoy the video with you explaining what you did and how it works

[@moosejawrc]

I am reminded why I became a history teacher. Only thing missing from this video was a lab coat. #MathIsHard

[@RTmadnesstoo]

That and the quiz at the end.

[@PhoenixRCCrawler]

👍🏽🐒