Brandon's VS4-10 Rear Portal Yota Build
 

With all the options and configurations available from Vanquish on the VS4-10 chassis now I figured it was time to have some fun and tackle a project I've been wanting to do for a while.

Once Harley mentioned the idea of running a rear portal axle only I knew I had to steal that and apply it to this project.

The concept was to create a very low COG performance oriented build on the VS4-10 platform while retaining the rigidity and durability of the chassis kit. I also wanted to incorporate the new VFD transmission and Dig into the build. I had a RC4WD Mojave body and I've been itching to do some hard body work again. Its been a LONG time.

Starting with the layout and modifications to the rear portal axle. Portal axles run reverse rotation due to the 2 gear portal box. The easiest solution was to flip the ring gear and run low pinion. Harley planned to use a F9 servo mount modified to replace the 4 link mounts on the carrier that got removed in order to flip it. Idea stolen and executed.

Re: Brandon's VS4-10 Rear Portal Yota Build
 

Awesome build and you get awarded all the credit for the idea by virtue of making a build thread first.

Obviously using Vanquish parts are preferred but was there any consideration for using reverse cut gears (at least 3 companies I'm aware of make them) to change rotation and keep the high pinion?

Re: Brandon's VS4-10 Rear Portal Yota Build
 

Yes definitely crossed my mind. I already purchased some OD gears from SuperShafty to make up for the reduction on the rear axle and committed.

Are there any reverse cut OD (27/8) gears on the market? That I did not search for... Easy swap though if the low pinion becomes a problem. The driveshaft is currently sitting in line with the lower links because I rotated the pinion angle up just a bit. Chassis pics to follow, trying to sort through them now.

Re: Brandon's VS4-10 Rear Portal Yota Build
 

What is the purpose of running a rear portal only? What does having only a rear portal do for the vehicle

Sent from my LM-G710VM using Tapatalk

Re: Brandon's VS4-10 Rear Portal Yota Build
 

I was thinking about this a while back so it will be interesting to see it actually come to life. The low pinion thing was definitely something I realized might be odd. Also, raw finish F9s for us plebians please!

Re: Brandon's VS4-10 Rear Portal Yota Build
 

Ahh, OD gears would be required to get the front and rear ratios even within the realm of what is considered an aggressive overdrive. I don't think there are any of the OD gears in reverse cut.

Swapping the 30T and 32T transfer case gears could be an option since you know a guy that could make a special set of bearing plates happen. Then you could run standard ratio reverse cut gears and be at a not crazy 30ish% overdrive with a high pinion. That is a lot more work but can you really put a price on executing Harley's idea better than him?

Anyway, proceed with said awesome truck. "thumbsup"

Re: Brandon's VS4-10 Rear Portal Yota Build
 

Very cool dude!! my brother just finished a rock buggy with this same idea using a VP rear portal and d44 front. He just used the GCM 1:1 tcase with 2 gears to get that oposite rotation and keep it high pinion rear but the overdrive is pretty crazy, he actually put your overdrive gears in the rear portal boxes to tame it down a little. But with all said and done it crawls like nothing I’ve seen before here in Utah!

Love the build parts so far! Excited to see progress...

Re: Brandon's VS4-10 Rear Portal Yota Build
 

I’m glad to see you are making this build thread. This was something that I thought about doing, but wasn’t sure exactly how it could be done.

I watched Harley’s video he posted yesterday at the ASD Crawlers Autism Crawl and really liked how well his Pro was crawling.

Can’t wait to see more!




Sent from my iPad using Tapatalk

Re: Brandon's VS4-10 Rear Portal Yota Build
 

It's ok I guess. When can us peons get a hold of the new trans?

Re: Brandon's VS4-10 Rear Portal Yota Build
 

The thought is that you're always dragging your rear axle around while steering with the front. More clearance means less dragging on obstacles while dragging. Harley talked about it briefly in his ASD event coverage video and does a better job of explaining.

Low pinion is not ideal. But once I had it mocked up and the driveshaft wasn't below the link profile I am not concerned.

I actually have a 1:1 VFD setup from our initial testing. The first Pro kit almost came with a 1:1 transmission and the OD sets were going to be an option. Once we drove it with OD there was no turning back. So I might throw a 1:1 setup in it if needed. I need to do the math on the ratio with the OD AR44 in the rear axle and OD 20/28T portal gears. I might be close already.

Having those optional portal ratios is nice, glad he got it to work. I think we might see more of these builds start popping up.

Josh was very happy with the performance, we've been talking about it a lot. He just won a 4Runner body in the raffle so I need to convince him to build a similar hard body build based on performance.

We're getting closer. I was just out testing some of the final specs for the VFD kit yesterday.

Re: Brandon's VS4-10 Rear Portal Yota Build
 

Here is a side profile shot of the assembled chassis. I cut the front and back drop sections off the chassis to lose some weight and add clearance for the stubby front and future bobbed bed.

Also some shots of the driveshaft height compared to the links.

Running Extended shock towers in the rear, standard up front. Rear shocks are mounted on the link tab of the axle. Height seemed to work out fairly level and the chassis allows for full travel in the rear still.

Re: Brandon's VS4-10 Rear Portal Yota Build
 

And some shots with the cab temporarily mounted with PL BFG Predator 4.19's on blacked out Method V2's.

My son is always very busy helping me with anything on the bench :mrgreen:

Re: Brandon's VS4-10 Rear Portal Yota Build
 

:badger:

Re: Brandon's VS4-10 Rear Portal Yota Build
 

Decided I am going to make the mojave bed work. Needs to get bobbed out back, and extended in front of the wheel opening to match the WB. Should be a good way to make me dust off those hardbody skills I havent used in probably 10 years?

Did a quick test run at Folsom lake too. Pretty happy with the performance. Extremely balanced with the 4.19's and just the cab. Now to make it worse.

Re: Brandon's VS4-10 Rear Portal Yota Build
 

Really like this idea and build. Hope we get to see some video of it in action.

Those raw axles are gorgeous.

Re: Brandon's VS4-10 Rear Portal Yota Build
 

This weekend flew by but I did manage to get some more cutting / planning done on the body.

Going to pinch the front, bob the rear and use the extra material to stretch the rear bedsides to match the wheelbase. Will probably dovetail the rear as well and come up with some sort of attachment method where I remove the cab by itself and leave the bed sides bolted on.

Re: Brandon's VS4-10 Rear Portal Yota Build
 

Applied some glue and styrene under the hood last night. Thats it.

Re: Brandon's VS4-10 Rear Portal Yota Build
 

Looking good. One step at a time. You'll get there eventually.

Sent from my LM-G710VM using Tapatalk

Re: Brandon's VS4-10 Rear Portal Yota Build
 

Some more work on the body, front is dove-tailed and rear bed sides have been bobbed and lengthened. Everything is still rough but the fitment is now where I want it. Need to figure out how I am going to mount the bed and clean up the body lines.

Going to run a spawn interior, fits pretty well and is nice and light.

Re: Brandon's VS4-10 Rear Portal Yota Build
 

Not to add to Jim's workload, but man I'd love that raw finish as a parts option. Rest of the truck looks sweet too."thumbsup"