Thinking about getting into RC again. Have an HPI RS4MT, looking for guidance

[RustyUs]

Some would call that a 4wd stadium truck. Some would call it a monster truck. I call that thing sweet looking! I know nothing about it. Must have came out when on one of my breaks from the hobby or forgot to renew RCCA that year. Maybe I had a one-track mind focused on buggies. I don't know. I do know a belt driven 4wd mini truggy would be awesome... even in today's world.

Enjoy it, and welcome.

 

[VoodooRufus]

It was classified as a 4WD stadium truck when no racing class existed for it when it was new. So, it ended up being a backyard fun truck instead.

 

[PainKiller]

Update: I spent a little money for this car and for future plans. Bought a 45mm turnbuckle to tighten the front steering up, modern radio, servo, 70A Spectrum brushed ESC, 12T 550 motor, and two new batteries.

I think this radio cost about the same as my old 2PCKA, but has all the features built in of a far more expensive radio from that era. Should be pretty sweet, and with model memory I can add any other future toys.

View attachment 208217

I like that 3PV radio. I may need to pick one up.

 

[RustyUs]

...If I do try a new machine, it would mainly before road/grass/dirt fun running. There's three tracks in my town if I wanted to try that. I was thinking along the lines 1/10th or 1/8th scale 4wd buggies or truggies, maybe a 1/8th rally car. Buggies have always had that cool factor look and lighter, and the trucks seem a little more capable when the grass gets thicker.

I started looking around and some things caught my eye:
HPI Bullet ST Flux - modern beefier version of my truck, but HPI has fallen out of favor it seems?
Kyosho Optima Mid 60th anniversary - gorgeous re-release buggy with a lot of cool factor. Looks like people build them for so-called shelf queens, but still looks like a lot of fun to drive. And cool to display when not running. I would definitely enjoy building it up. That's a significant part of the enjoyment to me.
Arrma Typhon 1/8th - Looks like a serious machine with some bash factor.

Well, there it is. Look forward to reading the replies and getting more learned up.

Hoo-wee! Got lots to think about when wanting one RC to do it all. I'm all for building a kit... taking a box full of baggies filled with hardware and plastic bits and putting them together... it doesn't get any better than that IMO. The kits section of available RCs is where I always start my searches for my next RC. But, it's so hard nowadays to ignore the RTR offerings out there that fit the bill.

 

[CertifiedMike]

Hoo-wee! Got lots to think about when wanting one RC to do it all. I'm all for building a kit... taking a box full of baggies filled with hardware and plastic bits and putting them together... it doesn't get any better than that IMO. The kits section of available RCs is where I always start my searches for my next RC. But, it's so hard nowadays to ignore the RTR offerings out there that fit the bill.

If you enjoy tinkering, building, upgrading... the kits offer a great level of satisfaction. More so than a fully upgraded rtr might make me feel I think.
I find more satisfaction in my self built beater hot rods than I would in a factory "hot rod" Z28 or similar in 1:1.
I most certainly feel more confident that I'll be able to fix my beater than "attempt to diagnose" the Z28 trackside too.

I have a folding table AND my kitchen table COVERED with r/c parts...
not a manual in the room. It feels good to KNOW there's an R/C car or 3 in this pile of parts and that I can make that happen!

 

[VoodooRufus]

So, I decided on the modest task of swapping the electrics on the HPI truck last night. Unsoldering the motor was slightly challenging so I removed it from the vehicle. Then to get the steering servo out I had to disassemble part of the front chassis. Then I found leaking shocks and diffs and dirty ball bearings, and parts came out that I'll need the manual to put back in correctly. And the whole thing could use a thorough cleaning. I think this poor thing needs some actual TLC. Le sigh, lol.

Thankfully, new bearings are easy to get and cheap ($20 for a set). The front shocks are 87mm extended and the rears are 103mm. 3mm mounting hole diameter. I rounded the measurements to 90mm and 100mm trying find some replacements and not sure what to get. Shocks on Amazon are cheap enough but seem prone to leaking from the reviews. Yeah Racing looks to have some that aren't too expensive.

 

[CertifiedMike]

So, I decided on the modest task of swapping the electrics on the HPI truck last night. Unsoldering the motor was slightly challenging so I removed it from the vehicle. Then to get the steering servo out I had to disassemble part of the front chassis. Then I found leaking shocks and diffs and dirty ball bearings, and parts came out that I'll need the manual to put back in correctly. And the whole thing could use a thorough cleaning. I think this poor thing needs some actual TLC. Le sigh, lol.

Thankfully, new bearings are easy to get and cheap ($20 for a set). The front shocks are 87mm extended and the rears are 103mm. 3mm mounting hole diameter. I rounded the measurements to 90mm and 100mm trying find some replacements and not sure what to get. Shocks on Amazon are cheap enough but seem prone to leaking from the reviews. Yeah Racing looks to have some that aren't too expensive.

Le sigh...

Before you go spending your good $$$ on bad chinesium... Most ppl sh*t on those shocks you mentioned for leaking and not being smooth.
Look into shocks from Jennys. Arrma 6s shocks are pretty decent. Losi shocks are around your measurements... I forget now the poster... maybe @9x19 or @332_RC
There were numbers I think!
Anyway, Jennys will tell you what lengths they have that might work if you email them.

 

[VoodooRufus]

Ted at Jenny's suggested the Arrma Vorteks 3S shocks. They are about the right size, and around $30, so I decided to see if they'll work.

 

[CertifiedMike]

The 3s shocks worked well for me too.
I found the trick was assembling them with the shock shaft pushed in. Otherwise the tiny orings get pushed out of the seal when you compress them.
They worked pretty well.
I used Traxxas springs to get a lighter rate for my application.
I felt like the 6s shocks were an upgrade from 3s but they are also much larger. Fitment issues could come up.
I'm glad this worked out for you!!!
I think you'll be happier with these than the others you'd mentioned.

I can't wait to hear how they fit/function!

 

[DavidB1126]

Update: I spent a little money for this car and for future plans. Bought a 45mm turnbuckle to tighten the front steering up, modern radio, servo, 70A Spectrum brushed ESC, 12T 550 motor, and two new batteries.

I think this radio cost about the same as my old 2PCKA, but has all the features built in of a far more expensive radio from that era. Should be pretty sweet, and with model memory I can add any other future toys.

View attachment 208217

I have that same radio. Thanks to @WoodiE and everyone else on RCT and I love it.

 

[VoodooRufus]

Vorteks shocks came in. They're the right length, but the shock body is a little too large at the top, so I'll have to get some 3mm ID steel tubing to make an offset for the fronts. I think the rears will fit. There's a little squeakiness nearing full compression on the Arrma shocks, but otherwise I think they'll do fine. I don't feel like tearing brand new shocks down unless I need to.

I washed the entire chassis after full disassembly, and took out all the old bearings. The original Redline bearings compared to the new Fast Eddy bearings are a night and day difference. My truck is definitely going to appreciate the TLC.

New diff shafts and rear universals arrive today. I might shim the outdrives depending on how much slop there is, otherwise the diffs are getting a thorough cleaning and fresh grease. Then I can start building the truck back up from the inside out.

The 45mm turnbuckle to replace the steering steel linkage was too long, but 35mm should work.

I played around with the Titan and the Firma motors on my power supply looking at current vs. varying voltage and timing. Played around with the timing a bit and settled on ~7-8 degrees on the Firma. The Titan pulls a lot more current throughout the voltage range for some reason.

Next up is trying to find a modern set of wheels/tires that will fit the 12mm hexes. The original tires are very cracked from age. I might strip the chrome plating off the original HPI wheels and repaint them also.

It probably doesn't make any economic sense to do any of this, but I'm enjoying the restoration. Might almost call it a resto-mod with the full electrics swap?

 

[Lostinthewoods86]

I like that 3PV radio. I may need to pick one up.

https://www.amainhobbies.com/futaba...ystem-w-r203gf-receiver-fut01004353-3/p506146

On sale right now

 

[CertifiedMike]

I enjoy resto-modding too! Screw the price tags!
I'd prob pop those shocks and refill them.
I and other ppl have found brand new Arrma shocks needed to be topped off.
Not leaking, just not filled from factory.
Nice work so far!!!

 

[VoodooRufus]

M3 bolts, locknuts and washers/shims have arrived to take care of the shock mounting.

Also, HPI black mesh wheels straight from China, and some new Pro Line Trenchers for new shoes. I think this combo is going to look good and go great.

I believe I have everything I need to reassemble this rig to a great functional state.

 

[CertifiedMike]

I like those wheels! Nice design!

 

[WickedFog]

...so I'll have to get some 3mm ID steel tubing to make an offset for the fronts.

Here ya go. These come in handy. You can get them in various sizes.
https://www.amainhobbies.com/search?cID=&s=3mm+spacer+aluminum

 

[CertifiedMike]

You can buy sets of hardware from Jennys that include shock stand-offs if you want to try that way too.
Ppl use nitro tubing as shock spacer too.

 

[WickedFog]

You can buy sets of hardware from Jennys that include shock stand-offs if you want to try that way too.
Ppl use nitro tubing as shock spacer too.

I've seen that before. I wouldn't. If the screw going through it is allowed to move around because you can't clamp the shock solid, it's going to eat it's way through the shock tower. Put solid spacers in there and lock it down tight. Just my opinion.

 

[JWBradley242]

here's my RS4MT still rips with modern electronics!

 

[Chubaka]

here's my RS4MT still rips with modern electronics!View attachment 233165View attachment 233166View attachment 233167

Welcone to the site. Syock up on parts for the rs4 mt. It's getting scarce.