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

[RustyUs]

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

I like your style with them Badlands on there.
My concern would have to be the belt and how much power it and driveline can take while throwing Mother Earth in every direction.

 

[JWBradley242]

I like your style with them Badlands on there.
My concern would have to be the belt and how much power it and driveline can take while throwing Mother Earth in every direction.

first run it broke the roll-pins in the gear shaft, swapped them out for solid pins.Using the slipper clutch and programing the esc for a softer hit on acceleration and less brakes makes it work pretty well. Its crazy fast, I also bumped up to a 22t pinion gear to add clearance for the new motor to clear the rear belt. The new motor case has a textured surface and the belt shredded pretty fast, I sanded that down too. Also I found a bearing kit on ebay and removed all the original bushing, this is the best the car has ever been. I never raced it, back in the day there wasn't a class for it, it would be pretty fun now though!

 

[VoodooRufus]

It's been a few months, but I finished the restoration in February and want to share the pics.

I spent more on this than the car was worth for sure, but it was fun. I also went back to the original factory wheelbase instead of the optional short wheelbase setup. Not a huge difference but fine for my driving.

To summarize the full body of work:

New Fast Eddy bearing kit (original bearings were so dead)
Rebuilt the diffs with new drive cups and Lucas red marine grease (nice limited slip action)
Added rear universals. Lubed all universals and drive cups with motorcycle dry chain wax
Turnbuckle to replace the wire steering coupling
Arrma Vortex shocks - had to drill out the front shock tower and use a M3 bolt/washer/locknut setup after grinding down the shocks for clearance. I also cut down the preload spacers to get the right ride height as the springs are stiffer and longer than HPI's.
New Spektrum metal gear steering servo (twice as fast and twice as strong as the original Futaba), 70A Spektrum ESC with reverse (yay for backwards driving finally!), 12T Spektrum motor
New Futaba radio
NOS HPI mesh wheels from China
New Proline Trencher tires
2 new 5000mAh NiMH batteries

I tuned the motor a bit on my bench power supply and settled on about 10 degrees of timing. I drove it on one pack for a while on grass and pavement and it drives better than it ever did. Then I slid into my driveway curb and promptly broke a rear tie rod mount. Thankfully I had spares! The only thing I would like to add at this point is a OEM aluminum heatsink motor mount, but those are unobtanium.

Now I can start my Kyosho Optima Mid Worlds build....

 

[CertifiedMike]

It's been a few months, but I finished the restoration in February and want to share the pics.

I spent more on this than the car was worth for sure, but it was fun. I also went back to the original factory wheelbase instead of the optional short wheelbase setup. Not a huge difference but fine for my driving.

To summarize the full body of work:

New Fast Eddy bearing kit (original bearings were so dead)
Rebuilt the diffs with new drive cups and Lucas red marine grease (nice limited slip action)
Added rear universals. Lubed all universals and drive cups with motorcycle dry chain wax
Turnbuckle to replace the wire steering coupling
Arrma Vortex shocks - had to drill out the front shock tower and use a M3 bolt/washer/locknut setup after grinding down the shocks for clearance. I also cut down the preload spacers to get the right ride height as the springs are stiffer and longer than HPI's.
New Spektrum metal gear steering servo (twice as fast and twice as strong as the original Futaba), 70A Spektrum ESC with reverse (yay for backwards driving finally!), 12T Spektrum motor
New Futaba radio
NOS HPI mesh wheels from China
New Proline Trencher tires
2 new 5000mAh NiMH batteries

I tuned the motor a bit on my bench power supply and settled on about 10 degrees of timing. I drove it on one pack for a while on grass and pavement and it drives better than it ever did. Then I slid into my driveway curb and promptly broke a rear tie rod mount. Thankfully I had spares! The only thing I would like to add at this point is a OEM aluminum heatsink motor mount, but those are unobtanium.

Now I can start my Kyosho Optima Mid Worlds build....

View attachment 235519

View attachment 235520

View attachment 235521

View attachment 235522

View attachment 235523

View attachment 235524

View attachment 235525

View attachment 235526

View attachment 235527

View attachment 235528

Mmmmmmmmmmmmmm mid!!!!

This turned out great!!! I'd love to see it in action!!!
I'd like to see how it goes long term too! I really like belt drive!

 

[VoodooRufus]

Well, it does run pretty great. Jumping it over speed bumps tells me I need slightly softer rear springs as the rear kicks up and wants to land nose down even on throttle. I don't intend to run this one very hard or often and just keep it happy, since spare parts are rather limited. As a pavement and dirt/grass fun runner it does the job well.

As a side note, I did finish the Optima build. I never had a 4wd buggy before and always wanted to try it. This was fun to put together. The quality is so much higher than the RS4MT also. It feels like a car show piece. The NiMH batteries feel like they weigh down the car too much as it wants to bottom out on the speed bumps outside my house, so I picked up my first LiPo's (gasp!) this week as I think it may be a better fit for this car.

I need to find better places to run these two. I get bored pretty quick just running them up and down my street and on the grass.

Since I have one vintage build and one racing buggy, I feel a desire for something more 'modern fun' oriented. I don't quite know what route to go, but 1/8th scale, electric or nitro, is an attractive idea.

Ideas I'm thinking of:
Associated 1/10th electric Hoonicorn kit
Kyosho Neo4 nitro 1/8th buggy
Arrma Grom/Typhon/Kraton/Felony - the big horsepower ones here are not in the current budget.

 

[CertifiedMike]

Well, it does run pretty great. Jumping it over speed bumps tells me I need slightly softer rear springs as the rear kicks up and wants to land nose down even on throttle. I don't intend to run this one very hard or often and just keep it happy, since spare parts are rather limited. As a pavement and dirt/grass fun runner it does the job well.

As a side note, I did finish the Optima build. I never had a 4wd buggy before and always wanted to try it. This was fun to put together. The quality is so much higher than the RS4MT also. It feels like a car show piece. The NiMH batteries feel like they weigh down the car too much as it wants to bottom out on the speed bumps outside my house, so I picked up my first LiPo's (gasp!) this week as I think it may be a better fit for this car.

I need to find better places to run these two. I get bored pretty quick just running them up and down my street and on the grass.

Since I have one vintage build and one racing buggy, I feel a desire for something more 'modern fun' oriented. I don't quite know what route to go, but 1/8th scale, electric or nitro, is an attractive idea.

Ideas I'm thinking of:
Associated 1/10th electric Hoonicorn kit
Kyosho Neo4 nitro 1/8th buggy
Arrma Grom/Typhon/Kraton/Felony - the big horsepower ones here are not in the current budget.

View attachment 249833

View attachment 249834

View attachment 249835

View attachment 249836

View attachment 249837

I see you forgot a part...


The part where you send it to my house!!!


Looks fantastic!!! I'd love to hear details on your build.
Which electronics did you choose?
What oils?

Springs... you can buy OTW124, UTW008 or look for 12mm springs from AE for say B44 or similar should fit.

I put the softer UTW008 on my car. Not sure how they will do but feel much nicer than the stock springs. I'll let you know when I get it going.

I can't wait to hear what you think with lipos!!!

The car looks beaufiful!!!

 

[VoodooRufus]

On the Kyosho build I went with their Le Mans 240S ESC and the 13.5T 240 gold brushless motor. Protek 160T low profile servo for steering duty, and it's quite strong and fast as well as barely sticking out from the chassis.

I think I went with the "high traction" setup with the "B" pistons and 300-400 weight oil on stock springs. And it will still traction roll on pavement.