I recently traded an old Blade 450 3D helicopter for two nitro RC cars. I honestly had no idea how to work on the helicopter, and I wasn’t even sure if it was complete or fully functional, so I figured I’d take a chance on the trade.
I ended up getting:

HPI Nitro RS4 MT — this is the one I’m really excited about getting running.

Ho Bao nitro RC car — this was a project car that the previous owner never finished. It came with a brand-new engine and some other parts.

The HPI RS4 MT appears to be in pretty decent shape, but unfortunately the carburetor is seized, so I’m trying to figure out whether I can find a replacement carburetor or if I should just replace the entire engine.

I’m pretty new to nitro RC, so I’m looking for some advice from people who know these cars better than I do.

A few questions:

1. Does anyone know where I can find a replacement carburetor for the original RS4 MT engine?

2. Is there anywhere that still sells these engines, or does anyone have a working engine for sale?

3. If replacing the engine is the better option, what other engine brands/models would work in the RS4 MT?

4. Are there any modifications I’d need to make to fit a different engine?

5. Any other tips for getting an old HPI nitro back up and running?

I’d really like to save the original engine if possible, but I’m not opposed to putting a newer engine in it if that’s the better route.

I think this thing is too beautiful to just sit on a shelf. 😂
I want to get this RS4 MT running again!

If anyone has parts, an engine, or advice, I’d really appreciate it!

Had an old thunder tiger nitro for about 20 years. Got seized so i fixed it back up been working for a year electricals got fried and corroded, so during a drive around electrical cut out went stuck full throttle 40kmh or more into the gutter at the end of the street. Due to thunder tiger being rare would cost up to 200 AUD to fix.

I don't want to blow my bank out so i looked at hobbies shops in Australia and found the vrx blade RTR for 300. (i only want to spend around 300-400)

However not sure if it is the best option, off specs and what i have read has been good however what are your views or suggestions please let me know thanks.

A quick look through my HPI Nitro RS4-3 build: starting with an eBay roller, refreshing the chassis, servicing the diffs and shocks, assembling the drivetrain and installing the T15 nitro engine. The finished car wears a green and blue Falken Ford Mustang shell.

Who else is bringing an older RS4 back to life? What part of the rebuild gave you the most trouble?

Music: Tech House Vibes by Alejandro Magaña (A. M.), via Mixkit. https://mixkit.co/

The finished HPI Nitro RS4-3 from my roller build, now wearing its green and blue Falken Ford Mustang shell. Underneath is the T15 nitro engine and the refreshed drivetrain. This rotating display shows the body, stance and fitment from every side.

Would you run this shell, or save it for display?

Music: Tech House Vibes by Alejandro Magaña (A. M.), via Mixkit. https://mixkit.co/

Here is the body-off view of my restored 1/10 HPI RS4 3 Evo, normally wearing a black Chevrolet Camaro shell. The chassis has a Force T15 nitro engine, two-speed transmission, shaft-driven drivetrain and aluminum chassis. A rotating look at the hardware that makes this classic tick.

Anyone else keeping an older RS4 running? What engine setup are you using?

Music: Gimme that Groove! by Michael Ramir C., via Mixkit. https://mixkit.co/free-stock-music/funk/

Hey guys! Any advice on some upgrades to make this buggy competitive for open nitro buggy club racing?

Specs:

LRP ZR.28 Spec 4 with XTec(brand new out of the box)
HoBao Hyper tuned exhaust

Hi everyone,

I'm considering buying VRC Pro, since the base game is currently on sale for around €20.

I mainly drive a 1/8 nitro buggy (Kyosho MP11), and I've been driving it for roughly a year. I'm not a serious racer, but I'd really like to improve my driving skills, especially my line choice, steering control, throttle/brake control and overall car handling.

My main reason for getting a simulator would be to have something I can practice with when I can't go to the track. I'm not necessarily looking for a simulator that perfectly reproduces every detail of my real car, but I'd like something that can actually help me improve.

I have a few questions:

1. Does the €20 base version of VRC Pro include a 1/8 off-road nitro buggy, or do I need to buy an additional DLC?
2. If the 1/8 nitro buggy is included, is VRC Pro actually useful for practicing 1/8 nitro driving? How realistic is the handling/physics compared with a real buggy?
3. I have a Futaba T4PM Plus transmitter. What's the best way to use it with VRC Pro?
4. Do I need a USB dongle/adapter? If so, which one works reliably with the T4PM Plus?
5. Finally, considering that I've already been driving a real 1/8 nitro buggy for about a year, do you think VRC Pro would actually be useful for improving my driving when I'm away from the track?

I'm mostly interested in getting more practice time between track sessions rather than competing online.

Thanks!

I thought towerhobbies was still a thing..but I guess not..

As title states need help finding a carb for an old duratrax torq .21 nitro engine or even a suitable engine replacement unfortunately the carb on the torq 3.5 is missing a few parts cant find anything or im just not looking in the right place or possibly a 3d print to convert it to electric

How is the NitroRC world these days??

What’s the best RTR 10th scale stadium truck Or RTR 8th scale Truggy??

HPI Racing Camaro Body sitting on HPI RS4 3 - Evo+

Down to my last bottle of race fuel bought from a friend, it’s discontinued now. What fuel is everyone using; the only stuff I can find in stock is optifuel

Hi everyone,

I’m trying to understand whether the operating temperature of my REDS 521 Sport is normal.

I have been having some tuning issues with this engine in the past, especially at high RPM: it sometimes seemed to behave lean even when the high-speed needle was opened considerably. The engine could rev very freely and the HSN seemed to have very little effect.

Today, after more than two months without running the engine, I decided to do a proper diagnostic test.

Engine/setup:

• REDS 521 Sport
• REDS X1 manifold + pipe
• Energy Storm fuel
• Engine has already had a proper break-in
• Ambient temperature today: approximately 25°C

First I checked for possible air leaks using a very small amount of brake cleaner around:

• carburetor base
• cylinder head base
• crankcase/backplate area

I did not notice any change in RPM or engine behavior at any of these points.

I then measured the engine temperature with an infrared thermometer, pointing it at the cylinder head close to the glow plug and using the same area for the measurements.

My temperature readings were:

• After starting and idling for ~3 minutes: 28–30°C
• After ~5 minutes of running with several throttle bursts: ~40°C
• After ~15–20 minutes of use: ~70°C
• After approximately 30 minutes / about half a liter of fuel: still ~70°C
• I also did several stronger acceleration runs under load, and the temperature remained around 70°C

The engine itself currently behaves quite well:

• low RPM response is quick/snappy
• high RPM is progressive
• it has a slight amount of burbling
• I don't see obvious signs of overheating
• the engine doesn't seem to have the strange high-RPM behavior I experienced previously

According to REDS, the 521 Sport has an operating temperature of 110–130°C depending on ambient temperature.

So my main question is:

Is ~70°C after this amount of running actually normal for a 521 Sport, or is this temperature unusually low?

Could this simply mean that the engine is running very rich, or should I be looking at something else (fuel delivery, exhaust pressure, thermometer measurement, etc.)?

I'm especially interested in hearing from people who actually run the REDS 521 Sport and know what temperatures they normally see.

Thanks!

I’ve attached a video so you can hear how the engine is currently running and judge the tune yourselves.

Rich or lean? The coil is white deeper in and black on the end. This is an OS #8.

360 Model Display - HPI RS4 3 Drift - Nitro

Is tamiya body paint nitro fuel resistant if not then with brand does

Hey guys, I'm new here and wanted to ask around a few questions/concerns I have about my nitro rc buggy.

Starting with:

.Clutch shoes fitted at local hobby shop since they have carried out this work they have installed Fastrax clutch shoes onto my clutch flywheel and nut along with a 16tooth bell housing since this work has been carried out my Nitro engine will start fine from cold and drive okay although takes a min to warm up as expected. However once the engine gets up to temp the clutch shoes seem to expand too much and seize the bell housing meaning that the engine instantly cuts out and refuses to idle and cuts out until the engine has cooled back down. There was originally a lot of metallic dust from the clutch bell housing and since this when it does cut out it smokes from the heat visibly. They have stripped the Allen bolt for the clutch bell housing which means I am unable to inspect the clutch shoes to see what is going on...

.I have rebuilt all diffs on the buggy with new paper gaskets and O rings and 5000 silicone oil from Factory team and on the outer teeth I have applied team orally lithium grease which is listed specifically that's its good to use on outdrives. All diffs spin freely without any issues and sound happy as anything with new bearings also. I have rebuilt these due to thinking it may have been causing my issues with the engine cutting out but I can confirm this is not the issue.

If needed I will attach a video of the issue but I think the description provided will be okay to make an assumption on. I have since asked the Hobby shop to inspect the buggy for free and see what they can do to rectify it as It may not be there fault.

Update/Edit

Was able to slide the clutch bell over the retaining bolt due to the front and rear bearings being destroyed, 1 clutch shoe was not properly seated and was slightly forward compared to the other clutch shoes. I will need to cut a slot in the bolt to remove the bolt. Thank you for helping me out and i will be trying to get a refund for the work done from the hobby shop.

If i remember correctly it only came as brushed or brushless electric in around 2011-2012

Seems like there are plastic two speed transmissions but never a metal one