Nitroholic

I swapped in HPI arms when I busted them on my KM. I seemed to break rear uppers .... but I did on my HPI too. Must be something in the way it lands in a rollover. There were aftermarket ones available from RPM which are a decent upgrade. KM shells are ABS, not lexan, so they crack and shatter. HPI ones are much more flexible. For a steering servo, I used a Hitec 5755 .... Don;t think they are used now...but the newer version should work well .. https://wheelspinmodels.co.uk/i/117691/ just check the dimensions of the sewrvo case, as there is limited room. I used 20kg Savox metal geared units for throttle and brake. Set the end points carefully, as you don;t want to stress the servo on full throttle pulling against the stops. As far as parts compatability go.... the only differences are in the gearbox and internal gears. HPI ones have a different gear ratio. One thing I would do, though, is to pull apart the gearbox, open up the diff and fill with good quiality 10k silicon diff oil. If the diff case inside the gearbox isn't metal...upgrade. Pack the gearbox with a good amount of CV grease, and that will be good. If you need better stopping power... this: https://www.rcmodelz.co.uk/rcr-brake-upgrade-kit-for-hpi-baja-5b-5t-5sc.html is worth fitting. Had very good results with this, but upgfrade the servo first. The KM servos were not very good as you have already noticed. I found the stock shocks to be OK, just play around with oil weights until you get a setup you are happy with. I found that stock Baja 5wt oil was good, as the buggy tends to squat under power, and the light oil helped with rebound. I used stiffer DDM springs too. Hostile big bearing rear uprights are a good upgrade as well.

Sure. I owned a genuine HPI BAja and still have a KM001 ... though its not anywhere near stock now...

my buggy .... Must get a better shell for itand some better rear tyres. Runs pretty well on 4S with a 150A ESC and a 4076 can. 6wheel drive, 4 wheel steer. Had a bit of tweaking since I first built it to stagger the steering. Front pair turn more with less turn on the second set. Stopped a tendancy for the front end to crab on loose surfaces. Stiffer springs on second shocks than frontmost, to improve traction. Other than that...it runs really well!

For the money .... I got more fun and better reliability from the Baja compared to the couple of FG's I owned.

Owned an Annsman Royal Flash for about 2 days. Bought it with the intention of making a cheap project truck, replacing the dodgy bits and getting it going for not much cash. Trouble was....ALL OF IT was bad. Poor materials, poor design, poorly built.

On a Force motor, especially if it's brand new, there are 2 places you could potentially have an air leak. 1) The carb neck. Loosen off the pinch bolt, slide the carb up a few mm, and apply a very thin bead of good quality silicon instant gasket. Set it back in place and retighten the pinch bolt. DO NOT overtighten. The pinch bolt stops the carb coming out, it doesn;t seal it. 2) The backplate. Again....pop out the 4 screws holding it on, and apply a thin smear of the same. Then replace and do up the bolts. Now...the brakes. There are a number of different brake discs you will find on a Savage. Some work well...and some of the aftermarket ones are junk. I prefer the red fibre discs with stock pad. A lot of folks will reccommend all sorts of aftermarket setups, usually involving carbon fibre etc. Don;t bother. Some will work well in the dsry, some will work in mud, some cope with dust .... but they all compromise. Stock works just fine as long as your brake servo is up to the job. If you still can't get the brakes to your liking....google Savage OFNA brake mod. What this mod does is to get rid of the odd servo saver setup and use a double rod linkage as more normally dound on a buggy. The brake then pulls more directly. I ran this setup for a while on my ...well..nearest stock Savage until I mid-tanked it. As far as things like fuel flow issues you will read about....this is a factor of the shape of the fuel tank and how nitro RC's use exhaust gas to pressurise the tank. If you look at the stock tank, the lower bit has a lot less surface area, causing a change in fuel pressure when the tank gets near empty. It's easy to avoid issues....just don;t run it that far down 🙂 The Mid Tank mod gets rid of the receiver box, which you replace with a flat plate to support the steering servo. Then you use a buggy tank. You then need to re-mount the throttle and brake servo to the rear, which allows a simpler brake and throttle run. It's not an easy DIY mod, and you won;t be able to buy an off the shelf kit....but it has a range of benefits. I did it to put hte tank in a less vulnerable position. My less stock Savage runs a twin .28 nitro setup. 1/5 scale steering servo to cope with silly big wheels and fat tyres. Single speed Flux gearbox with steel spur, rear tie rod deletes and a fully beefed up driveline. It has a Kyosho Gigacrusher air filter setup...which looks like a supercharger inlet, sticks through the bonnet...and feeds the carbs. That was the end result of owning Savages starting with a 25 ..... The only Savage project I have left to try is to find a way to hook up a 26cc CY motor to a Savage chassis and drive. It will be rubbish, and probably too heavy....but who cares!

I think a replacement motor is the way to go. The piston is supposed to cover the exhaust port in order to generate compression before the mix ignites. It really sounds like this engine has had it, or at least, it's going to cost money to replace what you know is broken, and may have other nasty surprises waiting for you. I have had a .32 in one of my Savages for quite a while, and I reckon it's the sweet spot between grunt and thirst.

Probably not....your car layout is not really designed for a rear exit exhaust. The motor sits too close to the rear suspension. Whilst nothing is impossible given the right tools and know-how....you would need to replace the pipe you have as a minimum. Imagine the exhaust coming out the back of the motor....and look to see how it would have to route to attach to the main part of your exhaust. Then consider how the suspension arms have to move at the back. The exhaust also has to loop far enough out to clear a pullstart. And when your car is driving...all these things must not be hitting each other. Personally...I would stick with a side exit exhaust.

Your buggy takes a small block motor, so really....18 is the limit. Most smallblock motors have a side exit exhaust,. The larger nitro motors use a different mount, and a rear exit exhaust. So basically, the larger motors would have an exhaust exiting where your rear suspension arms are....assuming it would actually fit, as the crankcases tend to be a little larger. What you can get is a better quality motor that should give you a bit more power. Just stick to motors of .15-.18 size with side exit exhausts. Also make sure you get one with the right crankshaft end, where the flywheel fits.

I found hte Force .32 to be a much sweeter motor than the .36 Not much difference in performance, and better fuel economy...so more fun per tank. The early .36 motors wer ealso unreliable. As far as checking for a stray pin .... well if you pull off the flywheel and collets, cooling head off and 'button' ... then you should be able to get the piston and conrod off the crank and take the crank out. Then you can check everything, clean it...and reassemble.

This is one of those upgrade dilemmas..... and it's VERY common in the RC world. If you start off with a brushed motor, brushed ESC and NiMh batteries, then the car will work perfectly fine, though as you have discovered, issues with the driveline have killed your ESC. Happens. Muck and rubbish gets in, grass gets trapped...then the stress of turning the wheels overloads the EC and out comes the magic smoke. Once that happens, the unit is dead. Now....your car CAN take a mild brushless setup. Nothing too crazy, as it's a budget end RC, but as they do a brushless variant, you can use that as a guide as to what is appropriate. They put in an Etronix 2950Kv motor, and a 60A brushless ESC. That setup will also need a LiPo battery to run well, which will need a suitable charger. None of which you currently have. Your ESC can be easily replaced with the 1060 Modelsport advised. It's a good brushed ESC, and will work just fine with the battery and motor you have. Gets you up and running again, for £25. This is a sensible way to go if you are stuck for cash and just want to enjoy your car. It's also perfectly fine if you are happy with the speed of your car as it stands. Upgrading is a choice. You absolutely don;t have to. As mentioned, RTR brushed motors are not the best things in the world. They are not designed to be serviced, and are essentially disposable. The things would last longer if you could get into them to lube bearing/bushings... They are cheap to replace though. Generic unbranded items are plentiful. There are also higher quality motors out there...but the prices go up too. Now....if you want to make your car go faster, you hit the upgrade wall hard here because you are at the beginning of the RC journey. You can swap to LiPo battery, which will give you a bit of a boost in power, better run times, and far less performance drop off as the battery runs down. At this point, you will need to invest in a charger that handles LiPo, and learn the dark arts of proper battery care. A step up in the hobby, but one which you will need to take at some point if you want to get into the hobby a bit more deeply. You will cook your motor a lot faster though. Every gain brings it's pain! It gets easier when you have been in the hobby a while, as a lot of us here have. You have chargers that will charge anything, plus bits and pieces lying around. Connectors, soldering gear...all stuff that makes tinkering easier. Then you would be in the position to go to brushless motor and ESC. Brushless motors have less friction, run better as a result, and give more power. They will make the most of your LiPo batteries too. But the pain here is the money. You will also need to learn about gearing, thougg, here, if you copy the brushless versions motor specs...you can use the gearing they recommend too. Correct gearing is important...as an overgeared motor will have the same result as you experienced with your existing setup, only now the magic smoke costs a little more! What you end up with here is a faster car, longer run times, and the fun that brings. But if money is tight....try and do it in stages.

Does the rear pass-through diff housing just get made from stock parts? I know when I made my 6x6 Hyper7, I had to trim the housings where they had a locating ridge...but they basically just fitted neatly together. Not the case when I looked at doing the same with Savage parts. The diff housing was not symetrical inside, and I couldn't make that work easily.

If you are swapping to a steel spur gear.... check what pinion you have. Brass ones are fine on plastic, but won;t last long on a steel spur. Shouldn't damage the motor, not if you are keeping hte same gearing anyway. Plastic spur gears are less tolerant of poor mesh...but can also die due to grit and dirt ingress. I had a Losi Mini 8ight that routinely killed spurs. The chassis did not fo a good job of keepng small stones and grit out, and the partial cover was very good at keeping them IN! Mesh it carefully and it should be fine. Mesh too tight, and a plastic one will strip, but a steel one wont...thats where the trouble happens. Usually in the form of failed motor or gearbox bearings.

LOL .... you post a vid of a 6S run .... which is barely driveable and balloons the tyres and crashes in a straight line. Not an 8S one. Exactly the point I was making. You stated you want a RTR truck as you have a load of projects you are working on. You want to build something like that...it's your money. But it's not a RTR. Which is what you started the thread about. The truck in the vid has an 8S capable ESC, which is not stock and neither is the motor. And if you do want to overpower a truck and then not use the power you added......well. Sorry...that makes no sense whatsoever. At the very least, I expect to be able to hit full throttle and still be in control whenever I wish. Just bear in mind...the advice I gave was based on your question......and in that you put 'The two that interest me the most, the HPI Savage X Flux V2......' AFTER my post you put: It's the HPI Savage XL Flux V2 GTXL-6 that I'm seriously considering, not the HPI Savage X Flux V2 .....

Seen a Savage run on 8S .... took the guy months to get it able to hold together for a whole bash......and it sucked up the money. When it did drive, it was impossible to use the power. It's for armchair pilots to tell their mates 'Mines running 8S .... ' when it's usually not running at all. The Savage is an old design, originally intended for a .21 nitro motor. It's handling doesn't need or want 8S, it's driveline is marginal on 6S, and it will just end up broken. Which isn;t very much fun. I found that out the hard way trying to put a 4082 motor in a Hyper truggy. Melted diffs, ripped tyres apart and it could crash in a straight line as it would lift the front end violently if it hit a bump under power, and end up flipping. The end result is simply not worth the trouble. You'd have more fun running on 4S.

Threre is no safe way to bring a dead cell back to life. The NiMh charging method isn't exactly safe, as it can work...or it can stress the cell to the point of a small fire, but it can tease a pack up enough for the charger to let you charge it. You need to know what you are doing to try it. If your cell is reading absolutely zero voltage...it's possible what has happened is a failure of the soldering, rather than the pack. If you are checking voltage via the balance lead, it may have come loose. A broken wire would read zero voltage. IF you check voltage across the pack as a whole, what do you get? You should get around 11.2 volts. You could try carefully peeling back the outer shrink wrap covering on the pack, and having a look at the soldered connections there. Basically...I assume you cannot charge your pack as the charger reads too low and won't let you charge at all. A broken connection could be resoldered if you have to tools and feel confident enough to do it.

Also.... check that the thing actually was at the base settings ..... I have had new engines set at all sorts of random settings, so while it ought to be set correctly for starting break in, there is no guarantee it actually was.

How long is you're piece of string ..... I don;t know what spur you have now, what pinion or what your diff reduction is. Gearing is something you need to work out from anumber of variables.

You are on the edge of specs for the ESC, and as long as you were just using 2S Lipo, it should be able to take it. Just NOT if it's geared wrong. Your car is geared for a brushed silver can basic motor running on NiMh ..... The chances of being able to go that far away from stock on motor/ESC and NOT have to change the gearing are pretty small. There are some overall reduction ratios suggested on the Hobbywing website for the ESC you had. https://www.hobbywingdirect.com/products/quicrun-10bl120-esc?variant=2139725987868 Shows how much the ratio changed from a 23T motor....to a 6.5T motor. You have gone further than that. Needs a much lower geared setup or your motor pulls too many amps, and the ESC smokes. Geared correctly, your motor should probably pull around 50A tops, and should work well with a 120A ESC. But you have to gear it right.

The blue springs look better. White was fine when the wheels were white...but looked out of place after. Blend in better now. And I am sure the lad will love a Lunchbox. Another RC that is BADLY in need of some serious modding!

It would increase the speed...probably...but you are trading power for torque here. You would need to find gearing compromises to keep things cool and usable, which erodes some of the benefits. I had a 1/10 on road with a 4.5T motor. It was really quick. But that was on smooth flat surfaces. It was slow off the line, but really got some speed up when it got rolling. Changing the gearing would give speed at the expense of acceleration. Really, going faster means adding more power.

Car looks good 🙂 I think you have just experienced the classic 'upgrade' issue. Metal parts can be stronger, but plastic parts can flex and spring back while metal ones bend. You can also find that impacts get transferred through to the next weakest part when you beef up one bit. But..if that was a high altitude smack onto the nose on a hard surface..it actually held up pretty well. The ally uprights could still work ( after a good hammering to straighten them ) but I would look at some way of fitting a bumper or similar to absorb an impact like that again.

Himoto stuff is rebranded under a large number of different names for different markets, but it can be tricky pinning down exactly which is which. I am pretty sure Ros has nailed the ID. The motor could be an upgrade as it looks a little larger. The ESC certainly is. Probably why the rear diff let go. The poor thing looks to have had a hard life, judging by the dirt and corrosion.

I higher amp ESC will make no difference at all to the cogging issue you have. Would be surprised if it fitted under the shell, but as you are buying it for another project....thats no matter. If swapping the ESC fixes it, then your previous ESC was faulty. Which may itself help you. Whatever, your gearing needs sorting....and if you run it with the motor angled like it is, it will chew the spur gear up in no time at all. You need the full surface of the gear teeth taking the load. At an angle, you are losing a lot of contact area, multiplying the load on the area left. Which will probably strip it. If it's not possible to get the motor straight....then you should just fit a smaller motor that does fit, or find a way to make it fit. Welcome to the world of modding RC cars. It's seldom as simple as just bolting in things and going out and enjoying it. There are usually loads of issues and tweaking to get it set up and working right. You may also find other areas of the car have issues once you have the motor geared, meshed and set up correctly.

Quite like the shell, really don;t like the fake rollbars on the window stickers .... I see they have taken the same approach most of the BMW drivers I see around town, and removed the indicators. No point in cluttering up the car with something you never use 😉