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Mfdriver

Dark Impact Upgrades

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I am thinking of buying a Dark Impact in the next few weeks and was interested to know what parts people use to upgrade the gearbox and drive train?

And where to get the parts from would be useful.

I don't want to go to extremes (limited budget) but just to ensure that with a motor upgrade the mechanical bits will be virtually bombproof!

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@Mfdriver Great choice, I built one early last year and have had a lot of fun with it on the rare occasions I manage to get out and use it

If your motor upgrade is either low-turn brushless or high-RPM brushed, then I would say the basics are:

  • DF03 Slipper Clutch (Tamiya 53925)
  • Modding the Main Gear pinion to hardened steel. Pretty straightforward if you can get the pinion made and own or have access to a bench vice. I'm a doofus compared to most on here, and I was able to do it! 
  • Aftermarket diff balls, eg Ceramic Silicon Nitride (readily available from eBay)
  • Aftermarket hardened diff outdrives for the rear diff if you can find them, or an extra set of front diff joints (19808059) to build the rear diff around. The stock rear diff is built using a separate plastic housing plate which apparently is prone to melting, where the front diff joints have an integrated metal plate

I think they're the main ones to secure the drive train

There are others to help it become a bit more crash-proof (bumpers, Carbon damper stays etc), but all quite hard to find now. Mine would be dead without the front bumper, but then I'm a useless driver :)

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IIRC the Dark Impact comes with a full bearing set so you won't need to change those.

Definitely get a steel pinion - the stock one is made of cheese and will wear out quickly and wear your spur with it.

Slipper clutch is a worthwhile upgrade if you can find it.  Annoyingly, lots of DF-03 upgrades were discontinued some time ago so it's not always easy to find, however it will protect your drivetrain if you're fitting hotter motors.

The rear ball diff is a known weak point.  The main assembly is plastic, the pressure plates overheat if not properly adjusted and melt the assembly.  There was a hardened metal hop-up but not sure if it's still available, however I have also heard (but can't confirm) that the front diff has metal outdrives, so you could track down a front diff assembly for the rear (check the manual but the rest of the parts are probably the same).  That said, recently I was talking to a newcomer to the RC scene and advising that he replace the diff as above, but he was insistent that his rear diff parts were already metal - so it's possible that Tamiya has addressed this issue and supplied harder diff parts.  Check the parts when you open the kit :)

Otherwise I found mine to be fairly robust, the ball cups for the upper arms would occasionally work loose and on one occasion came off and I lost a dogbone.  I did break a shock tower once but the car had been run over by an out-of-control E-Maxx so I think it fared pretty well, all said :)

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Thanks to both of you who have replied so quickly. I am very impressed!

So is the Dark Impact and old model as hop-up parts are now hard to find?

And if this is the case what would the current Tamiya 4WD buggy to have be?

At same sort of money.

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I can confirm what @Mad Axmentioned regarding the front and rear diff situation. I bought and installed a set of extra front diff outdrives and put them in the rear; they're drop-ins with no additional work required.

Now do address your point @Mfdriver a little over a year ago I was getting back into the hobby, and I made the exact same assumption as you did: the DF03 'must' be the most modern buggy that Tamiya has, since it has the number '3' in the name :) 

It turns out that Tamiya hasn't made a modern 4wd buggy in years, and the DF03 is not especially great as a buggy, with its own (well-known apparently) weaknesses. In fact I'm willing to bet that most on here would say that the DF01 Top Force is in many ways superior to the DF03.

So in short, there really is no current Tamiya 4wd buggy. They left that race years ago, and have resorted to mostly re-releasing older buggies from their heyday. Their on-road stuff is more or less still competitive though.

If you haven't yet bought the DF03, and want a Tamiya buggy that runs well, see if you can find a Top Force (DF01) or a Durga (DB01), they're pretty good buggies in their own right and do whats on the tin.

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Out of my price range I'm afraid.

I come from an era of racing Hirobo Alien and Kyosho Optima, but it all started with a Sand Scorcher and a Frog. Still got the Sand Scorcher body shell!

I think I will pursue the Dark Impact (if there are any available when I get the funds together!) and go for the front to rear diff outdrives mod if as has been suggested it doesn't have metal diff parts.

And perhaps upgrade the motor once I have got the hang of it!

Any further thoughts welcome, I guess ebay is the best place to look for the diff. parts?

 

 

 

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Two upgrades not mentioned (and hard to find) are these braces to strenghten the DF03 chassis. These braces were made by Yeah Racing but are not in production anymore.

DF03 brace.JPG

DF03 rear brace.JPG

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I think I managed to find the last Dark Impact in the UK at a reasonable price, which arrived from N. Ireland this morning.

Will crack on with the build and then worry about upgrades once I have got the hang of it. I have a brushless motor but will start with the standard one otherwise I might do some damage! ESC can cope with either.

The Yeah Racing parts look good - perhaps someone else does similar items?

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With reference to Mad Ax's comment about metal diff parts I can confirm the only metal parts in the drive system are the pinion gear and shaft - all the rest is plastic!

You would have hoped that if Tamiya had changed them to metal then there would be a spares bag for them.

I can't find any online.

 

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I don't remember that saying. I do remember "brake late, worry about the rest later" though... 😁

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Day One

Are the bags lettered and numbered? NO

Are the plastic bits lettered YES

Am I feeling confident? NO

186821588_Build1.thumb.JPG.e4f8999bd5568a5793b5b1ad6defb044.JPG

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Build commenced. Took an hour to get the drive in the casing. Grease ran out after two small squirts. and why does the concealed bolt which holds it all together have a tiny allen key type head - very strange1861276799_Build2.thumb.JPG.1fbc15d6630f78bcb30ab63f5dbe5800.JPG1340029618_Build3.thumb.JPG.60b58e31e214a72a8f2cd7def359ac68.JPG1850045848_Build4.thumb.JPG.593c906bcc0b38123c56862d51e4ab42.JPG

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Great work. I've really enjoyed mine. I made up two aluminium braces to join the suspension pins across the front of both gearboxes after snapping the rear gearbox on its first run put. 42mm centres and 3mm pins I think. 

I have the slipper clutch, adjustable arms and the df03/tt02b aluminium shocks which are all nice but not necessary for mine as I only have the tamiya sport tuned motor. I did buy a spare set of the metal diff out drives to fit to the rear and carbide balls for both diffs which I think is required. I ran my diffs in a bit with an electric drill and check the tension by spinning the wheels by hand after each battery pack and tighten accordingly.

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Where does one get the "metal diff out drives"?

And what does everyone run for damper oil. The kit comes with 900 which is rather stiff methinks?

The front diff was a real pain to put together and in the end I lost a ball bearing which set me back an hour searching for it on the floor! And why does one have to glue the shims on the rear diff, but not on the front?

This week coming will be the front suspension mounting posts and steering arms etc.

Getting there!

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21 hours ago, Mfdriver said:

Where does one get the "metal diff out drives"?

And what does everyone run for damper oil. The kit comes with 900 which is rather stiff methinks?

The front diff was a real pain to put together and in the end I lost a ball bearing which set me back an hour searching for it on the floor! And why does one have to glue the shims on the rear diff, but not on the front?

This week coming will be the front suspension mounting posts and steering arms etc.

Getting there!

https://www.timetunnelmodels.com/live/catalog/tamiya-19808059-9808059-front-diff-join-rmj1-p-16268.html

These I believe.

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11 hours ago, Mfdriver said:

These look like what came with the kit. Thanks for the link

They come in the kit for the fronts. The idea is to use a second set for the rear instead of the kit-provided half-metal/half-plastic ones.

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Sorry

I should have read previous advice more closely!

I have ordered a pair and will deal with the modification when the original rear ones give up

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Hi again everybody

Can anyone help with front and rear toe in issues?

I have almost finished the project and as you can see from the photos having followed to the nano millimetre the build manual settings for the front tie rods I have a huge amount of toe out at the front?

Also you can see a huge amount of toe in at the rear, but there is no way of adjusting this? The tie bars merely alter the camber.

The problem is that if I set the tie rods for a neutral setting there is only a couple of threads holding the ball joint clips in place, which can't be right.

Any advice would be appreciated or is the toe in/toe out set up as per the instruction manual what the model runs with?

Thanks

 

Dark Impact 1.jpg

Dark Impact 2.jpg

Dark Impact 3.jpg

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Those angles look great, but it is hard to really see from just a few pictures.  If it is set up according to the manual, settings are likely "neutral".  Give it a run and then determine of the handling characteristics leave anything to be desired.

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Thanks for advice

I have just given it its first run in the back garden and having set the track rods as near to neutral toe in with some thread left on connectors it ran really well. I can see that nothing can be done about the rear as that is how the bottom arms are set.

So I will stick with how I have it and enjoy. Certainly runs very well and at least I got the diffs running nicely!

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