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Japanscaledriver

The Dark Impact

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Be prepared for Impact.

Well, I have just moved to a new house and didn't really have the net, but I managed to pick up a Dark Impact for myself and build it. So here goes a little story about the build and the first drive.

The build.

I sat down for about one episode of "taken" (that's 1 and a half hours) by the end of the episode, I was ready to put the finishing touches on the chassis only, no paint, no radio gear. (radio gear is very easy to install, no need to take the top chassis plate off, or any of that stuff like the Top Force.

The chassis has some unique features, for example, quite a few different size bearings, but fear not, it is full ball raced! (except the steering 850 size) on the shaft beside a lot of the bearings are little thin metal shims, a little bit of a pain to build. The front diff housing and front chassis plate are seperate pieces and look to me like a possible failure point, will have to keep an eye on it.

The motor mount and rear gearbox are pretty cool, better for a possible racer, as it is not that hard to change the motor.

First drive.

I fitted a Tamiya tuned motor, the "endurance" one, so it is a lot faster than stock. But as an impression of full stock suspension setup (instruction book settings) the car seems to have not much in the way of lock to lock on the steering, but it does have a tendency to snap the rear out sharply when driven on and off brake into and out of corners on hard compacted dirt. i ran my top force just before with the same motor and the TF seemed faster and a little more neutral.

The wheelset is interesting, a little taller than the old Manta Ray tyres and they come with the shaped foam inserts and it is reccomended that you glue them, but I ran without glue and that may be the reason for the difference in speed.  (the wheels slipping inside the tyre?)

The front suspension runs the same type of upright as say the TB02, with the pivot "reversed" and has very lightweight looking uprights both front and rear. To tell the truth it looks a little like a TA04 with a shaft drive in some respects, a big spur high on the side and the motor in the middle of the chassis at the back! the big difference is the battery placement. I have some pretty big 3600Mah batteries that DONT fit in my WW2 or many of my other cars, but they DO fit in the Dark Impact.

the front and rear shock towers are quite flexible and look for alloy or carbon from the popular companies soon!

Overall, it drove where I pointed it in quite a tight space with trees and large boulders to avoid, so I think it is a good buy, but still needs some little changes, overall sounds like a Tamiya car!!

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Great report! Im glad to see such positive first impression. Mine should be here in a short while. I went ahead and got 2 pairs of thundershot universals. Also, I just happen to have a few 5x8 bearings to use in the steering. Hopefully Tamiya went with proper race spec 2.2" wheels, so we can use popular race tires. It would be nice of the tires are race spec as well!  Wow, Im really anxious to get one on the track!

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Yes, side-by-side batteries will fit. (I'm halfway thru building mine and that's the first thing I checked!)

The wheels will fit current Losi/Proline tyres (though the old Top Force wheels did that too!).

Front wheel width is the same as a standard 4wd front, but the rear wheel width is wider - possibly the same as the Losi wide rims.

Tyre pattern looks excellent for dirt tracks but I think the compound is just a little too hard. I think the tyres would work well on med/high grip dirt or grass etc but perhaps a little too hard for hard-packed low grip dirt.

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Good news that the side by side cells will fit. Now we need to only wait for the slipper clutch. I guess that Tamiya created a good buggy this time.

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I'm almost finished building mine, however there seems to be plenty of steering lock available.. ?

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Ok, building completed. Won't get a chance to drive before a month's time probably, but my impressions are;

* Superb drivetrain. Just hope it will be reliable, because it's very free, even though I greased everything (especially the bevel gears) very liberally..

* Quite stiff chassis, didn't expect that.

* A lot of slop on the a-arm hinge pins. And I mean a lot, quite dissapointing.

* Star-dish wheels won't fit at the rear unless you take some plastic away on the "spokes" with a dremel or something.

* Suspension geometry seems very well thought out, it "feels" just right with associated shocks on it. However, regular B3 shocks (.89") are a bit too long with regular ball ends, the short kit items were just the right length.

On a sidenote, I can't for the life of me figure out how to fit the small cap which covers the slipper clutch (or what will be a slipper clutch later). Isn't some o-ring or something supposed to be slided onto the cap, like on the dynastorm? Mine feels totally loose and won't stay on as things are now..

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What would be a good motor, for a 4wd open/modified class with this buggy??

I am going to order, just wondering if I should race my Top Force instead, hmm....

 

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* A lot of slop on the a-arm hinge pins. And I mean a lot, quite dissapointing.

On a sidenote, I can't for the life of me figure out how to fit the small cap which covers the slipper clutch (or what will be a slipper clutch later). Isn't some o-ring or something supposed to be slided onto the cap, like on the dynastorm? Mine feels totally loose and won't stay on as things are now..

My car has almost no slop in the a-arm hing pins. Are you talking about the fact that the pins can move forwards and backwards about 3mm? My guess is that is so you can fit a hinge-pin brace, since there is definately room to fit one (another option part?)

The hing-pins on my car can "rock" slightly in the gearbox housing, typical Tamiya [;)]

To fix it, simply drill a small hole in the gearbox housing a use a M3 grub screw to lock the hinge-pin down (the same as the hub carriers).

As for the gear cover - it doesn't need an o-ring as there are tiny locating lugs inside the cover. Twist it until it locks onto these and it seems to hold on fine [:)]

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I mean the inner a-arm pins. And I don't mean the "longtitudinal" slop, this seem to be made on purpose for fitting suspension arm braces as an optional part, much like on the XX4 etc. And I don't comapre it to other tamiyas when I say slop, I intend to race this car. For other parts (for instance, the front differential setup) the tolerances are so much tighter.

 

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Just finished my build and test run... here's my quick review of the Dark Impact.

THE BUILD

The build starts with the rear gearbox which includes the ball diff unit. The differentials - both front and rear go together nicely and feel very smooth. Rear gearbox looks like a typical 2wd 3-gear gearbox with an additional bevel gear to drive the center transmission. There is a metal idler gear which should improve durability since this is a weak part in some other cars with 3 speed gearboxes.

Gears are finer than your standard 32 pitch affair and go together nicely.

One tip while building this car... open up the bearing bag and measure and separate the different sizes. This is a Tamiya car but it features SO MANY more sizes than your typical 1150 and 850 bearings. I thought my eye-ball-o-meter was calibrated but ended up rebuilding some parts because of wrong bearings used.

While re-building though, I realized that wrenching on this car should be quite easy. The gears are easily accessible, as are the diffs. 6 screws and the entire rear end is in your hands. 5 screws and the rear gearbox is open.

As already known. there is no slipper clutch in this car although I'm sure one will be available as an option. While the gearboxes are made of what looks like typical Tamiya ABS plastic, the other parts like the spur gear cover is a more flexible material... as are the front and rear bumpers.

Interesting thing to note is that the spur doesn't seem to be the typical 0.4 or 0.6 pitch pinions that Tamiya normally supplies with it's cars. A quick comparison with a 48 pitch gear shows that the teeth spacing is almost identical - in fact almost impossible to tell apart with the naked eye. Meshing the stock spur with a 48 pitch pinion seems to work "okay" but it isn't quite as smooth as meshing 2 true 48 pitch gears, so my guess is some 0.5 pitch metric pinion or something...

When building the suspension - a quick test shows the shock towers to be somewhat flexible... no doubt to prevent breakage. While a typical competition car will have harder towers, these are pretty good for bashing. Some flex, but not that much.

Small nitpick... inner hingepins seem to have been taken from their parts bin somewhere... they work fine but are a tad long - being able to slide fore and aft about 2mm. Won't hinder performance I guess, but it'd be cooler if they fit more precisely.

The wishbones seem to be the only nylon-impregnated parts. That being said, they do seem VERY hard and should take a lot of abuse. The entire suspension moves freely but there is some typical Tamiya slop.

Center shaft is very nice and beefy... not to mention light.

The steering also has inherent Tamiya slop although I must say it's A LOT better than the TA02 cars that I used to own. The knuckles and the uprights seem to be a tad tight on assembly but that should work itself out after a few runs I guess.

Another nitpick... the lower front shock ends are captured on the wishbones using brass collars. It works, but this also allows for quite a bit of play in the area.The shock end has play riding on the collar and the collar has play riding on the screw... When time allows I'll be thinking of some other setup here.

Long steering link from servo to the front of the car is only 3mm but the rod is very stiff... I doubt there'll be any problems there. It's also nice that Tamiya used the new touring car 5mm ball ends that are only open on one end. These seem tougher and appear to fit better than the typical 5mm rod-end Tamiya has supplied in their kits for years.

When installing the electronics it strikes you that the chassis is freakishly small! On a 2WD it'd be a tight fit but there'd be room to mount **** on the shock towers and elsewhere. Because of the center shaft and steering rod there is no way to utilize any space in the driver area. Everything has to fit on the sides. Installing a BL is a tough affair and I'm suprised Gas managed to do it. The solder tabs don't fit into the motor space easily and I ended up spacing it out to make it work. Also had to re-solder the motor wires to exit from the back instead of the stock setup on the SS5800.

I wired the rx on the servo side and the esc on the left of the chassis. I tried a stock setup initially but it was just too cramped. Furthermore, it left a lot of wiring sitting right next to the drive shaft... NOT ADVISABLE. Mounting the Rx on the other side cleans up the install a lot and also leaves room in the left chassis to store the battery connectors.

And much to the dismay of all the Tamiya critics - this car does accept side-by-side packs comfortably... although corally plugs will NOT work.

Tires and wheens are nice and eye-ball-o-meter says they are the same outer diameter as the Pro-line bowties I'm running on my ZX.

Finished build looks pretty good and here's the interesting thing... fully loaded, this thing is LIGHTER than my ZX by about 100grams!

I'm surprised. Maybe tamiya's plastic has become lighter!!!

Running the car...

Only tested for a couple of rounds on the road so far... and the car is fast! The drive-train is smooth and acceleration is zippy. Although it's not fair to assess the performance on tarmac (it is an off-roader after all), the car feels like it pushes on power but steers nicely off-power.

Haven't tried any jumps yet but the sophisticated "drop-test" shows that this car is FAR SUPERIOR in the suspension department when compared to it's predecessor, the DF-02. It must be said that I'm using the aluminum DF-02 damper set so I can't say anything about the stock plastic set of shocks... but dropping the car from a couple of feet up sees it landing without any problems... I need to tune the shock oil a tad more but the suspension looks capable so far. I'm happy about that.

More notes:

- this car WILL have a front one-way option. There's even a spare bevel in the kit to accomodate this. Unlike the ZX the one-way is installed in the rear gearbox output to the center shaft.

- Tamiya was also feeling generous and included an extra pair of wing mounts with a greater slant angle for more downforce.

Pics...

01.jpg

02.jpg

03.jpg

Here's my wiring setup. When got time I'll show the previous one with everything crammed to the left of the car (rx and esc). This is much cleaner.

04.jpg

My friend managed to stuff the 5800 motor in there without mods... I tried like mad but couldn't find a setup I was pleased with... this was my final setup. Rewired the motor leads to exit the rear and then ran a motor spacer to space out the motor. Otherwise you can see the solder tabs hard to fit into the space there...

05.jpg

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Thanks for this review, after that I can't resist to buy it one.

And your paint scheme is great !

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Also agree, great review and paint scheme, thanks for sharing!

Cheers

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Bloodclod,

Are those blue Tamiya shocks you've got flourine coated like the touring car shocks?

I have been thinking about runing Losi Shocks on my DI, but the size of the front ones might not fit the car. If those Tamiya shocks are good then I'll use those.

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Nice one! I totally agree about the bearing sizes, I went nuts trying to fit regular wheel-size bearings in the transmission at one point, only to recognise that I was using the wrong bearings..

I've mounted a LRP Sphere/Reedy brushless setup and yeah it isn't a lot of space. If that sphere esc had been one mm wider it wouldn't have fit in the car, not anywhere. ;)

How much does your car weigh exactly? I thought mine felt a bit on the heavy side, but I've been racing only 1/12th scale for the last few years, so I've no real idea if it's heavy or not..

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Bloodclod,

Are those blue Tamiya shocks you've got flourine coated like the touring car shocks?

I have been thinking about runing Losi Shocks on my DI, but the size of the front ones might not fit the car. If those Tamiya shocks are good then I'll use those.

I've tried that already. Losi ones are too long for the front, they are fine for the rear but the front housings are just too long. Associated B3/B4 shocks or the optional DF02 dampers seem quite ideal in length.

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Bloodclod,

Are those blue Tamiya shocks you've got flourine coated like the touring car shocks?

I have been thinking about runing Losi Shocks on my DI, but the size of the front ones might not fit the car. If those Tamiya shocks are good then I'll use those.

nope - I don't think they are flourine coated. They're for the DF-02 set but since the part numbers for the shocks for both cars are identical I figured they'd fit. To be honest I'm not too impressed with the shocks... the "wonderful" blue-and-yellow color combination aside, some of it's design makes you wonder...

- rear shocks don't really have a proper upper spring retainer. There is just a nicely anodized aluminum ring. Firstly I think they should have milled a ridge for the spring to ride on... otherwise I can imagine the spring simply scraping on the shock body and removing the anodizing over time. Secondly, having a metal ring riding on a metal shock body just doesn't seem like a good idea to me.

- rear shock bladders don't seem to be big enough. There doesn't seem to be enough air in there such that when the shock is compressed it actually can't compress completely. To make this a tad better I installed the bladders and then used the tip of my finger to depress it a tad more to get more oil out before attaching the top cap.

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Glad you guys like the review. It's an exciting new buggy from Big T and I thought there'd be others eager to know more about it.

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Ok, I'll post some pictures of my ride as well. The quality isn't very good though, but this is how she looks like at the moment (the body is away for painting):

darkimpact3.jpg

darkimpact1.jpg

darkimpact4.jpg

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****, I can't understand why they're not working.. if you right-click them and copy the adress, everything works. Ah well, the url for each picture are like this:

Edit: changed to a server that allows linking..

 

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I am totally going freakin nuts waiting for my Dark Impact! All these pics and the mini review make me very anxious. Im glad the arms are composite. Mine will likely be fitted with Kyosho aluminum shocks, because I have them aplenty. I like the TRF sticker on the wing as well, Just so happens I have some of those too. Dont mean to be a copy cat, but its just too cool! Did anybody notice if there are any additional ball bearings needed INSIDE the diffs? Dang, its probably gonna be another 2 weeks or so before mine gets here from Japan. Guess I will have to "suffer" racing my zx5 for a bit longer..

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No additional bearings are needed for the diffs - the internals are already fully ballraced.

The only part that requires bearings is the steering assembly - it needs 4  5x8mm bearings (850 size).

[pUs] - What size Associated shocks did you use? And how well do they fit?

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No additional bearings are needed for the diffs - the internals are already fully ballraced.

The only part that requires bearings is the steering assembly - it needs 4  5x8mm bearings (850 size).

[pUs] - What size Associated shocks did you use? And how well do they fit?

I've tried all lengths on the table and given it a lot of thought, and even though I haven't tested anything on the track yet I think I'm on the right path.

I ended up with 0.89 up front with 0.71 shafts. For rear it's 1.32 with 1.32 shafts (no internal limiters on either side). Up front the hole next to the inside hole on the arms, on the rear it's the outermost hole on the arm. Gives a very similair feeling to how the XX4 is set up, if you set the rear dampers looser. 35WT #2 pistons front, 30WT #1 rear.

Edit: Well, they fit.. but you gotta be a bit creative. For the rear I have shortened (1.5 mm) yokomo ball ends, for the upper mount I actually use a regular blue tamiya ball-end and a screw which seem to work fine. At the front I have the kit short ball ends and stock screw at the arm (which causes a bit of slop, something better will probably be needed) and for the damper mount I have a regular screw and Yokomo/associated damper screw ball end.

What I'll probably do later is to drill the holes in both damper-mounts to 3mm and have screws + nuts instead, I don't think just a ball end or screw into the mount is secure enough.

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Yes, side-by-side batteries will fit. (I'm halfway thru building mine and that's the first thing I checked!)

After talking to Tamiya/Dicky and even holding this car in my hands, I strongly doubt that this car will be able to take side-by-side batteries. What makes you so sure? I want to see pictures please with a side-by-side pack in it.

UPDATE: OK, now I have read this great review and must say: All questions answered.

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