The Dark Impact

[terry.sc]

I think you will find Yokomo uses a smaller hex....

Yokomo uses standard hex drives on the MR4 BC and the new MR4BX.

BTW the MR4BX kit costs £400. Is it really 4 times the car compared with the Dark Impact?

[DCM71]

No, it doesn't, it uses a smaller hex on the BX to the kit

Tamiya/Kyosho/Touring car hex, it is about the same size as the Losi

XX4 and XXX front hex.

[terry.sc]

Yes, you are right. My info was based on a car I had seen briefly.

Checking this the Yokomo does have smaller hexes. My apologies.

[DCM71]

Not to worry, I think Academy wheels would be the closest fit for off-set.

[James4ihl]

Thanks guys, I'm going to check out a variety of wheels once I have the DI in front of me so I can gauge the size/ effect...

James

[technical.burP]

Someone in the forum said that the shock towers of his DI broke. After a lot of abuse I must say that these shock towers are unbreakable. There are no carbon parts necessary!

[GSM Storm]

Hi all

The shock towers look strong , the week point would be were the mounting screws are, I think this was were someone broke it.

Were I race is a bit rough, that is why I made my towers from carbon and aluminium.

[pUs]

GSM, please check your mail. I have a few questions regarding that shock tower.

[pUs]

Another question, for those of you who might have both a B4 and a Dark Imapct... will the B4 body fit the DI? The sides will be ok I guess, but would there be enough at the servo-saver area?

[DCM71]

You need to cut the sides longer so it sits higher, and trim the rear a little more but yes, it can be made to fit.

[James4ihl]

Help! Ive received my DI kit today, and found that (contrary to what my supplier told me) it doesnt include an electronic speed controller included. I have an Acoms AP202 transmitter receiver servo system I was advised to buy with the car - what is the best ESC to go with it? Should I get the Tamiya TEU101BK, or the Acoms AT-8, or what?

Whats the best one to use with that combo, or should I have got a different transmitter and receiver combo too? Sorry may seem like dumb questions but remember I am just getting back into this after about an 18 year break so I am a bit green on these things right now! Any advice appreciated!

Cheers,

James

[bender]

James-

It really depends upon your budget and what motor you are planning to run, both now or in the future.

IMO buying a top-line esc means a one-time purchase, one you wont have to worry about later on if you decide to run a hotter motor etc.

Top esc's from MRT, Novak, Tekin, LRP etc are all good, but I suggest getting one that is relatively small and has good manufacturer support.

I personally run a MRT VX Pro in touring cars - very small and very relaible.

I am also using a Novak GTX in my Dark Imapct and it too is very good.

The Tekin G10 is probably another one to recommend, as it doesn't require any extra capacitors like most current esc's.

 

[Tamiya King]

Help! Ive received my DI kit today, and found that (contrary to what my supplier told me) it doesnt include an electronic speed controller included. I have an Acoms AP202 transmitter receiver servo system I was advised to buy with the car - what is the best ESC to go with it? Should I get the Tamiya TEU101BK, or the Acoms AT-8, or what?

Whats the best one to use with that combo, or should I have got a different transmitter and receiver combo too? Sorry may seem like dumb questions but remember I am just getting back into this after about an 18 year break so I am a bit green on these things right now! Any advice appreciated!

Cheers,

James

 

I am running a Novak GTS ESC and it fits perfect as it is very small and handles down to a 12T. I am running a EPIC 13x2T motor, and the ESC hardly gets warm.

I also have 2 Trinity 4200mAH side by side batteries coming this week. That will cut down on the shrink wrap melting off the packs I have now! []

 

Novak is the way! I think they make the best ESC's.

I have a Explorer II in my GOLF V5 FF01 that has been in there with a D5 15T motor for 6 years and is still running strong!

I also have a Super Roster in my Clod running Parrallel with Trinity X Star motors and nothing wrong with it in over 6 years.

Novak stuff lasts! I have not had a Novak fail me yet! But many other brands have crapped out on me before in less time! Just my 2 cents!

[James4ihl]

Thanks for those recommendations - sounds like the Novak is getting a big thumbs up, I'll give it a go!

Does anyone know whether the tires will fit the DF02 gravel hound wheels, and indeed whether those wheels will fit on the DI?

Cheers,

James

[bender]

I think you need to trim some of the internal ribbing on the DF-02 rims to get them to fit.

 

My first shock tower design is now complete, just need to find some FRP to make a prototype.

Without being boring, there is a host of changes to the geometry of the camber links and shock positions, plus more wing positions too.

The tower is in 2 pieces (like the original prototype ZX5 Lazer) and bolts to both the front and back of the standard mounting point.

http://web.aanet.com.au/fir/bender/DI_tower.jpg

[Tamiya King]

I think you need to trim some of the internal ribbing on the DF-02 rims to get them to fit.

My first shock tower design is now complete, just need to find some FRP to make a prototype.

Without being boring, there is a host of changes to the geometry of the camber links and shock positions, plus more wing positions too.

The tower is in 2 pieces (like the original prototype ZX5 Lazer) and bolts to both the front and back of the standard mounting point.

http://web.aanet.com.au/fir/bender/DI_tower.jpg

Looks interesting! Can't wait to see the finished product.

 

If I think about it, I will try my Gravel hound rims and tires on the Dark Impact tonight and let you know if they are a straight fit or not!

[DCM71]

They are a direct fit, the only thing you will notice is that maybe the rear rims on the DF03 are a little wider.

[James4ihl]

Thanks - a shop near me has a set in which I'll pick up. In the end, a sale price decided my choice of speed controller, as the local model shop had a one off acoms at-8 at £30, which seemed too good to pass up. If I find myself getting more back into this for racing, I'll upgrade and the old Frog can have the at-8!

James

[pUs]

Good to see some new parts coming up for the DI. I really like the look of this rear damper mount...

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewI...item=6055195092

 

[jerrywasaracecardriver]

What I dont understand, is how does the front tower mount? Looks like possibly right on the back or front of the stock tower? Isnt there a mount required for this to work and provide real strength? Been watching those, but I just dont understand the front tower.

[pUs]

What I dont understand, is how does the front tower mount? Looks like possibly right on the back or front of the stock tower? Isnt there a mount required for this to work and provide real strength? Been watching those, but I just dont understand the front tower.

The seller has told me that their front mount requires the original plastic mount as well, it sits in front of this using the 4 holes in the middle. So it's not quite as nice as Gary's solution..

However that rear mount looks very handy indeed.

[bender]

There are 2 problems with that rear tower that's on e-bay.

1.

The spacing of the wing mount. The kit tower has the wing mount spaced 7mm further back than the shock mounting area so that the wing doesn't slam into the back of the tower. The wing will need to be shortened to fit this tower, and it will need cut outs due to the shocks being behind the tower (see point 2)

2.

The shocks will have to be moved to the back of the arms. You cannot use the outer shock mounting hole on the arm if the shocks are at the back because they will rub on the rims. From my testing and calculations, the outer arm hole is the best place to run the shocks, in terms of providing the right geometry.

No other competative 4wd in many years has ever had the rear shocks mounted so far in on the arms as the kit Di setup - running the outer hole is the only way to correct this.

It looks very neat and simple but for best race performance I don't think it any good.

The front tower is interesting, they've effectively copied the way the old carbon tower on the Top Force was done - a plastic mount screwed to the gearbox, with the tower bolted to the back of the plastic mount.

I think yif you could bolt their front tower to the back of the kit item down near the bottom, then trim away the upper section of the kit tower, you'd end up with a fairly neat and functional arrangement.

I'll be waiting until I get a spare kit tower before I start hacking mine up []

 

[DCM71]

When I get a chance to do my carbon mount, I will be attaching it to

the stock front shock tower base but the rest above the holes will be

hacked off as it will be no longer needed.  Not realy looked at

the rear yet, think the front needs the most work, noteable the

suspension travel and steering lock/geometry.

[pUs]

There are 2 problems with that rear tower that's on e-bay.

1.

The spacing of the wing mount. The kit tower has the wing mount spaced 7mm further back than the shock mounting area so that the wing doesn't slam into the back of the tower. The wing will need to be shortened to fit this tower, and it will need cut outs due to the shocks being behind the tower (see point 2)

2.

The shocks will have to be moved to the back of the arms. You cannot use the outer shock mounting hole on the arm if the shocks are at the back because they will rub on the rims. From my testing and calculations, the outer arm hole is the best place to run the shocks, in terms of providing the right geometry.

No other competative 4wd in many years has ever had the rear shocks mounted so far in on the arms as the kit Di setup - running the outer hole is the only way to correct this.

It looks very neat and simple but for best race performance I don't think it any good

 

I think the above mentioned points are quite easily solved.

First, the wing. I don't understand your point really. Using the kit mounts, the whole wing assembly sit further back and sure, perhaps this isn't ideal. Either you can shorten the kit mounts, or use something like an old Yokomo mount (YZ10/MX4). And if some material has to be taken away from the rear wing I don't think it will hurt the actual performance of the wing, many other 4WD cars have this and it doesn't seem much of a problem.

Secondly, the damper mounts on the arms. The rear a-arms (at the "back" mounting points) seem to have a lot of "meat" into which you can throw the damper mounting screws, and I see no reason why you can't machine down this area just a few mm's to be able to use the outer hole. I don't know how much material has to be taken away to clear the rims but I suspect not much.

At the moment my car uses the position next to the outside mounting point and it seems quite ideal for 1.32 *** dampers with 1.02 pistons. I would need a slightly longer piston to properly use the outer hole, but I'm not so sure it's critical. Further testing will tell I guess..

[bender]

What I meant with the wing mount was that they have to fit 7mm away from the shock-mount part of the tower in order for the wing to fit untrimmed.

If you use a flat piece of carbon fibre, you'll have to have a 7mm spacer between the tower and the wing mount (or use a different wing mount).

Running the middle hole in the arms might be convenient for the size of shock you're using, but that doesn't mean it's ideal in terms of suspension geometry.

In order for the DI to have a similar geometry to that of most other competition 4wds (such as XX4, BJ4x4, ZX5 Lazer etc) the shocks need to be mounted in the outer arm hole at the back, and the 2nd inner arm hole in the front.

It all has to do with roll axis, leverage rates, etc etc. For my way of thinking, duplicating the geometry of what is known as the best handling 4wd (Losi xx4) is the first step in having a consistant handling and competative car... I suppose it depends upon how serious you want to be.... for me it is easier if my base-line setup is close to that of a known top level 4wd.

Anyway, I have finished my DI page on my website.. it's an ongoing development, but it's ok for a start. You can check it out here:

http://web.aanet.com.au/fir/dark/index.htm

If anyone want to contribute to it with hints, tips, mods etc feel free to email me via the link on the page []