DNX 408 initial thoughts...

[andys]

Finally finished building my DNX 408, not had chance to run it yet, but initial thoughts on the build.

1st off, very impressed. Everything fits very nicely, super close tolerances on everything.
Only gripe is the fiddly throttle / brake linkage setup. Anyone else any thoughts on this ?

The ballraced throttle linkage which mounts onto a 'plastic' extended arm is the only real gripe I have with the car. Even with the throttle end points set properly, the plastic arm bends around quite a bit when engaging the throttle. This part really should be aluminium as it's pretty damn important. Just looked on the Durango site, but no sign of an alloy part as yet....

Apart from that, the rest of it looks quality.

[Chris Doughty]

Hi Andy,

I also recently built my 408 and all though its a complicated throttle/brake setup, once the time has been spent to get it configured correctly, its very effective.

the only slight bending I get on this throttle link mount arm is when the brakes are being used (which wouldn't matter) opening the carb the mechanism works just right.

[andys]

Hi Chris.
It's certainly an elegant setup, I have tweaked it so it's set up just right, I don't get much, if any flex on brakes as effectively there is no force applied to the throttle linkage on braking.
On the throttle linkage everything is free and smooth, and I'm only opening the carb just enough, but the arm still flexes more than I'd like.

I'm sure it will be ok, just seems like the arm should have been aluminium though !

[big p]

it's been posted on an american forum by someone from durango that there will be an aluminium post for the throttle co-ordinator.

i think the car need's quite a powerfull throttle servo, i've had to set my epa a bit deeper than i'd realy like to get the brakes i want, other than that i'm super happy with my 408.

[andys]

Cool if an alloy one is in the pipeline, then that's good news.
Chris, can you confirm or deny !

Apart from that the rest of the car looks bomb proof !

[Chris Doughty]

I've not started at Durango yet (still working out my notice at previous job) so I know no more than you guys, but I have also read the same statement on RCTech regarding the Alu option part.

[gddevey1012]

I have to say that i noticed very minimal flex in the arm but over time yes it could become an issue.

As for the car and my initial thoughts its by far the best kit i have built over the years goes and i have built quite a few !!!!! goes together easily and perfectly and even the ominous plastic bag breaks down very easily when you get your head around it.

Looking forward to getting it on the track hopefully soon for a few test days with the rest of the xtreme team and getting my head around setup before blooding it in a race situation.

Gareth

[Chris Doughty]

it's been posted on an american forum by someone from durango that there will be an aluminium post for the throttle co-ordinator.

i think the car need's quite a powerfull throttle servo, i've had to set my epa a bit deeper than i'd realy like to get the brakes i want, other than that i'm super happy with my 408.

what material are you using for the brake 'spring'? the regular kit fuel tube?

my initial setup of the car I am seeing that the brakes are stronger than my LRP car and ive had to reduce the EPA a bit.

I am using some LRP fuel tube currently around 8-9mm long, its a bit thicker walled than the Durango fuel tube.

brake feel is very driver specific so play around with the length and material used here to get the right kind of feel you like.

another thing to note, ive often found that strong brakes rarely lead to a faster laptime, and certainly not a faster race time, consistant brakes will get you round the track faster and more likely on the currect line

[big p]

i think i just need to fine tune the linkage, the throttle return spring was packing on sunday at ndor, i altered the length of the tie rods and moved the centre point on the servo, it's not too far off now, i think i'll take a few loops off the spring and give it a stretch.

i've never liked super power brakes, it upsets the car too much, i much more prefare to coast into the corners.

[Chris Doughty]

I stretched my throttle return spring a little too.

I think one of the most important things about any 8th scale car is to spend a lot of time setting up the throttle linkages, an amazing car with brilliant suspension geometry will be useless if you don't have an acurate throttle/brake control, the car can feel appauling

[andys]

Out of interest, did you guys end up shimming the brake disks. I did otherwise the brakes hardly engaged !

[gddevey1012]

Yes I did I used the 1/2mm washers from the dex410 kit and it works a treat now

[Chris Doughty]

yes I shimmed mine, ive got about 1.5mm worth of spacers

[andys]

Ok, so now that i've finally got to installing the radio gear, it's obvious how come the buggy is so narrow... They forgot to add in a proper radio tray !

My receiver is a small KO 302f, (just fits...) but where the hell do you put the all the wires !

Looks like i'm going to have to shorten them all, which I hate doing :(

[andys]

Update:

Ran the DNX408 for the first time at MMRX.
Pretty much kit setup apart from shock oils. The car went ok, couldn't get over the small quad jumps without the rear kicking up, but apart from that the car felt ok.

To be totally honest, it didn't feel much different to my RC8B on the dusty slippy surface. Granted, it looked nicer going around but wasn't initially 'miles' better in my opinion. That was a tad disappointing as the Durango 410 was a quantum leap up for me from my previous buggies. Just shows that with 8th scale, that maybe isn't that much difference between the top cars ?

Anyway - it ran well and appeared not to break all day long - good stuff.

On cleaning the day after I noticed a few things

1_The rear centre driveshaft spring clip was nowhere to be seen. The bearing was halfway out but thankfully no damage looks like it's occurred to the gears on opening up the rear gearbox case. I was super careful putting the 'spring clips' on so wondered has this happened to anyone else ?

2_3 of the 4 axles felt like they were binding, not running free at all. One on the rear almost couldn't be turned by hand. I dismantled them all and ended up removing the large shims that go on the inside of the hub. These shims look slightly the wrong size (a touch too large in internal diameter) which could be why they were not seating correctly and rubbing on the bearing covers rather than marrying up to the correct part of the bearing. All seems fine now re assembled, even with no shims there is little if any play. Again, anyone else had this ? Do you need the shims ? Are they the wrong size ?

Apart from that everything else was ship-shape. Servicing the diffs is so easy and not a touch of muck or dust had entered the gearbox case - nice.

Im guessing it will run a lot better next time as the engine was fighting against 3 binding axles !

Would be interested to hear other peoples first run impressions.