Keeping it cool - DEX410

[jo90]

Very happy with the DEX410 but have one slight issue when it comes to airflow to the electrics.

Im running a Tekin RS with a SP 6.5 V3.0 . I was finding the speedo was getting way to hot, to the point that the car started to cog, possibly almost at thermal shutdown.

I was running the Tekin on Dual mode, 5% boost and the timing fully retarded on the motor. Current limit set to 40%. Gearing was a 22/87t 48dp.

I know the RS is meant to be able to run down to a 5.5 but I will be likely switching this for the RSPro in my DEX210. However I still feel once we get out in the (I say this with tounge in cheek) summer, the car is going to run to hot.

So, how have those who have DEX410's running Tekin speedo's managed to keep things cool ?

I do have a high power 30mm fan to install that could slot in front of the speedo but i haven't seen that many who do this.

I have also cut holes in the airscoops on the shell to try and get some air into the body.

this is the current wiring on the car



I believe if i move the switch to a new location a fan can slide in there. I can drill through the side pod and countersink a small M3x10mm to hold the fan in place.

Any help though on what you have done will be appreciated, possibly if you have pics of your Tekin install also that would be great

cheers

[jimarea51]

Hi Jo90...

I've been runing the TEkin RS Pro in my Durango 410 for a couple of years now, I've attached a couple of pictures to show how i have it installed...

I believe that the solder posts aslo double up as the heatsinks, so direct the cooling fan at this area will work best at keeping things cool...

I'm runing a HPI 6.5 geared 23/87 and temps are usually ok outdoors during the 'Summer months'..

Hope that helps...

JIm DiXon

[jo90]

Cheers for this, and the pics. I think in that case I will swap the speedo's over and run the Pro in the 4wd and spin it round so that the fan works directly on the posts (aware they where the heatsink and to be honest should really have run it this way to get air to them)

cheers for your help !

[kartstuffer]

I have run a Tekin rs pro with a 6.5 tekin for summer outdoors and winter indoors now with no heay problems .Running sensored mode 10deg motor timing and basically the same settings as Kev in his Kyosho. at 23/ 87.

[big_boss]

Hi
I ran the rs pro/6.5 orion on sensorless only with boost and found this too hot for my liking (or the speedo or the motor). So I reverted back to dual mode and the car is much better now, no over heating just warm to the touch after a full six min run. I am geared 87/20 and find it plenty fast.If you run dual mode my understanding is that the boost doesn't apply.
cheers

[fil9144]

i noticed under craigs car hes cut some of the chassi out were the motor sits which iam thinking of trying on a spare chassi and see how much it helps but pretty sure hes running it with hole for that reason

[jkclifford]

where the lower sides of the shell wrap around the back of the brace, cutting this out allows hot air to flow out easier.

a rule of thumb for aircraft cowls is exit holes 3 times the size of the inlet.

[jo90]

I'll trim that bit to

[jo90]

So this is how the layout is now







Moved the solder pins round so they are right next to the fan and also swapped this for the RSPro out of my DEX210. Fan is blowing plenty of air over the pins now.

I'll give this a whirl next Tuesday

[jkclifford]

firstly nice neat job.

imo i think you might have made it worse, running the wires over the speedo is not allowing heat to escape.

not sure if once you put the shell on the fan work that effectively.

[jo90]

Not sure how else to get this to go in though. My thoughts are that the air is now being forced over the poles in full from the fan. If I place the speedo the other way round (so wires run away from poles and not over the case) then the fan wont be blowing direct on the poles but over the case instead. Damned if you do and damned if you dont situation

Air wise I have put two holes in the side of the shell so this drags air through, along with holes where the air scoops are at the front.

The lack of room on the chassis does lead to having to think outside the box to get air in too as the front of the car covers the chassis substantially too so no air flow from the fron around past the gearbox.

I have now though moved to the RSPro so im hoping as it is now will be enough. I always thought that the RS would go down to a 5t also, but now advised that it is a 7.5t limit in Mod/4wd. I am sure though i read 5t somewhere, but thats by the by now.

I am really happy with the car though. With a setup not really near to good at all I placed 4th on the grid Tuesday. It's quite stable and predicatable over the surfaces. Still alot more to come from it, but want to concentrate on getting this heat/airflow issue sorted first so i can then concentrate on gettin the car right, rather than hoping it will last 5 minutes

Thanks to everyone for your input so far, it's all good info and im taking all on board. Will provide an update after the next run, and will temp stuff with my temp gun to see how it is all working out.

PS..ive got a Proline Bulldog to fit yet...this has no front air vents...that should be fun !

[rcjunky]

They had a 5t limit, but the changed that as too many were running them to the limited and frying them. You always need the pro in 4wd

[jo90]

Thats what i thought, so bit naughty of them saying 5t then changing it !

[jo90]

So I ran the DEX410 agani last night. What a difference! Running the speedo the other way round with the fan against it, and of course runnning the RSPro, the speedo was cold and the motor averaged 45deg over the night. Very happy bunny

It meant I could concentrate on racing and i felt i made some improvements forward with the setup and car last night and I know as well there is room there to up the speed once im on a larger track outdoors too.

Thanks for all your help guys !

[rcjunky]

thats the reason I got fan mounts made, basically a L braket that a rs or rs pro goes on with a 30x30 fan blowing on the soldering posts, they work like a charm and don't need to worry about the fan moving. Make sure you has sufficiant flow to the fan though