I guess I was just being overly cautious, with no test time I don't really want to smoke my Neu first time out. But it seems that I shouldnt have anything to worry about. What temp range is considered good and what is too hot for the Neus?

That is a nice looking unit too, thanks for the link. I will def. consider that one is I have heat issues in the race. Not to mention the "bling" factor :lol:

sorry for 2 posts in a row

Thermal grease is really only very effective if its applied very very thinly and used to smooth out any minor defects. It really can't be used to fill in large gaps. By large I mean 0.1mm. I mean I guess its better than air being there, but it won't make a crappy HS work great if its poorly machined.

IDK if you've ever played around with building computers and attaching HS's onto CPUs. Things are easier today, but the HS for CPUs use a huge amount of spring force, like 30lbs+ to attach a HS onto the little die. Some extreme overclockers or terribly anal people would go further than even the huge aftermarket HSs and "lap" or sand down to a mirror-like finish w/ 1000 grit paper, then use Artic silver to fill in imperfections.
This is a bit of an extreme example as you are trying to dissipate 10's of watts out of a 1 sq cm die, but you could also easily see the results of your HS attachment skills. If you slathered AS all over the die, temperatures would be quite a bit higher. The thinnest scraping produced the best results.

Motor HS don't have to be nearly so efficient as that, and they have a much greater area to dissapate heat, but they do not attach to the surface w/ any amt of spring force, nor are the HS or motor surfaced generally well prepped for HS's and thermal transfer by contact. The machining is fairly rough. If you get some poorly machined cheap chinese HS, I wouldn't count on it doing a whole hell of a lot, and may actually be counter productive (trap air pockets.)

A 2.5D on 5S will be solid and lots of power for the track. More than anything its going to come down to driving skill and proper gearing to being with. With too much power its easy to drive out of control and just bounce off the walls as you watch the slow and steady guy just lap you. If you are getting anywhere near 160 or so, I would look at gearing and setup before fooling with HSs or fans or anything.

Don't those have those 2.89 ratio diffs? If so you are @ ~9:1 FDR which seems qutie a bit overgeared to me. Personally my trug runs ~14:1 and seems just about perfect temp wise and power wise.
I'm not a Cen expert, so maybe this is off, but if anything that much overgear will be sluggish and hard on the ESC. Motor temps will be low tho most likely. It takes a bit of testing to get it just right. g/l

The matrix tr uses 11/38 diff gears...

My truggy is running Hotbodies 43/10 truggy diffs with a 46 tooth spur on it a la JHautz's conversion, this truggy is formely Jeffs, I bought it off him last year. I have all the numbers and ratios in a chart at home, unfortunately I am at work now so I can't look at it but I can post later if you guys want to look it over and let me know what you think, that would be a huge help. With no real chance of testing I am sort of going into this first race guessing. But I will have a few other pinion choices with me for tuning 13,14,15,16 probably.

43/10..ok so that's 4.3. A 15/46 would be a 3.07 ratio.
With 4.3:1 diffs that would be a nice 13.2:1 ratio. The pinions you have should be a nice range to play with. I would start w/ the 15 or 16, watch temps, and adjust from there. If the motor is hot and esc is cool, but a bigger pinion on, cool motor/hot esc, drop the gear ratio (smaller pinion.) If both are in a decent temp range, tweak gearing for more punch or top speed as desired.

Based on the calcs I did that is exactly where I have it with the 15 tooth pinion gear on it. Thats a good sense check that your math matched up with mine. I was going to do exactly as you suggested run some practice laps temp it once im happy with temps I will adjust to feel.

Sounds like you are on the right track. Have fun and good racing. It will be a blast. :)

Thanks again for your help. I will let you guys know how I do.

15T pinion on that setup and you will be golden. I amost never see motor temps over 140 running all summer on my truggy. I run the exact same setup. Just plug it up and let it rip. You should have no worries.

Geez.... Your just now getting around to running that thing?

:lol: Yah ran a little low on funds after I got it from you and was waiting for the mmm to come out ended up with a v2 that lasted a week, got 5 laps in and it kicked the bucket :oops: by the time I got a replacement the season was over and the weather had turned bad. The first chance I will get to run it on a track is mid April. I have been doing my share of wheelies up and down the road, the wing makes a great wheelie bar!!!! :whistle:

Thanks for the tip on the pinion, thats what I thought you had said to run.

hey,

I am currently seeking a heatsink for my loxi xcelorin motor (39mm diam.), I have found out that the losi-heatsink fits neu motors:

http://www.impaktrc.com/product_info...osCsid=d5e22ae

if you use a heatsink, use some thermal-paste. I used a novak HV heatsink on a 88mm long inrunner, and it lowered the temps definately (fits VERY tight and is heavy), for a good thermal transfer I use thermal paste. but in the end, the motor was a bit crappy...

of course, gearing etc. has to be right etc, furthermore, neu motors are top of the shelf stuff and are very efficient. but under racing conditions at high temperatures it could make sense.

Cool thanks for the tip on the Losi heat sink. This thread should be helpful for anyone else who looks for a heatsink for a 15 series Nue in the future too.