Sand slinging/Beach runs
 

I tried out the new monster heatsink on my Quark125b w/dual 40mm fans. I was amazed how cool it ran. Perfect fit ! . Prior I was using Wond 8xl 18/51 and it would thermal after minutes. I did swap in A fiego 9xl 16/51 grears. However I did notice a big differance in speed, slower.and the additional torque seemed of little benefit. It did however run cool non stop for 25min. Hard running. Spur has washers& nut super tight no spring.
How can I achieve faster speeds again. ? remain cool Maybe put in the 8xl again. 18t pinion or 20.? Dual fans seem to have very little effect on run times. I usually just stop after 25 min to be safe.
2 speed emaxx trans
spyder 8
apachee 5s 18.5v two parallel
Paddle 40 / 23mm
New era extended chassis
6mm UE cvd w/ racer x suspension.

Since you're using the 5s lipos, just reput the 8xl and go.
Does your truck cog when it launches?

NO it does not cogg.

This may seem like a dumb question but why did you drop your gearing down when you went to the 9XL (18/51 to 16/51)? Shouldn't you have stayed the same or geared up?

Just foolin around I have 16 18 20 pinion gears. Monster Mike suggested fiego 9xl . Sand is an enemy and an expensive$ motor could get ruined. It did run very cool w/ constant running. . I will try 18 or 20 teeth on street see what happens.

whith the quark 125+heatsink I run my 9xl in my emaxx at 66/22 (3.0 gear ratio) with standard maxx diff ratio and 5.8inch tires in heavy grass fields with no heat problems. I use 66/26 (2.54 gear ratio) on pavement with 5.25" tires.

You should be able to run 18/51(2.84 gear ratio) on the beach without issue. Depending on your tire size and diff ratios. The 51/16 (3.18 ratio) is conservative IMO.

9xl is the right motor for 5s. 8xl on 5s will run hot just from the high rpm.

Did you try the 16 51 gearing on the 8xl?

Thanks guys for the replies. I have not tried 16/51 on the 8xl yet w/new fan heatsinkset up. I plan to. But on pavement the old set of 18 or 20/51 no heatsink/ fan combo would not thermal, only in the sand, At least now Im not just breaking drivetrain parts and am able fine tune gearing. Thanks to this forum & monster store .

The sand has some restriction though. Make for a few higher amp draw.
Let us know how it works out.