My CRT.5 conversion w/ ET & radar data

[Finnster]

Setup is a LMT 1920/10, MM, Align 3S 2100 20C lipo, 14/46 gears riding on the CRT pro kit w/ the ofna ext chassis. Weighs 2020g with the heavier 1:10 scale road rages pictured below (was a temp setup waiting for other tires to come in). Weighs 1900g w/ the buggy dirthogs & proline rims inc w/ the kit. That's lid, batt and all. The goal was a lightweight truck as a part time basher/racer. Drives absolutely wonderful and makes the Revo look like a slog in comparison.

Also have blue springs and slightly heavier oil (5pts) than stock. Went upto 3K oil in the center diff and seems about right. The shock settings may take a bit to work out. Having too much fun playing w/ it now.

Does about 42mph+ on radar w/ the above batt. Temperatures stay around 100 for the motor and the MM. I may go upto a 15t to even out the temps a bit, but either way it feels good.

I am waiting for a couple Neu 30C 2500 batts, one in 3S and the other 4S. The amp load is a little high for the 20C 2100 batt. Runtime is about 12min or so. I was aiming for 15min, so the 2500 should get me to my goal. The 4S batt should put be above 1000W and close to 60mph. The motor put my chunky 5.5lb rustler to 55mph on 4S and the M2Ks. The LMTs are awesome motors. Have plans to redo the batt tray slightly to move it a bit back and slightly away from the spur. Its tight, the the batt is quite safe. Mike's adapter is bigger than the spur, so provides a nice guard, but you can never be too safe. Really well done.

Nevermind the mismatched tires below in the topless pic. It was just for testing. Also, notice the huge amp spikes in the 1st graph. I'm not sure how accurate they are, but I turned down the punch control one step for the 2nd session. Since there is no slipper, no limiter is very hard on the driveline. The actual performance loss is not really noticeable. Calmed down the huge spikes tho, and the batt is getting nearly so hot (no wonder.)

[jnev]

Nice conversion!! How is the small Lehner liking the CRT.5? I have heard of that the 1920 is a little on the small side for a truck that heavy...

[Finnster]

Originally Posted by jnev

Nice conversion!! How is the small Lehner liking the CRT.5? I have heard of that the 1920 is a little on the small side for a truck that heavy...

The 1920 is fricken wicked. I don't see the need for a bigger motor than that. Its already overkill on 4S, I can't imagine needing to go up a size on the motor. Also, it stays really cool regardless. I put the huge mashers on, but didn't change the gearing. The temps really don't change. The amp draw went way up tho, and is putting out ~900W+,and top spd is faster. It still wheelies quite easily as well on the undersized 3S 2100. The motor is just smooth and powerful, but still controllable. I'm very happy w/ it.

In fact, it was driving it a bit Fri, I wheelied and flipped it going ~40.... holy road rash. It slid really far on the roof and actually ate all the way thru the antenna tube and sawed the antenna in half. Surprisingly the rx still works fine. I'll have to post a pic...

Hopefully my Neu 30C 2500 batts will be in next week (god they shipped slow...) It should easily do 60 on 4S, but I'll be mostly keeping it to 3S.

The mashers are funny on the little CRT. Like 40 series on a Revo. Tons of ground clearance and drives over everything. Cornering obviously suffers tho. Drives more like a MT. Have some buggy dirt hogs for going fast and bashing, but nothing beats the mashers for offroad.

[kulangflow]

Originally Posted by Finnster

It still wheelies quite easily as well on the undersized 3S 2100.

Hey Finnster, is that 3s 2100 a MaxAmps battery? Is it really able to handle the current well, or does it get pretty hot?

Thanks.

[Finnster]

That's actually a 140g Align battery I got on clearance. Its only 20c, so its a bit pushed. I did order the Neu batts (30C 2500) and they handle the current better. I have some ETs for that I'll put up when I get a chance.

I could prolly run that batt, but i'd have to cut the amp draw, basically lower the gearing. I'm saving it for more race situations where top end won't be so high.

With the 4S 2500 batt I was pulling 120A+, and ~75A pretty steadily. I had one peak of over 1300W IIRC. Insane. 3S is more the daily batt and runs really well but can still put out ~1000W.


The nice thing about the LMT is the gearing isn't picky at all. As long as its not grossly over or under loaded it runs cool no matter what.

[BL_RV0]

wow! looks great. have one suggestion thugh- why not plane the MM over the center diff? it seems like it would run cooler because of better airflow. just my double pennies.

[FullMetalGrave]

That is very cool. I like the fact that you are using some bashing tires on there, I want to get mine setup that way eventually.

[Finnster]

I also added some LED headlights and taillights for those midnight bash runs...hehehe. Just came back from testing it and works great. I can only imagine what people in cars are thinking seeing a little flashlight zipping at 40 mph thru the grass in the middle of the night....

I tried to make it easily removable, 3 screws and two microplugs they are off.

[miniGranis]

Pics please....

[Finnster]

Short video on the 3S 2100 batts. Just some bashing about with the mashers on. May need a little heavier diff oils, but gets over the rough ground really well.

<object width="425" height="350"> <param name="movie" value="http://www.youtube.com/v/HuHAZkBmpgE"> </param> <embed src="http://www.youtube.com/v/HuHAZkBmpgE" type="application/x-shockwave-flash" width="425" height="350"> </embed> </object>

[DRIFT_BUGGY]

Is that the RC Monster Battery Tray?

[Tobbe]

How big battery could you get to fit in a CRT.5? Would a regular 1:10 battery-pack be too big?? Going to order som MaxAmp LiPos for my B4 and later maybe convert a CRT.5, so if the LiPos would also fit in the CRT.5 I use in B4 I would save a lot of money

[jnev]

You can fit a normal 1/10 scale truck battery in it fine, even without the extended chassis. I will actually be running a 4s pack in mine on the stock chassis.

[Tobbe]

Originally Posted by jnev

You can fit a normal 1/10 scale truck battery in it fine, even without the extended chassis. I will actually be running a 4s pack in mine on the stock chassis.

That's nice to hear. Thank you!

[Finnster]

I got some ET data for some of the spd runs. Same setup as in the vid, but no radar, but spds are about the same. What is interesting is that the amp draw and wattage is so much lower than when I had mashers on with much lower gearing. Top spd then was only 50 on even with 1400W. Barely a 1000 and it pulls to 60. I could prolly even gear up a bit for a few more mph as I know the setup will handle it.



Here is some ETs for 3s. Top spd was 50mph, Again, amps are pretty low.

Also, notice the little voltage spikes after the big drops from the spd run? I think that is from the motor braking. The graph shows a hard accel from a stand still (ramping up the thr gradually as not to flip,) finally WOT (the big spike halfway thru the peak,) wattage/amps tapering off at full spd, then thr release and coast for a few seconds, then motor brake to stop it. Then repeat. Cool