XTM MMT does it again and resets record....

[jzemaxx]

Well did a test pass today on only 10S again with new gearing. 79.7mph and 80.3mph!!!!!! No video yet....so its not offical passes until this weekend if the weather cooperates. Doesn't look good though for the weather.... Those passes were not clean passes either, the truck was skating bad from side to side. Need to work on the suspension a little. I think it should go 81-83mph on a clean pass, then the 12S lipo goes on and cross your finger for 85-90 maybe somewhere in between. Also that is still on the small 1521 motor. My 1527 has not been installed yet.

[xcntrk]

Nice work and very intriguing to follow your progress.

Have you considered using a more accurate means of speed detection, maybe a radar/laser gun? I imagine they’re relatively expensive. I’m surprised no “haters” argue the accuracy of your onboard GPS.

[jzemaxx]

Originally Posted by xcntrk

Nice work and very intriguing to follow your progress.

Have you considered using a more accurate means of speed detection, maybe a radar/laser gun? I imagine they’re relatively expensive. I’m surprised no “haters” argue the accuracy of your onboard GPS.

I have a bushnell radar gun. The GPS has always been within 0.5-1.0 mph of the radar. The GPS will go to the 0.X decimal where the radar gun does only whole #'s and no decimal. Also I don't like getting people close to the truck at those speeds....a 15-18lbs truck at those speeds would kill someone with any sort of direct hit. A baseball at 80mph does damage and its maybe 1 pound.

My old emaxx runs would be 67.7 on the GPS and 68 on the radar, and many other runs. The radar always reads a little higher then the GPS.

[magman]

You are shooting for close to 90... I can't wait to see that vid...good luck

[jzemaxx]

Originally Posted by magman

You are shooting for close to 90... I can't wait to see that vid...good luck

Actually I was only shooting for 80mph with this truck, but it keeps suprising me. I am heading back out again here in a few mins......wish I had a camera man around...lol. Oh well better saved for the weekend..

[magman]

Even 80mph is very impressive for a truck that size.

[jzemaxx]

Originally Posted by magman

Even 80mph is very impressive for a truck that size.

I was shocked when it did 76.0mph 2 weeks ago, now I really am excited to see the truck just keep powering through even with more gear...still no problems.

[jzemaxx]

Well did some more testing and it looks like my Turnigy HV might be smoked. Got the white smoke of death but the controller still works, but power dropped big time. Also one of my phaltlines blew completely apart.

[aqwut]

Originally Posted by jzemaxx

Well did some more testing and it looks like my Turnigy HV might be smoked. Got the white smoke of death but the controller still works, but power dropped big time. Also one of my phaltlines blew completely apart.

10S and smoking.... :) that's AWESOME!! you must've been pusing 3700+ Watts... I dont' think 12S will be possible if you're smoking that ESC on 10S, 12S would be really killing it.... I just finished modifying my MGT for 12S setup on the KB...

Hook us up with the pics of the burnt ESC..

MGT, ready for 14S 123 or 12S1P Lipo

[DrKnow65]

No pack left for that dewalt drill in the background?????? hehehe

[aqwut]

Jzemaxx... you seem to be pusing that 1521 to the limit... and it's working great.... I can't believe that small motor is able to push that heavy truck to those kinds of speeds.. I guess that's the power of 4-pole motor & high rpms... that's awesome.. I can only image how powerful the 1527 will be...

[jzemaxx]

Originally Posted by aqwut

10S and smoking.... :) that's AWESOME!! you must've been pusing 3700+ Watts... I dont' think 12S will be possible if you're smoking that ESC on 10S, 12S would be really killing it.... I just finished modifying my MGT for 12S setup on the KB...

Hook us up with the pics of the burnt ESC..

MGT, ready for 14S 123 or 12S1P Lipo

What I don't get is the controller is still arming and working but it has a power loss. Any ideas??? I can't figure out why its still working after puffing white smoke. Visually I can't see anything wrong with it. Maybe some of the Fet's smoked??

[jzemaxx]

Originally Posted by aqwut

Jzemaxx... you seem to be pusing that 1521 to the limit... and it's working great.... I can't believe that small motor is able to push that heavy truck to those kinds of speeds.. I guess that's the power of 4-pole motor & high rpms... that's awesome.. I can only image how powerful the 1527 will be...

I would imagine its got to be coming to the end of its power. Cause its staying cool (~108-115) after each pass, but the controller is getting to 185-200 after 1-2 runs. Guess its overgeared. I will probably back down on the gearing which might hurt the speed, but I don't feel like replacing controllers every 2-3 runs. I don't think the voltage is hurting it at all, its just the amp draw must be nearing 200 or so at the top end cause that is went it puffed, puffed...hehe. Leaving the line its great cause I have the soft start enabled.

[jzemaxx]

Also keep in mind the timing is turned to low as well, so more power is still on tap.

[aqwut]

How does the ESC smell?.. if it's a FET that's gone, you can tell..could the smoke be coming from the ends of the caps. take the heatsink off and take a peak man... and put a fan on the heatsink and stick it on with polyurethane glue...