Stampy Gearing Question ? ?
 

I just rebuilt My FLM Stampy after sitting for a year with a bent chassis after getting run over by a Van. I decided to put in a above avarage power plant in it and I'm having a small temp issue.
It's geared 58/12 running on 4s with feeding a Mamba Max and a new HobbyCity 2300KV motor, Castle Voltage regulator/BEC. The ESC has ben tuned down to 80%Punch Control and normal timing. Has good power but not super crazy.
The temps outside during testing are 63degrees. The ESC is ice cold, battery was 84degrees and the motor was 127degrees after a 10 minutes of hard driving and speed runs.
Mr BrianG's Speed calculater says 45mph but theres NO WAY it's even hitting 35mph. I'm a little confused ???

When I ran it previously (befor the van incident) It ran on 3s with a 4600KV Mamba motor and was CRAZY fast and uncontrolable, now it tame and almost lame ?

Do I need to gear up to drop motor temps ??

Pardon the Shizz-ity pictures and messy bench.


http://i88.photobucket.com/albums/k1...z/PC060018.jpg

http://i88.photobucket.com/albums/k1...z/PC060016.jpg

http://i88.photobucket.com/albums/k1...z/PC060017.jpg

Nice Pede Bondo.

Ummmm........you should be getting more power than that.

There is something you should check on.

See if your reverse power is set to 50%.

One time, I had the throttle channel reversed, AND the motor leads were reversed.

I was wondering where the rest of the power was too, until I stabbed it in reverse.

Check on that. There might be something there for ya. :yes:

Sikes,
Thank You Sir,
Reverse is at 50%
Direction- Nah, Thats all good. The power is not so much a issue because I have the settings cranked down. It's the motor temp and lack of speed verses the calculator that's puzzleing me ? Even with the setting like they are the top speed "should" exceed what it does .

Ya know, I just commented in another thread about lipo temps being a issue. Even though my packs were in the house maybe the temp is just low enough to have a factor for these older packs I'm using for this application to cause this power loss and motor temp ? Need a big brain to comment on this? Where you at BrianG ?

Punch control doesn't affect final top speed. Punch Control is just a momentary pause or delay in applying serious power.

Lipo Temps? You're still in the 60's there. I run my Lipos even when it's 30 degrees outside. I just keep em in the house, nice and cozy warm until I get ready to make a run. They usually stay warm enough not to affect performance. The packs don't have a chance to get cold. I run my stuff pretty hard usually.

Hmmm...........perplexing. LOL

It could be the age of your Lipo. What kinda Lipo you got there?

Thats one of the lovely Mr Chris Fines lipos I believe, might be one possible explanation..

S can motor should be able to push more than that speed for sure, though how heavy is that pede- lot of metal & large tires on it?..

Jeff according to your numbers you're down about 20,000 rpm....

Your 4S/2300 is 38,640 at 16.8 full charge, your 3S/4600 is 57,960 at 12.6 full charge.

Huge drop there between the two.. might be the problem?

Neil & Sikes,
I hear ya on the Crime Design packs but they have treated me very well for the four years I had them, They propel my 13lb LSTs just dandy. They are not the prob, they still charge to 14.80 and balance perfectly. I did try another 4s and same results. OBTW, the tires are 1/10 scale 5" tall Imex tires and RPM rims.

The Pede weighs in at 6.4 lbs with 3700mah 4s and body. Nothing for a 4s set up ?

Jason/Redshit,
So with the numbers you posted I need to gear way up like I suspected my problem might be ? Why does the calc say it's pushing 45mph when I'm not ?
I'm not the brightest bulb in the box but I can't see the prob .

"Jason/Redshit" hehe

Yeah 20K would be hard to make up for with gearing, and you'd need 6S to get the same with the 2300.

The hell were you thinking dude?

JK:mdr:

Who thinks around here, ceretainly not me ?

I did try a Polyquest 4s pack under the moonlight and same results.

I will gear up several teeth and try again Monday afternoon when it's nice and warm to hopefully aleviate 2 potental possibiltys at once.

Thank you for your input this evening gentlemen.

Boy O boy, 20K will be a stretch w/gearing.
I can get another couple teeth w/the spur possibly and test some pinions and go from there. With the adjustabilty of FLM tranny I should be able to get pretty dang close ?
I'm feeling kinda stoopid not seeing this combo was gonna have such a difference. But this motor in my LS10 on 3s was pretty dam fast geared at 54/12on 3s ? I guess the diffs were geared considerably higher ?

Thanks J !

I don't believe BG's calc includes moonlight as a variable, this is one particular enhancement he may not be aware of. Well I guess he is now, thanks for letting that slip. Big Mouth.

:mdr:

Gearing prolly won't help with temps at that KV, but worth a shot. Good luck!

Did they send you the correct motor? might be a misprint on the sticker?

Make sure your lipos are around 90-100f before the run.

I have a 4500 6s 30c fp lipo, and ran my muggy last week with it. It had been sitting in the lipo drawer for a few months, fully charged. Performance was terrible, not even getting 25mph. It was stone cold (maybe 50f) so I stuck it in front of a small electric fire for a few mins, got the pack up to 85 or so. Then I figured I would check to see if it was charged fully. 610i put about 70mah back in so it was very close to full. Put it back in the muggy and performance was better. So I did alot of stop and accel to warm the pack up a bit. After a few mins I was wheeling down the street and doing 45mph.

Conclusion, lipo temps matter. Some lipos like to be warm (enerland 30c run warmer than the 25c do) and I can imagine that all lipos will benefit from being around 85-90f before the run.

I thought the "Redshit" was funny too... Just cause I do the same thing when I am typing and do not even notice.

So since I figured this out, can I have a job at Fat Kid Engineering? Sounds like a great place, completely lacking and public correctnees!!!!

I try SO hard not to let that happen it isn't funny.
I know Linc is always prowling around looking to bust my Nutz for anything !
I even double check my spelling just not to look like clown unlike most fellas.

BB16,
Excellent point but I have 2 of these motors and I've already weeded out this possibilty.

"I thought the "Redshit" was funny too... Just cause I do the same thing when I am typing and do not even notice"

Yeah, except he meant to- don't think your cool old man, I haven't used a tenth of my wit here... :intello::na: