[TracktionRC]

Hey Guys....

I'm a noob....I admit it. I brought my 8th scale to the track a couple of weeks ago and after just ten minutes I puffed my batteries.

I guess I should have at least changed my gearing since my last dirt race.

So this brings me to the reason for this post.

What should I change?

1700KV + 15T on my MP9E
5K/5K/2K in my diffs
Shocks...your guess is as good as mine.
For tires I used 50% AKA Enduros

Yes I know I should test/change/test change, but as I said I'm a noob and setting up a car can be like rocket science.

Can you give me some pointers?

[imported_kyle]

what batteries u using?,usually puffing happens when you try and draw more amps than a lipo can safely supply...hence the heat and swelling issue.One option is ya check gearing first,second is get a higher c rating lipo so more amps can be drawn.start off small and then increase gradually on the speed settings as well maybe that way you can check heat etc too.Another possibility is that you are using older lipos and they just aint what they used to be...hence lipos do have a shelf and cycle life that causes this problem too,maybe too much summer cycling racing in the dirt bud? trying to draw 200 amps from a 20c lipo aint gonna happen basically and running on carpet is a lot harder on batteries I think like way more grip and strain on electronics possibly.

[Nick411]

When was the last time you balanced it? Normally good quality batteries won't have a balancing issue but if you stored it between the dirt and carpet season without balancing it and at 70% charge you could have caused the cells to get out of balance and when you ran it you over discharged one of the cells.

[TracktionRC]

Originally Posted by kyle

what batteries u using?

Batteries were decent....5000mAh 50C.

Originally Posted by Nick411

When was the last time you balanced it?

I balance every cycle.

I've had these batteries for a season and I understand they are disposable at some point.

My concern is I now have a new set and would prefer to avoid a $200 lesson twice in a row.

Thanks for your input.

Looks like I'll be taking the pinion down a few teeth. The down side is the car felt awesome and drove awesome the way it was.

[Guest]

go to hobby king.. goo cheap batteries

[imported_Steve]

I have an MP-9 and have been running alot at universal

I run 1800KV with a 13 tooth

my diffs are F10000/C20000/R7000

My shocks are 1.3mm x 6 hole pistons and F45 / R35

But i have changed almost everything on the cars setup since going on the carpet
I'll be at the trophy race if you want to come ask some questions

Steve

[Michael_Lambert]

Was it a new ESC? I know the RX8 comes not in lipo cut off mode on.. i found that out the hard way when i puffed a pack.. you need to turn on the cut off.

[Gump]

I second the cutoff point. make sure you're good in that department.
13 tooth should be fine, or even 12 if you don't care for any more speed. the lower the tooth, the lower the temp.
try something like 7k front, 15k center and 5 to 7k in the rear.
stiffest springs up front, 2nd stiffest springs in the rear
very low to the ground for ground clearance
thick sway bar up front, thin in the rear
short as possible rear camber links for lots of rear camber gain
rear toe either 2.5 or 2.0 (not 3)
a touch of toe out in the front
front camber maybe -1.0 to 1.5 and rear you may have to play a bit 1.5 to 3.0

heres the biggy (i added an extra space to make sure you see it!!) - DROOP!
you'll have to limit the front and rear droop much more than any offroad track you've ever driven. It makes a HUGE difference, and you have to go by feel. you will want both the front and rear arms to fall below level just a bit as a starting point. change one end at a time and note the difference.

with all tuning for carpet, you will have to suffer a bit in jumping and landing ability to make the car handle very well in the corners. Put it this way, you'll have to pretty much always land the downslope off the double to make the triple nice and easy.
and other than that stick with known good tires like barcodes or 7's in gold (clay) or switch 2.0's in clay.
your batts may have been at the end of their life. did they sit around for a while, maybe in a discharged state before being used again? That'll do it..
Above all, watch the temps. if you're always hitting 190 or more on the motor that's a bad sign. maybe aim for 170 or less at all times.

[TracktionRC]

Thanks Guys. The ESC was new however I did set the cutoff.

Thanks for all the points. I'll be at the track today to test and play.

[imported_Sparkie]

Thanks Gump Thats very helpfull advice for any 1/8 scale