asimons07

yeah mine with the 7 cell nimh would never be able to spin the tires... it occationally cogged...

BigTb17

What is your gearing? Does anything get hot (ESC, motor, battery)?

asimons07

no nothing became hot but i didnt run it long enought to really tell, maybe 3 minutes. the pinion and spur are the stock ones that come on the slash. id look but im at work till 11...

Slo-V Flyer

Correct me if I'm wrong, but the stock motor the Slash comes with is a Titan 550 size right? In that case, the gearing is is WAY too high for regular sized motors which in this case would be the 5700. I would try a more normal gearing of 18/87 or at something close. If I remember, the stock brushed motors come with a fat 25t or so pinion. That would explain the anemic performance, which as you describe seems to be crappy acceleration and top speed.

I owned a Mamba Max + 5700 motor and 3s 5000 lipo. I ran that in my Rustler and Bandit. Suffice it to say, that setup geared about 18/78 in my bandit was overkill (probably a good 60+ mph if the tires didn't balloon to nothingness). Wheelies galore and stupid hot within 3 minutes of driving.

Check your stock gearing. I bet you anything if you lower to pinion tooth count to the high teens for use with 7-cell or 2s lipo (higher voltage = recommend lower pinion size) you should see some improvement. That is of course assuming the stock pinion is 20+ teeth.

Good luck.

Lilredmachine

Nah, the stock Slash comes with an 18t/17t pinion and a 23t optional pinion for 7 cells and tarmac running. Always an 86t spur...

The fact the mamba couldn't fight it's way out of a paper bag is it's main issue here. It's simply too higher a KV for the Slash, you have to gear it ridiculously low (like 15/90) to get it to run for any length of time without overheating. I'm presently running my speed Slash on 31/76 gearing with the VXL on 3s and can get 5 minutes of full throttle running before I have to shut it off due to heat. I can run it indefinitely on 25/83 gearing.

john01374

asimons07 - It really sounds like the battery is your problem. The whole, tore it apart to make this, then tore it apart to make that makes me think the battery is trash. Any number of things could of happened during that process. A 5700 on 7 cells should run about 35 - 40 mph depending on you gearing. My slash on a 2S lipo runs right around 40mph and a 3S put's it right at 50mph at which point the stock slash body starts to do it's airplane impression.

xxxnt236

My Feedback: (1)

to get 70 get the novak gtb 3.5t brushless put a 5000mah 6 cell in it gear it as low as it can go and in the traxxas rustler with a 31 76 you would be looking at around 80 to 85mph.

asimons07

john01374- i took two matched battery packs and discharged them on my trinity dyna pro digital discharger to make sure all the cells were properly matched. i then took one pack apart and added one cell to the other pack to make my new 7 cell. that would not be the problem. i then added a little charge to the pack just so i could discharge it one more time (to match the cells again) before i fully charged it. ive been buying single cells and making batteries myself for a while. im going to have to say thats not the problem.

it very well could be the gearing... i just bought a mamba max. im going to throw that in my slash so i can run up to 12 cells or a 3s lipo. im then going to use my sidewinder in my axial crawler. i will check the gearing on the slash. what do you guys suggest for a good starting point? thanks, Adam

gasfreak

My Feedback: (13)

Have you not tried the lipolys yet

asimons07

no not yet... i had to work till 11 last night, i didnt get home till 12:30 and then i got called in this morning to work a double. hopefully i will get a chance tomorrow given that it doesnt snow. i will def let you guys know what happens with the lipo.

1maxdude

You need a lipo. The nimh batteries and castle motors don't mix too well. They are not efficient and require large amounts of current. The lipos will provide the 80+ amps that the motor will call for under hard acceleration and still keep the voltage fairly high. A nimh will strain and drop the voltage hard. KV + volts =rpm = potential speed. In my personal experiences, I geared my rustler 23/83, somewhat high, for my 6900, on 2s it ran 55mph, on 3s i ran 66-67 consistantly. 8 cells, I didnt even try, but on 17/83, on 8 cell nimh, I got 46mph. It was equal to my 2s lipo at that gearing, but took a long time to get there, and had no balls. nimh to lipo, is night and day, it would be a wimpy setup to wheelie poppin tire shredding mayhem. It would flip the car on its back with little effort. 70 mph might be harder than you think to achieve, but I think you can do it with right conditions and a 3s.

asimons07

after reading everyones posts, you all have me set on using lipo's... id be very happy with 55 mph and mid 60's would be great but id have to buy a 3s for that. is it possible to purchase a 3s lipo fairly cheap? i dont need anyhting to crazy, im just bashing in an open parking lot. no racing or anything like that. i found some 3s 11.1v 4000 lipos online for about 25 bucks... i doubt they would be any good though. has anyone had any experience with cheap lipo packs???

fusebmx13

Cheap lipos are the only way to go . No point in paying twice the amount for the same product right? I get them from hobbycity.com. I would give you a link to the packs that I get but they are currently out of stock. They are Zippy brand if you want to know.

I would like to see those ones for 25 though if you have a link?

asimons07

http://cgi.ebay.com/ws/eBayISAPI.dll...m=260330265059

2 for $37 shipped. these are only 15c though and a would be coming from hong kong. im not usually worried about shipping times from hong kong because its still snowing out here in ny so everything is generally sitting on my shelf until spring anyway. let me know what you think

one thing that makes me wanna try them is the amount of ppl who have bought them. click on purchases.

xxxnt236

My Feedback: (1)

ya but what will the 15 c do to you compared to a 25c?

asimons07

im not sure if 15c would work ok just for bashing around. the price is great if they will work. ill have to wait for some more responses before i purchase anything. hobbycity really does have some good batteries.

i think im gonna wait till hobbycity has their 4000 mah 3s 20-30c lipo back in stock. at 31 dollars and 5 shipping how can anyone pass that up. plus the hong kong specials are actually 10c with a 15c burst.

SidewaysLS4

Low 60's on 2S will need around the range of 80 running amps, and just any old lipo wont do. I had a Reedy 5000ma 20c that dropped voltage too much, a switch to NeuEnergy 5000 (probably Enerland cells) gave .4v more under load and close to 5 mph. I stopped using 2S (GTB/3.5r) after the esc would thermal in cool weather towards the end of the pack resulting in no brakes. Not good at 60mph as you can imagine.

I'm currently doing low 60's with 3S with a MM/Medusa combo. Running amps in the 60's. Waiting for more gears to come in to see how fast that will push my 1:10 buggy without motor saturation/other issues.

Make sure you are using high enough mah batteries with good enough C ratings to supply the needed amperage. Have fun!

1maxdude

Good info right there. If you want cheaper batteries, I'd go for some of those rhino 4900s on hobbycity. I havent tried them personally, but it seems the 8th scale guys like them. I have a true-rc pack that performs flawlessly, great packs for the money. And of course my enerland 3s. My 10c 8000mah true-rc performed just as well as my 6000 20c maxamps. I don't recommend maxamps because of their price. Mine works great, others have bad things to say about them, but mine is awesome, just way over priced compared to what else you can get out there. The higher C and the higher mah you can get, get it. I'd look for 85-100 amp constant battery rating at the minimum, anything over that is fine of course. Generally the higher C rating, the better the cell, and most likely less tendency to drop in voltage under load.

fusebmx13

I have a SPC 15c 5000mah 3s pack right now and it works fine for what I do. But I am going to get one of those zippy flightmax 5000 30c packs from hobbycity.com. Should be plenty for me .

Lilredmachine

Another vote for Zippy/Rhino packs here. I run them in my slash and they don't break a sweat. The 30c 3s 5000 Flightmaxes are a steal, huge performance from not much cash.

fusebmx13

Yea they are great, my brother has some of the 25c ones and they do great in his MMM e maxx. But the only problem is finding them when they are in stock .

ScottStaypuff

Thanks for the info on that battery, that is a steal.

asimons07

yes, hobbycity def has great deals on lipo batteries. thanks for pointing them out for all of us. they actually have a new option where we can have an email sent for when the batteries come back into stock. im in for at least one 4400 2s and one 5000 3s. im going to be trying the lipo in my slash in a few... ill let everone know if there is any difference between the lipo and the 7 cell nimh.

asimons07

well i just got back in from the test run with the lipo and all i can say is wow... what a difference. wheelies and top speed what more could i ask for. now i just have to wait for my mamba max/motor to come in and for the 3s lipo to be in stock... i cant wait. thanks for the help everyone.

Adam