7XL 0r 9L with BK 9920 on LIPO?
 

Would a 4s lipo pack be ok to use in my EVO or RACEBOMB with the stuff mentioned titled ?. Also i would use a trition charger because thats what i have.

No problem at all, rcheppie.

Make sure you get a low voltage cut off or detector.

Would the trition charger be okay also ?. Maxxamps has a 4000 4s pack that i was looking at. Are there any other 4s packs in that price range ?.

That is fine for the triton. It can do 4s but only at 2.5 amp.

Hippie, are you gonna get 2 2S packs or one 4S?

If i do it i will get one 4s pack. Maxxamps said they can make me a 6000mah 4s pack.

Wouldn't you be throwing off your weight distribution?

Yes it would i just dont know which is the better way to go for me. Two packs costs more than one.

Could i use two 2s2p 8000mah packs in my EVO or RACEBOMB, or is a single 4s pack better ?.

There actually gonna be the same thing, just in different configurations. I would go with the 2S2P packs. It shouldn't cost any more. Maybe, 5 or 10 dollars for the wire, connectors, heatshrink, ect.

You could go smaller 2s packs like the 6000 for weight. They 80 a pop verse 110 to. Get two packs for 4s 2p 6000 mah. for under 600 grams of weight.

If i go with either two packs of (6000 2s2p) or two packs of (8000 2s2p) can i charge both of them at the same time on my triton charger ?.

Well that is up to you. Some say yes some say no. It would be faster to charge them in series. I would stop them before full and charge seperate to the full charge.

Leroy if i chrage them both at the same time by a jumper from the charger they would be in series.

Yes, that would be in series. But with the Lipo packs, i would charge individually with triton charger. IMHO

Agreed, definately charge by themselves with the triton charger

the 7XL gets my vote, the 9L is quite a hot motor. the 7XL is less hard on your cells, and it also has more torque

8xl may be better for Lipo though IMO.

we are talking 4S here..

I guess, but me, i would run the 8xl, gives more leway if you want to bump up a little in batts, and still would run cooler

and what if you have got the 9L and the 7XL?

LOL, sell the two and get the one! if that's all he has, then the 7xl, definately dump the 9l though. Agreed? :P

that's what i said 7 posts back... LOL

Yeppers, just read that too!!! :)

CHILDREN please stop argueing :005: .

All i have is a 7XL or a 9L to choose from. I talked to leroy on the phone today & i'm really looking at the 2s2p 6000mah packs from maxx amps that mike has listed.

I have this same setup -- 9920, 7XL, 4s lipo. It runs great for about 6 minutes and shuts down. Sometimes runs again for 6 more minutes, sometimes only 30 seconds or so. I ordered a 125b controller which will hopefully work with the 7XL cuz it's so darn fast! And pulls wheelies at 30mph! If the 125b doesn't help with overheating, I'm going 8XL. (or, more likely 1950/8 or Neu 1515/1y)

are you running a seperate reciver pack or are you using a UBEC ?. I use a seperate reciver pack with 14 cells & have no problems so far. Does anybody else that runs this setup have any problems 7XL with 9920 ?.

If the esc is getting to hot. Try to drop down a few teeth. If the motor is running hot. Try a few teeth down or up.
What gearing are you running?

The lipos leroy suggested will be fine, but i would still dump the two motors and go 8xl. And the Qaurk, gets hot as well, need to have heatsinks to keep it cool.....or, gear up and that'll help as well like chc said to do.

Guys thank's for all the advice & opinion's they are appreciated. But if i have to change my motor & possibly my charger in order to run lipo's, i dont think it's worth it in my opinion.

I don't think you will need to change your motor at all.

If you change motors as well as the batts. How do you know what makes more power? If the 9L don't work out put the 7xl on. I think it do better on heat issues.

If you're not going to use lipos, 14 cells, 9920, 7XL will be perfect. I do use a UBEC, and geared so the motor only hits 155f I can run for about 6-7 minutes before I thermal. Given the abuse my ESC has seen I do not think this is bad. The problem seems to be the constant high current and long runtimes make things heat up too much...

the 7XL on my 9920 doesn't thermal at all with 14 cells.

I had a 7xl on a 18.97 with 18 cells on it. I could run a whole pack with no thermal. The motor would be hot.

I know, I think 14 cells is a good match for 9920 and 7XL. I think though that 4s lipo is more like 16 cells. I know they are 14.8v, but that is almost at no charge. Fully charged pack seems to be more like 16.8v? And it puts out higher constant voltage than nimh cells, nimhs start to drop off very quickly and loose a lot of punch into a run, where lipos run strong till they dump.
More avaliable current over longer duration equals more heat for longer time.

I think I've weakend my 9920 anyway by thermalling it really hard when I first got it trying to run a 6XL, I shorted it once too and metled the shrink off it! I didn't even think it would work anymore, so much smoke came out. Maybe that's why I have thermalling problems?

Yes. It sounds like you fried a few fets and thats why it thermals. 4S LiPo is more like 14 cells actually. Hippie, don't worry, you shouldn't have ANY problems with 4S LiPo and a 7XL if geared correctly.

Squee right now im geared with a 12-51 mod 1 setup with a 9L on my EVO. My racebomb has a 16-51 mod 1 setup with UE diffs. On my EVO i have got 12 minutes of runtime in a race on 14 3300's, before i broke & still had 5 minutes of battery left when i dumped them on my integy 30 amp dumper. I have'nt raced my RACEBOMB yet. I just got offered a deal on some NIMH cells. My buddy jeremy (BOMB PROOF PRODUCTS partner) offerd me 40 IB 3600 cells for $100.00. They are brand new the only time they were used was at monster maddness this year. They have maybe 2 or 3 runs per pack.

That is a good deal. Hard to pass it up. Deals like that it is hard to go lipo.

Leroy i think thats agood deal also. I know they were built right because i built 2 of the packs for him . 20 of the cells are promatch & 20 of the cells are smc.