4.5 vs 5.5 mah usage

[DaveG28]

Ok clever ooplers, I am using SP v3 motors, and currently use a 5.5 in my 4wd. It's taking @2100mah out of my LiFe cells, with gearing to recover top speed then my esc set to a lot of punch to recover that side. However, I still need a bit more speed to get back into Lipo territory, my options are:

1. Go up one more pinion and then set mega everything esc punch. My temps are not as bad as I expected using higher gearing, will the lower LiFe voltage save temps or am I being lucky so far?

2. Put a 4.5 in to recover the speed. If I do this and run equivalent gearing to currently (probably take 2 teeth off the 5.5 gearing) can anyone roughly estimate (just rough is fine) what mah I am likely to take out of my cells given currently I am taking @2100??

Thanks all,

Amish!

[MattW]

I'd be surprised if you got up to 3000 - you'll be fine on LiFe.

When I tested a 3400 Life in touring car with a 3.5 I got 4.30 before it went flat.

[GRIFF55]

4.5 Amish, YOU PUSSY!!!! MAN UP!!!! (thats revenge for the jesus comment somewhere mate!) lol

[colmo]

Does anyone know what the kv ratings of the 5.5 and 4.5 are?

For roughly equivalent performance, you'd be looking for:

7.4 x (5.5T kv) = 6.6 x (4.5T kv)

Higher voltage is more efficient and generates less heat, but its not a huge difference here.

[DaveG28]

Originally Posted by MattW

I'd be surprised if you got up to 3000 - you'll be fine on LiFe.

When I tested a 3400 Life in touring car with a 3.5 I got 4.30 before it went flat.

Do tourers use more or less power?

My LiFe is only 3500, so may be a bit on edge!!

[MattW]

I'm sure you'd be fine with a 3500.

[suthers]

i know 4.5t is roughly 5000kv

[colmo]

Originally Posted by suthers

i know 4.5t is roughly 5000kv

Not too sure about that - that's more 7.5T territory, I think.

I checked the Novak chart; the 5.5 Ballistic is 7400kv, the 4.5 is 9000kv, a 21.6% increase.

Presuming the SP v3 winds increase in similar increments, going down a wind should more than make up for the 12% drop in nominal voltage from lipo to li-fe

[RogerM]

Dave, TCs use loads more power as they have the grip to use it ... I can punch the throttle on the touring car the way I could only dream of doing with even the 4wd buggy!!

Does this mean you have found LiFe cells that are likely to be legal for 2011 or are you just playing?

[DaveG28]

Originally Posted by RogerM

Dave, TCs use loads more power as they have the grip to use it ... I can punch the throttle on the touring car the way I could only dream of doing with even the 4wd buggy!!

Does this mean you have found LiFe cells that are likely to be legal for 2011 or are you just playing?

Just playing, I'm pretty sure no LiFe saddles will be legal in 2011 sadly

They seem ok so far, the key is whether I can get the right power/speed balance out of them without dumping!

[RogerM]

FAiry snuff mate. I'm sure there were higher capacity packs available though. Back to the good old days of worrying if the extra lap was quick or a crawl hey ... how I miss those days (seriously ... I'd have that back to get rid of LiPo!!!)