As alot of people are Im thinking of going to LIPOs. Im running 8.4 Volt 7 Cell NiHm packs right now. My question is, if I do switch to lipos will I need to get 11.1 Volt packs rather then 7.4 Volt to see a increase in performance? From the way I understand it the only pro to switching to a 7.4 volt lipo in my case would be weight? Am I out to lunch or is this right? Thanks alot guys.

Yes, More voltage = Faster

So the only advantage of 7.4v would be weight

Yes the weight is an advantage, and you will be a little bit faster over a regular six cell stick pack (with the 7.4, alot more with the 11.1). Another benefit is that with the LiPo you get a consistent voltage and power until the battery dies. Meaning the car will run as if the pack is fully charged for the duration of the battery life. Where as with the stick pack you will notice your car getting slower as the pack dies.

DisturbedJato

Go with the lipo, they're voltage hovers around 8.2v anyway and the same pack can be charged many times in the same day.

What're you going to run this in - brushed or brushless? If its brushless, you need to figure the impact based on motor's kv - if its something like a 5700, a 3S (11.1v) will make it a lot faster to the point it will be hard to control and possible exceed max motor rpm. You're prob going to need a separate low voltage cutoff to protect the lipo from being overdischarged. There are add on LVCs available.

You would see a performance gain with a 2S (7.4v) lipo thats more than just the weight. Lipo maintains voltage better under load and your car will have that "fresh off the charger" NiMH performance through most of the charge. A 2S fully charged is 8.4v, a 3S fully charged is 12.6v.

Thanks for the info. I'm running a velinion vxl esc and brushless motor set up in a slash