Lipo is fine. In both the manual and Tower's product page, 7.4v/8.4v is listed as acceptable. I've been running an old rx Lipo in my 4PX for a couple months, been great. The 1850mah LiFe I was running didn't have the capacity I needed.

The 4pk had issues running lipo, and I've seen several fail when a fully charged lipo was used.

I know several people who have used lipo in their 4px without the same failures that the 4pk had, but neither Tower nor the manual recommend using lipo. Page 19 and 20 in the 4px manual recommend life or NiMH. Tower also has the same recommendation. I get plenty of runtime on my 2200 life, and just never wanted to risk running lipo. It would be interesting to hear straight from futaba if running lipo voids warranty.

Sure enough was the receiver specs I saw... It is interesting though there's no mention not to use a lipo either. They're very clear with the non-HV receivers. Then there's this, the first video around 0:28, they state 2s [comma] Life [comma] Nimh.
http://www.futaba-rc.com/systems/fut...4px/index.html

Taking that to mean 2s lipo, life. nimh. Saw that several months ago and is why I tried lipo in mine. There are some other things, like the low voltage alarm on the tx is adjustable up to 8.0v. If not compatible with batteries that high, why have that adjustment?



Unrelated, the second video about the "condition" feature is very cool. I know there was talk before about setting up a second model for the same receiver. This looks like the very easy way to accomplish that.

:(

http://i57.tinypic.com/10xv6vo.jpg

The extra voltage of the LiPo would get dissipated as heat from the internal voltage regulation circuitry of the 4PX. This will either damage the circuit or shorten its life span and is something you will not see.

Is there an advantage to using the wired version versus the wireless? Who wouldn't want 1 less wire in their car? Is the range an issue with the wireless? Thanks!

As far as I can tell the one with an external antenna wire actually has dual antennas. An internal and an external. I haven't had any range problems and I use some of both kind of recievers. But I really only drive on a track so range requirements are limited. If I was planning on using this for speed runs or something where range really would be tested, I would pick the dual antenna version for sure. Other than that I don't see any difference in performance personally.

The R304SB does not have an internal antenna unlike the FASST Diversity receivers. I have tried removing the antenna and running the car without it, and the range was terrible (less than the length of a basketball court). That said, I am running my R604FS FASST receivers with the antenna removed, no range issues at all.

I ran the e version of the 614 receiver for a long time with no issues. I took it apart and its the same receiver as the non e version but it has a antenna glued to the inside of the case. As far as any differences in range, if your racing you won't see any. Bashers may see it if they are going long distances away. I've raced on very large tracks with out issue. I would imagine the 304's would be the same.

I stand corrected. Thanks for pointing it out! :nod:

Stuttering and jittery servo
 

I sent this to Futaba support tonight but if anyone on here has the same issue please help:

Futaba Support,

Hello, I have a 4PX that I use in offroad and onroad racing. Since new a few months back I have a stuttering servo problem. If I crank the wheel back and forth quickly it seems smooth. If I move the wheel back and forth normally and even stop and hold, the servo seems to want to jump around and is real jittery. I have tried both the stock receiver and the 204GF-E. I have tried multiple servos: Xpert 3431, Futaba S9351, Orion 1409. I have set them all to analog as well as digital with the same results. Tonight I upgraded to 1.1 and still the same. I even tried putting the ESC in the #1 slot and the servo in #2 slot and used the my throttle finger to steer with the same results. This gave me the conclusion that it is not the wheel. The throttle and braking on the other hand is really smooth.

I am at a loss. I have raced for over 20 years and have used multiple transmitters. I recently had the KO EX-1 for a year and the Spektrum DX3R Pro for the 4 previous years. I don't think I am doing anything wrong.

Is there a setting I should check or something I can try? Is the response just so quick the it makes the servos jittery or stutter?

Thanks for the help,

Troy

My output for steering was choppy. The car didn't even have to be on, I could see it on the display as I would turn the wheel. I started trouble shooting by pulling the steering wheel off and checking the connections. The main steering connection was not pushed all the way in. When I got the radio new, I switched to the drop down for steering and when I plugged everything back together I guess I didn't get it seated correctly. Anyway, check your connections for the wheel.

Is there not a setting to reduce sensitivity around the zero/resting place of the wheel and throttle? It might be worth trying to open that free zone "window" up a few ticks in setup to ensure its not just jitter of where the wheel or throttle are reboundibg to.

Maybe the servo is worn or going bad?

I too added the drop down. I will give that a try and make sure all cables are connected properly.

has anyone used the 4px with frsky receivers? i have a bunch of tfr4's that have been great with my 3pmx and let me run lipos direct for my nitros, ive been wanting a new radio but to replace all my existing receivers is a big expense to add