# Gtb 4.5r



## Rocksalt (Mar 15, 2006)

Hello all. I recently had my MP5 and 4WD HPI stolen from my garage. Interestingly enough... they stole those 2 cars and left my serpent impact, fully loaded, on the shelf with the radio as well as 2 other cars. I guess that's the good news.

Anyway... I used to be a road racer here in Houston. 1/10 scale 2wd and 4wd serpent gas powered. Won lots of races and enjoyed the sport. I am now replacing my stolen cars. I bought an xxx-4 G+, a GTB ESC and 4.5R. I am planning on using an 8000 lipo pack with this new car. I may have jumped the gun on the motor here... Might be to much power, but who has to much? I can always de-tune it? Do you think I made a mistake with this combination? I will not be racing in ROAR or any other sanctioned events. I am just playing around with this to reduce some stress 

Things have changed over the years with batteries and brushless motors. I am in need of a charger for the lipo as well as my old nimh batteries. I don't want to spend a fortune on a charger, but want something good(don't we all). I notice that the hyperion charger(80+ dollars) has an input voltage of 12V. Are most chargers 12V only and no 120AC? If there are some that are 120/12V are they more expensive by alot?

What I am also concerned about is the torque curve of this 4.5R motor. The Novak website says the motor is for sedan cars with HIGH traction(LMAO). This motor must be a beast. If I detune the max voltage to keep the runtime up, will I suffer in torque with this motor? I would like high speed, but I would also like to be able to launch the buggy at short notice to clear triples.

One more thing.. will a 8000 lipo pack fit in this car? The dimensions are something like 50x125x29. I think that's a 2S2P lipo pack. Will I have to add weight to balance the car since the car's made for the c-cell NIMH?

Any help would be appreciated.


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## xxx-s_t-maxx (Jul 21, 2005)

*I have a XXX-4G+ and GTB 5.5*

Hey I bought a 5.5 a while ago, i had to tune the dead band, becuase my radio's settings wouldnt go any lower, hah.

Just gearing it a tad lower i think would be the best solution, and wow ur useing lipo.
-I use 3300-3800 NMIH.
-Batterys last a very long time with this motor and esc.

And for your battery weights and fit, im not sure about the fit nor the wieght becuase isnt the lipo batterys less wieght than a NMIH.
I dont think you have to worry too much, i jump mine of small to very large jumps and im able to whip the car around, i can get it side ways and land striaght.

Oyah, id make sure ur GTB esc is double sided in your buggy *real* good.
-Mine didnt like to stay taped down.

I hope I could have been some help to you. :wave:


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## NitroStar (Dec 30, 2004)

Hey there, I want to get a Losi 4WD also, but am concerned that Stormaer hobbies still sells the DOUBLE X 4wd for more than the TRIPLE X 4wd. I think I have heard something about the XX 4 being faster than the newer one. Is there any truth to this. Any input would be appreciated. I know they probably will stop making parts for the older one before they quit making them for the newer one. Thanks


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## hankster (Jan 1, 1998)

The Double X was just recently reintroduced by Losi after it was discontinued when the Triple X came out. It was found the Double X is better on rough tracks (Team Losi drivers still run run it). Yes, it is more expensive because it is a more expensive design.


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## Rocksalt (Mar 15, 2006)

Does anyone have experience with the 4.5R velocity motor? I don't see any specs on max current and rev/volt. Trying to determine if the 8000mah LiPo can handle the current. Looking for comparison between the 5800 or 4300 and the R series motors.

xxx-s_t-maxx, thanks for the input. Looks like I am just going to have to try it and see what happens. Monitor closely and RUN IT, hehe.


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## hankster (Jan 1, 1998)

The 8000 LiPo are 20C cells meaning they can handle 160 amps.... I doubt you'll have any problems running any current brushed or brushless motor that is now available.


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## NitroStar (Dec 30, 2004)

Hankster, you are talking about the "Max Amps" 8000 lipo right? Do you use these? Are they a great choice to make if I want to start using lipos? Thanks very much.


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## hankster (Jan 1, 1998)

Sorry, I have personally used them so it would be hard for me to make recommendation.


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## Rocksalt (Mar 15, 2006)

I finally got my 8000lipo and my car put together. The XXX-4 is really not that good of a car IMO. It lacks steering tightness, droop settings, poor-one way design. How this car made it to nationals is beyond me. It's still DAMN fun. Tried 2 hitec servos in it ,5925 I believe, and the steering will just quit after a long decel. Not like a glitch, but more like the voltage drops enough for the servo to power down and re-power back up. OK, let me get back to the lipo.... wow... I was running a 15T pinion with a 92 spur and 3300mah batteries. It WAS very controllable. I stuck the 8000mah lipo in and holy cow.. I added 2 teeth to the pinion and I can throttle this thing and flip it on pavement. It's accelerating so hard it wants to break loose on pavement. I can't believe these batteries make this much of a difference. The voltage drop must be less under load than with the nimh. I think the batteries are heavier than the 3300 pack(surely they are bigger). I am getting some pulling to the right when accelerating, so something is off kilter. Might be the weight.

For anyone thinking about lipo, hold on to your socks.


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## NitroStar (Dec 30, 2004)

Did you buy it from Max Amps? This is the one I'm looking at. Gonna have to put velcro staps in because it is about 3 mm to high for the strap.


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## Rocksalt (Mar 15, 2006)

I got it off fleebay. I am still concerned about bumping and jarring though.. one end has some sort of foil louvers in it. Looks like it's to dissapate heat. With all the talk about them blowing up I am a little concerned. I wrapped each end in electrical tape to cushion the pack from bouncing on the chassis. The strap definatly does not hold. I tie wrapped it for the moment and will end up making a new strap, might even make one from velcro. It would be nice to make a taller mounting point so as to use the stock strap.

I would have never thought you could wheelie a 4wd, this thing just flat out hauls ass!


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