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Old 01-08-2009, 09:23 AM   #526
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Which servo are you using? Spektrum has stated that their receiver doesn't care about the voltage on there site. So i'm not worried about that one.

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I'm using a Hitec HS-5245MG and it seems to be fine.
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Old 01-08-2009, 11:38 AM   #527
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First race night with the new lipo in my 12R5 with a 13.5 Novak motor. I ran at 740g. Balanced side to side, but otherwise no weight added. Double pinks F/R, Jack the Gripper, Speed 12 body mounted wheel well center. I originally had it up to 800g +/- but decided to try it out light and see how it worked.

The overwhelming factor was the lower weight (obviously), and its affect on the car's stability and steering. As our track is not billiard table smooth, I had a hard time keeping the front end down. One sweeper, in particular, has a roller that unweights the car and my steering just disappears. With NiMH I have been able to pin that corner without issues, but not with the lipo. So I started softening up: blue center spring, kit side springs, 0.18 front springs, and I took out some front droop, which all helped. But it still wanders unexpectedly. My best laps were very throttle-y, for lack of a better term. Like I imagine mod, but with a 13.5.

I can continue to work the mechanical aspect and rearrange the electronics. But I am intrigued by the challenge, overall. I suspect the aero elements will be significant. Before, I have simply tried to square up the body and establish a rear height of 70-72 mm or so. And to get the wheels centered in the wells. I have known that the good racers finesse body position very carefully. I am going to try mounting a new Speed 12 5mm forward (more projection over the nose of the chassis) than previous. I may also try 0.5 mm of raised rear rake. I don't want to simply add lead. That would stray from the essential opportunity of the new technology.

As a side note, I appreciate even more the engineering and optimization of these cars around the existing battery standard. Those on the nickel side have a point that the cars are really great as-is. Lipo is not simply a drop in and go-enjoy the lower tire wear-leave the soldering iron home-proposition. This is going to take some doing.
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Old 01-08-2009, 11:51 AM   #528
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Had my first run with the 1s SMC battery last night in my DB12r. Ran the same set-up as I did with 4cell previously. Really the only change that I noticed was that the lateral movements were faster. Car had good speed but lacked a little punch. I am not using a booster yet, just powered everything from the lipo. Was not using a transponder. I am using a T-Bang 13.5, KO BMC speedo, KO rec, and KO servo. All in all...I am very happy with the results.

After each run the battery was taking about 2200 mah to charge to 100%.

Last edited by phattyphatty4x2; 01-08-2009 at 11:53 AM. Reason: added text
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Old 01-08-2009, 12:04 PM   #529
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I've had a couple of guys ask about how I mounted the booster in my car so here's a pic. On the input side I wired from the speedo (battery) to the booster input with a switch on the positive lead (either would work). Then I soldered in a new lead to go to the receiver. Reshrunk it and threw it in the car. Not exactly a clean install but it works.

I don't take the booster out of the car when I run 4 cell. I just power it up with the speedo switch only and run.
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SMC 4000/25C/3.7V single cell Hardcase pack.-r5booster.jpg  
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Old 01-08-2009, 12:10 PM   #530
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I've had a couple of guys ask about how I mounted the booster in my car so here's a pic. On the input side I wired from the speedo (battery) to the booster input with a switch on the positive lead (either would work). Then I soldered in a new lead to go to the receiver. Reshrunk it and threw it in the car. Not exactly a clean install but it works.

I don't take the booster out of the car when I run 4 cell. I just power it up with the speedo switch only and run.
That looks very similar to what I was thinking for mounting and mods to the booster. I dont have my transponder in the front of the car so I was actually planning to locate it where your AMB is on my car. Sounds like front end weight is needed in some of these LiPo setups so a few grams up there shouldnt hurt nice and clean install.
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Old 01-08-2009, 12:45 PM   #531
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If you look closely, you'll see that everything's pushed back in my car. For the R5 you want to keep some of the rear weight in the car.
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Old 01-09-2009, 02:56 PM   #532
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So I got 4 of those boosters from HobbyKing in hand. They ring in at 4 grams without the shrink wrap 5 grams with. With wire and a switch they will still be WAY lighter than any rx pack especially if you have a VR with it.

Here is some pics of the booster naked. I do agree that a shrink should be used on it, I am going to try and use some very thin stuff after I re-solid leads on to it.
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SMC 4000/25C/3.7V single cell Hardcase pack.-img_3659.jpg   SMC 4000/25C/3.7V single cell Hardcase pack.-img_3660.jpg  
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Old 01-09-2009, 03:24 PM   #533
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So I already have a question. with this booster, is there any reason to need to wire in a seperate switch, etc..? Cant you just run the connection coming from the ESC to the booster and then the booster to the Rx? to me that seems like how it should be used. Then you use your standard ESC switch to turn on and off. When you want to use 4 cell, you just remove the booster form the loop.

just a thought.
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Old 01-09-2009, 07:12 PM   #534
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So I already have a question. with this booster, is there any reason to need to wire in a seperate switch, etc..? Cant you just run the connection coming from the ESC to the booster and then the booster to the Rx? to me that seems like how it should be used. Then you use your standard ESC switch to turn on and off. When you want to use 4 cell, you just remove the booster form the loop.

just a thought.
If you power it like that the speedo will run on the lower LiPo voltage. Most of the speedo's out there are rather unhappy running on the lower voltage. By running the booster voltage from the battery to the receiver it runs the speedo at 5 volts.

This thing is so light I just leave it in the car when I run 4 cell. Just use the speedo switch for 4 cell and the booster switch for LiPo.
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Old 01-09-2009, 09:00 PM   #535
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Yeh I could easily do that too... I do want to avoid having a marshal make the mistake of turning on or off the wrong switch if the car breaks or needs a reset as my rx seems to need some times after a hard hit.
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Old 01-10-2009, 09:37 AM   #536
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Just tape over the switch so they can't get to it. That's what we used to do with receiver packs in mod.
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Old 01-10-2009, 01:45 PM   #537
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I ran this battery last night with a 17.5 with some great results. The car weighed 695g, Sphere Comp 07, JR3550, Spektrum micro RX,and a 120 mah receiver pack from Rc4less. I rolled out at 3.75 and it was great.

I'm far from and excellent 1/12 racer, but not exactly a chump either. I actually ran the same number of laps then what I did with a 13.5. However, my times were FAR more consistent and mistakes were less then half. My fast times were .4 off of TQ fast lap times, but over the 8 minutes I ran the same or better then I ever did with 1c 13.5 or 17.5 nimh.

I think I'll stick with this combo a while. My runs are far better and much more consistent. The 17.5 doesn't exaggerate handling problems as much as the 13.5.

I'm not exactly trying to promote a new class, but this combination is just what I need to polish some skills I've been working on. This speed makes better sense to me as a "stock" class, and I'm sure 75% of the guys running stock right now could benefit from a little less speed. The problem is that only 5% of those guys acknowledge it or would even admit it.
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Old 01-10-2009, 07:44 PM   #538
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I have just ordered the boosters for my car - where is everyone getting input voltage from?

I gather you want to feed the booster in to the batt slot on the rx and then have the esc, servo and transponder fed from the rx voltage.

What has been the set you guys have wired in with success?
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Old 01-11-2009, 08:58 AM   #539
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Just tape over the switch so they can't get to it. That's what we used to do with receiver packs in mod.
Can't you just remove the red wire from the speedo to the reciever . I just heat shrinked it over and use both switches. That way no one can jack my junk up no matter what !
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Old 01-11-2009, 05:44 PM   #540
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Can't you just remove the red wire from the speedo to the reciever . I just heat shrinked it over and use both switches. That way no one can jack my junk up no matter what !
Doesn't work well with my Tekin because it enables the radio priority circuit. Some speedo's might be fine with the red wier removed though.
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