B4 Lipo fitment

[sosidge]

I wonder what some of you are doing to get the slightly larger BRCA-legal LiPo packs into the B4 neatly?

I've finally switched to LiPo with an Intellect 5000mAh pack (same pack as many other brands).

Unfortunately this pack is just a tiny bit tall to fit under the rear shock tower - probably a mm or less in it, but just enough to stop the cells from going all the way back and to stop the carbon strap from fitting properly.

So what mods are you doing?

I've narrowed the options down to...

1) Grind the locating bumps down (which I don't want to do)
2) Trim the rear shock tower (wary of weakening it)
3) Change the strap to an extra thin one (needs to be 0.5mm by my reckoning which is too thin to be effective!); cut down the existing strap so it only braces the front of the cells; or lay the rear of the strap across the top of the tower
4) Something else?

Changing the LiPo is not an option.

I can see how the LRP-style packs work so well, if I flip the Intellect pack it fits perfectly under the strap, only problem is there is no easy way of unplugging it!

[Mike Hudson]

Shave a few mm off the rear tower, it's not really a weak spot on the tower tbh if it's going to break it's almost always near where the shocks mount on them

[bigred5765]

we shaved a few mm of the rear shock tower and the battery strap as well,,

[bodgit]

If your not too keen on grinding any material away why not just shim the shock tower. That way if you ever use a smaller battery you still have the origional gap as an option.

[Scouser]

I am running a brass weight under my Li-Po so my problems were even worse!! The way I got round it was to take a palstic battery strap, cut the very end off and bond on a kinked piece of plastic that drops down behind the cells and under the shock tower. This only works if you wish to run your cells in the forward position. Fortunately I always run them in this position so this solution works really well.

[Cooper]

Originally Posted by bodgit

If your not too keen on grinding any material away why not just shim the shock tower. That way if you ever use a smaller battery you still have the origional gap as an option.

and altering the shock position height.. not a very clever solution.

[bodgit]

Originally Posted by Cooper

and altering the shock position height.. not a very clever solution.

It does but when you have three optionional holes positions to choose from it wont matter that much

[bigred5765]

it will, your altering the amount of droop on the car and the up travel,bad idea

[bodgit]

I did it on my car I just wound out the ball cup a turn to compensate for the .5mm shim I used. I did not notice any real difference to the performance.

[Spencer Mulcahy]

I have looked at this before could raising the shock tower be a tuning aid for certain tracks? Sorry a bit off topic. I run my bar just resting on the shock tower not had a problem touch wood.

[tony6187]

i run the rredy 5000mah lipos in my b4 and all i did was fit longer screws for the bodyclips and just let the strap sit on top.its a stick pack and is held front by the strap and at the back the shock tower holds it(am also running with a lead plate under the lipo).dont know if this helps with your lipos though

[Welshy40]

I agree especially on carpet. Ive had to drill another hole on each wishbone to lower the rear using lipos with rude tony bits and trishbits rear block. Maybe getting a k factory rear shock tower mount with carbon fibre and design a new bit with another set of holes so i can lower or raise depending on the track.

[Zoea]

Hi - I hope no-one minds me bumping this old thread..

I love my b4s, I have 2 with electrics and one almost roller. They are all rc10b4.0 buggies

I am running a couple of 6000mah Intellect (ip) 2s lipos in one of them. The problem I see is the battery thickness means that when I use them with the factory team thumbscrews, I can't tighten the thumbscrews down. They are loose and so far I've lost 2 (of 4 I think). What would be the way to get them to tighten at a larger height, could I just undo the screw cups they tighten into a bit?

By the way, the factory team bar won't fit in it's proper place, I've just been running it above that on the shock tower (So it's only the bar's tension and the 2 blue FT thumb screws holding it in place - but then it's already in a cut out chassis hole)

I see quite a few posts about people even running 3s in theirs, if you managed to fix a tall battery in your B4 and are not loosing thumbscrews "bashing" as I am, I would love to know a fix. I have velcro and a dremel handy

Thanks Everyone

[ste_lazzaro]

Hi,
The trick I used to fit thicker packs was to replace the long setscrews with actual longer screws.
After tightening the screws all the way in you have to cut the heads, keeping attention hot to generate too much heat.
Having the strap fixed just by the nuts is not going to be an issue, if you can avoid big crashes.
For added security I think you can build something to fasten with the rear tower screws where the strap can lean against.
B4 was and still is a great car!

[bretts]

Agreed! the B4 is great.

The trick with tall lipos (25mm in height I mean) is to use a B4.1/B4.2 rear shock tower which was designed to allow Lipo fitment. My thumb screws seem ok with the carbon brace and this tower, so far???

there is a picture of mine with lipo fitted halfway down this thread. I now use the carbon battery brace instead of the brass one.

http://www.oople.com/forums/showthread.php?t=160834&

hope this helps.

[Wig]

I have no answer for the thumb screws as I use the body clip bolts.
I run lipos in mine, the B4.1 shock towers are slightly different allowing 25mm thick lipos to fit in with the battery bar.
You can also dremel 2mm off the underside of the shock tower where the bar fits.

Wig

[Zoea]

I popped into a hardware store (nice big old one) and got some brass 4/40 fixings, quite long will be long enough.

I also have some 4/40 lock nuts on the way thanks to the bay.

This should fix both models, and leave me with spares

I'll also dremel up the rear shock mount and any spares I need will now be 4.1 parts.

I think this is solved! Thanks all :P

edit: did not of course need the brass bits!