b4 and lipo , weight ?

[charles08]

Hi.
I am racing lipos next week end for the first time and won't have much time to practice since then .
So i am wondering if you guys can help me on where i should put the weights in the car knowing that the lipos i 'll run are 260 gr ( Corally 4200 30c).
I don't have the heavier front bulkhead and i'll race it on carpet .

Thanks to all !

[Mike Hudson]

standard nimh cells weigh around 450-470g so when you use lipo you need to add a fair bit seen as your losing around 200g! Get some thin roofing lead if you can (quite a few people on this forum have plenty to sell at low prices if you don't know where to get any and cut out a rectangle the same length and width as your lipo (you can cut it with scissors easily!) and put it underneath the lipo and all should be ok, maybe drop a spring rate front and rear on the car aswell

[charles08]

Thanks mike !

I thought it was going to be something like adding 30 gr on top of the servo, 50 on the battery tray etc ...

Your solution looks very simple, i'll find some lead and cut it to get the 200gr back and put it underneath the lipo then.

Thanks again , cheers .

[Mike Hudson]

you won't get the full 200g back you'll only gain about 100g max but it's ok just drop down to a softer spring on the rear and maybe drop down to a softer spring on the front too or lighter oil and it should be ok,

[V-Rossi]

I fitted a lead plate under the battery of around 110gr and the car was planted with the standard Associated astroturf and carpet set-up.

[Zipper]

This is the latest set-up from the Associated website for a B4 running LiPo. I know they are trying to prefect a LiPo set-up without the need for adding lead. Maybe an ok starting point?

http://67.199.85.166/racing/setups/b4_team_crcrc_2009.pdf

[Mike Hudson]

without adding weight the car is under the legal brca weight though :yawn: and that setup is for american dirt tracks so may not work so well here

[Zipper]

I ran almost the same set-up at the Petit RC (carpet), just with lead running down each side of the battery tray to get to the legal weight and blue front springs and was very happy with how the car performed.

[charles08]

Thanks guys for all the infos,

I'll try that setup on a training day, but black springs/rear on a carpet track that must feel kinda weird ?...

[Zipper]

oh yeah... I also ran silver springs on the rear!

[zaquiz]

I fitted a lead plate under the battery of around 110gr and the car was planted with the standard Associated astroturf and carpet set-up.

Where can I find lead plates that fit the B4 & B44?

[RudeTony]

Have a look at this!! - Made from Brass and has exact 60g weight. Perfect and no nasty weights showing everywhere - Also your name can be put on it. Cheap enough as well. David Burton former National winner and an engineer by trade makes them to order - 5 days and they can be with you. Anyone wanting one, let me know and I can arrange for you.....

[Lee Martin]

nice work DB, could your name not be cut out though? rather than stamped?

[russmini]

But then you'd Lose Weight....

[Lee Martin]

not a great deal though! and would look wayyyy cooler....or groove the name using a lathe etc?

[RudeTony]

Hi all - the name is engraved on the brass - it can also be cut out if you wish - in fact anything is possible. Some people even like logos etc etc....Brass is expensive as some of you may know and this unfortunately reflects in the price a little - the brace is £12 (plain) and £2 for your name - obviously plus a little for shipping - if you think about it, the weights are some £4-£5 alone! - Good luck with everyones racing by the way - Tony

[RudeTony]

Added another few pics to show the engraving and the thickness - hope this helps you.....

[RudeTony]

PM send to those relevant

[Chris Green]

I've put a sheet of stainless steel underneath my Lipo. My Complete B4 now weighs in at 1581g?

Is that too heavy?

without the stainless steel sheet, it is 1430g ish? what is the ideal weight?

[Mike Hudson]

for brca events legal minimum weight is 1474g (mine is around 1530g with minipins, minispikes are a little lighter) with 50g added around the front and rear of the car, run what weight you like, it's more down to how you like the car the to feel, less weight it's more agile and on the edge but with more weight it calms it down abit and keeps the car planted and abit easier to drive/more predictable

[RudeTony]

Totally agree Mike - with more weight it's also better over bumps etc etc .
The design of the brass brace is there for people that know their set up with heavy cells and now with Lipo they want their car similar. I think it looks good as well.....

[Chris Green]

Ahh, ok. I guess my current sheet of steel is too thick then. if I use 1.5mm, the weight would be 75g ish, which would bring the car up to minimum weight. I could then tune in the final weight using sticky weights.

Do people still run the weight in the rear of the chassis with Lipo's, as previously with nimh's?

Thanks.

[RudeTony]

The new Lipos, example the great LRP stick ones, they are the right size so you can't run anything under the battery = no brace will fit if you do that. Like I said our brace not only looks good and is solid but adds 60g of weight exackly in the right place. There are though some Lipos that are thinner and you could do what your doing now.....hope this helps....60g by the way should make a car with Lipos spot on the legal weight limit....mine is 20g under so I add weight either side of 10g and decide whether I want it froward or back depending on the track....this is all choice of course....

[markwilliamson2001]

What people are also doing is running the GHEA Racing Brass Bulkhead, and rear pivot mounts in brass. This adds substantial weight down low, which is a nice place to have it!

HTH
Mark

[charles08]

Hi there,
I ended up adding 49 grammes on top of the battery tray and softened the rear as Mike advised, the car is around 1500 gr and it was flying.
The race was carpet indoor.
I guess that would probably be better to ad more for a bumpy track .
Would have a try to those heavier front bulkheads !

[flipside]

I would also try to fit the weight as low as possible. Brass bulkhead and anti squat blocks are great, together with a lead plate under your lipo. I tested with adding weight on top of the lipo too, since I have orion 3400's which have a hole on top you can fill up with lead. But I really didn't like the car with that weight this high up! Getting your weight +- the same as with nimhs is a good idea, but mounting it even lower as with nimhs is a big advantage, car is super easy that way. Tried it on high grip carpet only.

[RudeTony]

PM - sent

[RudeTony]

Agree that weight as low as possible is correct but to be honest there are so many drivers that can actually tell the difference - I bet that if 2 cars the same were given to a driver - one with weight high and the other with weight low - I bet he could not tell the difference - this actually was tested with a National champion and he couldn't tell - but like stated - the lower, yes the better although very very little difference

[flipside]

True, but that's the case with so many subtle adjustments on these cars. I tested it on an indoor carpet track one heat after the other, and the difference was not that huge, but with the lower weight the car was easier, without being slower. With the high weight the car reacted a lot more to slightly touching the curbs, resulting in many many mistakes. So that's when I decided to put it low and never look back :-)

[RudeTony]

Just as a matter of interest - some top drivers are now running the brace and feedback is all positive - see you all soon - Tony

[zaquiz]

Has anybody tried running a low weight lipo setup (1515-1530g), such as the Cactus Classic setup, on low-grip (clay, dirt) conditions? Does these setups work, or will additional weight be needed, in order gain traction?

[mccrash59]

Zaca, I´m about to try it. As you know I´ve just moved to Asso again (sponsor needs) and copied the cactus set up with minimal changes. Tomorrow I´m gonna practice in CAPA and we´ll see.

[zaquiz]

Cábrón, tu por aqui!

OK, so tell me how it goes! I think some extra lead will be needed in order to get the back down, nice and low... I will also try some low-weight-low-grip-setups this weekend, hopefully.

[mccrash59]

While waiting for number 2 shock pistons and 30ºcarriers, I noticed the back a lil bit bouncy and a bit of off power understeering. This weekend I´ll try 30w oil at the back (now 25).
Anyway I´ve been as fast as with my Losi, just less confident overall.

[zambo]

HI, i'm also new to Lipo in my B4... i always run in tracks with low grip (like Collegno just for example), and i always used to weight my "Nimh B4", Weight in front of rear transmission and in the rear quarters of the chassis. The car is good, overall good traction, steering and good driveablity!
I don't want to try a "light" setup, so my idea is to weight the car as it weights with nimh....

Now with Lipo i have to add 160gr. (5.6oz.) to have the same weight as Nimh, my question is:

- is better to place all the 160gr. very low, under the lipo pack (weight in this place tend to lower at maxium the center or gravity)

or

- is better to place some weight in the sides of the battery case and the rest of the weight placed over the battery strap? Weights in this places tend to raise the CG, but this can also increase the roll of the car and maybe more roll give more side bite and pressure on tires on low grip surface...


What's your opinion? It's just an idea, maybe i'm wrong.... let me know if raising the weights can improve roll or lower the weights is always better, thanks! :thumbsup:

[RudeTony]

It is known and agreed that weight as low as possible is correct but to be honest there are so many drivers that cannot actually tell the difference - I bet that if 2 cars the same were given to a driver - one with weight high (above the Lipo) and the other with weight low (under the Lipo) - I bet he could not tell the difference - this actually was tested with a National champion and he couldn't tell - but like stated - the lower, yes the better although very very little difference - also bare in mind that some Lipos won't allow you to add weight under them as they are simply too high and the brace won't fit - Hope this helps

[Jonesy]

Hi guys, to add my 2p worth to the conversation.

I ran the B4 all Winter with around 70g added to the Battery Strap (above). This was all well and good indoors until I got the car outdoors at Kidderminster on Sunday. Really struggled for the first 2 rounds until we added another 70g under the LiPo.

We're not running and other weight to normal and the car felt really good to drive, something which I'm hoping will help at Tally this weekend.

[lynx75]

Start from scratch, you suggested us to add all weight approx. 160g under the lipo battery in order to keep low CG, keep in mind only for certain lipos battery due the width

Do I need to add extra weight in front of the B4? :thumbsup: It should good enough

Thank you in advance.

[thom.p]

Does anybody know what the ideal weight front/rear % is?

[RudeTony]

The brass 70g straps for the Lipos should be in again this week after waiting for the high quality brass to arrive back in stock.......if anyone wants one then let me know ASAP so it can be reserved for you - see you all soon, Tony E

[RudeTony]

Hi all and thanks for all the comments and PMs sent.
Extremely happy that all are satisfied.....

Due to the poplularity a new web page is now up and running and purchases can now be made direct through there or here as usual.

Check out www.rudebits.co.uk (http://www.rudebits.co.uk/) for all the info and new products that may be produced

Thanks again Tony Evdoka

[stical]

Just a stupid remark but might be good to know.

In Firefox your top banner hides the first product which is the B4 strap.

In IE it doesn't , all looking good there.

[RudeTony]

Thanks for pointing that out - wasn't aware - we will look in to it straight away - Thanks again Tony Evdoka

[mikeyscott]

Thanks for pointing that out - wasn't aware - we will look in to it straight away - Thanks again Tony Evdoka

Also test Chrome, Opera etc. Mac browsing

[zaquiz]

Can anyone post a/some low weight setup for the B4, from the first two UK national rounds (astro and grass)? Thnx

[RudeTony]

I do beleive the lads tested the light set up but went back to the heavier set up at the end.
I apologise if this is wrong but I'm 99% sure that's what happened......

[charles08]

Hey,
So we can see on the pics that Lee Martin 's B44 at Oswestry has those Rudebits piece, the battery straps that are 50gr and the battery tray that are 70 gr ad the reedy lipos that are 285 gr that bring us to a total of 404 gr.
Pretty close to nimh isn't it ?

On the B4 the battery brace is 60 gr, which is what most people ad.
Should bring the car around 1520 gr, not sure .
Well that is still pretty light isn't it ?

Except if the guys also use some heavy front bulkhead and those rear brass toe in piece .

I would still be pretty curious to see some setups with details on what they use to ad weight .

I noticed the Americans try to use the cars as light as possible with mods like drilling a 4th hole on the rear shock tower, 20 or 25 oil and very soft springs .0,5 degrees rear hubs.
But their tracks are much different from what we have in europe.

[millzy]

Can anyone post a/some low weight setup for the B4, from the first two UK national rounds (astro and grass)? Thnx

At tally they ran a 4th hole on the rear shock tower
green springs number 2 piston

Tally was very bumpy and from what ive been told the 4th hole gave less pack and helped the car ride the bumps

as Oz had jumps they wanted a more pack set up to keep the rear from chassis slapping of the jumps

[RudeTony]

Lee runs his car close to the original weight with NiCads. Yes he uses the brass tray and the brass strpas in the B44.
Some of the top Associated drivers using the RudeBits brass parts are just using the tray.
I have been testing this a lot and I meam a lot and with the help of some of the top drivers running the brass parts I can conclude the following.
If you are happy with your orginal set up with NiCads then run both top and bottom brass parts.
If you wish to keep experimenting then only run the tray and go from there.
I personally still run both - if loose or in other words slippery and I need grip, I certainly run both, otherwise I oly run the tray.
Lastly, with both brass parts the car is slightly over weight like you pointed out and without the straps it is spot on weight if not a little under
Hope this helps a little
Regards Tony Evdoka

[millzy]

just put my order in for the b4 brass strap

all the lead i have under my lipo has to go

[RudeTony]

I wonder whos this is?
Regards Tony Evdoka
:drool:

[millzy]

Picked up my B4 brass battery strap today- Super fast delivery and clear communication from Tony at Rude bits- even got an email asking if I wanted it engraved stating that if i did it would be take to the engraver straight away ( I didn’t but nice to be asked)

Anyone thinking about getting on should pop onto the web site and get an order in fast- its a must for any one using lipo. You would think it cost a lot more for the quality and finish you recive.

will post some pics up later

Chris Mills

[RudeTony]

Hi all
Firstly thank you for the kind words - I have always tried to get items out ASAP because as a racer myself, I know how important this is....
I would like to apologise for those that wanted some parts this weekend National at EPR and I couldn't deliver on the spot - there has been so many orders that it has been difficult to make such quantity and still have some stock with me at the meeting. Just email me or order though the website to get yours for the next time www.rudebits.co.uk (http://www.rudebits.co.uk) or email me at [email protected] ([email protected])
Thanks again to everyone

[gazhillAE]

I'm using in my B4 the following!

Not checked the weight since the new bits were added so will do so asap.

This has and should be perfect and similar to running normal batteries!

Trishbits front brace
Trishbits front bulkhead (removed depending on conditions)
Trishbits rear bulkhead (always run)
Rude Mr Tony Battery strap
10g in either side of rear pods (depending on conditions)

that's around 50 over the front and a well planted rear with between 100-120g added

obviously the front is your on choice but the rear is about spot o

hope it's helped

[mikeyscott]

I have the trishbits front and rear bulkheads on my B4.

Are people running lead underneath the lipo as well as the brass brace? I have trakpower 3600s and may use my 5300 speed passions from my Cat SX instead

[sparrow.2]

I used to run a 100g of roofing lead under the lipo along with around 50g in the front and none in the back on high grip stuff only putting weight in the back for when it was wet.

Made the car nicer over bumpy stuff and easier over curbs.

[Adam F]

Brass F&R bulkheads & ghea f brace

Rudebits battery strap

Rudebits rear pod weights 10-30g per side depending on weather..