Anyone running taper pistons in their cars?

New lightweight chasis kit for the Bmax 4 III
allows use of a shorty lipo

Apparently available Mid July

http://www.redrc.net/2014/06/yokomo-...it/#more-82280

http://www.teamyokomo.eu/yokomo-euro...Conversion-Kit

My carbon one is lighter, but that milling does look nice. Nice they did a revised gear case to allow the diff direction to be swapped. Saves the dremmel job.

I wonder how long before they make a new (v2) kit with this chassis included? that will be nice.

knowing Yokomo its probably already in the works

Going off how much the worlds chassis is for the B-Max2 is I'll give it a miss and get the Arrowmax carbon chassis to save weight.

On the yoko euro site it says 90euro
So you'd be looking at around £75-£85
As your getting a full conversion set.

Doesnt seem too bad

Arrowmax chassis ordered. Once my lipo saddles need replacing I'll look at the conversion but until then I'm not remotely interested. It looks good but running saddles with it the benefits will be minimal unless you're changing to shorties relatively soon.

I ran my modified B-max4 III at torch a coue of weeks back. I loved it. It felt sharper, more nimble and jumped better.

I think you would like it in shorty mode.

The car seems quite sharp and easy to drive in standard layout but when driving it you can tell it's carrying an extra few pounds compared to other cars.

Despite it being on the heavy side it's still a great car.

Once I change to shorties then I'll probably get the conversion. In the meantime I'll wait and see what people's views are before taking the plunge.

what's the deal with the updated composite gear boxes? is it just a material change?

molding updated to allow the diffs to be swapped over so the rotation can be changed for the shorty chassis.
I hope they updated the front gearbox top to strengthen it.

I fitted shorter bolts in the bottom holes of front mount, seems to be holding out so far.

Just ordered two shorty packs. Going to do the mod too the standard chassis, are there any other tips that would help, TORCH is my local track and it appears that this setup is the way forward. What shock and diff oils are you running with this setup.?

Just fitted my new Penguin body. The OEM body is to flimsy and doesn't protect the electronics imo (allready costed me a brandnew esc and almost a motor). The Penguin body is very strong and fits nicely, the only downside is that there are no window decals included.
Great price though!

Arrowmax Chassis
 

I ran the Arrowmax chassis for the first time on Sunday and what a difference it makes. It has a little more flex than standard but it generates a stupid amount of grip and because it's lighter the car is definitely more nimble.

How much lighter?
What did you do to your oils and springs to compensate?

My shorty carbon chassis drops the weight by 200g, and as a result the damping needs work from the full weight setup.

At this point I prefer the heavy car, but more time needed to get the lighter setup right

I just left them the same.

Front
10k diff oil
Piston No.2
450cst shock oil
Blue Associated Springs

Rear
7k diff oil
Piston No.1
400cst
Green Associated Springs

With the lighter rear end the car could rotate more under braking because of the difference in weight transfer. It jumps better too.

That rear is quite a light spring rate. I could never get the lighter AE springs to work on the rear, they just collapsed, and the grip went awful mid corner. Car improved grip and cornering the heavier the spring. I find the Yok orange now is the best on RHR and Batley. I'm running no extra weight, and cells forwards. Car is heavy though at 1919 grams (saddles) at last regional weigh-in.

I found the light/shorty car very bouncy at the rear on the same shock setup, went to the 2x1.7 piston, 400, and then down the AE springs from grey to black springs, but it was still bouncy, but less so. I've not had chance to work on the shock piston/oil and spring setups for the lighter car. 2x1.6/400 had far too much pack for the weight of the car, even with the lightest spring, it couldn't respond quick enough. Not tried the kit pistons however.
The saddle car is working really well for me, and with big-ish meetings recently I've just wanted it to work, so kept it as it was.

I think the thicker anti-roll bars will help to run a lighter spring. I currently run the 1.6mm rear bar, but think a heavier one will help with running lighter shock springs.

I'm running currently
Front
2x1.6/600cst
Yok orange
10k
1mm anti-roll bar

Rear
2x1.7/400cst (or maybe AE32.5/388cst)
Yok orange
10k
1.6mm anti-roll bar

Indoors at York (low traction gym floor and carpet) I run Yok black or even Purple springs, much heavier which really helps with the low traction. Light springs just turn the rear end into mush and donuts.

What is your car weighing in at?

1481g but that's without cells.

Does anyone use a shock tower protector? Looking for something like a shock tower bra used by the 1/8th guys.

Yeah, I've been using old one on the front cut from old wings. Not blown a shocktower mount since.
I'm just about to do a hack with a cougar KF front mount. Need to dremel and drill it to fit, but it will. Photo when done.

I wonder how this works with standard motor mount or is new mount required?

http://www.redrc.net/2014/07/psm-b-m...it/#more-83281

Looks to be standard motor mount, but you can't use it in saddle config.
Telling that they added chassis stiffeners in the carbon chassis. There is quite a bit of flex in my carbon chassis. I'm not convinced the centre line battery mount is needed tbh, certainly not on the alloy chassis, but I guess they found the flex different each side with the pack mounted the traditional way.

I wonder if it works at all. In theory: yeah great. But to be honest, the B-Max4 III is great on low-medium traction tracks and the new conversion kit is great and makes the car lighter as well. I'd prefer to pay a bit more for the Yokomo kit than for the PSM "kit".

I agree. in my mind the standard " heavy" car is great anyway on low traction tracks. mine runs at 1919 grams (saddles) so i can see that if running a stock class or super high grip you would want a lighter car. In a high grip situation you'll want the chassis to be stiff, not super flexible (generating more grip). so in that respect if running blinky stock 4wd on low traction track, this carbon chassis may help, otherwise i think the alloy Yokomo one will offer the desired performance. I guess they missed a trick... offering the shorty centre mount as an addon for the alloy chassis as well.

Going to give my new 3 a run next week, iv put on a 23t pinion using a 7.5 motor , this about right ? (Stock spur gear)

Is there a front roll bar available for the bmax 3?

There is but I don't think it's in stock anywhere.

Ok cheers, I'll keep my eye out on MB models site for when they come out.

Is the gearing about right for a 7.5? (23t/stock spur)

This is the roll bar pack you need:
http://www.rccarshop.co.uk/index.php...0mm-1-6mm.html
It is labelled rear kit, but they fit front fine. In stock at MB...
I've not seen a front bar kit. There are a set of thick bars coming, both front and rear versions. Not sure what the difference is, the car looks setup to run both the same? The new sets will include the ball end links.

I tend to run 1mm or 1.1mm on the front. Not had a need to run anything higher. I run 1.6 rear, which is included in this pack.

You need the ball links. I found the AE ones for B4/B44 roll bars work just fine if you have them already. otherwise you need:

http://www.rccarshop.co.uk/index.php...izer-ball.html
http://www.rccarshop.co.uk/index.php...rts-short.html
and a long grub screw to join the ball ends.


Gearing. I tended to run a 21-22 pinion with my 7.5, but i was mostly on indoor tracks with the 7.5. I've motored up for outdoors now. A 23T should be fine, just check your temps.

Thanks Neal for the response :thumbsup:

BM-412 is the anti roll bar kit i use on the front

Hello everyone,

I would like to find a setup for my B-MAX 4 III

I ride the track or is outside is low traction earth with portions carpet over bumps.

I ride outside, I'm a carbon frame to ride with a shorty

thank you for your advice.

Nicolas from France :)

This is a good starting point: http://www.petitrc.com/setup/yokomo/...Arena20140129/

Else you should ask Sylvain ;-) He can help you out in French :lol:

That's the one for the rear of the BMAX2, and touring cars I believe. It fits, but the wires are too long and bent at a different angle to the correct one. Also the weights of the wire is lower than needed for the rear. The ball links are the same, and it will work however.

hi skyaflake,

I'll try this setup to see what gives the earth.

springs is what? : Front spring: Yellow
Rear spring: White


Thank you Nico.

Kyosho/X-Gear springs. I found them too light when I borrowed some to try on the saddle chassis.

This is Lee Martins latest clay setup: http://l-m-racing.co.uk/wp-content/u...ordics-4wd.jpg

I've not yet run on clay myself, will be doing for the Oople Invernational.

hello neallewis ,

thank you for that.:)

Nico.

Lee Martin lightening his car?

http://www.my-yokomo.fr/wp-content/u...2-74722660.jpg

I think this is not so much to lighten his car, but instead to increase flex. I've heard the Euros track was very low bite at the warm-up, to the point where some drivers removed the entire centre cross/x-brace inside the wishbones to increase traction through flex. It seems like there was enough traction yesterday (there was even a groove on the track), but based on earlier conditions Lee might have made one or two mods, just in case.

Not running any sway bars/stabilizers either. And indeed, removing some plastic wouldn't shave off that many weight. Still running saddles so his car is a bit heavier.

It looks weird though.