I'm no engineer but it seems that with the batteries in that configuation that you would get less weight transfer thus the push in the corners.

This is a cool project you are working on. The car looks really cool. A few suggestions i would make are to not move the links inboard. The links are the only structure you have to hold the pod square. If you move them inboard you will lose some of the strength. To me it looks like CRC moved the links inboard a little to make room for the battery.

Another is something you have already mentioned which is going to .018 front springs. An inline battery is very neutral feeling and i think you can get more reaction this way. Also,just for the hell of it, try adding 1/4 oz. of lead weight to each side of the chassis plate as far back as you can get it. This should help out also.

Best of luck with it buddy. It looks great and sounds like it is working well for you also.

The opposite is actually more what you find. Look and the few in-line cars that are out there and in most cases they are trying to find more rear grip. The Diggity used to run the old style front suspension to balance the car, the Darkside runs the 5 degree caster blocks instead of the 10 degree. I was constantly battling having too much front bite with my Darkside.

Lack of rear traction is the biggest issue with inline batteries in both 1/12th and 1/10th. Once you get the rear end biting good, the car seems to push. Softening the setup on a car with this layout seems to help alot. It is difficult to get any weight rearward and there is minimal weight transfer for and aft. This is one of the reasons i recomended adding weight in the furthest rearward position.

Thnx trailranger!
That was my point with the Arrow : improve battery holddown.
The push I was talking about, concerned the M12. The Arrow didn't hit the track yet, normally this WE. I focus on the M12, somebode else of my local race club (who saw the initial Arrow CAD drawing and wanted it) on the Arrow.

InspGadgt,
Good point! Got same thoughts here ;-)
The idea of the Arrow came after seeing the Darkside and Hatzenbach pic. A few months ago, I saw the Hatzenbach in action on the 12thscale Masters in Holland. Immediately I thought : not enough space for electronics and with a battery bar/tray ON the battery.... hmm, but what a great car (look at that rear suspension bar!).
That's why I tried to solve those two "issues" (..issues, imo!) by
* creating a battery tray that encloses the 2 middle cells
* chassis cell cut-outs that exactly fits
* adding spaces in front/back to attach the battery with tape
=> the battery is locked down in the chassis! no play (side/side+front/back) whatsoever.

Before cutting down the (standard) long standoffs (holding the tray) with 2mm, we've attached the battery with tape and tray... no way, you could ever ! lose the battery during (crash)impact.
Bottom view (lots of space to use wide enough tape)
(Have to admit, it was a guess -> the post in front or tape slot? + it's a bit more work -> tape and 2 screws - but that's one solved issue for me

The ESC space is solved for brushed electronics but for BL, a big no no I'm afraid (the guy who 'ordered' the Arrow will be using a LRP Sphere BL, so I'll try to post some pics after he run it).

CU!

Thanks for the advice InspGadgt and protc3 !
I'll give this to the Arrow driver
What do you suggest for tires to start with such a car?
Yellow/2XPink or
Pink/Purple or ...
start with White in the rear?

Yellow rear and 2x pink front is always a good starting point.

It may feel locked down but so did my Darkside and my old EV10. Only crashing will tell in the long run.

With my Darkside I ran outdoor asphault and used magenta rears and purple fronts. Any softer then that and the car had too much front bite. I had also tried blacks and magentas in the front and pinks in the rear but the car felt best with purple front magenta rear.

That sounds right to me. With the inline battery layout, rear traction is hard to find. The false sense of too much steering is a lack of rear bite. sucka.

OK, so I'll go with Yellow / 2xPink on carpet and Magenta / Purple for outdoor (= if I ever get my Pro10 idea of the ground...)
(although I have to say, we never race 12th scale cars outdoor... yep Europe = 100% carpet)

Now I'm really curious on the driving behavior on this type of car ...
and it's not even in my hands

It can work well. When i get home i will PM you some things to try. I think that you can really get it working the way you want it to.

Sent you a PM buddy

Any more news?

Sweet car deserves some attention.

Yep
I've talked to Thijs yesterday (the guy who's driving the Arrow).
He found the car great to drive and very stable (that's the
most important thing for me, a well balanced car, great!).

I had given him the tips&tricks all of you PM'd me as starting point,
'cause I was a bit surprised to hear the rear would be tricky to get
it right.

After a few (very first) runs; this is what he came up with:

Body = Protoform Speed 12 GTP (.030)
Tires F/R = Black / Yellow
Tire additive = CorallyTC2 / F : 50% R : 100%
Springs F/R = 0.020 / CRC White
Center shock = CRC Copper / 20Wt
Front suspension = Old Skool (no xtra shims)
Rear suspension = CRC Tubes (crc red lube)

Motor = 19T
Gearing = 37 mm
Total Weight = 825 gr (without PT)

Remarks =
car handles good, very stable,
not as direct as it should be when entering corners:
maybe switch from Black to Purple ? (no Purple at
hand) / change front spring;rear traction OK - stick with Yellow.


I guess purple would do the trick in front?
I'll keep you informed about car handling on some other set-ups !

Benedict.

can i ask about your steering knuckles? i need to produce my own and am unsure how they are constructed. or did you buy them? i know some do

thanks
Joe