John Stranahan

iTrader: (27)

Joe-The car will hold two of these MaxAmps 4000 mA-h batteries side by side wired in parallel for a total of 8000mA-h. I think it will do a 20 minute main with two packs on board.

John

Marcos.J

iTrader: (239)

wow 20minutes!! are you racing them in the main with the nitro cars? how is the heat in the motor after 20minutes?

John Stranahan

iTrader: (27)

I plan to race in the Nitro main one day. I have had an assortment of difficulties so far that have prevented me. We don't race very often, twice a month. Motor temps are never over 170 F, but its winter. We have stopped treating the track with sugar water. This lowers the motor temp even more.

ljohnson

I wonder if your run time would be better if they where wired in series - ~14.8v 4000mah vs 7.4v 8000mah. You'd need different electronics though, A lower rpm/v motor and speed control + bec that can handle 14.8v. In theory at least, higher voltages are more efficient for a given power output due to less amp draw.

John Stranahan

iTrader: (27)

lJohnston-I posted the same thought previously on this thread. I have a new Tekin R1Pro esc on order that will handle the two batteries in series. There should be less amp draw and less heat produced. I will use a less powerful motor with more winds for the test. I am hoping the speed control will adjust the BEC voltage. This is not in the specs.

John

Marcos.J

iTrader: (239)

let me know how you like that tekin!

John Stranahan

iTrader: (27)

MarcosJ-will do. It is not available yet as far as I know. It is backordered.

Here is a pic of the new double A-arm front suspension showing the recent changes. The upper shock mount ball is now attached to the upper A-arm hinge pin. This is a Traxas ST (2) kingpin. The picture also shows the slimmed down head of the IRS kingpin.

Caster
I have added a third spacer at the rear of this hingepin to increase caster slightly. This will kill a little turn in and add some midcorner steering traction. Because my outer A-arm vertical spacing is longer than stock, these washers have less effect on caster than on the stock suspension. This long spacing will provide more rigid camber support which I think is neccesary on the sweeper.

Roll Center
I have added one washer under the outer A-arm pivot. This raised the roll center slightly. This will reduce the front cornering traction slightly.

Shock Oil Weight
I have upped the shock oil to 35 weight. This will kill a little turn in.

Reactive Caster
Because I have used the arms and reactive caster blocks on the opposite side of the car than the one intended, the reactive caster blocks work in reverse and add caster late in the corner. This will not be a useful tuning aid.

New Brushless Motor, Ceramic Bearing, Source
I have some parts ordered from Murdock RC. A new part there is a ceramic brushless bearing set for $10. This is a significant savings on perhaps a better motor bearing. I have been looking for these. The endbell side will need to be installed with high temperature red locktite and pressed or hammered in with a suitable tool that bears on the outer race. The Novak part has the front bearing already installed in a new endbell.

Marty Peterson

iTrader: (3)

Hi John Great Job again Buddy!!!!!! Looks sweet!!!!!!

I have finished my GT2 Car and waiting for a servo and body to come in Then I will be working on this one next like you did.

InspGadgt

Hey Marty looks nice! Only thing I'd suggest is move the body mounts back to the main chassis. On the pod the body is going to restrict pod movement. Also downforce is better applied to the chassis through the suspension to the wheels rather then directly on the wheels. F1 used to mount their wings to the wheel hubs too but moved it to the chassis once they figured that out.

Marty Peterson

iTrader: (3)

Thanks I am moving them to the main Chassis it was to test and see how long and high my body post plate needs to be.

SKJ

iTrader: (20)

Marty
That front end looks nice. When will it be put into production? Would like to try it on my velodrome car.

Steve

Marty Peterson

iTrader: (3)

What car are you running?

Can you drill the holes and countersink them?

If so I can make front end kits ready to ship when we re-open in mid to late Feb 2007

email me

YR4Dude

iTrader: (44)

Marty-Nice looking car except what really would be interesting is a car that is the reverse of what you did. Instead, how about the same battery layout with a TC rear-end and a pancar frontend (reactive caster)? Also, instead of using the larger TC shocks on the rear, switch them for the AE Macroshocks.

Now that would be something I would be interested in getting from you. Thats unless I build it for myself first. However, I'm sure the quality of your work is better,

John Stranahan

iTrader: (27)

Marty-Thanks. Nice looking front end on your GT2.
John

Pic is of my revised lower arm.

InspGadgt

Couple problems with that...first...there was an early gas conversion that did exactly that...used a Kyosho rear end on a pan chassis and front end. We had one at our hobby store and really had a hard time getting it to handle. Second it would be hard to find a class to run it in if you plan to race it.