PCB mod

pingguru1 · #1 10-14-2002, 10:01 AM

After a day of running my new ZZ Porsche with the red motor and green gears (reds were too slow on acceleration) I have decided to cut it. As a test I cut the yellow wire and spliced it into the red (from battery) to see what improvements would be made. Impressive to say the least! The car will now spin the tires from a dead stop with the red motor and gears but of course lacks reverse. Now that I know what works I will fit a PCB from my MiniZ into it and ejoy the added power. The run time with this mod is pretty much the same as before with the increased power bing the only notable difference. Was going to keep the miniZ just in case but forget that! This is a worthwhile mod. Now to find some traction. I did remove the front sway bar which made the steering acceptable (1.5-2.0 ft radius) but it will do doughnuts if you let it and that isn't the fastest way around the track. Just wonder what the NOS motor would do (evil grin).

Mattydiah · #2 10-14-2002, 11:02 AM

Do you have/can you make a diagram/labelled picture? I'm sure lots of people would be interested in this.

pingguru1 · #3 10-14-2002, 04:56 PM

I am in the process of moving so I don't have everything set up for creating a picture for you. If you remove the PCB cover and look at the board you will see that there is a yellow wire going to the motor. Cut this wire and strip 1/8 inch. That done remove the battery from the car (just pops out) and you will notice that the metal contacts that pass power from the battery are loose now. Take the yellow wire and pinch the stripped part between the positive battery contact and the plastic sidewall. With the battery in place this is a good connection and temporary in case you decide to go back to stock. By doing this you are providing full battery power to the motor when you move forward. The only bad news is that you no longer have reverse but with it's ability to do doughnuts you probably won't need it

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Hope this helps but I will try to get before and after shots to help out.

pingguru1 · #4 10-14-2002, 04:58 PM

Just realised that I was a bit vague. In doing this mod the idea is to run the yellow wire from the motor directly to the positive side of the battery. You can splice the yellow from the motor into the red battery positive wire or just pinch it at the battery contact as I mentioned earlier. The PCB will no longer need to be attatched to the yellow wire.

Barry · #5 10-14-2002, 09:31 PM

I just did the same mod, but I did it a little differently though. Since electricity always takes the least path to resistance(in this case the motor), I just soldered a new wire onto the motor(same place the yellow wire is soldered) and ran it to the battery. Reverse went out so I know its working properly. I seemed to have gained a little speed, but its hard to tell.

The way I did the mod there is no need to cut wires and to get reverse back just pull the wire out from the battery.

Enjoy and as always do this at your own risk.

pingguru1 · #6 10-14-2002, 10:46 PM

Barry, my only concern with the way you have done your modification is that when reverse is chosen via the remote you are now providing conflicting signals between the pcb and motor. When forward is chosen the pcb provides positive through the yellow and negative through the blue. When reverse is chosen these are reversed and positive is now blue and negative is now yellow much like a power window circuit in a car. Your modification is running voltage through the ground path when reverse is chosen and I suspect it might cause damage down the road. Another thing I noticed in your post is that you are unsure of the improvement in performance. With the yellow wire cut from the pcb there is no mistaking the improvement. I suspect that the pcb is interfering with your mod. No kidding, this thing will literaly spin tire from a dead stop with red motor and gears. The pcb is the weak link in these cars as it offers too much resistance in the power circuitry which deprives the motor. The idea of the mod is to bypass the power circuit of the pcb by removing the yellow wire from it. Hope this doesn't sound like I am being critical but I would hate to see you ruin the pcb. Worst case with the way I modded it is that you reconnect the yellow wire to the pcb. If you feel up to a little experiment give it a shot and see what happens. I know I am curious.

Russ

Barry · #7 10-15-2002, 12:06 AM

I tried what you suggested, but the car got extreamly slow. Maybe my batteries are low or something. Ill pickup a new set of batteries tomorrow and give it another shot.

pingguru1 · #8 10-15-2002, 06:40 PM

Hope it works out otherwise mine is a fluke

Barry · #9 10-15-2002, 08:28 PM

Quote:

Originally posted by pingguru1
Hope it works out otherwise mine is a fluke

I couldnt get it to work, the car just went dog slow and it drained the battery quite quickly. I put everything back the way it was and everything seems to work fine now.

Mattydiah · #10 10-15-2002, 08:34 PM

Well, this mod is in the FAQ, I have noted the problems with the wiring.

catman25 · #11 10-16-2002, 04:44 AM

we need pics asap for retards like me :-)

pingguru1 · #12 10-16-2002, 07:15 PM

I will dig out some hardware and see if I can't get a picture up for everyone. I can't believe it made such a huge improvement with mine and not yours. Bumming.

pingguru1 · #13 10-16-2002, 07:44 PM

Here is a picture I threw together. Sorry it isn't better but not much time.

Mattydiah · #14 10-16-2002, 07:46 PM

Um, pics not showing up.

pingguru1 · #15 10-16-2002, 07:50 PM

Sorry that didn't work

seems it won't let me attatch the image.