Okay, i will just let it all go:
There are about 3 solutions to the problem, or *possible* solutions. I *have* messed around with a few, and some of them I like, and some of them I dislike because they limit the runtime too much:
1) raise the gate/source voltage on the N channels - There really doesn't seem to be a good way to do this unless you use another stage on the N chan hi fet, and then you can run into issues whereby you lose some of the proportionality where the N chan fet output rails itself. Look at the gate resistors: 151 (150 ohms) on the fwd, and 103 (1000 ohms) on the rev.. If you follow these up to their source you might be able to do something other than an extra stage by changing their sourcing voltages somehow, but I have good results already so I didn't go that far.
2) P channel current limiter resistor, labeled 102, reduce it to 500 - Find and reduce the P chan current limiter. As you should know by now, the path that the current takes is through one P chan and one N chan, so you have to fix THE WHOLE PATH.
3) P chan gate resistor 750 change to 250 - P chans are fed from the output stages of the N chans, so you can try changing these to 250. They have to swapped out in the same ratio with the P chan 102 to set the bias properly.
For those of you making disparaging comments, either say something nice or go screw yourself.
I can see why Microamps bails out on you. You would prlly treat him like crap too, and he doesn't want the BS.
Simply look up H bridges, get a volt meter, turn the car to the OFF position, remove the motor, and start drawing what connnect to what by beeping out the wires. This H bridge has a crossover stage, the P chan gates aren't driven by the same signal as the N chan.
I honestly don't have time for much more, which is why I don't just TELL everyone.. As you can see, its a bit more involved than what you originally would have thought and takes some *outside the box* thinking. You can't just go after the first thing and think you are going to get good results, you have to keep at it and look at the entire system.
Besides, after working for 7 years at 6 jobs, each one ending in moving my job to China or ending in a big layoff, I am back in college, I own my own business and modify REAL cars for a living (engine building, head porting, machine work, etc), and make a decent living at that. But heres the thing: if I DON"T WORK I DON"T GET PAID THAT DAY, so I don't have DAYS OFF where I can take a bunch of time to tell you guys everything, because if I do, guess what? I DON"T EAT. This is literally just a hobby/game and I have alot of other things to do.
So with that note, I find it odd that I came in to HELP you, and all I got was a bunch of BS.
There are quite a bit of you that need to rethink your strategy on how you deal with ppl, because I can tell you with the attitude in here, not only will it get you nowhere, it will get you the backseat in your entire life if you don't deal with it effectively now, and eventually you will miss the ride completely if you tick off enough ppl.