The thing about power adders is, they don't add up, 2+2<>4. Why not? Because you can't get power twice from the same place. If you have a device, like a Comp, that gives you the maximum power increase from timing advance, adding another device that advances timing doesn't help (could hurt) because the power gain from timing advance has already been used. Adding fuel via wire tap or injectors encounters similar overlap.
You say your friend want a "little more" power, how much is a little more? If I'm running a stock truck at 200 HP and add 50HP, that's a substantial 25% increase. If I'm running a highly modified 500 HP truck and add 50 HP, that's only a 10% gain, not so impressive. I think you friend is up against the old equasion of more fuel + more air = more HP. He's done all the "easy" stuff. Now it's up to bigger injectors and bigger turbo and all the requirements of all that pressure. Drivability and economy go to heck, but what does he really want?
Attention: TDR Forum Junkies 
, just what does a superchip do??
