Re: HP gains
Not to mention most companies measure HP increases at the flywheel, and not wheels. Some calculate in other ways, but typically when advertising, most companies don't say where they measured at. You also have to account for other factors besides bolting on parts. Although they claim to increase a certain "HP level", you have to take into account altitude/pressure/humidity, and total parasitic loss, engine wear (mileage), and various other things. Typically getting custom tunes for each add on you do is the best way to maximize each gain. I wouldn't be surprised after all that if it were dyno'd if you only gained 10-15 HP. Plugs, and half an exhaust aren't going to do much if anything without headers (best gains from LT's), and you'll need some quality COP's to make your plugs worth anything and they still may not give HP. UD pullies are only going to free up a small amount of power, not gain it, and it's typically not noticeable but you may notice that you rev a little faster. 3.73 gears won't gain you power, but you will CERTAINLY feel the effects of torque amplification. They will definately help with launching, and you'll redline faster, however, your top end speed will be reduced. Lemme know, or post another thread (or look up the hundred already here) asking about good HP gaining mods. Remember, it comes down to cost and budget as well.. and what you use the car for.