Sorry if this might seem like a stupid thread, but I know very little when it comes to mods. Anyways, I'm wondering the benefit of a harmonic underdrive pulley. Plus, when you install a MAF does it always require a PCM tuning?? Thanks for your time

 

Do not install an aftermarket MAF. They are the devil.

I'm not too knowledgable on underdrive pulley's, but it's basically freeing up horsepower by not having to rotate as much mass. You may need an overdrive pulley for the alternator to keep the voltage up. Like i said i'm not too knowledgable on them. Try searching in the external engine section. If you can't find what you are looking for then post up there.

 

You can get the underdrive pulley kit for about 225 and yes it frees horsepower up by reducing the drag on the engine. From what I have heard the stock MAF is the best route, most tuners won't touch aftermarket ones.

 

If you're going big on the intake (90mm manifold and TB) then you'll want to change your MAF. I'd only change MAFs if you're doing tuning at the same time.

 

Yea, I agree w/ xp3 that the only reason to upgrade ur MAF is w/ a larger manifold and throttle body so it matchs up.

 

Thanks for the help

 

Underdrive pulleys provide only a few extra rear wheel Hp and really aren't worth the hassle and cost to pull the stocker and put this one on for that gain. Your money is better spent elsewhere. If you're doing heads and cam or something big, then it's more of a benefit. It will allow the engine to rev quicker but if you do a lot of sitting in gridlock you can run into charging issues. Usually a minimum of 1,200 rpm is needed to maintain sufficient charging (at least on my car anyway).

As to the MAF, the stock MAF is capable of supporting up to 500 - 550 rwhp. There is no need to upgrade the MAF even if you do a bigger TB and bigger intake as the stock MAF flows more than enough to feed it. If you do heads, cam, supercharger, turbo, etc and get a dyno tune, your tuner will most likely prefer to tune with the stock MAF anyway. If you install one, you will notice a temporary power gain from the system leaning out until the O2's catch it and correct it, then you're right back to square one that you were with the stock MAF. The MAF is not the restriction in the intake.

However, I do have an SLP MAF that I bought to play with and test some things and now have it up for sale if you insist on getting one.

If you're gonna spend money on freeing up your intake, buy a CAI instead and relocate your IAT sensor. The IAT sensor in it's stock location is right next to the radiator which leads to errant high temp readings which scales back timing unneccesarily in the PCM.