possible performance mods
Thread Starter
Senior Member
Joined: Aug 2011
Posts: 679
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From: houston, tx
lol im not looking to go that performance crazy with it. just a programmer, CAI. exhaust some headers. maybe hi flow cats, and now im thinking these underdrive pulleys and E-fans but i cant find any sites that sell these pulleys
Senior Member
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Prius Eater
Joined: Oct 2011
Posts: 110
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From: Asheville NC
being that the front cover assessories (alternator, power steering, A/C, water pump) create parasitic drag- you lose horsepower as a result. kinda the same way that a transmission robs horsepower- flywheel vs. rwhp. so the underdrive pullies change the ratio at which the front drive assessories are rotated in relation to rpm of the harmonic dampner (the "pulley" on the end of the crank) which in turn lessens your parasitic drag. You are not making more horsepower per say, but rather freeing up some you already had.
'08f150stx
Joined: Jul 2010
Posts: 1,605
Likes: 16
From: Wisconsin
being that the front cover assessories (alternator, power steering, A/C, water pump) create parasitic drag- you lose horsepower as a result. kinda the same way that a transmission robs horsepower- flywheel vs. rwhp. so the underdrive pullies change the ratio at which the front drive assessories are rotated in relation to rpm of the harmonic dampner (the "pulley" on the end of the crank) which in turn lessens your parasitic drag. You are not making more horsepower per say, but rather freeing up some you already had.
Prius Eater
Joined: Oct 2011
Posts: 110
Likes: 0
From: Asheville NC
they can usually free up 10 or so hp, as for the water pump- it will be fine. If however you do experience some higher ECT's you can put a different tstat in to offset the difference.
Thread Starter
Senior Member
Joined: Aug 2011
Posts: 679
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From: houston, tx
if i were you i would have a second battery under your hood, just because youll be drawing so much power with- (an audio system and e fans and anything else you might wanna add i.e. cb radio ) along with everything else that the battery needs to supply. buying a second battery, you wont have to sacrafice dimmed headlights
Thread Starter
Senior Member
Joined: Aug 2011
Posts: 679
Likes: 6
From: houston, tx
how much hp can i expect to gain from this? and headers are in strong consideration for me right now, what about adding hi flow cats into the equation? ive heard having headers and hi flow cats can allow the exhaust to breathe too much and not give any restriciton or back pressure
Senior Member
Joined: Oct 2010
Posts: 859
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From: Wyoming
Programmer:400
CAI: 250
Exhaust: 450
Headers: 700
Hi Flow Cats: 250
UDP Pullies and E fan: 500
Total: 2550 (Average cost) HP Gain: 60-70
Roush non intercooled Supercharger
Cost: 2200-2600 HP Gain: 100+
You tell me?