porting my tb and upper intake

[homerunhitter629]

Could u guys give me a few tips on how to port my throttle body and super charger on a 2001 gtp??? How hard is it to do??? Most common problems?? How will this affect my mpg??? How many hp gain could I expect??? Right now my gtp is bone stock but headers, cold air and a 3.4 will be here shortly. Is there anyone in the chicago land that does these??

[Explicit_Spade]

First, you cant drop to a 3.4 with just an intake and headers, you'll also need a colder thermostat and colder plugs. The following info is from ZZP:

97-03 Grand Prix & 04+ supercharged Impala & Monte Carlo SS
3.5 pulley totally stock car
3.4 pulley Colder Tstat & spark plugs, downpipe, Cold air intake (still could have KR)
3.3 pulley all of the above plus a VS cam, SS intercooler, or headers
3.2 pulley 3.4 mods and a XP cam
3.0 pulley 3.4 mods and a fullsize intercooler or an SS ic and a VS cam.
Anything smaller than a 3.0 pulley will require a camshaft, headers, intercooler & injectors.



04-05 GTP or Comp G & 06 GT supercharged
3.8 pulley totally stock car
3.6 pulley Colder Tstat & spark plugs, downpipe, Cold air intake (still could have KR)
3.4 pulley all of the above plus a VS cam, or SS intercooler
3.3 pulley 3.4 mods and a XP cam
3.2 pulley 3.4 mods and a fullsize intercooler or an SS ic and a VS cam.
Anything smaller than a 3.0 pulley will require a camshaft, headers, intercooler & injectors.



You may still have knock after colder plugs and t-stat, so you may want to get an Aeroforce scangauge, LS1M, or a tuner such as DHP powertuner or HPTuners. Now that we have that covered. Porting a stock supercharger housing and throttle body won't net very large gains if you don't have other mods. When you do get to the point where porting is necessary you will need to port your Lower Intake manifold to match the port on your supercharger. Your stock throttle body ported will not flow as well as a factory northstar, so that is also something to keep in mind if you plan on going further with modding. For more info on safely modding your 3800, click on the link in my sig.