Heads on a FI setup: necessary or no?
#1
Heads on a FI setup: necessary or no?
I am going to be going D-1SC procharger eventually and i already have a blower cam installed. my question is would a good set of heads be worth the $$$ or should i just leave the stock heads? i have heard from various people that heads are kind of pointless because they dont need to flow as good since the blower already is forcing the air in, opinions? thanks!
#2
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Depends on you goals. If you want 550-650rwhp, it's not worth the money. 1 lb of boost will override a port job. If you want a max effort car or want to run the absolute most hp on pump gas, then it will be worth power at high levels. A lot of folks are bolting on the Caddy aluminum heads to lower the compression and leaving the ports stock and making good power.
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Like its been mentioned it does depend on the goals of the car.Anything to lessen the restriction of air going into the motor is a good thing.It might be true that 1-2 more psi usually equals the power you'd get from a port job,but 1 thing is left out.For example,say you get 40 rwhp from 2 more psi.Or you add heads and get the 40rwhp.But when you add the heads the psi drops so youre now making more hp at less boost.So in reality you have to add the 1-2 psi ON TOP of what boost would drop to to make it fair.With the heads youre now running less boost making the same if not more power and the intake air will usually be cooler as well.LQ9/LQ4 heads are the heads that drop the compression and they flow better than regular ls1 heads so those would help just bolting them on.But to just raise the boost is definitely a misconception as stated.
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I believe that heads are more important on a N/A car than a Turbo/Supercharged car for sure, however the thought that heads are totally pointless is not true. I have 69cc ported, polished, valve job, etc heads on my car and they work great but I did not have to pay for them (above the price of the car).
Overall I would say this is the order of importance for a F/I car
Fuel System & Tuning
F/I Kit
Forged Internals & Cam
Rearend & Drivetrain components will give out before you can turn the boost up at this point
Heads
Overall I would say this is the order of importance for a F/I car
Fuel System & Tuning
F/I Kit
Forged Internals & Cam
Rearend & Drivetrain components will give out before you can turn the boost up at this point
Heads