Question about supercharging and how it affects your engine?
 

K I was wondering how does forced induction affect your engine components.

I mean by this is since hte air is actualyl forced in what shoudl you try to make your heads and volume ?

SHoudl you have huge ports?

Or try to optimize a N/A combo then bolt one on and that would be right?

How do you figure the size of ports you need to optimize the air flow and teh valve sizes?

If i have my heads dynoed could they forced air in at certain levels to see what would be most benificial?

All info would be helpful as i dont want to build a N/A motor then lose evrything and make a completely diffrent one for forced induction.

Excellent question, first off if you plan on building a blown motor, Nitrous, or turbo, you need to start off with a strong motor, rebuilt or freshened in some way.

Supercharging effects your motor in several ways, first obviously the increased cylinder pressures, many purpose built blower motors have decreased compression ratio, such as 8.5:1, bearing surfaces are always stressed as compared to naturally aspirated, etc.

big improvements to the fuel system are required, the list goes on and on, what you need to do is really think what you want ultimately from the car and go from there.

I want a street driven car that isnt exactly the best ride but can be driven on the street with appoximately 500-550 RWHP.

You can see my mod son my sig but i think once i do a little cam swapping and porting and polishing along wiht a conversion to mass air and upgrade a few compnents i plan to be near 400 RWHP N/A so if i get a 30% boost I will be in my range of what i desire so teh compression doestn really need to be that high.


I would prefer the engine to never see above 6500 RPM


I hope this is what oyu mean

Basically I want a really quick barely legal street car
(Also. i realized abotu teh fuel system upgrade i more ment how do i need to design my combo for optimum forced induction such as teh diffrent sizes of ports and intake choices, shoudl i upgrade to 75 mm thorttle body and not have to sell a 70mm when i upgrade evreything?

I dotn really got the money to buil agood motor then ditch nearly all of it and rebuild another one i woudl prefer to build a motor that woudl be quick but not the best it can be N/A and jsut wait till ic an afford the supercharger.

Thanks Guys

Your goal is 500-550 rwhp supercharged, you want have any trouble meeting that goal, but don't expect your block to last to long, unless you've upgraded it to something stronger. Anything around or over 600 hp at the crank on a stock block is about all you can get and expect it to last any length of time. A 70 mm tb is good to 600 hp, so I'd say you'll be fine there.

Anyone know how to build a motor thats gonna be supercharged?

Also will my 10:1 pistons be okay if im only runnign liek 8 ibs of boost or less as i would htink thats all i nee to reach my goal

Check out the latest 5.0 Magazine. THey test a bunch of intakes on a warmed over 306 motor that they bolted an S-trim on it.
Almost every intake was 501rwhp.

550rwhp is more porting of heads and intake, and stouter cam... But you are playing with fire at that level of hp IMOHO. Its a matter of time before engine lets go at that power level.

Also, compression is too high. You dont need to back down to 8.5:1 or nothin, but 10:1 is not optimum for boost. Whether its only 8# or 12# (recommend that range).

p.s. 500rwhp is about my goal for this spring.:D

Vetteeatr, to achieve 400 hp, you'll need better components than you have listed, with stage 3 twisties, custom cam, and fully ported Holley intakes, done by ANDERSON, AND a PMS, Anderson dyno'd me at 368 horsepower, so i think you'll come up a little shy of 400, more like 320.

my buddy used to run 10.2@1xx with 14#s on a 10.5:1 motor..he only have 24# injectors and a 255 intank..go figure..doesnt sound right but i swear to you it is

What kind of fuel was he using, methanol?

:D naw 87 i think?jk..he prolly ran race gas and he had 2 other pullies for less boost for the street...car was blowing head gaskets every 2 months thou

Well, I did run a blower with 11:1 compression/iron heads. The intercooler helped, but the combo was really difficult to tune and remain in tune. Either too rich or too lean. Too much timing or not enough. I had to tune at every change in weather, or even after a fill-up...no joke.

I was kinda wondering mroe of hwo to build a forced induction engine....

I see cams for superchargers so there must be some diffrence between cams for N/A vs. supercharger.

How does the forced air effect flow in the intake and heads?

Does it flow the same as but increased due to to mroe pressure or is the somethign diffrent you need to do to make the combo work better with forced induction?

What would you guys think the most compression i coudl run on a supercharged motor shoudl be . 9.5:1? 8.5:1?