boost numbers with bigger ci, same small blower?

[musclemustang65]

To make it short and sweet i have an 02 gt with a kenne bell 2.1 making 15psi with the mammoth intake and stock heads/cam/etc. Made 466/472. My question is if i did a big bore 5.3 what would the same pulley make with the increased displacementand what hp it might make with it?

Just weighing out options for a new shortblock with my current blower.

 

[musclemustang65]

stock heads/cams for comparisons sake

 

[svtshadow]

You will see very little increase. Blower way to small for that motor powerwise.

 

[encasedmetal]

You will see very little increase. Blower way to small for that motor powerwise.

horseshit. the big bore block shows on average 100hp/100tq under the curve. OP- each psi has been found to be worth 14-20rwhp in PD blowers. So the more you can make n/a the more you make with boost. the trick is to make your motor as efficient as possible so that boost is decreased while still making the same power and leaving room to increase the boost level if you so wish.

 

[slvr35th]

you need heads and cams to make that thing a beast !!

 

[musclemustang65]

I got screwed over going all out in another car so i figure forged shortblock first, heads/cams later. My concern was the blower making less boost with increased ci.

 

[musclemustang65]

I know its a small blower but my plans were to have a forged motor, later do heads/cams, and in the meantime i could run 100 shot on top of the boost i just dont have the cash for a shortblock plus bigger blower.

 

[01yellercobra]

Not really apples to apples but....

Stock motor with a D1 at 12psi was around 450rwhp. Not sure exactly since the car never made it to a dyno like that. But the blower came off another 01 and the only difference between his car and mine was he had shorty headers and I had stock manifolds. I think he hit 475rwhp.

The motor in my sig with the same blower at 12psi made 570rwhp. That was low timing too.

With the stock motor I hit 12psi with the stock crank pulley and a 3.9" blower pulley. On the big bore I ran a 12% overdrive with the same 3.9" pulley to hit 12psi.

 

[musclemustang65]

Def helps, mine has the mammoth intake so itll push more than normal.

 

[03svtcobracoupe]

It will make more yes

Sent from my DROID RAZR

 

[coposrv]

I got screwed over going all out in another car so i figure forged shortblock first, heads/cams later. My concern was the blower making less boost with increased ci.

Boost is just a measure of restriction. More boost doesn't always mean more power.

 

[itSSlow98]

The problem your gonna have is over spinning that blower and creating a lot of heat. If your fine doing the bottom end and really but gaining a lot of power then go for it. It's a good base for down the road. I just wouldn't expect to slap it back together and make a ton more power.

 

[jasonmark1993]

Someone already said it:

Blowers push a volume of air. If what you are pushing it into is bigger, the pressure will go down.

If you have to do it in stages thats fine. The foundation will be there.

 

[mtrsprt]

Blowers push a volume of air. If what you are pushing it into is bigger, the pressure will go down.

Only if the volume of air your trying to compress is going through something that is bigger AND pumping more air on its own....

In certain situations, bigger displacement, doesn't always move more air on its own.


Boost is more than a measure of restriction also. Boost is the compressed air being forced into the combustion chamber during the intake stroke. More boost (measured), always equals more power, given that there are no other engine changes.

 

[95PGTTech]

Boost is measured at the manifold...what's the pressure of all the air crammed between the blower/piping and closed intake valve.

Increased CI it is usually assumed your air pump of an engine is capable of moving more air in and out per cycle, therefore on the same pulley setup (volume of air between supercharger/intake valve) it can evacuate more of that. Which would mean a lower boost number, but higher horsepower.

Yes, it will make more. How much more needs to be solved car to car. Since a blower is such an easy install, I would do your shortblock and worry about the blower from there. Why you're not doing heads and cams when doing a shortblock though is another question...