403rwhp on just 9psi?

[MysteryMachine]

he's obviously making more power. I sorta kinda tried to answer that with my straw scenario. He puts better flowing (than stock) parts on and that's like moving to a bigger straw. More air flows through it without as much backpressure. Even though it registers as less backpressure.... "less boost" .... it flows more air. Blow through a big one and a small one and see which one makes you run out of breath first
An engine is basically an airpump...flow more air and it will make more power.

say you have an inefficient combo....and you spin a supercharger 50000 rpm on it and it's making 11psi. Get an engine that is efficient and flows well....and put that same 50000 rpm blower on there.....and it'll make say 8-9 psi. This is because the engine can pass that air through rather than just let it build up in the intake. That blower is still flowing the SAME AMOUNT OF AIR regardless of "boost" readings. A blower turning 50,000 rpm (given the same internals are used)...is gonna flow the same amount regardless of what's behind it.

It's all about the cfm, folks

you didn't mention my name thats funny right there

 

[buddyf87]

ok grady, i got another semi-conceptual question for you:

turbo vs. blower- a blower setup on a stock 5.0 at the typical 8 or 9 psi usually makes around 100rwhp less than a turbo setup at the same boost level (very general numbers, but you get the idea). since boost is just a resistance to flow (provided by the engine components), wouldnt this mean both are forcing the same amount of air into the engine? a turbo couldnt push air in with less resistance (meaning it would actually be pushing in more air if this were true). the difference in power cant be caused by the blower draining the engine to spin it, accessories on the belt dont drain more than 10 or 15 ponies, do they? im confusing myself more and more as i write this haha.

 

[final5-0]

Wow

I can see someone has been thinking and puzzling over a thing or two

I certainly am not greatly versed in blowers and turbos but I think I won't
be too far off with my thinking if I stay with general kinds of things

besides ... if I hose up in my attempt ... some of my SN friends who
have more experience can clean up my mess

Yes things hanging off the front of the motor turned by a belt take more
hp than you would imagine.

The blower on top of all those things just takes all the more.

You also have to consider the way various devices build boost

The most obvious differences are the most common like a Centri and KB

One does well down low and the other up high

Turbos on the other hand kinda gives you the best of both
and
As the heat rises ... a turbo can be more effective

You really have to get into the application and look at the maps on the
turbos to be effective at choosing their size and housings.

For now ... let me give you a common thing you see on KB's that kinda
show what all you are asking.

The smallest size KB will work pretty well on a little stock Stang
or even one with some bolt-ons

however

You build up a really nice after market h/c/i combo on that same OEM
sized block and that baby KB is gonna start to run out of breath before
it approaches the redline.

See how the application and the capacity of the device can .......
make or break ... a successful combo

Does any of this junk make sense

Hope I answered your Q's and if not ... more peeps can get involved but
for now ... I kinda tried to keep things with a broad focus so you might
not get all bogged down in a bunch of specific details

Grady

 

[cbarr300]

It takes a lot more power than you'd think to turn a blower.

10psi going in is 10psi...whether it be by a blower, a turbo....or your breath (ok so that couldn't happen)

Another thing to think about is heat. As air is compressed it can generate a good deal of heat. Would you rather have 10psi of hot air..or 10psi of nice dense air? Obviously dense air would be better because it can create more power. You can actually get to a point where you have higher boost but less power due to the temp. increase

with that said..think about the combos you mentioned earlier...comparing blower to turbo. Other things come into play. Was the air cooled by some means on both combos? Take note of the vortech combos...they don't come with any means to cool the charge (unless custom fabbed). It may be at 10 psi...but it's putting all kinds of hot air in the engine.

now, get a turbo setup with a cooling method....it may be putting out 10psi......but that's 10psi of nice, cool, dense air.


butttt, I'm young and dumb so take it for what you will haha,

Clay

 

[buddyf87]

haha yeah i have been giving this some thought. i understand the way the two kinds of blowers work to build boost, and how they can how they can run out of breath when one builds a bigger combo, whereas a turbo would not (on your typical hci setup).

however, on the same setup- for the sake of argument lets say a stock longblock 5.0- putting on a vortech or kb will net you say 75rwhp, whereas bolting on a turbo to the same engine will get you 200rwhp if not more at the same boost level.

what im asking is what accounts for the difference between the two; why the turbo can make so much more power at the same psi. as i understand it both are forcing the same amount of air in (correct me if im wrong here), so is the difference due to the fact that the turbo is free power, and the blower needs hp to make hp?

sorry if im being thick-headed but ive just been kind of thinking out loud and found this pretty interesting. and anybody else who can shed some light on it feel free to chime in!

EDIT: just saw your post clay, very good point i didnt even think of. i guess its a combination of blower draining power + turbos almost universally being intercooled.

 

[cbarr300]

This kind of goes with my earlier post...

butttt


Air temp and parasitic loss have a lottttt to do with the diff in power

EDIT: haha, I figured you were posting while I was posting. This is why you want an efficient set-up...otherwise it'd produce extra heat and thus you would have less power. Now, on to your buddy with the 4.6...I'd love to see how the torque curve looks to a similarly boosted 5.0. I have a hunch that would tell a little bit.

 

[buddyf87]

yeah im anxious to see the graph too, i havent seen it yet. as soon as i do ill post a copy.

 

[sl03gt]

4.6's with the PI (99+) heads respond very well to boost especially on a centrifigul. I have had both 5.0 and 4.6 and the 5.0 has great low rpm punch but the 4.6 with larger lift cam and better flowing (modern technology) heads flow better in the 3000+rpm range. Where does a centrifigul charger really kick in. Steeda sold a blower combo with a computer swap that would give you 400rwhp. Your friend with 4000rwhp is not that unbelievable especially with long tubes. 4.6's love long tubes. It gives them more low end and even better high end.

Like Grady said H/C/I 5.0 with a blower will easily be in the ball park.

5.0 225hp stock
4.6 260 hp stock 99-04
similar torque

5.0 small valve heads factory
5.0 .444 cam lift stock
120-135 cfm stock?

4.6 aluminum better designed head (spark plug in middle of cyl)
.500 cam lift stock
ohc=more efficiant faster reving valve train
heads flow 150-160cfm stock from what I understand
coil on plug ignition

Long tubes, blower, and a good tune should be around 350-400rwhp on a 4.6 is normal from what I've seen.

Downside
4.6
Blowers are more expensive
engines are more expensive
tunes are more expensive
parts are more expensive

Upside 5.0
blowers are cheaper
motors are cheaper
parts are cheaper
anybody who grew up in they 80's or early 90's thinks your car is fast because it has a 5.0!!!

Whitesnake rules and dyno racing sucks. It only matters what the car can do at the track or if your friend can drive.