which makes the most power at the same boost levels?

say all were running at 20 psi. the max cfm on the roots was 700, turbo was 900, and the centri was 1000.

i know that makes a difference but im not too schooled up in that or reading an airflow map.

i guess efficiency between each system at the same boost level is the question. ...

 

well all things being equal as far as boost and efficiency the centri should make more power because it is flowing more air
i only have a little knowledge about this stuff tho

 

awesome comparison...
http://www.musclemustangfastfords.co...o_results.html

 

Boost is only a measure of restriction to air flow. Assuming you were putting each of the setups on the exact same engine you could probably make comparisons between the two blowers but the turbo would alter the overall volumetric efficiency since the turbine/hot side of the turbo assembly sits in the exhaust stream and creates a restriction to overall flow through the engine (that the pistons have to expend some energy pumping the exhaust gasses out through it during the exhaust stroke). That means in addition to what's going into the engine (i.e. intake charge), the exhaust side of the turbo is introducing a restriction that's altering how easily it can get out, therefore it can have an affect boost (there's many variables that will affect that such as valve timing overlap, the turbine efficiency and housing, exhaust manifold design, how much wasted combustion gasses end up remaining in the cylinder, etc.).

If you're making comparisons, throw boost out the window and pay attention to mass air flow. In your example of the three different setups all producing 20 psi, without looking at what the efficiency is for each device we don't know the temperature of the compressed charge. And without knowing temperature we don't know what the density is and therefore don't know how many oxygen molecules there are to burn. For example if the conventional Roots-style blower was making 20 psi but it was all hot air (less dense with less oxygen) a turbo setup making 14 psi might make more power.

Too many people get caught in the habit of thinking the boost gauge is a power gauge. It's not. If you're interested I'd really suggest taking the time to learn to read those compressor maps. That will give you an idea of the compressor side but remember there are also other factors that will determine how much power is made. If you want I can dig up some good links on the internet and some reference books that might help explain it.

 

ill re-simplify.

Turbo-that size turbo you will make mad power up top but not so much down low
centri-im not sure how they perform low end but up top will be good power to
roots-will make good power to start but not so much towards the end of the power band

in terms of efficiency i would say the turbo will or the centri will win it, prob with the turbo out on top. mainly just have to decide what your goals are?

 

keep in mind even though the centri flows more CFM, it is driven off of the accessory belt and takes power away from the engine. our little eatons take about 40hp to run them if i recall correctly

 

They all take some power away from the engine. A turbocharger may be able to utilize some of the heat energy that would otherwise be wasted from the combustion process but it's not completely free power. It still places a restriction to the flow of air through the engine and the engine still has to utilize some of the power it's producing to pump the exhaust out.

 

it is by far the least power robbing one, and its not taking power from the crank shaft like an accessory would (or a supercharger), its just placing a restriction in the exhaust.

To OP: No comparison with twin screws?

 

http://www.kennebell.net/techinfo/ge...REWvsROOTS.pdf

 

It is taking power away from the crankshaft but just not in the form of drag on the snout and the accessory drive pulley, instead slowing down the piston that's on the exhaust stroke which reduces the force (torque) being applied to the crank. It's more difficult to ascertain how much power the turbo is costing compared to the power required to drive a blower, but in general you're absolutely correct that the turbocharger is going to better maximize wasted energy but make no doubt that it isn't completely free. That's why it's important to choose the correct exhaust housing and turbine sizing for the application. Many times it's easy to overlook the hot side and just focus on what the compressor wheel can support.

 

I have been there when (chevytech? I think was his name on here)did his with the procharger!

The problem with the procharger is its lack of moving air like the roots or turbo. Also you are stuck with the boost! You can not overspin a procharger! it will make too much heat at that point and make the engine knock!

So you can only run 15-18psi before you start overspinning the blower to get the boost up! Now if you could fit a bigger headunit (p1sc or better) in then great but I saw that crap and it didnt really fit that well.

The turbo on the other hand makes a crap ton of power!

The "lag" is worth the overall power plus with a wot box/2 step you can eliminate most of that lag! And you can run higher boost levels with the turbo without increasing the intake temps too much!

Thats just my .02! lol

 

This is going to be an absolutely EPIC thread with alllll different types of bullshit, misconjecture, and downright ******* comments being made by people who have no ******* clue as to what they are talking about.

 

If you're going supercharged you can't beat a screw charger...

 

watching

 

this should be interesting lol i'll put my 2 cents in later

 

um hi. you're a little slow in the head. this statement. is wrong.

 

huh? what is the 15-18psi about? what head unit are you talking about??

 

im am talking about the C1 headunit. C2 could make a little better but not much! Procharger rates the superchargers in free flowing no restrictions. So the 1000 cfm they clam it a bit lame in my book!

And the cost of a headunit! they are over 2k just for that! (no pullies ect)

I know area you can overspin the procharger if you want but in the case of the lsj and the C1 unit it was knocking everytime it hit the magic 80,000 rpm mark!

Im just posting what i learned!

 

riiightt do you have any idea what causes psi sleeperbalt?

 

yes psi is the build up of air from the restiction of flow! im just telling you that a centifical supercharger is not really the best forced induction for max power!

The question was will a centrifugal supercharger that puts out 1000cfm, a root blower at 700cfm and a turbo at 900cfm which will make more power!

The turbo hands down! 900 cfm is like what 70lbs/min? thats like a gt37r so as far as power the turbo will take it home!

 

so wait you're saying if the car is made to somehow flow 1k cfm.. ( which would mean it could easily flow for the rest of them) that the procharger wouldn't take peak numbers..

a turbo of that size isn't going to play all that nice with spooling either..

 

I think when you compare a turbo that flows 900 cfm(on a turbo map that is under pressure or resticition) to a procharger c1 or c2 1000cfm (no restrictions) that the turbo is going to make way more power even with the lag the procharger couldnt keep up.

I love the idea of the procharger and it sounded awsome at idle and yes it was a bit laggy too!

But we also have 2 step/wot boxes to get rid of most of the lag!

And the thing is at 20 psi the turbo can hold that pressure better then the procharger. Im not sure about the tvs I think it does it fine but i have no expirance with it!

Let play a game or start a thread to compare these!

elecblue: procharger
TVS: (anyone with a tvs can chime in!)
sleeperbalts: t3/t4 60 trim

My will be done next month how about you elecblue? the turbo I have only flow 58 lbs max or 650-700cfm. We can run them all at 20psi and see how far each gets!

 

mine wont be done again for like 5 months .. and my engine would probably go boom at that psi...

remember i have a 2.4 so it's really not the best compairison

but he'll i'm up for a challenge

i'm not saying i'll win all the races i'm not going for the fastest car... just to be unique...

wot box / 2 step will help as well as brake boosting... procharger is like a MASSIVE turbo lol made for like 12k rpms lol

 

The 2.4l will like the procharger with its bigger cylinders and higher C/R!

I dont think you could get to 20psi on a C1 and a 2.4l without overspinning!

It will be fun to compare them all! lol

Good luck you your build elecblue! I look forward to seeing it on a 2.4l!

 

supposedly the 2.55 is pretty much the limit i can go.. and thats supposed to be close to 20 psi... but we'll never know without putting it back on lol.