ArcticFormula

Mightymouse,
I didn't realize the costs between a turbo kit and supercharger kkit were so close. I would opt for the turbo then. The efficiency advantages have been pointed out by many. I would want the most airflow for a given level of boost, as I would probably not venture past 5 psi (I'm pretty conservative), without some low compression forged pistons, maybe 8:1) and forged rods. At 5 psi with say a TE-60 turbo, what kind of horsepower increase do you think would be realized at the rear wheels?
Turbo or SC, I am envious of your setups, I just don't have the cash to join the club.
Regards,

SJH

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">no SJH, actually I meant what I meant. Having already had a t-60 and a t-76 I can promise that 7psi on each is not the same.
If what you say is true, then how come everyone is not running around on p1's and t-60's.. they both can put plenty of 'numerical' boost out, over 15# for the turbo is easy.. but the airlfow just isn't there.
I might have my terminology a touch off, but I am definitely not wrong.

</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Sorry, but you are definitely wrong.
Boost is a function of more air being forced into the motor than it can ingest N.A.
Once airflow exceeds what the engine can take in by itself, only then will pressure begin to build in the intake manifold.
If you flow 1000cfm of air into a mild V8 with either a t-76 or D-1 or a s-trim, boost will be the same( IF YOU KEEP CHARGE TEMPS THE SAME), example maybe around 15psi.
That same 1000cfm on a 4 cylinder might be 30psi.

You can not make boost if the blower/turbo can't exceed the cfm of the engine on it's own.
Put your t-76 on a NHRA pro stock motor and it won't make a single lb of boost and would rob the motor of hundreds of HP.
Boost is pressure, not airflow.
There are differences in the efficiency of the units at different flows.
This is where things change.
When you are looking at the ultimate power of a turbo or blower, you need to look at how much Mass Flow it can move.
Boost/flow relation efficiency ratings are how much the device will heat the air over perfect compression.
Assuming you can keep charge temps identical with either a T-76 or D1 and force 15psi from a theoretical 1000cfm as a number needed to make that boost into the same engine, power difference would be based off crankshaft power loss from the supercharger vs the more efficient exhaust backpressure loss from the turbo.
The turbo would make more net power, this is pretty much a given.
But airflow into the motor is not the reason for the power difference.
Steve

Gold Phoenix

iTrader: (1)

Something else to consider. Turbos and Centrifugal are dynamic air pumps. The don't flow a fix amount of air like a root blower. A turbo generally has a simpler compressor compared to a S/C due to the fact that turbos will spin up to 120,000 rpm and can stay at a giving speed at almost any engine rpm. S/C need a more aggressive impeller to force the air at a lower impeller RPM. The more you try to force air to move (compress it), the more heat is built up. That is why turbos are more efficient that centrifugal superchargers.

Big Stick

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif"> Sorry, but you are definitely wrong.
Boost is a function of more air being forced into the motor than it can ingest N.A.
Once airflow exceeds what the engine can take in by itself, only then will pressure begin to build in the intake manifold.
If you flow 1000cfm of air into a mild V8 with either a t-76 or D-1 or a s-trim, boost will be the same( IF YOU KEEP CHARGE TEMPS THE SAME), example maybe around 15psi.
That same 1000cfm on a 4 cylinder might be 30psi.

You can not make boost if the blower/turbo can't exceed the cfm of the engine on it's own.
Put your t-76 on a NHRA pro stock motor and it won't make a single lb of boost and would rob the motor of hundreds of HP.
Boost is pressure, not airflow.
There are differences in the efficiency of the units at different flows.
This is where things change.
When you are looking at the ultimate power of a turbo or blower, you need to look at how much Mass Flow it can move.
Boost/flow relation efficiency ratings are how much the device will heat the air over perfect compression.
Assuming you can keep charge temps identical with either a T-76 or D1 and force 15psi from a theoretical 1000cfm as a number needed to make that boost into the same engine, power difference would be based off crankshaft power loss from the supercharger vs the more efficient exhaust backpressure loss from the turbo.
The turbo would make more net power, this is pretty much a given.
But airflow into the motor is not the reason for the power difference.
Steve
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Ding! Ding! Ding! We have a winner!

The amount a s/c or turbo can flow in cfm will determine the amount of boost it can produce on a given engine.

<small>[ December 04, 2002, 03:51 PM: Message edited by: MarkSS ]</small>

BIGBOS

This is becoming the kind of topic I wanted it to be...hardcore comparasions <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

MIGHTYMOUSE

iTrader: (59)

lbz: http://community.webshots.com/photo/...4156KjfwnpdMfG

turbo here:

http://community.webshots.com/photo/...6139rWorUCPbki

good luck on the home built set up, no one has done this sucessfully yet, i hope you have a lot of resources.

arctic: 8:1 is way too low IMO for a street driven car you will loose a lot of driveability..
the t-60 from turbonetics really cant feed air to make you much more than 450rwhp. i would go with the t-63(ls1 motorsports kit) or the t-76

if you only want 5psi, no need to go into the engine at all.. you'd be lucky to see over 400rwhp.. but if your'e going into the motor anyways and doing rods/pistons, then you should run at least 10psi to make it worth the investment and shoot for around 600 at the tires.

SJH: if im wrong, not the first time, but i will claim i was mis informed <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

i think your statement here is pretty much the same as what i was saying or in a round about way.
"When you are looking at the ultimate power of a turbo or blower, you need to look at how much Mass Flow it can move.
Boost/flow relation efficiency ratings are how much the device will heat the air over perfect compression.
ASSUMING you can keep charge temps identical

when the air gets hotter, the air gets less dense, meaning less 'mass flow' which is basically exactly what i said. 15# of hot boost can equal 11# of cold boost (i was ASSUMING everyone knew about the relationship of air density and it's temperature)

You are 100% correct to say IF you could keep the iat's down on a p1 that it would make the same power as a D1.. but you cant, so you dont... therefore you have to run more boost to get the same massflow you would have had if the air stayed as cool as the d1.. follow me?

are you ready to agree yet?

SJH

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">when the air gets hotter, the air gets less dense, meaning less 'mass flow' which is basically exactly what i said. 15# of hot boost can equal 11# of cold boost (i was ASSUMING everyone knew about the relationship of air density and it's temperature)

You are 100% correct to say IF you could keep the iat's down on a p1 that it would make the same power as a D1.. but you cant, so you dont... therefore you have to run more boost to get the same massflow you would have had if the air stayed as cool as the d1.. follow me?

are you ready to agree yet?
</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">well I'll agree with those statements.
yes guys can get into a situation where boost rises with no increase in density.
Similar to heating a sealed air cylinder.Pressure(BOOST) will build inside with no increase in density.

But a good intercooler goes a long way.
The difference in a few % points in adiabatic efficiency does not mean so much anymore when using a good intercooling system.
So I just look at the mass flow capabilties of the units now.
A D1 vs P1 with good intercooling is really going to boil down to the fact a D1 just outflows a p1 and probably uses less power to drive it at the same flows(I'M GUESSING), not so much the fact a P1 will heat the air more.

Steve

purevilss

Can you get the turbo emissions legal, with cats, like you can a supercharger?

MelloYellow

I don't know why everyone sweats emissions so much. Just drop some dude a C-Note and I'm sure you'll pass.

<small>[ December 05, 2002, 05:28 PM: Message edited by: MelloYellow ]</small>

MIGHTYMOUSE

iTrader: (59)

pureevil: you can put a cat on a turbo kit if you want, but it will still be illegal, just as illegal as the headers with cats that you will run on the supercharger.

cats block hp.. drop em and go find a friend who does inspections.

RedBaron

iTrader: (2)

Which setup (turbo vs. supercharger) would be better for daily driving including long road trips? With both setups putting out similar figures.

XLR8NSS

iTrader: (4)

Hey SJH

So basically you could make up for running a turbo/supercharger out of it's most efficient range by compensating with a more efficient intercooler setup?

It makes sense. It would just be trading addiabatic efficiency for intercooler efficiency. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

John

ZYA_LTR

Red Baron, if i could do it all over again, i would go the route of a ball bearing watercooled turbo, instead of the Procharger, and yes my car is kinda daily driven. On sunny days only, no rain or snow for my baby, and living in Michigan, that means storing you car half of the year. In the three years i've had the car, i've put on a little over 11,000 miles, bummer huh?

flynbludream

iTrader: (1)

LBZ, how do you figure you need 430 rwhp to pull on a 250 rwhp car? Are you saying an N/A car up here with 430 corrected or uncorrected? I agree that most of the 5.0's around here with SC's are not very impressive at all. I have beaten more than my share of them with my measly little 267 rwhp (uncorrected) ls1. I thought you ran a lot more hp than 250? <img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

RedBaron

iTrader: (2)

ZYA_LTR, Yeah that sucks that you can only drive your car a few months a year. Living in Houston I get to drive pretty much 12 months a year, putting atleast 15,000 miles on it yearly. Thats why daily drivability is important to me.

BIGBOS

Here in chi-town I get a good spring, summer, and fall to drive my car...since feb of 2001 I have 14,250 miles on my car....which isn't too bad at all...

my car was down for about 2 months over summer though, restricted to driving on beautiful summer days... <img border="0" alt="[Banging Head]" title="" src="graemlins/gr_banghead.gif" />

MIGHTYMOUSE

iTrader: (59)

red baron: properly set up and tuned i cant say that either would be worse/better than the other as far as daily driving or long road trips.
if its a VERY long road trip you will have to bring a change of oil for your supercharger (special oil for the d1) where as the turbos oil would get changed during a regular oil change.
after that, it would come down to vehicle weight, which i expect would be similar.

xlr8nss: if you could swap in and out different intercoolers it would certainly help, but too big is not good either. the problem is that with both the procharger and single turbo kits, you only have one type of intercooler to work with so youre kinda stuck. good thing for me cuz i dont know much about intercooler sizing so i'd leave it anyhow.

MelloYellow

Thx guys. Based on this thread I placed my order for a Vortech V2-SQ.
<img border="0" title="" alt="[Razz]" src="gr_tounge.gif" />

SJH

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Hey SJH

So basically you could make up for running a turbo/supercharger out of it's most efficient range by compensating with a more efficient intercooler setup?

It makes sense. It would just be trading addiabatic efficiency for intercooler efficiency.</font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">yep.Of course that might get mighty expensive if it meant upgrading intercoolers for some.Then it might make more sense to upgrade the blower instead. But it just depends on the persons system.
All I watch is boost and iat numbers and maf lbs/min. If boost goes up and my iat won't stay stable, then I would know I am getting a bit beyond where I should be pushing the blower.
But so far at 67lbs/min flow which is 11psi peak on my motor, my iat's stay flat at 20 degrees above ambient with my triple nozzle water/methanol system and I use no intercooler at all.
So much for adiabatic efficieny islands.
Flow baby! Flow is all I need! Liquid intercooling does the trick for me.
Next year this lil' blower gets pushed to it's max <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> .

Steve

XLR8NSS

iTrader: (4)

I was just putting together some combo's in my head. <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" /> <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" /> I'd like to try something with boost again down the road but, I'd like to make my own system. That way I'll be forced to learn about every aspect of it. <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

It seems that running a single turbo on a big motor would be hard to do and keep it in an "efficient island" <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> at certain flow/power levels. It's good to know that you can make up for that with a properly sized intercooler setup.

Water/alky and no intercooler...now that would be a VERY easy setup to build. <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Steve, I thought you were already running that poor little Vortech at it's max. <img border="0" title="" alt="[Eek!]" src="gr_eek2.gif" /> If you destroy it make sure to give it a proper burial....It's served you well. <img border="0" title="" alt="[Razz]" src="gr_tounge.gif" /> <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />

John