I thought it might be helpfull for those that are new to the world of turbo,SC,and nitris.
turbo ,SC ,and NO2 all do the same thing they add air to the cylinders. turbo and SC do it machanicly NO2 does chemicly both giving the same result.
on a n/a motor the piston pulls air into the cylinder on the intake stroke. for example a 1.5liter 4 cylinder 4 stroke motor will pull 1.5 liters of air every two revolutions at 100% efficientcy (not hard to accoplish with todays cylinder heads).

remenber atmosferic pressure is at 14.7ps1 (n/a) ,if you add 14.7 psi of boost you will duoble the the effiecntcy of the motor ,like haviimg a 3.0liter engine instead of a 1.5liter engine .so in theory at 14.7 psi of boost you should double your power.this is where it gets technical. in order to produce more power at less boost you have to increase the efficientcy .this is where the big differances in power adders come in.

we'll start with NO2 ,this is hands down the most efficient power adder . your adding air to the motor with no parisitic draw ,plus your dropping the charge temps to 125 degrees below 0 (now thats a CAI)

S/C add air to the motor w/ a compressor via belt that runs of the crankpulley .their are to types of S/C 's avalible root's (positive displaysment) this style moves air very quikly and very spacific .for every rotaion of the roots blower it moves a spacific amount of air.the other is a cyntrifical S/C best discription is a belt drive turbo.dosn't respone as fast as a roots blower but has better eficientcy,hoever it is still govenerd by engine rpm

and last but not least my favoret TURBO. turbos are driven buy the exuast not the crankshaft .to be more specific the heat of the exhust .this is wasted energy that is directed into the turbo to drive the exh. turbine (much like jet engine)the compressor side of the turbo is drivin via the comon shaft between the two sides(comp./exh.)becuase the turbo is not drivin by the crank and uses the wasted energy of the exhust it is far more efficeint than the S/C's also it is not governed by rpm .it is controlled by a waste gate whitch allow exh. to be routed around the exh.turbine .thus alloing controll of the compressor speed.by speeding up or slowwing down the comp. you raise and lower the boost level .this is controlled by a boost refrace line from the intake manifold or comp. housing.

PRO's AND CON's

NO2 is the most efficeint but has a limited suply and is abrupt and violent when actavated.

roots S/C instant responce good for low end power but not real efficient has lots of parasitic draw it is governd by rpm .cfm spacific not boost .(rpm determands cfm not the boost level)

cyntrifical S/C not as responsive as roots but has less parasitic draw dosnt heat the air up as much as the roots but is still governed by rpm .cfm specific not boost.

turbos not as responsive as a roots blower but more responsive than cyntrifical.far more efficient because it is drivin by exh. not crankshaft (little parasitic draw) governed by boost level not rpm ,dosn't have a limited cfm per rpm..

THE KEY TO ALL FORCED INDUTION

althought there is more than one way to boost your car there is one constant AIR/FUEL RATIO their is nothing more inportant than the right amount of fuel. if you have too much it will be slugish and foul plugs if you have too little you go boom!
too little fuel is called a lean condition this increase the burn rate of the of the of the fuel in the cylider cuasing it to be an explosion rather than a controlled burn.this is called detonation or piing most common result of this is broken ring lands (the space between the rings on the piston)cuasing the rings to leak and allowing cylinder presser to leak in to the crankcase(blow by). .this also increases the exh. temps whitch can melt pistons and burn valves. i like to see air/fuel ratios between 10.8-12.3 on pump gas depending boost level you can run leaner on race gas,but thats a whole new ball game

the next big ajstment is timming controll this is directly related to air/fuel setting remember both affect the burn rate it is best to think of timing in its relation to the burn rate of the fuel not in its relation to TDC. for example if the engine pings or detonates at 19 degrees BTDC at 12.5-1 air/fuel ratio it might make perfect power at 19 degreesb BTDC at 11.4-1 ratio . also you can slow the burn rate by putting in colder plugs but this is just the basics so we won't get into that this time.

hope this helps some of you to understand forced indution a little better

Mike Stafford
Stafford Fabrication.

 

Nice wirte-up, Now explain Twin-Charging?

:twisted:

 

are you sure yoiu ready for that

 

Mike that's why your the man!

You know what your doing! Thats why I went to you, and not be foolish;and not to try to do things myself! Best Turbo kit that I ever had! :D

***** 5 star rating for (Mike Stafford) Stafford Fabrication

 

Yes, most defenitly.

:twisted:

 

Thanks for the info.
Orange XB coming any day now!

 

And how many turbo kits have you had?

Andrew

 

another piece of important information that will directly relate to getting your "theoretical" limit of power from xx psi.

just because you pump in 7psi of boost at the correct amount of cfm, still doesn't mean you're going to get your 1.5x power, just as 14psi of boost doesn't equate to suddenly 168 hp(assuming 89fwhp baseline) for a scion xB.

you still have to attribute things such as valve timing +overlap, combustion temperatures, combustion efficiency, ignition timing, intake air charge temperature, limits to detonation, etc.

with a perfect motor with all variables being perfect, you'll get your 168 whp, but this isn't a perfect world.

1, with vvti, at high rpm, your intake and exhaust valves are designed to overlap intake and exhaust cycles, though vastly inefficient, it gets you to that 89rwhp you all so desperately milk. without vvti, you'd have only one set powerband range.

-this is not forced induction friendly. whenever your valves are overlapped, you can imagine your motor acting as a pass through, that extra 1.5 liters from the "3.0" that you're pumping through at 14.7psi goes right into the exhaust along with your gasoline. also, when the exhaust valves open up, your fuel mixture isn't even close to being burned.

it's very important to be able to allow the combustion chamber to do its work unmolested by intake/exhaust valve overlap.

2, ignition timing, with a certain amount of ignition timing, you can add power to your motor at the risk of detonation and running much hotter than normal.

3, combustion temperatures, mainly controlled by sparkplugs, ignition systems, and a/f ratio. the hotter your egts, the more extreme your a/f is - which can be very lean or very rich - neither of which is good. in a turbo setup, this will put stress on your downpipe and possibly burn a crack into it, for your cat? it will hate you and turn you into mr gross polluter if it's all too rich. if it's waaaaaaaay too lean, say goodbye to your motor as you force a rod through your block and into your groin or something.

4, intake air charge temps, the lower the temp, the denser the air, the more air you have put inside the motor. either from cold ambient air temps, an intercooler, or water injection, it's all the same end result, denser - colder air. of course you'll have to compensate with more fuel to keep the a/f from leaning out. but remember, anything to increase the amount of air into your motor will give you more power, up to the point of detonation. another nice attribute to cooling down your air is making it less likely to detonate in your motor.

5, CFM + PSI. PSI alone is not the end all be all of forced induction. If I had some 30 gallon craftsman air tank with 150 psi inside, it can't blow like a turbo can. CFM, or cubic feet per minute, is a measure of how much air blows by. The more CFM of a specific PSI that goes into your motor means more power. Just because you pump in 14.7 psi of boost into your motor, if you're not getting the same CFM as a 3.0liter motor gets at 1 atm, you won't get that 2x power, not by a long shot. To get that power, you need the same CFM as a 3.0 motor but at 14.7 psi.

-This is the exact reason why some turbos, though they may spool later, end up making more max power at the same psi than other turbos that do not flow as well, with all other things being equal.


----------Now the last part.

Just because you know this theory doesn't mean you will know how to apply any of this information. research into each of these ideas will provide you with a greater big picture on what roll Forced Induction plays in your motor and your eventual power output, as well as how to make it work for you, instead of you working for it.

 

i'm sorry but.. i will now never buy a turbo kit, or anything designed by a "COMPANY" represented by someone who can't even take the time to spell check..

c'mon man, show a little professionalism! or as you would say propheshinnalitsm

oh, and btw, there is another type of supercharger readily available. the twin screw. look it up man.

 

plees fourgive mee four knot taiking thu time two chechk da spelling.

as for the twin screw it is an internaly compressing roots most commonly known as a whipple .this blower is capable of making alot of power .the only real problem is getting one that is the right size for this engine .whipples start of with a 1.2 liter per rotation .so to keep it from overboosting a 1.5 liter engine you have to slow it down and that makes for lag .to get a smaller unit you have to get an autorotor from a company called opcon they make a twin screws from .5 , .89 , .1.5 .but the last time i used an auto rotor i had to buy it from kenny bel becuase he has the sole distrabution rights in the US. if you want to find one in the junk yard you'll have to go over seas .to my knowlage the only car to ever come with an autorotor was a mazda millinia (not avalible here)

two years ago i built the first hot side mount auto rotor on a miada w/ an intercooler .i used a blow throw design w/ a bov like a turbo.the performance was great but the noise was like a firetruck sirien.
the seconded ove the two project cars i built a cold side .this was a sheet metal intake manifold w/ an air/waterv intercooler in it . the blower mounted on the intake and the throttle was bolted to the inlet of blower .for this to work you need to put a bypass valve (magnason valve) between the vacume side and the pressure side blower so it dosn't load up and start over heating the case . this system was my favorate of the two ,driveability was sweet and the power was instant .it just isn't real cost effective. i made more power w/ the turbo on these cars for less money ,but yea that was the sweetest positive displacement blower i had ever used

oh, just for some useless info this blower was originaly designed to pump air into mine shafts so the workers could breathe.
anyway is that enough research for ya!

 

actually, whipple does not build the twin screw. they buy it from lysholm. a 1.2 liter/revolution SC would be FINE with the 1.5...

why wouldn't it be? haven't you heard of relieving/recirculating excess boost on superchargers? toyota's been doing it since the mid 80's..

 

where getting way off track this tread was to heip people understand the basic forms of forced induction . i used the most common forms as examples .maybe you would like to start a tread called all the possible ways of forced induction and the technical aspecs of there opperation.

but for now i think it would be most usefull for the members of this forum if we keep on track and help them to understand the options avalible to them .it is apparent that you have some knowlage on this subject lets see if we can use this knowlage to help the members instead of a ____ing match of the turbo intellect

 

lol whatever you say man..

u presented part of the options, gave some pretty crappy examples, some incorrect information (such as.. the centrifugal SC is more efficient than roots type.. which thermally is true, but volumetrically isn't even close) and i added to that.

people learn best by seeing both sides of the coin, not by swallowing whole everything people tell them.

 

WOW!!!you gotta be kidding me.You guys just have TOO much times on your hands.to argue about this.Hey,just let mike speak,damn.He's probably been doing turbos before your were just a nut stain.He sells his turbo systems all over the country.Obviously you havent checked out the magazine MAX POWER.Ya check out the yellow TOYOTA CELICA.Look whos name is on the front of that car.HIS not yours.so until you can prove that your not just some "kid" on his mommies computer,let mike help others out.
These threads are to give info,not to argue."so cant we all just....you kow the rest.
ok mike good job.......continue

 

at least THIS nut stain takes the time to spell..

 

First of all sfpower thanks for the info.

Second of all, wtf civiceater. why all the hostility. sfpower didn't do anything to f@%k with you, so stop f@%kin with him. It's just not neccessary and not what we're here to read.

Thirdly, you invest way too much liability in taking the time to spell check. Its a lousy button on every computer, that doesn't demonstrate any bit of intelligence. However, much of the info by sfpower is intelligent (perhaps not complete or well rounded but it is unarguably intelligent)

If you have something intelligent and worth reading to offer to this thread please do so, otherwise ...Andrew just lock this ____ up!

 

So, SFPower what is your opinion for the daily driver type of a Scion (excluding NOS) which is more practical, is FI only about the speeder?

What about smog/CARB cert, do OEM FI options have difficulty passing smog?

Thanks, man!

 

as long as an exemption order applies for the vehicle and the mod, then there's no problem with smog.

realistically, some smog stations may decide not to even bother with it because of a lack of informed knowledge on the legality of mods. cops on the same hand will give you a fix it ticket for any mod depending on their knowledge of the law and whether or not they want to hassle you. there are a lot of cops out there that are mean and stuff, this is when you need to bring a tape recorder and record the conversations you have with them to protect yourself.

a state referree will know most of the laws concerning any mods.

 

Thanks for the FYI Mike...I was totally confused about all the equations...i.e. PSI, forced induction, Turbo, Supercharge, Aem, Blitz, I'm like spinning in circles. I've had a 2001 Focus ZTS (traded) for a 2002 Firebird (stolen) neither one I did ANY work to besides rims. The Xb will be my first, and all I really want to do is add a little more power to it, like maybe have 120 horsepower give or take without having a REALLY loud buzzing sound when you accelerate. I'm not power hungry I just want a bit more zip to it without having to break my bank or neck trying to afford it. What would you suggest?...Anyone can respond, Thanks!

 

what does forced induction do to your gas mileage?