Turbocharge VS Supercharge

i forgot to mention
it;s AWD, ugly car buy i'd drive it

pictures with BOTH

nice car

thanx everyone for your help, when the cars done i'll post some vids of some races done with itto show my thanx and appreciations

Hi all,
Some very interesting view points and some good ones at that. Loads of people believe that displacement is everything and yes it is important but not everything. Dont get me wrong nothing sounds as sweet as a V8 or more motor singing to purrfection, but believe me when I say some small 4 - 6 cylinder motors tuned properly will out perform big 8s +. It comes down to power to weight ratios and this is the reason why you dont see 4cyl motors running in the top fuelers, just like you will never find a top fueler running a tight multi directional turn circuit. So its horses for coarses. But down to personal preference regarding turbo or super chargers, taking out the heat element of the turbo (which through the correct venting and insulation can be sorted pretty easily)and coupling a pre-turbo to the main turbo so as to achieve the grunt from 1000rpm through to +10000 rpm (even higher on correctly balanced crank, weighed con rods and pistons and lightened fly wheel, and correct gear ratio (manual preferably) there really is no other alternative for street racing. But to couple a turbo and super charger together the turbo being the pre and the super the main would be the ultimate, where the small turbo is quite capable of producing the required 5-20% extra torque to help the super along, now with this setup I dont think much could out perform and more importantly look and sound better. Okay maybe add a NOS tank or two.
Great views from all on this subject.
Cheers

i like big v8's....so i have to say supercharger....but i've driven a turbocharged 4 cyl 1,6l....120hp....and it felt like a lot more than 120...especially that the car was light....for the connoiseurs i put a 1,6l renault fuego engine onto a renault 12...strenghtened the body....and got the weight under a ton...mounted turbo, replaced injectors with carb...well u know the rest...

another solution for the heated intake temps from a turbo, is a 50 or 75 hp dry shot of nitrous into the intake tube after the turbo, this will greatly reduce the intake air temps. Makes very good power and is fairly reliable

well as much of opion between a turbo than a superch i have seen mustang with the same internals the only diference was one was with turbo while the other with super. the turbo was running 15 pound of boost while the super was running 17 pounds and the turbocharged one was faster. i myself have a '95 347 strocker with 150 wet shot and no ricer has stayed on my bumber for more than 1/8 of a second. my cousen had a stock 302 '94 and he put down 700 on the rear with a turbo only cams and fuels system. when it gave up last summer we took it appart and it was very bad. the pistons had holes. if you want to beat the 500 hp ricers you might want to get a stronger block but a different piston are a must, and a turbo is better if you are not going to stroke the motor. tubos are more efficient since they go use wasted energy to make power. superchargers use the power of the motor to make power so they rob some power from the motor to beggin with. supercharger are good of the line since they do produce boust idle but with the new tech for turbos it really is becaming hard to see why to put a super other then the whining sound they make. hope this help. if you need more information about turbo Mustangs email me and check this website: http://turbomustangs.com/ check it out.

I agree ^^^^ you need a good set of forged pistons for any substantial power adders. Anything over 600 hp I would recomend that the entire rotating assmebly and the block be aftermarket. Yes people do it with stock stuff all the time, but people re-build them alot too.

So very very true, we all have learnt the hard way, but it is fun. Excellent views from everyone

yeah gotta love those fireballs in the windshield otherwsie known as Lessons the hard way

gr8 topic guys!!! some good info here

Quote:

Originally posted by bachiotomy

It's really opinion. They do each perform better than the other in specific applications. Generally you feel little to no lag with a supercharger... but the turbo has a greater surge of power... like bursts... supercharger you have a consatnt flow.

I prefer superchargers.

Right on. My preference is for a constant power curve. Depending on the turbocharger, lack of sufficient back pressure can cause a thrust lag. I personally do not like this effect.

There's a lot of good info here, but there's also a lot of wrong info here.

There are 4 basic styles of superchargers:

Roots (Eaton M90/M115, etc)
Twin-screw (Whipple, Autorotor)
Centrifugal (Powerdyne, Vortech)
Axial (AxialFlow)

A roots blower is a positive displacement (meaning it creates boost 'instantly', and is one of the most inefficient designs there is. A roots blower will heat air up MORE than a turbo will. This is an effect of it's poor adiabatic efficiency (generally in the 50% range). They also don't compress air internally, they compress it either in the intake manifolds or intercooler piping/etc.

A twin-screw (Whipple, Autorotor, etc), is again, a positive displacement rotor. However, it has an internal compression ratio, and has a considerably higher efficiency than roots (72-80%), rivalling turbo's in adiabatic efficiency.

Centrifugal's are basically a turbo driven via a pulley, it's a turbine compressor with an internal compression ratio, they build boost expotentially, meaning boost will rise as RPM's increase (for example 0psi at 2k rpm, 2psi at 3k, 4psi at 4k, etc). They usually have similar efficiency to that of a turbo (68-75%). They're not very desirable due to their lag, which can be worse than a turbo application. They are beneficial though due to their compact size and ease of installation.

Axial flows are rather unique, they build boost by spinning an impeller, which draws air in, then stacks it on stationary blades (usually in opposing direction), as the air 'stacks' it compresses, then moves to another spinning impeller, and repeats the cycle, this is generally called 'stages', they require very high RPM and have exceptional efficiency, but aren't very common due to inability to make them very stable.

Now, it has been said that turbos create extreme heat and heat up the intake air more-so than a supercharger. This really isn't ture. The exhaust turbine housing will be the hottest section, and will heat up your engine bay, but this is preventable with a turbo blanket and some heat-wrap. As for heating the intake, there is very little heatsoak from the compressor housing to the intake air. The heat is generated from the compression itself, and is also a result of the adiabatic efficiency of the compressor. As mentioned above, most common superchargers (ie the roots blower), don't even come close to most modern turbos in efficiency (52% vs 79-82%), thus the superchargers outlet air temperatures are extremely higher which will result in higher pressures (so you'll see higher PSI on a boost gauge), while a lot of people are confused into believing that more PSI magically means more power this also isn't true. Your goal is more air volume, not pressure, and again, science class teaches us pressure is a product of volume and temperature, so it's not always good. Turbo's also allow easy adjustments to power, depending upon your boost controller you can either turn a dial, or simply press a button and instantly have an additional 100hp (if your turbo/fuel setup can support it), versus having to swap pulleys and possibly belts/etc with a supercharger setup.

As mentioned, turbo's suffer from lag. Lag can be easily combated by using a smaller turbine housing increasing velocity, however this decreases the maximum flow, so you can have a turbo that spools up rather instantly, however in the upper band it struggles. How much it struggles in the upperband varies depending upon engine size/compressor/etc. There's also various methods to increase velocity in the lower band then have a solenoid actuated 'flapper', that will then open another runner (increasing total flow), to have the best of both worlds (See the Mazda twin-scroll setups), or you can really get involved and use twin-turbo in sequential.

Anyway, they all have their place and their uses, most are personal preference. Turbo's generally provide much more peak power at the cost of lag/low-end, where most common superchargers are applicable for low-end and mid-range torque, but suffer in the high-end (twin-screw and axials work well in high boost high rpm applications, but are rather expensive compared to a similar turbo setup). And it's becoming increasingly more common for top drag cars to be turbocharged, if you happen to attend any local events you'll see many many categories dominated by turbo vehicles.

good topic

im a v8 guy i have a 350 in my s10 and i want to put a supercharger. superchargers all the way!!!!

if turbo's are maintained properly then they are quite reliable... people dont realize that turbos get so hot ... you gotta let it warm up And warm down... if theres no oil/coolant flowing through to cool it down after a good run then its going to seize it up/ warp it/ruin it .. blah blah

im turbo charging my Kcar to turbo II status... hoping to get 250hp 300ftlbs torque which is an easy task for a well built turbo dodge motor.

i helped a buddy build a 350 and put it in his jeep yj.. and its making pretty good power... but im going race him when im done and ill prolly win. then im going to race a buddy from work with an 85 camaro with a 350 in it and ill probably win that too

All forms of power adders have their good points and bad points. Have heard of big alcohol injected blowers freezing up, turbos melting down, and who hasn't seen a nitrous backfire. They can all be very tame and reliable, they can also be as nasty as you want to make them.

T78 turbo in a 94 Supra cant beat it 800+ hp

Excellent info as usual, I am currently building a BMW327 stroked to a 329 to fit into my 3 series pickup, I have decided for starters to just stroke and not charge it in anyway. due to the weight of the pickup i am drifting it quite happily with the 325 in it at the moment.......but more power is always the added bonus. But putting any form of charger on initially without seeing how the car will react in small power increases will probably see anyone who has done such conversions before....quickly sitting up a tree wondering how you got there so fast.....my point being.....to all us petrol heads ....dont just think power!!! you have to stop the lump properly...if not it will be the most expensive mistake you make! Big up power......bigger big up for anchors!!
Great thread by all