Ottawa Fiero Club Forum

TOTD  Turbocharger or Supercharger?

What do you prefer and why?

Once we have some responces I'll give my take too.


Aaron

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i like turbos.  you can run boost from 2 pounds to 30 pounds with the twist of a button .  easy to put an intercooler in the pressure line.  also you can spray nitrous on the intercooler or run race fuel and run evin higher boost for a money run.  easy to put a junk yard turbo on a moter.

supercharger is limited by the pulley you have bolted on it.  if you have a 8 pound pulley than thats what ya got.  got a 1000$ money run tough sht thats what your gonna run.
you want 25 pounds of boost tough sht cant with normal surpercharger.  want to put an intercooler on it for more hp.  tough sht cant on most.   the higher boost pulleys usually cause high heat proplems. the temp of the air being pumped by a supercharger would make you cry. very limited setup.  they are good for a reliable stock setup  thats it.  

think about it what would be better.  a supercharger that  is maxed out at 12psi or a turbo you can crank up to 18 psi with race gas and nitrous cooled intercooler?   we all know.

well you forgot to mention the most important difference of the two.. and the reason i would do a supercahrger.. you put the gas on and you have the hp.... on a turbo you have to wait for it to spool up.. who wants to wait for power..

supercharger also makes more sense on a larger motor and turbo on a smaller motor.. v-8 super charge it
4 cylinder.. go turbo

just check out this supercharged 240z and tell me that you dont want a supercharger

http://servinitup.com/videos/240z.mpeg (http://servinitup.com/videos/240z.mpeg)

I love the Super Charger!

it has one major downfall, it robs power to make power.

But after you get over that, it's a no brainer to go supercharged!

Here is why...
A supercharger is CONSISTANT, HP is there when you need it througout the power band. The boost is fully adjustable by computer. (and possible mechanicaly, but i never looked into that).

You can run a 3" pulley and have the blower running at 50% (we have a blowoff valve as well, you just can hear it because it blows back inside the supercharger, releases high pressure back into the low pressure section of the charger. ) Then with a flick of the switch, close off that valve and you got hight boost. (may ping or blowup, but you have high boost. :P )

Just want to leave you with this, it mostly depends on the driver. I can drive a high powered engine that is supercharged and spank someone really good, then sit me in a car like a Honda with turbo with the same hp ect, I would lose bad because I have no idea how to drive that properly. Shift points are different, spoooling, reving at this line (I never got that... )  ect.. .


My vote is supercharger all the way.

Why not Turbo and Super together on the same engine. Best of both worlds and what you lose in weight you gain in hp (if your engine can take it.

Small correction Eric.  :)

Both types of blowers use power to make power.  It's called the "nothing comes for free" rule.

The turbocharger obtains its drive energy from exhaust pressure.  It also represents a restriction in the exhaust system and some "extra" energy must be spent pushing exhaust gasses through the turbo which would not be spent in a non-turbo'd system.

The supercharger obtains its drive energy from a belt, just like the alternator, water pump, etc.

Both blowers require energy in order to do their thing...  they just obtain it from different sources.  The reason why a blower works is that the overall gain in power exceeds the power "lost" in operating the blower.  Well at least this is how it goes if the system is designed properly.   ;D


As for a preference, with my rather limited experience piloting each style of blown motor, I'd have to go with the supercharger.

I drove a turbocharged Probe GT once, somewhen around 1990.  It was pretty cool at the time; I loved the sound of the blower winding up, and the smoothly rising shove into the back of the seat.  At the same time though I found that the constant transition from no boost-to-boost when shifting (manual transmission) made for very choppy acceleration.  It would have definitely required some refinement of my driving skills to get the most out of it, but I was just a kid with a gopher job at the time, and my employer likely wouldn't have let me take the car out for regular practice sessions.

The Taurus SHO (3.?L supercharged V6 IIRC) which I took for a spin later, was an utterly different beast.  My dislike for the Mack-truck weighted shifter aside, it was smooth all the way, and all of the power was "instant on."

I think at this point I've read pretty much every pro & con going for either type of blower.  On paper, they are different but equal as far as I'm concerned.  For my driving ability however, I'll take the supercharger.  Unless of course someone wants to lend me some seat time behind a turbo so that I can figure out what to do with the thing.   ;D


Hey look... there I go answering one of Aaron's questions with a case of verbal diarrhea again.   ::)

I prefer turbocharging over supercharging, because the exhaust is power which is just wasted, so why not use it instead of throwing it away.

It is true it does use some power to overcome the obstruction in the exhuast, but nowhere near the power a supercharger robs.

turbo lag?   at launch the engine should be at 3000 rpm.   at shift points the engine never goes below 6000 rpm and up to the redline for 9000rpm.  where is there going to be this turbo lag you are talking about>??  id say that exaust gas is flowing realy fast.   opps sorry i forgot i drive a domestic now.  we havnt figured out how to build a race engine like this, stock, in north america.

turbo on a crap engine with low redline  and low tourqe band might be a problem.

but if you put a 12 psi pulley on a stock supercharged engine get ready for a mess.  you could not imagine what the air intake charge temperature will be. what if its mid summer? can you say detination.  now try road racing this car for an hour or two.  impossible. you could melt lead with that intake charge.

at least with the turbo you can have a huge intercooler your intake charge will be cooler at same psi.  and like i said you can spray nitrous on the intercooler for a absoulute chilley intake charge of dense cold air.  compared to air that would pop popcorn id say this is the way to go.

like i said before if your just a drive to the mall kinda guy supercharged is the way to go.  stock pulley wont heat up the intake charge very much.  low rpm non racing will keep the intake charge less hot.  very reliable.
if your car is automatic and has low tourqe curve and low redline its the only way to go.  turbo would be a nightmare on that kind of engine.

i want the 3800sc  in my fiero.  its automatic so i would put the sc tranny in as well.  perfect launch with auto and sc.  hp where is should be. less screw ups in quarter mile with auto as well. i would put a smaller pulley on it.   im cutting the hood open and putting open mustang  1985 hood scoop.  both side air scoops on the sides with fans to draw air in. i have 93 mrs turbo side scoops . have to keep the sc cool.  on weekends i would run c16 race gas and pack sc with dry ice.  is there a way to adjust psi from the cockpit?

it's already been don on pff with a 3800SC-I  not sure what the results are. But i think one would restrict the other,.

             
we havnt figured out how to build a race engine like this, stock, in north america.

Excuse me Mr jaygt, but have you forgotten that grand nationals dominated before the imports came on the scene, if you want proof just take a look at the early 90's turbo mag.

Can't you use an intercooler and spray with a supercharger also?

Not so.  See:
http://dtcc.cz28.com/87fiero/87fdrive.htm

Yes, yes you can. *grin*

that engine is only turbo. Was the question not an sc and a turbo together?

tibs im sorry to hurt your feelings but a bone stock grand national off the showroom floor did mid to high 14's.  documented at a car show by a gn nut, with a gn at the show,  with the paperwork on his windshield.  oh ya thats a fast car!! ;D ;D   well actually that was very fast for the time.
you say the gn had a race car engine?  starting in 89  the honda  civic had a high compression twin cam variable came lobe (VTEC) 1.6 rated at 170 hp.  factory lsd with a 9000 rpm redline.  that sounds more like a race car engine to me. heck 20 more hp than the fiero gt and 1.2L smaller.  bone stock times of mid 14's  in the quarter mile. mmm sound familiar tibs? ;D

the gn would get fast with mods but hey you can make any car go fast with mods.  bolt a turbo on a 89 mustang ,  same vintage,  and watch the frame twist in half.

mr dough tell me how you would put an intercooler on a 3800sc fiero.  this should be interesting.  just like the guy that said putting a 3800sc in a fiero gets ya 11's . ;D

yes paxton makes a supercharger that is designed like a turbo but run off a belt. intercooling that is fine but  we are not talking about mustangs here.

just thought i would add something.  since i have come back to the pontiac family i am getting trashed on my old toronto streetracing forum.  they are tying to make fun of me getting a fiero.  i have always raced with around 500 people watching so its hard to hide from these guys.  so im getting a hard time from them goin to fiero and a bit of a hard time from you guys for use to owning a honda.   by mid summer i will show toronto what the fiero is made of.  just hope i dont piss you guys off to much.

Mr Jaygt my feelings are not hurt. So what you're saying is that an engine in order to be considered a race engine it has to be high compression. If that is what you like knock yourself out, but don't say that north america doesn't know how to do a race engine, when your interpertation is a high compression only engine.

I thought that we were talking about turbos and superchargers, and I think gm has had great success with both.

I don't understand what it is you are trying to prove, with guoting all these hondas with this amount of hp doing this much time, in the quarter. Open your eyes and see what is what, nobody is reinventing anything all this stuff hasbeen done before.

Oh by the way a paxton has been done on a fiero before, it's not only for mustangs.

putting a paxton on a fiero would be a complete wast of time.   bolt in the 3800sc and kick ass with reliablity and it would last forever. probly cost around the same if you do it yourself. bolt a paxton on a fiero v6 and watch the parts fly.  plus slow.  

Maybe for you it is a waste of time, some people don't want to do complete swaps, besides this was over ten years ago.

I would like to know what parts are going to fly.

tibs how many miles are on an averarge fiero v6?   lets say 100 000 miles.  now you bolt a air pump to it and expect it to be reliable?  with the egr problems most have we are all having detonation problems as it is.  and the car would still be slow. just seams like a silly thing to do when the gtp moter is available.

my gt engine has around 100 000 miles on it and trust me it could not handle any extra psi.

Like I said before it was done over 10 years ago, and I wouldn't add a turbo or supercharger to a tired motor. I don't think all fiero owners want to swap a 3.8 sc into a fiero, what would be the point of being an individual.

I don't think it's silly to do something different from what everyone else is doing, that would be boring if everyone in this club had a 3.8 sc.

Jay, the fat of the matter is the Fiero can handle massive amounts of hp, when done properly, the Fiero can kick some seriosu butt on the 1/4mile and take a hard corner at the end just to piss the other guy off.

ANYONE who just slaps on a turbo or an sc on ANY engine without prepping it first will kill the engine. Even a regular 3800 and a 3800SC have different internals. I don'r care how old the engine is, when you do it right, it will be just as reliable.

Please tell me all this racing stuff you are talking about is on a track? Because this clubb is TOTALY against treet racing and we don't need anything like that to tarnish our reputation.

thanks,
Eric

I totally agree with Eric street racers are punks who shouldn't be allowed on the road. Driving a little fast on an empty road where only you own life is at risk is one thing but racing through city streets to try and prove something is for assholes especially when you consider that there are tracks to safely race on. Reason some do not use tracks is because thier cars are unfit due to things like pieces of wood shoved into suspension and many other cheap unsafe mods.

well someone racing through city streets would have there licience for about a month.  ive had myn for 16 years and havnt had a ticket in 6.  both my race cars had bilstien shocks with iebach coils.  because the car was so light the back sat very high and stiff keeping the weight on the front drive tires.   some guys  with track cars just weld a steel in place of the coil and shock.  the wood is good for poor person thats getting bad times cause of bad setup making him think his car is slow.

any car can handle massive amounts of hp bla bla bla.  i could go to the moon if i had a space shuttle.

mr. dough you just proved my point.  you would have to change  the internals.  now your dumping money on a small engine with little potential.  yes anything can be made reliable if you have deep pockets and rocks in your head.
the 3800sc already has the internals. it is already 1 lt  bigger.  it already has a sc.  what more can you ask.

you can honestly tell me that you have never put the gas peddle of your car to the floor board before on the street?  well you would be the only person in canada, that drives,  that could say that.  thats amazing.

mr. dough you just said this club is totaly against street racing.  now your good friend 2ml67 just said he likes to race his car on  empty public roads.    ah ok i see how it works.

I think you are missing the point here I said driving fast on an empty road not racing this I do once in a while not regularly not racing someone else but concentrating on what I am doing and on the road not my competitor or pushing further because I am falling behind or he's closing etc...
Racing on city streets is crazy even worse is idiots using things like NOS on the streets and in areas where I live and my children are. No not the street but the sidewalks or parks or boulevards where these out of control idiots end up usually killing others instead of themselves. Thats where I have a problem. When I actually race its not down some main city street or soem residential area or even a some what deserted industrial area it is on a liscenced track where all safety precautions are taken and both my car and my competitors cars have been checked so I do not have to worry about what or whom I am racing. You see I believe one has the right to risk his or her own life not others.

Not everyone on this forum is against street racing.  What I’m against is doing something unsafely.  Lets face it, someone could fly around downtown safely if all the precautions were taken and on the same note the same person could be following the speed limit on a deserted road and be doing it unsafely.   What does it all come down to?  Well, it’s all relative, isn’t it?  Driving a car in the first place isn’t safe, that’s why we have to have dedicated roads and laws to follow.  The government wouldn’t mandate insurance on the matter if they didn’t think that it was going to be a common to need it.

On another note, as I have said on this forum before.  It’s almost imposable to piss me off; no one here has.  I’m just that kind of guy.  Cheers.

Aaron

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well concidering 10 000 people a year die of drowning and about 4 from streetracing  i dont think you have much to worry about.   your more likely to win a billion dollar  lottery than get killed by a organized streetrace.  unless you walk your kids in a deaserted industrial zone at 3 in the morning and like to dart infront of cars.
now you racing, oh im sorry,  driving fast on my street in the middle of the day.  i live on  a 8 minute long street that you can see the next stop light from the first.   old punks race, drive fast,  on it thinking hey i cant see any other cars on this straight new road so its ok.  well  my grandma pulls out of her driveway not noticing you and  you kill her and my kids she was taking to the mall.  and for you this is ok?   how often do you think this happens?  more than 4 times a year?  happens all the time.  so its old punks  that are killing people not organized streetraces.  

i admit i use to drive 260 klh  alot on this street in front of my house.  usually around 4 in the morning going home.  with my high beams on id probly only kill myself.  still stupid.

i dont think any one likes 17 year old kids racing around on busy streets with there stock cars with fart cans.  not sure why you would bring that up.
thats like saying  " i hate these guys that go around raping young girls in parking lots"   what you think someone likes these little kids putting everyone in danger?  kind of silly thing to say.

Jay why can't you just accept the fact that some of us like our 2.8 and would like to rebuild them, instead of saying we have rocks in our heads. Our we supposed to do whatever you think is best for us, maybe you should post your guide to what we should do to our cars, since you know what's best.

 tibs from what i understood he was saying you could change all the internals to accept the extra psi of a bolt on sc.  i was just saying thats an odd thing to do when a bigger 3800sc is  cheap and available already built and reliable.  if i was to rebuild my 2.8 i would wind up having to change the cradle and mounts. so after spending the money on rebuilding the engine i would now be stuck with a 2.8 making 150hp gettin beat up on by most new cars.  the 16 year old auto tranny of myn probly would be a liability so i would have to spend the money to rebuild it at the same time.   now i have spent a huge amount of money and im still stuck with boring stock slow times.  this is why it seams logical to get the 3800sc swap.   you get the engine and tranny.   sounds good to me.  

if you cant do the work yourself then yes it would be a tuff job.  if your car is standard then it would be ok to just rebuild the 2.8 if you dont want a fast car.

i think im going to sell my jeep and buy a southern fiero.  i would fly down and hopfully drive it back.  has anyone done this before?  i want to keep my fiero forever like my trans am.  would be nice to have a rust free frame.  just switch over all my gt panels and interior.  would also be easyr to do the 3800sc swap with a rust free car as well.

Mr. Jay? I hope you are aware that even dropping in a 3800SC you still need to at least bring the engine to "like new" ie rebuild. I agree with you on the 3800SC, but lets face it. Someone can build a 2.8L that can kick my ass and here is the real knee slapper.. In a REAL race, that person would probably be in a lower catagory then me in my 3800sc, therefore against even weaker competition. So to rest this case that is way off topic, some people have reasons to make the stock engine perform.

now with the street racing, I do not condone driving fast even tho I have as well. Fact of the matter is, you get caught, you get nailed with sppeed or if you were "really" hitting 260, wreckless driving. When there is a car speeding next to you, now that is racing. That gets you in jail. :) Car seized, no insurance would touch you with a 10 foot pole.  (this is only the legal side of it, not to mention the moral)

What I'm saying is, if you street race, you are chicken.. that simple.. You are too affraid to pop open the hood because you don't want people to see your secret mods? (chicken) can't race in a category? (Chicken) Can't race on a clear track were you can't use traffice to slow the other guy? (Chicken)

And again, my father in law knows alot about Civics ect, is still don't think your car can hit 260... that thing would wobble in every possible direction, there is too much air turbulence in the rear that the back is tossed around.

Anyhow. Be smart about it and if you street race, makes sure you don't have anything that identifies you to the club, we don't need any bad publicity.

Cheers!
Eric

Well I'm not Mr. Dough, but since in a quick skim of the remaining diatribe which this thread has turned in to I didn't see anyone show you an example of an intercooled L67, I feel obligated to post this link (http://www.fiero.nl/forum/Forum1/HTML/025998-7.html).

Scroll about 1/3 to 1/2 way down the page, and start reading.   ::)

So Aaron, now that yet another thread you started has wandered off on a rather spirited tangent, care to share with those of us who are interested in the original topic what your preference is in blower styles, and why?   :D

wow that is a neat intercooler.  not the kind you could get at the junk yard for 50 bucks but still it exists.  i never would have thought you could cool that type of sc.   i guess you can get anything if you have money to burn.   i stand corrected.
 
i have a jdm 94 toyota supra twin turbo intercooler that i got shipped from japan.  i think it was 80$  from my guy.  also a twin turbo setup, blow off valve  and the big single ct26 turbos as well.  was going to go turbo around a year ago.

I really don’t know too much about superchargers and turbochargers, but I may be able to offer some insight.  I know that there are three basic types of superchargers and one basic type of turbocharger.  I also know that it’s the application that determines what it is you should be looking for.  Plus it should also be noted that a turbocharger is a specific type of supercharger and not something different altogether.

The three main types of superchargers are roots, screw and centrifugal.  The roots type is a positive displacement s/c (supercharger) therefore is always compressing the same amount of air per rotation which is dependant on the engine rotation, therefore has the tendency to always produce the same boost pressure regardless of the engine rpm.  The screw type is also a positive displacement s/c, however the screw design allows this type to compress the air with less recirculation or turbulence than the roots type, resulting in a smaller heat gain per boosting psi.  With a centrifugal s/c you have the most number of options.  However when hooked up to a pulley has one major disadvantage.  It may not produce any boost until engine rpm rises over 2500 rpm.  It is however the lightest unit and allows for more options to cool the air.  It also has the most un-linear throttle response of the superchargers.

A turbocharger is a centrifugal type of s/c that has been doubled up with a second centrifugal s/c to run one unit on the exhaust and another in the air intake.  The net result is a slightly more efficient system of boosting your intake than the conventional belt driven s/c.  This efficiency comes with one slight disadvantage, there will be a small lag in the throttle response.  This lag depending on how much you want to spend can be almost nothing.

Now down to the part that people may care about.  Lets say that we are to compare the three units at lets say 8 lb of boost on the same motor (lets omit the different cam grinds for now).  So you have an 8 psi pulley on your roots s/c, and an 8 psi pulley on your screw type s/c, and a turbocharger that produces 8 psi at maximum engine power rpm.  The result is going to be this; the turbocharger will produce the most power, the screw type the next and the roots the least amount of power.

So why does anyone bother with pulley type superchargers?  Because there are many other factors to take into account.  Ease of installation, cost and availability are a few of the largest factors, but the largest factor is likely the type of throttle response desired.

Car manufactures prefer to put on positive type s/c because they offer more predictability to the driver and fewer options to increase boost.  With a turbocharger the amount of boost increases with the engine rpm therefore creating an element of unpredictability to the engine life and driving response.  Large companies don’t like surprises.  But the demand is there, so what they do is use a very small amount of boost so that the driver that will likely present a problem will also likely modify the units and therefore void his warranty or any manufacture responsibility for mishaps.  Driver gets the car he wants and auto manufacture gets to sell more cars without having to worry about the consequences.  So everyone is happy, except the guy that gets his house driven through by Mr. Dilwad running a turbocharger and nitrous without learning how to drive first.

Anyway, lets say that you wanted to build a drag strip racing car.  I would recommend using a screw type supercharger.  Although you may loose some power over turbo you will also make your power in less time,  and as we all know, your launch off the line can be more important that a few extra ponies.

Now lets say you wanted to race a car over a longer distance than a ¼ mile.  I would recommend using a turbocharger.  It is lighter and more efficient, which is always a good combination when racing.  Also when on the track, turbo lag is much less of factor, and in many cases not a factor at all.  You simply learn to hit the throttle a fraction of a second sooner.

But if you were to ask me what my preference is.  That is a different story all together.  I have no interest in drag racing, but my preference is for the screw type supercharger.  Although the efficiency is less, I also find the engineering more sound.

This is getting long.  So I’ll stop before people stop reading my posts.  I can just see many people reading the first few lines and then skipping down the last few.  Are you the type that skips right to the desert?


Aaron

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Have you ever come across any diagrams or photographs of the internals of the roots and/or screw types?  I've seen more centrifugals than I can count, but seem to have no luck with the other two.  Then again I had never heard of a screw-type s/c until reading your post this morning, so I haven't yet looked.  ;)


All depends upon what the main course looks like.  ...and I like the way you cook.   ;D

if they always have the same psi (roots, what eatons is based one) why is a smaller pulley give you more psi? I know the eaton superchargers have a pressure valve that can be adjusted by vacuum or computer.

cheers!
Eric

Does that mean that I can adjust the boost on my eaton series 11 by a computer adjustment?

"if they always have the same psi (roots, what eatons is based one) why is a smaller pulley give you more psi? "

(End Quote)


Lets say that the pulley on your s/c runs directly off your crank and that the crank pulley is twice the size of your s/c pulley.  Just for the ease of calculation lets also say that it’s the circumference of these pulleys that are in relation to each other.  So for every one rpm of the motor you would get your s/c pulley to turn twice.  Now lets say you decided to put a pulley on the supercharger that was twice as small as the one above.  Now you would have the s/c pulley turning 4 times for every one turn of the motor.  Does this answer your question?

Aaron

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Have you ever come across any diagrams or photographs of the internals of the roots and/or screw types?

(End Quote)

Screw s/c

Centrifugal

These three are only the basic styles of s/c.  There are literally an infinite number of variations that could do the same thing, and an endless number of combinations to upgrade and virtually an endless amount of time and money that could be put into a s/c.

Fascinating stuff...  thanks for the follow-up!