Whats "better" - a supercharger or turbocharger?

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toph99

Diamond Member
Aug 25, 2000
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don't forget that a supercharger is usually easier to put onto a car, because you don't need to rerout your exhaust. a lot of 4 bangers have factory turbo charged engines, so it's easy to either swap engines, or pull the whole assembly off of one and stick it onto your car, which is probably why you see more turbo'd small displacement engines, and fewer large displacement
 

oLLie

Diamond Member
Jan 15, 2001
5,203
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So many times I've felt a wistful sigh as I pass by the Jackson's Supercharger place in Westminster. I wonder whatever happened to the Endyn modified superchargers... I remember back when I was all into imports I heard some crazy stuff about Endyn blowers.
 

shabby

Diamond Member
Oct 9, 1999
5,782
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A supercharger gives linear boost, your not going to get 15psi at 3000rpm, your going to get it at 6000rpm. The faster it spins the more boost it builds.
A turbo however can build 15psi by 3000rpm(depending on size) and you'll get more mid/hi range hp than a supercharger.
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
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<<Yep. There's a definite "lag" with turbo engines.>>

In single turbo engines, yes. However there have been significant strides made with twin turbo setups in recent years and turbo lag can now be essentially eliminated by using a "low speed" turbo with a wastegate feeding into a "high speed" turbo at a certain RPM. Still, a supercharger will probably be slightly more linear than even a sequential twin turbo setup can be. Also, sequential twin turbo setups open up a whole new can of worms because when the exaust gets ducted to the high-speed turbo, fast moving exust air slams into the stationary turbine which has been known to cause early failure of the high-speed turbo.

As has been said, neither is really better. A supercharger has a more linear power delivery but it saps some engine power to spin the compressor. A turbo generally is more "peaky", but it delivers "free" power.

ZV
 

Shagger

Golden Member
Feb 12, 2001
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Since Turbo's are driven off of the exhaust gases they don't kick in until 2500 RPM's so there is some "lag" - The turbocharger is an engine killer for exactly that same reason. The heat transferred to the engine oil from the red hot turbine (heated by the exhaust gases) invariably leads to turbo failure sometime after 50K miles unless the oil is changed RIGOROUSLY every 3K miles.

The SC loves the big V8's though - I had a buddy in HS that drove one on a '65 Mustang 454. You needed 2 people to drive the thing since the driver couldn't see over the big a$$ scoop for the SC. It hauled tho...

Those were the days..
 

db

Lifer
Dec 6, 1999
10,575
292
126
"What's better" depends on what you want it for. Daily driver? Fun-only car for weekends?

Things have changed a lot. A turbo can save you gas if you are only using it when you 'get on it'. Or a turbo can be set up to where most of the old disadvantages between it and a SC are eliminated.
A SC works continuously whether you are taking it easy in traffic or going full out, so you are really sucking gas for no good reason; not to mention that load is constant on the parts too.

Decide what you want it for, then apply whatever serves that purpose.
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
44
91
<<Since Turbo's are driven off of the exhaust gases they don't kick in until 2500 RPM's so there is some "lag" - The turbocharger is an engine killer for exactly that same reason. The heat transferred to the engine oil from the red hot turbine (heated by the exhaust gases) invariably leads to turbo failure sometime after 50K miles unless the oil is changed RIGOROUSLY every 3K miles.>>

Wow, that's a lot of F.U.D. It's not that the turbo suddenly kicks in at a certain RPM, it's just that it builds boost slowly until at some RPM the turbo's boost becomes useful. It's not like it suddenly slams a bunch of compressed air into the engine at a pre-determined RPM. The turbine is not heated by the exaust gasses in any appreciable manner, it is heated by the extremely high rotational speeds seen by the turbine. The turbine spins at tens of thousands of RPMs which is what generates the heat, the exaust gasses are at most an academic contribution to the heat generated by the turbine's rotation. A turbo done properly will include some sort of oil cooler as well, which will negate much of the thermal transfer from the turbine to the engine. Finally, lack of oil changing is not what kills most turbos. Turbos are generally killed because the driver does not allow the engine to idle for 30 seconds before shutting off the car. While a consistant oil change interval is certainly important to a turbo, it is FAR more important to allow the engine to idle for about 30 seconds before shutting it off. By allowing the engine to idle before shutting it off, you allow the turbine to spin down while it is still pressure fed with cool oil. If you just shut the car off, the turbine may still be spinning at high RPM (inertia's a b!tch) and by shutting the engine off you have deprived the turbine of pressure fed cool oil, thereby overheating the oil that is stuck in the turbine housing and leading to the phenomenon known as "coking". You may want to do a touch more research into turbochargers, somewhere along the line I think that you have been mis-informed.

ZV
 

Shagger

Golden Member
Feb 12, 2001
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Ladies Man - Sorry, it was a 351 NOT a 454

Zenmervolt - I don't think I said anything about the compressed air slamming in at 2500 RPM's I merely paraphrased the "build up" of compression. The only thing I got wrong was the exhaust gases part. I know about "coking" and the need to idle in the driveway after a nice quick run - sorry to leave them out but Wingnut PEZ had already covered them up above...

Peace out.
 

Zenmervolt

Elite member
Oct 22, 2000
24,514
44
91


<< Zenmervolt - I don't think I said anything about the compressed air slamming in at 2500 RPM's I merely paraphrased the "build up" of compression. The only thing I got wrong was the exhaust gases part. I know about "coking" and the need to idle in the driveway after a nice quick run - sorry to leave them out but Wingnut PEZ had already covered them up above...

Peace out.
>>

My bad. I seem to have read more into you post than you had intended. I just wanted to re-enforce that a turbo is no more of an engine killer than a supercharger so long as the oil is taken care of. Also, by spelling my nick right on the first try you have joined a highly exclusive club. :)

ZV
 

Shagger

Golden Member
Feb 12, 2001
1,046
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How tough is it to spell Zenmervolt?!?! ;)

Anyway, no harm no foul - I was trying to harken back to my salad days when MotorTrend and Car&Driver used to be required reading in my HS and my primary vehicle was a 1966 Chevy Impala
with a 283 in it - so I didn't wan't to come off as a COMPLETE idiot! :D


 

LAUST

Diamond Member
Sep 13, 2000
8,957
1
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WTF is going on in here

Okay for starters not all SC's produce boost off idle, only 2 of the 3 types do, Roots seen on older cars like the one seen in Mad Max 2 (Road Warrior) where it uses brushes, and Twin Screw found in my truck, (Whipple, Kenne Bell) These use two intertwined screws to create boost, it is the most reliable of the 3 and great for Marine and Truck applications as it produces the lowest ambient temperature and right at idle, though we only see about 8lbs of boost max, Twin screws can also be stacked tho, in some Auto and marine kits you can get 2, the twin screws origional use was in Trains locomotives, where they would stack multiple ones ontop of each other.

the 3rd is the one that doesn't produce boost off idle {b]Centrifical[/b] , this one most resembles the turbo (Hair Dryer) but is powered by the crank also, these were 1st found in WW2 airplanes to allow them the reach higher altitudes, they do NOT produce boost off idle but start around 3K typically and can have much greater amounts of boost, D3's are seeing around 27lbs in some cases, Centrificals are the newest to start running self contained oil rather then share off engine oil, allowing for greater reliability and no carbon build up. Centrifical can also be found with stright cut fins or helical, stright cut will produce a more linear amount but starts producing it faster, helical will not produce it as fast but it reaches ungodly amounts of boost.

During a shift all 3 types will loose boost, Centrifical the most, and why all your fastest drag racers found in classes like renegade use C6's not Manuals like all the kiddies think are the only fast thing on the planet. Auto's with performance tranny's will hardly loose a beat of boost.

Superchargers have a cost from running off the crank, it takes about 50-80 HP to actually power a SC now comes the turbo's, where I'm not the most verse in but I know enough as where they fit in..... For starters it's big drawbacks are Temperature and Cost to install... Look under a guys hood that been running a Turbo for a few years, rubber and plastic will be cracked to $h!t they make a lot of heat.

Turbo's have many good features though, for one there is no cost to the motor to power it like there is to power an SC off the crank, with that they can also be controlled at any time with a boost controller, where with a SC you have to change out the pulley for different amount of Boost (My pulley takes less then 2 minutes to change....1 alan wrench and a 3/4 drive) The extra cost with Turbo's is the Exhaust work, you need a downpipe and wastegate, if anyone has done their own exhaust work they know it SUCKS....

With the combination of exhaust work sucks, and the heat it's why my vote Always goes to Superchargers, Common install's of SC's run hours less then Turbo's and there isn't the cost of under hood components getting damaged from heat.
 

LAUST

Diamond Member
Sep 13, 2000
8,957
1
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<< A SC is better because it delivers compressed air into the intake almost immediately off idle. Whereas a turbo needs to spool up, and won't supply a significant compression until say 2500rpm or more.

However, during normal driving SC's are noisier and get lower gas mileage, and are generally more expensive and arguably less reliable.

Smaller engines don't provide as much power at the lower rpm's, so there's not much a SC will do for them in the low range, anyway.
>>


Actually thats also dependant on the type of Supercharger, Jackson racing makes many Roots style for cars like the Focus, that type of blower (SC) will produce boost off idle, it's all by type. And many types like my supercharger (Twin Screw) can not only up your milage but also are much more reliable, the Twin Screw desighn is the most reliable compressor type in the world, and are known to easily go to 100K miles without a single issue and why they were used on trains.

In racing conditions my milage takes a hugh hit but in Towin and cruising my milage went up as my engine is running more efficiant, now in the case of a centrifical (Needs rpm to begin producing boost as a tubo does) those can cut milage as it's an addition accessory on the drive, so below the RPM to produce boost (3000rpm on average) it's got that weight on the motor good for taking a lot of horsepower... and then getting to the point of finally producing boost your most likely racing at that point, therefor the SC making it so you can put in more Air, you also have to put in more fuel... down goes the milage, so a Twin Screw can actually up it (I get 19 MPG on a 5300lb 4x4 ex-cab with 4.10 gear) a centrifical can usually chop 2 mpg off but is also much better for racing then my Twin Screw is, the Twin screw is desighned for Marine and Trucks where Torque for towing and stuff are much more needed.
 

Mill

Lifer
Oct 10, 1999
28,558
3
81
Screw superchargers or turbos. Nitrous all the way. :)

LAUST is right there are several types of superchargers. Cars with a bad torque profile will benefit more with a roots blower in my opinion. It really depends on what you want. If you want lots of low end grunt then a roots or twin screw is better for you. If you don't need the boost to launch with or you like your power higher in the RPM band then you go centrifugal.

There are turbos with very minimal lag out there. I don't like turbos because of expense and they are much harder to work on. Time consuming to say the least.

I like nitrous because it is pretty damn easy and cheap.

Now if only I could get my tranny finished and get a tune... then we could see some 10's out of this bitch.
 

TuffGuy

Diamond Member
Jul 6, 2000
6,478
0
76
nitrous = viagra

for those who can't get it up naturally, yet still want a few seconds of fun. ;)
 

LAUST

Diamond Member
Sep 13, 2000
8,957
1
81
I'm drawing a blank on their name, it's something simple (3 letter word) Zax or something, but they are the NOS kit with the Purple bottle... that system is supposed to be very very easy as it's computer controlled, and handles the problems of when a bottle gets low on NOS.

Thats the only real problem with NOS is the person doing the system, if done wrong it's not good, but if done right which with todays kits it's getting easier and easier it's a great system.

Other then that the air charge is so cold you don't have to worry about detonation as much and why you see them on cars with 13:1 compressions, over 11:1 I'd be very frightened to slap a Blower or Hair Dryer on that motor, even now 9.5:1, I'd still like to get a water injection on my system since I don't have room to intercool.

The only other small drawback after a great kit is installed is pulling up along that Viper and finding out your bottle is empty :Q ;) but if your conservative about it, it's no problem ;)
 

Kadarin

Lifer
Nov 23, 2001
44,296
16
81


<< Thats the only real problem with NOS is the person doing the system, if done wrong it's not good, but if done right which with todays kits it's getting easier and easier it's a great system. >>



Heh.. The "drawback" is twofold: You have to remember that in addition to adding nitrous to the engine, you also need to increase fuel delivery to maintain the correct air/fuel mixture. Otherwise the motor leans out and you end up with an expensive boat anchor. The other concern is the "shock" to the system the moment the button's pushed. Poorly designed systems will cause additional stress throughout the drivetrain at the moment of application (and you can lose traction, etc.) If that's an issue, there are solutions such as 2 or 3 stage kits, and other kits that allow the nitrous to be applied "gradually".

Some good points above also on superchargers, and the different characteristics between centrifugal units (Vortech, Paxton, etc.) and roots-style (B&M, Eaton), and the twin-screw design (Kenne-Bell, etc.). Not all designs will have a boost lag.
 

Mill

Lifer
Oct 10, 1999
28,558
3
81
BTW, I have a remote valve opener, bottle warmer, safety cut off switch, and msd window switch. Also I have a larger fuel pump...


Here are my mods:


2000 Mustang GT
Lentech 4r70w transmission
Full Saleen S351 Body Kit
Steeda Cobra R Hood
Performance Red
FMS-4.10 Gears
Eibach Pro Springs
Tokico 5-way Shocks
Flowmasters 40 series
MAC Off Road H-pipe
FRRP Tranny Cooler
Moser 31 Spline Axles/Eaton diff.
Steeda Subframes
Steeda Pullies
Steering Rack Bushings
Steeda lower control arms
Upper adjustable control arms
caster-camber plates
Nitto Drag Radials
17inch Konig Villains

--------------------------------
In car waiting for tune...
SHM built 2V with ported polished heads
250 shot of nitrous(Holley NOSzle system)
Walbro Fuel Pump
JBA shorties
3200 Stall
Looking for 10's
 

vi edit

Elite Member
Super Moderator
Oct 28, 1999
62,484
8,345
126


<< Performance Red >>



Hehe, is that like a "perfomance" window decal or "type R" sticker?

:)