hey guys..im just wondering what the difference between a SC and a turbo is for a fox mustang, and how they work, and do you need a special header for the turbo kit??
They both compress air, the turbo is powered by exhaust gases and the supercharger is driven by a belt. You don't necessarily need special headers for a turbo kit, lots of people flip their shorties and fab up a crossover with a flange to bolt up to the turbo. Do some searching... you sound kinda new to the whole turbo thing, so I suggest you pick up the book "Maximum Boost" by Corky Bell. It's a killer book with tons of good info.wow alot of misguided info in here...... obviously you guys have all ran turbos on your own cars
I learned a long time ago alot of these guys are s/c guys. Brained washed by the mighty advertising dollar and sponsership money that influences the racing sanctioning bodies. I have ran a DIY tt set-up now I run the juice on my high compression 347 but would love a pre-made tt set-up by Urist or Pro Turbo Systems. The funds are just tight since the plant closing and me going back to school.I think it has been explained. Turbo seems to be the answer for large amounts of power. Many big power dragsters use the S/C because it is controll they need more than power.
jrichker said:Roots and screw type superchargers (Eaton, Kenne Bell, Blowzilla, Whipple ) provide max boost earlier than a centrifugal supercharger, making them good candidates for heavy cars with small engines. However, they tend to drop off the increase of boost level as RPM increases. They also tend to heat the intake air charge more than a centrifugal supercharger or turbocharger. That makes an engine that is prone to detonation and lower power levels for the same amount of boost when compared to centrifugal superchargers or turbochargers.
Just wanted to make a couple of notes here. Eaton, Kenne Bell, and Whipple Chargers (the Blowzilla is a version of the Kenne Bell) ALL have lower air discharge temperatures than do comparatively sized centrifugals. That is to say that if in stalled on identical engine combos showing the same boost on the gauge that these blowers typically run between 20-30% lower discharge temperatures provided neither type is running a cooler of any kind. Where folks often run into trouble with this type of blower is when they attempt to over spin them or run too small a blower for X engine combo.
It should also be noted that Eaton's are roots and modified roots type blowers while Kenne Bell and Whipple are screw type blowers. Both types have distinct properties that are apart from the other. Screw type blowers tend to be more efficient and discharge less heat in boost across their entire efficiency range than any other type of forced induction. They are the top portion of that 30% mentioned above (the rotating screws do not touch one another or anything else).
Like ANY type of forced induction, there is a thermally efficient range for the build of the blower. Eaton superchargers are great for roughly 9 psi and down. There are modified Eaton super chargers that move that range a hair further up the range but not much further. Spinning the blower outside of it's thermal range creates a LOT of heat regardless of type.
Kenn Bell and Whipple chargers are much more efficient in the upper ranges. They are thermally most efficient from roughly 8 lbs all the way up to around 16 depending on the size and build of the blower and how well it matches the engine combo that is being fed. These blowers DO NOT run out of steam up top as I've seen so many folks say UNLESS they are not of sufficient size for the application or are being spun out of their efficiency range. The EXACT same thing happens to every type of forced induction.
Moral of the story... Makes sure that you match your blower to your combination.
One small note about turbos... They are really getting damned good. By that, I mean that the latest and greatest stuff out there spins up allot quicker than it ever used to and stays efficient for a really wide range of revolutions and boost levels. They DO however (just like any other form of forced induction) create a parasitic loss just like Superchargers do. Not nearly as much as a supercharger does though. The parasitic loss on a turbo comes from the restriction of the exhaust gasses as they're trying to leave the motor whereas a blower pulls it right off the crank. Parasitic loss is SIGNIFICANTLY less with a turbo than it is with a blower. This is the efficiency that folks above are talking about.
Thermally, turbos are not all that efficient and you will require an inter/after-cooler of some sort. Turbo discharge temps are extremely high.
As far as the great debate over which is best? It's a tired and beat to death subject. Figure out what your goals and bank book are then go from there.![]()
Andy, you are right on this one. I looked back at the information I had to roots & screw type superchargers. I saw that the the added heat and pressure drop off problems were associated with using too small a unit, and then trying to spin it faster to try and recover the pressure loss. Good call on that one...
r since its not taking a percentage of your power to produce that 10psi. its basically free