But I'm on the street all the time. Right now if I want to go I have to push the pedal down to where it downshifts (sometimes 2 gears) and then it's screaming. So it's a little more towards all or nothing than I'd like. Sometimes I want to push the pedal half way and get a good response without dropping a gear. TS for me please.
Well with 505/506 NA with a 3000 stall on the street, who needs a SC of any kind? N2O can be added at the track in mass quanities in stages and percentages. Just got over 20 MPG driving from Orange County to Chula Vista. Was 103 on the 15 coming down. Heavy traffic. Maybe the heavier the mods a Centri might be a better choice unless the motor is built with low CR, which I don't think is the right choice for the street. I'm of the opinion that once we try to go past the 600/600 mark we are making race cars, not street cars. My new motor NA is a handful. I'm going to have to run the Nitto 20" DR's on the street. 1/4 throttle can light up my 295 RSA's.
no this one i SAW with my eyes haha....spoke to the owner and the guy who built it....it was badass..... as far as TS vs Centri....im still up in the air.... i can say this 100%....TS has the centri on looks all the way....i dont like having that big snail in the middle of the engine bay :sorry: lol
http://cgi.ebay.com/ebaymotors/Proc...arms=39:1|65:1|240:1318&_trksid=p4506.c0.m245 will this work on my car? I know I need to get diffrent intercoolers.
this is the kit that has sparked a BIG interest in me!!! i alo like the fact it is coming from a place with a PROVEN track record over a longer period of time.
really???? for some reason i always thought you could get more from the screw types. learned something new today!!! :ilovesrtc: don't the centri's have a longer powerband under the curve as well?? or do i have it backwards compared to the screw types???
Both will make plenty of power, but all else being equal the top end HP #'s generally will be higher on a centri. As Mikey said earlier this is why you don't see Roots/Twin Screws on Drag Cars, they tend to use Centri's and Turbos. Twin Screws are used more on street cars for that reason...here is some info stolen from Superchargersonline about the different S/C types. For a street car it is really about your goals and personal preference. Personally I am not a fan of the sound of a twin screw, but love the Centri Whistle and looks. Thats why choices are so nice...everyone wants and likes something different! The Roots Supercharger (aka "blower") The roots supercharger was originally designed as an air moving device for industrial buildings. The roots supercharger features two counter-rotating lobes that trap air from the intake side of the supercharger (normally at the back of the supercharger), move it around the outside casing of the lobes, and out the bottom of the supercharger through an outlet / discharge port. Like the twin screw supercharger, the roots is a "positive displacement" aka "fixed displacement" supercharger, meaning that it moves a fixed volume of air per rotation. Notwithstanding minor amounts of air-leak at low rpms, the roots supercharger cannot flow backwards like a centrifugal supercharger, and is thus nearly as efficient in its ability to pump air at low rpms as it is at high rpms. What this means is that roots superchargers are very capable of making large amounts of boost even when engine rpms are very low. This makes for great low-end and midrange power, and also makes them great for trucks and towing vehicles. The roots is also self lubricated, and is the simplest of the supercharger designs, meaning it is reasonably priced and very reliable. This is why roots superchargers have been the choice of GM, Ford, Mercedes, and Toyota for OE applications. The only real disadvantage to the roots supercharger is that it creates a lot of heat. There are two reasons for this. First, the roots supercharger does not compress air - it only moves from the intake port to the discharge port (i.e. it is the only supercharger design with no internal compression ratio). All of the compression is done in the intake manifold. Laws of thermodynamics kick in in favor of supercharger designs with an internal compression ratio (centrifugal and twin screw) because they do less work on the incoming air charge. We will leave the mathematics of this phenomenon to a later (much more boring) discussion. Another reason roots superchargers create higher amounts of heat is because they tend to carry some of the compressed air in the intake back into the supercharger because it gets trapped by the rotating lobes that are exposed to the hotter air in the intake manifold. The Twin Screw Supercharger The twin screw supercharger at first glance appears to look similar to a roots supercharger both inside and out. The two technologies are indeed similar, however there are significant differences. At the heart of the twin-screw supercharger are two rotors, or "screws" that rotate towards each other. The rotors mesh together and draw air from the back of the supercharger. The twisting rotors move the air to the front of the supercharger, while compressing the air before discharging through a port at or near the front of the supercharger. Because the compression is done inside the supercharger, this design produces less heat than a roots supercharger - in fact, it is almost as thermally efficient as a centrifugal design. Like the roots design, the twin-screw is a fixed displacement supercharger (meaning that it pumps a fixed volume of air per revolution), and because the tolerances between the rotating screws are very tight, its ability to create boost at low rpms is unparalleled. These characteristics make it ideal for trucks and towing vehicles, where low to mid range power is primary in importance. Another important advantage of the twin screw compressor is its reliability. Unlike a roots supercharger, the rotors in a twin screw supercharger do not actually touch, so there are virtually no wearing parts. For this reason, twin screw compressors are commonly used to pressurize cabins in passenger aircraft. Like roots superchargers, twin screw superchargers are self lubricated and do not tap into the engine's oil supply. One disadvantage of the twin screw design is that, because it has an internal compression ratio, the twin screw is compressing air even when it is not sending boost to the engine (i.e. under cruising or deceleration). An internal bypass valve releases the pressurized air, but because it takes work to pressurize the air in the first place, the twin screw supercharger draws more power from the engine than while not under boost. Like the roots, the throttle body must be placed before the compressor because it is a fixed displacement supercharger. The Centrifugal Supercharger Although the centrifugal supercharger is founded on a technology much newer than either the roots or the twin screw, it was the first supercharger to be successfully applied to automotive applications. Unlike the roots, the centrifugal supercharger is NOT a positive displacement / fixed displacement supercharger because it does not move a fixed volume of air per revolution. The centrifugal supercharger essentially operates like a high speed fan propeller / impeller, sucking air into the center of the supercharger and pushing it to the outside of the rapidly spinning (40,000 + rpm) impeller blades. The air naturally travels to the outside of the blades because of its centrifugal force created by its rotating inertia. At the outside of the blades, a "scroll" is waiting to catch the air molecules. Just before entering the scroll, the air molecules are forced to travel through a venturi, which creates the internal compression. As the air travels around the scroll, the diameter of the scroll increases, which slows the velocity of the air, but further increases its pressure. The centrifugal supercharger enjoys several advantageous characteristics that make it the most popular supercharger design in the aftermarket world. First, it is simple and reliable because it has very few moving parts - just a few gears and the impeller. Second, the centrifugal supercharger produces very little heat because of its internal compression ratio. It is also small in size and very versatile because it can "free-wheel" and allow the engine to suck air through it or even flow air backwards. For this reason it can be placed anywhere in the intake tract - it can even "blow through" the throttle body, meaning it can be mounted nearly anywhere. It is also the most thermally efficient supercharger, meaning that it produces the lowest discharge temperature. The only significant disadvantage of the centrifugal supercharger is that it must be spinning at a relatively high speed before it begins to make a significant amount of boost. For this reason, it is not helpful in creating boost (and power) at low engine rpms. Normally the supercharger only begins to create boost at around 3000 rpm, and the boost curve gradually and increasingly rises with engine RPM. Many centrifugal superchargers do not have a self-lubricating oil system, and draw oil from the engine's oil supply. The disadvantage to this is that you must tap the oil pan for the oil return line. However, in doing so, the supercharger becomes virtually maintenance free. Some manufacturers make a "self-contained" centrifugal supercharger that is self-lubricated like roots and twin screw superchargers.
NHRA yeah, but they also pretty much rebuild their engines after each run LOL NMRA/NMCA the top dogs run Turbos/Centris...and the NMRA/NMCA cars are closer to street car engines than the NHRA cars
I knew someone would say that, I almost said excluding NHRA dragsters! Well unless you plan on running nitro methane lol! Correct...only when you get to that level do you see the Roots...any street car based series you will either see big block N/A/Nitrous and in the faster classes Turbos and Centris only...I am talking about 6 second Street based 1/4 mile cars. These are much more comprable to our cars than a NHRA dragster. Of course we are partial to 10 time champ Mike Murillo's car lol...he runs twin rear mount Turbo's now..which we are also fond of I am not saying anything bad about twin screw/roots blowers...we deal w Saleen/Roush/Whipple etc and many people love them, and we have sold quite a few. It just seems there is a common misconseption about centri's being unable to make power.
What do you guys think the main reason manufacturers like Chevy and Ford are using roots type blowers for the ZR1 and GT500? Is it reliability, fit and finish, cost???
