112

 

The boost simply does not come on quicker with a twin screw. Roots blower are popular because the boost comes on quickly. Why? Because unlike a centrifugal or turbo, the roots is a positive displacement pump, adding a fixed amount of air per revolution.

Guess what -- so does a twin screw; it is also a positive displacement supercharger. But in addition, a twin screw is also a true compressor, not just a "blower" like a roots.

A twin screw is not just better in "high boost" applications, it is better in ALL applications. The more accurate statement would be: "A twin screw is only slightly better than a roots in low boost situations, but absolutely decimates a roots in higher boost situations."

While this thread has been entertaining and informative, it seems to have disgressed into pointless rehashing of the same old information. I and others have provided real, hard data. In return, we have only received unsubstantiated assertions.

Bottom line, eatoncharged: Name one installation where a roots performs better than an equivalent twin screw at any rpm, boost level, or airflow. Until such an example is identified, I feel that nothing further can be gained from the discussion. I don't mean to be rude, but it seems like we are no longer debating, just bickering.

 

Tim again I dont want to argue with you, but the "hard examples" you have given have come from where? Where is the side by side comparison? I hear stuff from Whipple, and Kenne Bell, and Eaton and they all say they are the best. Until I see a screw 112 that I can compare it too, I will stick with a roots supercharger.

 

http://www.holley.com/HiOctn/ProdLin.../f300-520.html

You find away to mount that biotch to a Lightning and I guarantee it will hand the a screw its @$$.

 

Is this a joke? This is for the 5.4. It can be bolted right up to our engines. And the numbers it puts out are even less than a stock Lightning.



I don't get it. A twin screw would spank it every time.

 

Right above. Both articles by Richard Holdener are fully documented with hard numbers -- every comparison you could want. The KB whipped the Eaton over every objective performance measurement -- at any RPM, at any boost level. Both articles can be found here.

 

Tim, your website seriously kicks a**!!!! I read it everyday hoping to learn something new!!! Thanks for the awesome info buddy!!!!

 

At 4 psi Tim it is making more power than the stock Lightning. Try that supercharger against the Kenne Bell. My money is is slaughters it.

 

Please explain.

 

Bueller? Bueller? Bueller?

 

The chart that was posted shows the Holley making 310 HP and 360 ftlb of torque.

I hope there is diff data somewhere because that is clearly not going to compete with the stock Lightning...

Doug

Edit:
Its funny the text right next to that "dyno chart " says [quote]What's more powerful than Ford's limited edition H.O. Lightning pickup truck? Answer: A standard 5.4L Ford pickup with Holley ThunderTM. Boasting an incredible 390 horsepower and 445 Ft-lbs of torque at the flywheel,[quote]

So did they use a chassis dyno or a engine dyno ? Why would they quote one set of numbers and post a picture that is completely different.

My truck bone stock made 332 RWhp and 430 or so Ftlbs of torque. That was the low average for a 2000 back then. Without arguing over how much drive train loss there is My truck made 15 or so less at the rear wheels than they are bragging about at the crank... I know that the 2001, 2002's adn 2003 even make more power. What was the Holley marketing dept thinking ?

 

They say 390 FWHP and 445 Torque and they attribute the loss due to the wheels due to a 4x4 transfer case and a less efficient tranny.

 

Sorry but I wouldn't trust the numbers from Holley. There was an issue of MM&FF where they tested this blower kit, and it made less than advertised HP even with higher boost and supporting mods like injectors, exhaust, etc...

 

I searched the site pretty close. Where did they say they put the blower on a 4x4 ? And where is it posted that they made those numbers at 4 lbs of boost.

So are they making up numbers or did they do an engine dyno ?

If we are gonna make up Crank HP numbers, mine made 395 crank HP and 475 FTlbs of torque... My Tranny is inefficient too.... LOL.

Eaton. Im not trying to argue with you- Just trying to show you and others that we are holding our Lightning vendors to a standard that is higher than what a company like Holley is doing.

 

I really don't trust anything in a magazine, but when I called them about this, they said that 4 psi was barely safe on a stock engine and that they dynoed 390 with it. They said there has been some people with better rods and so fourth making 450 ish to the wheels with it at 12 psi.