dufference in High helix, retro, standard, 120* roter, std roter.

just looking for some info on
what makes a blower a retro blower
what makes one a high helix
what does the pie shaped opening / front discharge do and what is it called?
What is the differrence in the standard and 120* roter
just looking for some information so that i can better understand the termanology.
Thanks

 

A retro is a front discharge, named that when high helix blowers were being retrofitted to frt discharge brng plates, a high helix or 120 degree is twice the twist of a STD rotor, STD rotors can be billet and cast, all high helix are billet rotors, the pie opening coincides with high helix rotors, but some have used STD rotors in pie opening cases, hope this helps,

 

A standard rotor is twisted at 4 degrees per inch of length. A high helix rotor is twisted at 6.5 degrees per inch of length. However, if you look at the 3-lobe shape profile at the end of the rotor, they are identical.

For example, a 6-71 standard rotor is 15 inches long and twists a total of 60 degrees.

A 14-71 standard rotor is 19 inches long and twists a total of 76 degrees.

And a 19 inch long 14-71 high helix rotor twists between 120 and 123.5 degrees, depending on who makes it.

Patrick Hale
www.DragRacingPro.com

 

can you have a high helix with a standard bottom opening?
does the high helix still discharge the air at the front of the opening whether it is a pie shpe or open bottom?

Thanks for the replies guys.

 

You can put high helix rotors in an open bottom housing, but why? The purpose of the pie is air is discharged at the frt, so the bottom was closed off and in so doing the rotors didn't have up fight manifold pressure, remember high helix blowers were designed for high overdrive and high rpm, that's where the benefits of them came in

 

Another thing to add is, boost isnt horsepower if you make heat to acheive more boost, heat kills torque and torque is horsepower

 

Hey Andy on my high helix I have been running around 50 over what do you think? also I do watch manifold temp..Dave...p.s. don't forget to water the plant..lol

 

how can you tell a high helix roter from a standard helix without taking the blower apart. Is it the black and white strips?

 

So, the high helix retro pieces are made for big overdrives.
At what % over do they start to show their advantages?
Or put another way if driving 0 to +20 is spending the extra monney pissing in the wind?
We can only run 8.0 et quickest. This takes somewhere between 0 and 8% over with a 10 gas blower (running alochol). We turned this blower +16 to 20 over to run the 6.0 at 1000'. That is as quick as we can go.
So, is a retro pissing off money?
Wags

 

The advantage of the high helix start around 45%, but there is no disadvantage running one slower, the frt discharge (retro) is always a good Idea, because it helps get the discharge out of the blower more efficiently

 

It takes less power to drive giving you the extra you need on those bad air days 5000 ft ect.Just a lil more in the bag of tricks (just in case you need it ) At 30 over it can save a 100 or so hp.

 

Roger. You know I need and use all the tricks I can get.
Gotta keep the competition on their toes!
Wags

 

if you open up a helix to a standard opening in the plenum, the rotors will "see" more plenum backwash pressure which will try to turn the rotors backwards. It will require more power to turn.

http://www.northernthunder.com/turningscrews.html

 

Good article. Worth the read.
Thanks
Wags

 

Craig, you know our program somewhat. We have some success. Am I foolish for sticking another 10 on top of my piece?
10 replacing 10 tune should not change drastically. 14 replacing 10... well, start over on tune up sheets.
What you think?
Wags

 

It just depends (how much you want in the bag) You have it covered now. A good std full open bottom 10 alc. stripped piece should get you where you want to be. A 10 hhr will get you about an extra 75-100 hp extra in the bag. The tune will change more on the retro cyl to cyl. If you go with the retro call Spud at www.fuelinjectionenterprises.com He had me within 75-100 deg on my deal. An 8 hhr woud work as good or better than a std 10 stripped full open bottom. (I think ??)