Is NHRA afraid of a Roots???

Is NHRA afraid that some poor fool might develop a roots blower to run with the screws or are they trying to keep control of the Pro Mods.

Help me understand this change.

DELETE:

“Roots-type maximum size: 14-71, 22 1/4-inch case length, 11 1/4-inch case width,19-inch rotor length; maximum rotor diameter: 5.840 inches including fixed stripping. The case must be one piece with removable front and rear bearing end plates; rotor must be contained within one-piece case. Helix is restricted to a maximum rotor spiral of 6.5 degrees per inch of rotor length. Manifold burst panel meeting SFI Spec 23.1 plus restraint system meeting SFI Spec 14.2 mandatory.”

REPLACE WITH:

“Roots-type maximum size: 14-71, 22 1/4-inch case length, 11 1/4-inch case width,19-inch rotor length; maximum rotor diameter: 5.840 inches including fixed stripping. The case must be one piece with removable front and rear bearing end plates; rotor must be contained within one-piece case. Helix is restricted to a maximum rotor spiral of 6.5 degrees per inch of rotor length. The rotors must be driven from the front (both the external drive and the internal gearing). The entire inlet opening must be on/in the upper surface only. Any inlet/outlet cavity in front of the rotors is restricted to maximum one-inch, measuring from the face of bearing plate to the back of the cavity. Billet cases prohibited. The maximum length from the front of the supercharger drive pulley to the leading edge of the rotor is 15 inches. The use of spacers, modified cases, offset drive pulleys, or attaching methods to move the supercharger rearward in excess of the specified amount is prohibited. All manifold configurations and supercharger modifications and locations must be accepted prior to competition. Variable multi-speed supercharger devices prohibited. Manifold burst panel meeting SFI Spec 23.1 plus restraint system meeting SFI Spec 14.2 mandatory. Supercharger must be in conventional location above the intake manifold and cylinder heads, and supercharger restraint device may not be modified.”

 

typical NHRA bullsh**....why can't you run a billet case? they run them in T/F....F/C. you know what really makes no sense to me is this....... why do the pro mods run there anyway? i mean seriously, they get treated like dirt and always come back for more. go run ADRL, make more $$....get treated better....no $1000 entry fees...etc. maybe i'm the dumb one....i dunno
Darren

 

I have to believe that someone was in the process of developing something that would make a roots blower competitive again in TAD and TAFC. NHRA squashed the idea to keep their current program in line.

I would just like to know what drives these changes. Someone saw something!!

It would be nice to put some of the roots supercharger guys that started the class back on the front lines.

Wouldn't anyone here like to see a Mert Littlefield supercharger #1 qualifier at a national event again?

 

Roots blowers

I'm imagining they were thinking about blowers like DMPE's new Psycho helix.

http://www.dmpeinc.com/current_engineering.php

That sucks as I was actually considering going this root...no pun intented.

Besides Haven't all of the roots guys have suffered enough with IHRA and the constant sliced fingers from restripping...?

Trev

 

Interesting.

Maybe NHRA wants to avoid another "blower wars" in TA/FC like we had in the early 1990's. I remember ordering a blower that by the time I paid for it, another newer/better one was out. Aren't some of the excellent billit blowers about twice the price of a PSI screw, or am I dreaming again?

 

your right about that randy. but whats even better is back when I ran a roots I bought a brand new mert and it was $4500. everyone in IHRA was screaming "ban the screw it cost $9000.00 and that will put racers out of business"!!! and now how much does a Roots cost? off the shelf Kobelco is around $9000. or an off the shelf PSI roots is over $9000.00 or the bad ass M5 is over $13,000.00 . .hmm and then add in the cost of restripping. trust me, once you run a screw blower, you will never want to go back.

 

The screw blower market is kind of cornered at this time.

Why punish the guy that is trying to inovate and sell a product that would perform and maybe even make a living at it. Plus all the guys that have shops that can service these units. RBS, Gerardot etc.

Hats off to PSI.

They invested, tested, retested, certified, recertified....etc.

If someone could come up with a supercharger that could make power and keep engine rpm down would you buy it?

What is a competitve teams valve spring bill run this year?

Wouldn't it be great to compare a competitive AFD and BAD expenses at the end of the year.

Long live the TAD and TAFC classes and everyone that supports the cause.

 

Brad:

We had that. It was when we were allowed to run 125% overdrive with a "D" model (current) PSI, but in 2001 some genius decided we needed less boost so they limited us to 92% over and we lost 10 pounds. We fought and kicked and screamed telling them we were going to be reving the engines up higher to recover the lost boost but the genius said we were nuts. For years following the rules change intake valves were dropping left and right and they still didn't get it.

Back in 1999 (10 years has flown by) we ran a 5.64 with Pete Swayne driving my TA/FC. He shifted 1-2 at the Christmas Tree and 2-3 at 8,800 RPM. I still have the run on the computer.

If other companies were allowed to develop better blowers for use in TA/FC I feel the NHRA ban on the "C" model PSI should be lifted. You'd be hard pressed to find a better blower than that.

RG

 

From what I understand The Two lobe blower that Don Hampton makes, at 8/71 size puts out more air than an 12/71 stripped, going out on a limb i would think if he made an 14/71 size, it would compete with the Screw, and it don't have any Teflon strips to change too. Gene Terenzio Sr.

 

Randy,I'm not trying to sound smart, but don't you think even if 125% was still allowed that guys would still run the motor to the max rpm that they thought it could take, to try to get an advantage? Just curious.
-Dale

 

No problem asking.

We made many runs back then and it didn't go any faster if you shifted at 9,500 or 10,200. Norm Drazy (PSI) claimed the intake runners would go supersonic and not pass any more air at 125% over at higher RPMs yet the boost gauge would climb because the air was backing up in the intake manifold like a stopped up toilet. Meaning, it was useless to rev it to the moon. While some may not believe it I have about 150 times slips that don't lie.

Credit where credit is due. The 260 miles per hour barrier was first broken by my former driver, Larry Miner, almost 10 years ago at 125%. Unless my brain is malfunctioning I think they told me they did it with a 2 speed and a 2 disc clutch.

RG

 

The rule sounds like its banning the supercharger that Les Davenport built for Yirka Kaplans comp altered. That is on bad piece! It went over a second under the index in Vegas

 

Squashing ingenuity at someone elses expense.

I bet the document by itself wasn't cheap.

Is this what a guy gets for his hard work.

If this is the reason for the rule change I hope he can recoup his costs by selling this blower to some tractor pullers!!

Les...are you out there to explain??

Good reading for all the horsepower geeks here.

http://www.faqs.org/patents/app/20090148331

 

wow that looks nuts!I have never seen anything like it.