2008 Cobra Jets belong in Stock

[Tim Kish]

Originally Posted by Chad Rhodes

now that the cat is out of the bag, what is the HP potential or airflow potential of that blower? answer the question honestly, or any further input to this thread will be meritless. I know what other blowers of similar displacement are capable of, even on the 4.6 4v motors. NHRA has admitted that they have no specifications on this blower (rotor specs, case clearances, pulley sizes, boost@the rated 425 hp, max boost and or airflow of the unit, etc). All of this info will determine the potential of that combo.

I once spoke with a very well regarded engine builder who specialized in turbo motors. I asked him what the ideal comb was for xx turbo. His repsonse was that it doesn't really matter, the turbo makes the power. I think that holds alot of merit with supercharged motors as well ( i understand that the positive diplacement blowers are somewhat more affected by upstream restrictions.

NHRA tech has access to any information they need. I met with them in Indy and even brought hardware to educate them on what was coming. As you know the supercharger is a positive displacement pump, the faster you spin it the more air it pumps but its only part of the engine system in terms of HP potential. As one of the parameters that NHRA has indicated must be maintained for Stock eliminator is the stock pulley size - That pretty much limits the blowers potential.


BTW - the 700HP Shelby Mustang offered by Shelby Automobiles (not Ford) uses a different supercharger, they are using a larger displacement Screw Compressor to achieve this power level.


Congratulations to John Calvert for winning Stock eliminator at Pomona in the debut of the Cobra Jet.

[Arnold Greene]

I can assure you all that my 427/425 with 401 heads made 596 peak horsepower on a DTS dyno. I ran it as light as I could because IHRA's AA/S class is a 7# class. At a test session in Darlington, SC, December 10, 2007, @ 3230 pounds (200# light for NHRA AA/S) I ran 9.520 @ 138.30. 60'(1.279) 330(3.820) 660(5.998@113.61) no 1000' time....9.520@138.30. The air density was 420'. It was full of oil, so it MIGHT have gone high forties. My point is the CJ's have already gone 143(was told it was the car John won the Winters with. CONGRATS to John and his crew!) You will see these cars in the 9.20 range when all is said and done.

As I said in a previous post, NHRA had factory advertised hp to rate cars, which they did not have with the CJ's. They had to take someone's word for 425. Whoever accepted that number needs their head examined. If anyone with a conventional stocker thinks they can compete with this package, I suggest you save your time and money....just my opinion.

[Greg Hill]

A really good stock eliminator motor will make about 1.5 times the rated horsepower. These are motors that have been flogged over the years and a lot of r&d done. For the new cobra jet that number would be 637hp. The problem with this whole deal is the hp rating. Everyone on this site knows it's a bogus number. If this new Ford was rated properly it would not even be in stock and we wouldn't be having these discussions.

Greg

[Evan Smith]

Jeff,

The Shelby GT500 is 100% built by Ford on it's assembly line in Flat Rock, MI, This car is a Shelby in name only. The Shelby GT, which is naturally aspirated or can be supercharged is a Mustang GT that is modified by Shelby Automobiles in Vegas and is sold new through Ford dealers. The Super Snake is a post-sale modified version.

Evan

[Jeff Lee]

Originally Posted by Evan Smith

Jeff,

The Shelby GT500 is 100% built by Ford on it's assembly line in Flat Rock, MI, This car is a Shelby in name only. The Shelby GT, which is naturally aspirated or can be supercharged is a Mustang GT that is modified by Shelby Automobiles in Vegas and is sold new through Ford dealers. The Super Snake is a post-sale modified version.

Evan

Evan I agree. But a Shelby is a Shelby no matter where it started life. I invite anybody to look in the NHRA class guide. There is a dedicated Shelby section. It has been the argument of Shelby racers for years that Shelby is a car manufacturer and that is why they have enjoyed privledges that Mustang racers have not had. Now they want it both ways. And to put it into perspective, that would mean the 1967-1970 Mustang should be allowed all Shelby engine packages. Right?

I also recognize NHRA states in the Stock rules "need not be showroom available" an inclusion that has only been in the rule book for a few years as previously a vehicle had to be "showroom available".

Obviously my argument is supportive of "the way it was". The newest rules on this issue are clear; this CJ500 is acceptable to NHRA. Obviously, as John Calvert just won the premier showing of these nicely crafted cars. Great job and congratulations to John for a truly spectacular debut!

But stand back and ask yourself "is this the direction Stock should go?" How about if Chevrolet decides to offer a race-only Camaro next year with a SC 638 HP ZL1 engine and lowers the compression 1 point, gives it a smaller cam and valves and calls it a 400 HP rating with all carbon-fibre body panels? As long as they build 50, it should be allowed.

Since 1965 race only packages such as this have been directed to Superstock. I believe that tradition should still remain. That or allow all the old "race-only" packages in Stock.