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-   -   2008 Cobra Jets belong in Stock (https://classracer.com/classforum/showthread.php?t=15797)

Tim Kish 02-11-2009 03:56 PM

Re: 2008 Cobra Jets belong in Stock
 
Quote:

Originally Posted by Chad Rhodes (Post 105309)
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 02-11-2009 04:30 PM

Re: 2008 Cobra Jets belong in Stock
 
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 02-11-2009 06:36 PM

Re: 2008 Cobra Jets belong in Stock
 
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 02-11-2009 06:57 PM

Re: 2008 Cobra Jets belong in Stock
 
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 02-11-2009 09:17 PM

Re: 2008 Cobra Jets belong in Stock
 
Quote:

Originally Posted by Evan Smith (Post 105419)
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.

Jeff Lee 02-12-2009 01:57 AM

Re: 2008 Cobra Jets belong in Stock
 
Quote:

Originally Posted by Evan Smith (Post 105269)
Ed F.,

You can look at the engine specs on line and see the differences, but in a nutshell, the CJ has less compression by a full point (which is a big deal even with a blower), smaller valves, smaller cams and smaller throttle body.

Evan

Evan,
You need to have a staff meeting on this! Seems to be some ambiguity on the specs between the GT500 & the CJ500 engine specs. But for the real tech heads, it's all on-line at www.nhra.com .
(From Muscle Mustangs & Fast Fords online 02/11/2009, see complete article and source @ http://www.musclemustangfastfords.co...jet/index.html )

"...Ford delivers the Cobra Jet cars with a glaring 400 horsepower (nudge-nudge, wink-wink), a rating far under the combination's potential thanks to Ford Racing electronically controlling output so that it fits in the rules. Let's be realistic, the engine is a GT500 powerplant with a TVS blower, larger throttle body and MAF sensor, and long-tube headers amongst some other minor details. The 400 horse rating is far less than what that engine could produce with a little bit of a workout on the chassis dyno...."

Seeing that Ford Racing is "Ford Racing electronically controlling output", I'm still sticking to my prediction of 9.38 @ 142 that will ultimately be unleashed from these Shelby's, err, Mustangs!

And one last thing and then I quit, if these were labeled "Shelby's" with the "lite-weight drag-pack" option instead of Mustangs, I wouldn't have any beef.

Congratulations on Ford putting together one helluva package!

Tom P 02-12-2009 02:09 AM

Re: 2008 Cobra Jets belong in Stock
 
Ford did that with the 428 Cobra Jet too but it's been worked out fairly. The engine relies on boost rather than RPM and if that is limited so is power. These things have tiny 3 1/2" bores and huge 4 1/4' strokes.

The Shelby GT500 could just as well have been called the Mustang Cobra but marketing it on the Shelby name and heritage seems to have worked well for sales. Check the window sticker on one and see where they are shipped from.

Evan Smith 02-12-2009 10:00 AM

Re: 2008 Cobra Jets belong in Stock
 
Jeff,

Respectfully, Ford wanted to run Stock because it wanted a car in the top class. NHRA has reserved the top class of Super Stock for Chrysler products only, so why should Ford build a car to be second fiddle? I disagree with the SS/AH-only class, because it is unfair to other manufacturers and racers who would like a shot at the lime-light. In addition, Ford wanted to build a turn-key racer, much like it does in road racing. We all know this would be out of the realm of a OEM to build a turn-key Super Stock car.

So. where does the CJ really belong? Perhaps Super Stock is a better place, that is certainly a good argument.

If Chevy or Chrysler builds a car that fits the current guidelines I am all for it no matter where it falls. I would be pissed if I raced a "A" or "AA" car, I'll admit that, but any racer gripes should with NHRA, not Ford or the guys racing them. If the cars fly like all of you are predicting, then I'm sure NHRA will take action. I can't speak for NHRA, but I'm sure it doesn't want egg on its face over this.



Evan

Bruce Noland 02-12-2009 10:16 AM

Re: 2008 Cobra Jets belong in Stock
 
Evan,
There is a strong possibility that both of them will have egg on their faces. Placing the CJ in regular Stock is something that nhra and Ford wanted. At Pomona, Brent Hajek said it was his impression the cars would run in a separate class such as FX but somewhere along the line the CJs wound up in regular Stock.

On a personal note, I'm very happy for John. He worked his butt off for weeks on end and showed his world champ class by winning a marathon event. All of our cars are just chunks of metal, plastic and rubber but it is the human aspect of the sport that is so appealing.

Jack Matyas 02-12-2009 10:25 AM

Re: 2008 Cobra Jets belong in Stock
 
Holy Cow Bruce -- your last post is showing a "soft" side we've never seen before...............Is this the 2009 version of a kinder / gentler you ?


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