CLASS RACER FORUM - Factory experimental

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Re: Factory experimental

Quote:

Originally Posted by Tom P (Post 101185)

The Cobra Jet really is an 08 Shelby GT500 with less weight and a few racing modifications already done, some normally allowable in Stock and a few that aren't. A GT500 would be legal already, they've built thousands. Ford doesn't really need many of the mods to sell the car to racers who can change that stuff.

I think it'll be interesting to see what happens.

well then, it should have a 500hp rating.........correct?

Re: Factory experimental

Gump, I see your point but the CJ with a 425 rating and a 720 potential I dont think the factor on Bruces camaro was quite that soft ever!!!!!!!! Jim Baileys post should show the potential of where this combo may be headed.

Re: Factory experimental

Cylinder pressure could be a problem ....Pushrod failure!!!...OH, we don't have any...cool, that solves that. Wonder why the McGee and all over head cam engines are banned in the Ultimate Classes in Drag Racing, Top Fuel and Fuel Funny Car? I think it had something to do with cost to the racers?

Re: Factory experimental

Quote:

Originally Posted by Jim Bailey (Post 101195)

Quote:

Originally Posted by Jim Bailey (Post 90734)

Hey Bud, no need to wonder. I'm in the mood to build a new car (or "two"). Yes, one just might be a new Challenger. JB.

I would just love to see these cars go down the track one time!!!

Re: Factory experimental

In regards to the McGee DOHC T/F motor "ban", Jim Bailey said, "I think it had something to do with cost to the racers?"

Are you kidding me?

If NHRA had ANY concern for the racers' pocketbooks, they would have allowed compressed air valve springs, screw compressors, and 2.80:1 rear gearsets in these cars years ago.

ALL F-1 cars have used nothing BUT compressed air valve springs for many years now; steel valve springs won't hold up at 20,000 rpm in a F-1 engine for very long... and, the compressed air springs only have to be bought ONCE. T/AD and Alky Funny car racers, particularly, spend a FORTUNE on valve springs, unnecessarily, because of NHRA's insistence on steel springs. Ask yourself, why would NHRA do that if they were seriously interested in keeping the cost of racing down? Who has convinced them that steel springs are a good thing in a 10,000 rpm Hemi (the alky engines turn that fast, routinely, killing expensive "battleship" springs in just a few runs.)

From what I've heard, screw-type compressors don't require the maintenance that GMC-style Roots blowers do... another cost savings.... but you can't (legally) put one on a Fueler. Why????????

At 335 mph, a Fuel motor is wound up like an 8-day clock with the requisite 3.2:1 ring gear and pinion... spitting pieces of valves and pistons out at the finish line due to the excessive rpms that wouldn't be at all necessary if NHRA would let the racers choose a numerically-lower final drive ratio.

Is that supposed to save money for the racers? I don't see how...

If NHRA is trying to keep the cost of running a Fuel car down they sure have a funny way of doing it (no pun intended.)

Jim, I know you ran a Fueler for a long time, and probably know a LOT more about this stuff than I ever will, but am I off-base with this, or what? What do you think about the foregoing? Am I nuts, or is NHRA deliberately ignoring some ways they could be saving the racers some dollars, here?

Thanks for any information...

Blown Stockers' boost numbers would be easy to police with a tamper-proof telltale boost gauge read by the fuel check Tech guy. But, getting the Ford factory guys to come up with a legitimate boost number for the Tech inspector to observe might be the hard part.... with NHRA on their side.... and, you can bet they are.

Re: Factory experimental

Bill, # 1.... yes I am kidding.... # 2..... Safety..... #3...... It's not about boost, it's about how efficiently you make the boost (ie:screw blowers). Point; which is better, If it takes 300hp (from the crank) to make 40# boost, or if it takes 150 hp (from the crank) to make 40# boost? How do you monitor that will a tell tale?

Re: Factory experimental

Quote:

Originally Posted by Jared Jordan (Post 101154)

One aspect that hasn't been discussed in this thread is the effect the supercharger will have on those cars at an altitude track. Those of you in the Eastern U.S. don't have nearly as many of those as we do out West. If you're getting blown off at sea level by one of these cars how much further behind are you going to be in thin-air against a forced-induction vehicle?

I'm not railing against the Cobra Jets. I think it's fantastic that the factories are injecting new technology into both Stock & Super Stock, but I worry that the playing field won't be entirely level. I never understood the uproar over injected cars vs. carbureted cars. As it turned out, there wasn't as great of a difference in performance as many feared would exist. Perhaps this is the case here, though I don't believe it to be so.

I don't currently have a "dog in the fight" so to speak, but 430 HP seems a little low. If these engines are indeed making 700+ HP (I have no doubt that they are capable of doing so...), then 3395 lbs in AA/SA and 3610 in A/SA seem a tad light. These cars will be capable of bettering the -1.40 number required by the AHFS out of the box, but I guarantee you won't see one go that fast for a couple of years. The system remains the problem, not the car(s). A truly "automatic" system without any degree of human input will never effectively maintain a level playing field. Systems can be manipulated. Common sense cannot.

the thing is with the NHRA systyem, I dont think any of the combo's are really being maxed out or run hard per say.

Re: Factory experimental

Quote:

Originally Posted by bsa633 (Post 101168)

Exuse me for being a little "slow"..but is it the "Roush car" that will be at Pomona or the "Cobra Jet" like NHRA says on thier page..i am a little confused...maybe this is going to be the same as the old Shelbys..what combo of the week are you running?..small valve,big valve,Dove,Edelbrock and so on..

NO these are not the Roush cars,

Re: Factory experimental

Straight from NHRA.com regarding 2008 Ford: (note the 330 CID is the 5.4L and 281 CID is 4.6L). These are all the supercharged engines. Also note both of the the 281 Supercharged engines are rated HIGHER than the 5.4L Supercharged engine.
Pistons have more compression on the 281 engines. The 281 engines have larger camshafts also. I don't believe either compression or cam lift will be significant in gain due to the supercharger. Nothing compared to the 50 CID difference.
What I haven't been able to figure out is if the 2007 Shelby 5.4L supercharged engine is rated 500 HP, then what justifies a 75 HP drop for the 2008 Cobra Jet engine? A slight difference in cam lift and compression on a SC engine does not warrant the -75 HP. It would seem one needs to be adjusted up or one needs to be adjusted down.

425 330 9.38 Supercharged EATON RF7R3Z-9K461 1.8 H/R 48.0 B,3,4
w/follower

430 281 10.0 Supercharged EATON R07060034-13-BB 2.00 H/R 48.0 A,1,3
w/follower

510 281 9.5 Supercharged EATON R07060136-13-BB 2.00 H/R 48.0 A,4,3
w/follower

Notes
1= Throttle Bore 2 @ 57mm = 2.244"
2= Alternate manifold 5R3E-9424-BB
3= Intercooled
4= Throttle Bore 2 @ 62mm = 2.441”

Cylinder Head Castings
A= RF3L3E-6040/6C064-K, RF9L3E-6090/6C064-B
B= RF7R3Z-6C064

Deck Piston
HP Disp Cl Type Height Vol Valves Cam Lift Gasket Springs

425 330 .074 Dish .118” 13.5 cc 2@1456/2@1259 413/413 .037 Beehive

430 281 .000 Dish .050” 4.8 cc 2@1340/1@1500 473/473 .037 Beehive

510 281 .000 Dish .098” 10.5 cc 2@1340/1@1500 473/473 .037 Beehive

The 2007 Shelby 5.4L supercharged:
500 330 .059 Dish .128” 13.5 cc 2@1456/2@1259 468/468 .037 Beehive

Re: Factory experimental

Quote:

Originally Posted by Jim Bailey (Post 101212)

Thanks for the response, Jim; I appreciate it!!!

On #2, I am curious as to what the safety issue is with compressed air valve springs (or, did I get the numbers wrong?) Formula 1 cars race around CORNERS at 200 MPH and the F.I.A deems these springs as safe to use (they've been on all F-1 cars for years), so what's the problem with straight-line racers' safety isues with them? I don't understand what "safety issue" of concern is, here.

And on #3, your answer of "How do you monitor that will a tell tale?" relative to boost didn't really explain anything RE: why screw superchargers are banned. They have a reputation as being more efficient than Roots blowers, and I'm sure somebody's "blower dyno" has all the answers about how much power it takes to drive any of the popular configurations to X-pounds of boost, but the question was, "Why are they banned?" I'm certain NHRA doesn't ban them because they're inefficient...

I have my own ideas, but you having been "in the business," would have a much better idea than I would.

Thanks again for your response. Is your A/SA car a Stage III Wedge? Good luck in 2009!!!

Bill