450 flywheel hp with twin screw?

[Black2003Cobra]

Easiest, maybe, most accurate, definitely not. There are far too many major differences (twin screw vs. twin rotor, 37/30mm valves vs. 37/32mm, etc.) to accurately scale anything from the old 4.6s.

I'm well aware that the valve size differences, manifold changes, cam differences blah blah blah will certainly change VEe, sure, but how much is that going to change the final result? I doubt it would be that far off so as to make those numbers way out of line. Sorry, but it's not going to make a huge error, IMHO. And yes, I know about the difference in the superchargers, too. Based on the AE data from the Eaton M112 and Lysholm 2300AX compressor maps, I estimate a difference in drive power (Pd) of roughly 14-16 hp. Remember, Pd scales with more than just the adiabatic efficiency....the larger engine displacement means the mass-air flow rate (mdot) has to go up to support the same boost pressure, and that brings Pd back up, since Pd = mdot*Cv*DeltaT. And then there's the difference in the air density, too. Yes, I know all this. But let's not get so picky here, shall we? After all, it's just an estimate!

 

[Fourcam330]

I'm well aware that the valve size differences, manifold changes, cam differences blah blah blah will certainly change VEe, sure, but how much is that going to change the final result? I doubt it would be that far off so as to make those numbers way out of line. Sorry, but it's not going to make a huge error, IMHO. And yes, I know about the difference in the superchargers, too. Based on the AE data from the Eaton M112 and Lysholm 2300AX compressor maps, I estimate a difference in drive power (Pd) of roughly 14-16 hp. Remember, Pd scales with more than just the adiabatic efficiency....the larger engine displacement means the mass-air flow rate (mdot) has to go up to support the same boost pressure, and that brings Pd back down, since Pd = mdot*Cv*DeltaT. And then there's the difference in the air density, too. Yes, I know all this. But let's not get so picky here, shall we? After all, it's just an estimate!

I'm saying the best way to estimate the potential power of a GT500 motor is by using a GT motor as the baseline. It's a much closer model to the GT500 than the 03/04. :beer:

 

[Black2003Cobra]

I'm saying the best way to estimate the potential power of a GT500 motor is by using a GT motor as the baseline. It's a much closer model to the GT500 than the 03/04. :beer:

Now that I will agree with, Fourcam!

But unfortunately, we don't have a heck of a lot of really solid measured data for the GT. Heck, we don't really even know for sure what the boost pressure is! According to Road&Track it's 12 psi, (but that was an older article). At any rate, we'd have to scale for Pboost (and the impact on the SC parasitic drive power). And of course we'd have to scale by RPM, too. (GT makes peak power at 6500 according to the spec.) And then there's the static compression ratio. The Ford GT is 8.4:1, but the '03 Cobra is 8.5:1, but we haven't seen anywhere what it is for the Shelby. And what about dyno measurements for the GT so we have a better idea what the true power is. (I'd bet the spec'd 550 bhp is under rated, too.). Anyway, I guess my point is that with so little data available for the GT, one really can't scale from there. (If someone has this data, I'd love to see it!) So at this point, this is sorta the best we can do! Can't wait to see the real Shelby numbers...it's going to be a long wait! Cheers! :beer:

 

[Jpjr]

The new Cobra is a step in the right direction power-wise but everything else including rear-end, weight, and looks is two steps back. I'm fine with the power of my Terminator especially knowing that I can get 700hp out of it without rolling on an F-150 axle.

 

[Fourcam330]

GTs are seeing 11-11.5psi with the stock pulley, and are putting down 545-560rwhp and a like amount of TQ in such trim. Granted the rear mounted transaxle may account for slightly less driveline loss-maybe, maybe not--but their results give us something to work with. Based on those #s, @ 20+psi, there's no reason they won't put out 700/700.
Regardless, these things are going to be absolute monsters :banana:

Now that I will agree with, Fourcam!

But unfortunately, we don't have a heck of a lot of really solid measured data for the GT. Heck, we don't really even know for sure what the boost pressure is! According to Road&Track it's 12 psi, (but that was an older article). At any rate, we'd have to scale for Pboost (and the impact on the SC parasitic drive power). And of course we'd have to scale by RPM, too. (GT makes peak power at 6500 according to the spec.) And then there's the static compression ratio. The Ford GT is 8.4:1, but the '03 Cobra is 8.5:1, but we haven't seen anywhere what it is for the Shelby. And what about dyno measurements for the GT so we have a better idea what the true power is. (I'd bet the spec'd 550 bhp is under rated, too.). Anyway, I guess my point is that with so little data available for the GT, one really can't scale from there. (If someone has this data, I'd love to see it!) So at this point, this is sorta the best we can do! Can't wait to see the real Shelby numbers...it's going to be a long wait! Cheers! :beer:

 

[Black2003Cobra]

Thanks for the numbers. Do you have any links to that kind of info? I'd be more than interested in checking out the dyno graphs, et al.. Thanks in advance.

 

[Black2003Cobra]

P.S. Using the avg data that Fourcam gave for the GT the scaling would go like this:

GT: Pboost = 11.25 psi, peak power RPM = 6500, avg power = 552 rwhp.
GT500: Pboost = 8.5 psi, peak power RPM = 6000, (assume same static CR, same mechanical efficiency, yadda yadda, etc. etc., and neglect SC drive power difference.)

Est’d GT500 RW HP = 552*(6000/6500)*(1 + 8.5/14.7)/(1 + 11.25/14.7) = 455 rwhp
Est’d GT500 FW HP = 455/0.85 = 535 bhp

From the engineering standpoint, that’s not too far off (<5%) from the 510 bhp estimated from the ’03 numbers. And if you add in the ~15 hp from the blower diff, that would have worked out to 525 bhp. (But again, this is just splitting hairs since we're only estimating anyway.)

 

[Formula51]

Nicely done Black2003Cobra, are you an engineer by chance? It will be interesting to see how much if any Ford has to restrict the output because of emissions and other pain in the arse reasons. Regardless, I think it is pretty safe to say that the next Cobra will have 50+rwhp more than the 03-04' Cobra if it is built with a similar engine configuration as the one debuted. Couple that with the all new chassis and the overall better quality of the new Mustang, throw in good ole' Shelby's touch, and it should be a very nice car indeed. I think it is likely it will cost $40k or a smig less, which would be great. Of course that is just a guess.

 

[Black2003Cobra]

Yes, I am an engineer. BS (something I'm often told I'm full of) and MS. What gave it away? (LOL) There's no doubt this is going to be a nice ride. I just hope they don't have all the quality issues they had with the '03s. I had so many problems with mine I'd have gotten rid of mine a long time ago if it wasn't such a blast to drive! I would have liked to see an IRS in the Shelby, but from what I've read, it just wasn't that much better to warrant the estimated $5k extra in cost. (According to Shelby, anyway.) I really should take an '05 for a test drive to check out the handling differences. Thanks Formula51.

 

[ygohome]

"Based on those #s, @ 20+psi, there's no reason they won't put out 700/700. "

... thats all I needed to hear

 

[03soniccobra01]

750/800 with a little work and thought!

 

[ygohome]

to me, I think the solid rear axle is the perfect match for this type of power. better than the busted halfshafts from the 03's IRS anyways. Of course if it's an 8.8 then it could use a "little" improvement still

 

[Fourcam330]

750/800 with a little work and thought!

Definitely possible, I try to estimate on the conservative side. :beer:

 

[Formula51]

Yes, I am an engineer. BS (something I'm often told I'm full of) and MS. What gave it away? (LOL) There's no doubt this is going to be a nice ride. I just hope they don't have all the quality issues they had with the '03s. I had so many problems with mine I'd have gotten rid of mine a long time ago if it wasn't such a blast to drive! I would have liked to see an IRS in the Shelby, but from what I've read, it just wasn't that much better to warrant the estimated $5k extra in cost. (According to Shelby, anyway.) I really should take an '05 for a test drive to check out the handling differences. Thanks Formula51.

Thats cool. I am a Senior Undergrad in Mechanical Engineering at Clemson Universtiy. Should be starting grad school in the Fall, acceptance hasn't come yet, and will be focusing on the thermal fluid sciences as they are the most challenging and therefore the most interesting to me.

Man, I just got back from the Michelin test track with my vehicle dynamics class and that was a blast! Slinging Crown Vics around on the wet road course with bald rear tires was awesome! That and spinning out Toyota Camrys with bald rear tires on the wet skid pad at about 55mph! Damn test drivers have an awesome drive. Also got to ride in a 03' Z06 and a late 90's M3 and both cars understeered more than I expected. Of course this was wet courses with all season tires.

 

[Black2003Cobra]

Sounds like a blast, Formula51! Glad to hear you plan on continuing your education right away. It's always best to go straight on to grad school (if that's what your future plans are), in my opinion. If you put it off, it often times doesn't happen. Fluids seems to be a fairly popular area of specialization. The son of a friend of mine at work is planning on going into CFD, so maybe I'll get to brush up, too! Best of luck!

 

[03RedCobra]

probably too early for me to be asking if they've improved upon the t56 input shaft on the newer cobra and also the retainer sleeve issue from the 03/04's. ANyone hear anything about it? - Ben

Well, I talked with a Rep from the Tremec company at the World Ford Challenge last year and he was personally going to be a part of the next Cobra project and he stated that no matter what Cobra they made, Ford had already contracted with Tremec to use the T56 again. He said that they will have the 26-spline input shaft though. He told me that Tremec had actually recommended the 26-spline on the '03 Cobra, but Ford was the one that decided to go for the 10-spline instead.

 

[blueovalkid]

750/800 with a little work and thought!

WOW with that kind of HP potential it is not going to matter what size tires they put on the car. :burnout:

 

[hpbyhermann]

first of all the car ISN'T GOING TO HAVE A TWIN SCREW!

It is still a roots rotor pack design, this is from a very reliable source, so the blower will have to be replaced for really big power...thought you guys should know, i can't wait to get mine, i'll have the new blower ect here waiting before the car gets here!! :burnout: hermann

 

[roushraven]

It is still a roots rotor pack design, this is from a very reliable source, so the blower will have to be replaced for really big power...thought you guys should know, i can't wait to get mine, i'll have the new blower ect here waiting before the car gets here!! :burnout: hermann

Whoa, that's really big news. Looks like Whipple will be doing lot's of business.

 

[BillyGman]

first of all, if it's not going to be equipped with a twinscrew, then I for one probably won't buy one. Second of all, there seem to be alot of people assuming that just because it might be an eaton that this means that it won't be a twinscrew, and what they don't realize is that Eaton makes twinscrew superchargers also, and it wa Eaton that made the twinscrew supercharger for the 2005 ford GT supercar. So I wouldn't bank on that info about the GT500 not having a twinscrew as being concrete since there are a lot of people getting the eaton info mixed up.