450 flywheel hp with twin screw?

[ygohome]

Just a curious thought... sorry if it's already been asked here...

If the new cobra is rated at 450 hp with the twin screw... what room is there for improvement? Other than smaller snout pulley and a larger crank pulley and a tune.

If the 03 was getting close to 600 rwhp with a twin screw how will the newer gt500 cobra get to that level? Are the pulley swaps sufficient to get it there?

Curious, not doubting, just curious.



Thanks,

Ben

 

[EddieGT]

Just a curious thought... sorry if it's already been asked here...

If the new cobra is rated at 450 hp with the twin screw... what room is there for improvement? Other than smaller snout pulley and a larger crank pulley and a tune.

If the 03 was getting close to 600 rwhp with a twin screw how will the newer gt500 cobra get to that level?

Curious, not doubting, just curious.

Thanks,

Ben

You really think the SC 5.4 truly has 450 HP? Remember, the DOHC 4.6 Terminator motor is rated at 390, but average numbers are closer to 435 ~ 450 crank HP...

I wouldn't be surprised if the GT500's dyno in the 415 ~ 430 rwhp range, stock. I'm thinking close to 500 crank hp.

Also, they always quote 450+ (the plus sign)... So once the official cars hit showroom floors, the advertised number may be closer to actual output (500, maybe?) They gotta make the '500' denomination mean something, since there's no 500ci engine in there.

 

[ygohome]

not doubting that it's under-rated.

just wanted to know what can be done to improve that considering it already has a twin-screw? The 03 big mod was to replace the eaton with a kennebell or whipple, etc... what will it be for the new cobra.

 

[ygohome]

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

 

[Fourcam330]

Just a curious thought... sorry if it's already been asked here...

If the new cobra is rated at 450 hp with the twin screw... what room is there for improvement? Other than smaller snout pulley and a larger crank pulley and a tune.

If the 03 was getting close to 600 rwhp with a twin screw how will the newer gt500 cobra get to that level? Are the pulley swaps sufficient to get it there?

Curious, not doubting, just curious.



Thanks,

Ben

The GT/GT500 motor isn't going to be comparable to the 03/04 motor at all.

 

[ygohome]

so your saying that with a pulley swap the gt500 should be able to surpass the #'s produced by an 03 with a twin screw?

 

[jshen]

Feel free to quote me............

When the final numbers come out....You will see "just" under 500 hp for insurance purposes....but figure on 510 at the "rear wheels"!!!!!!! I have no personal knowledge other than SVT people here and one reliable source on this Site..............

 

[Fourcam330]

so your saying that with a pulley swap the gt500 should be able to surpass the #'s produced by an 03 with a twin screw?

I'm saying with full exhaust, CAI, pulley/tune, they will put out 700/700+rw.

 

[Fourcam330]

not doubting that it's under-rated.

just wanted to know what can be done to improve that considering it already has a twin-screw? The 03 big mod was to replace the eaton with a kennebell or whipple, etc... what will it be for the new cobra.

After the basic stuff like exhaust, CAI, the blower is going to be the next restriction, even if it's a twin screw, followed by the emissions friendly cams. The rods/pistons may or may not prove to be an issue with regard to durability.

 

[Formula51]

When the final numbers come out....You will see "just" under 500 hp for insurance purposes....but figure on 510 at the "rear wheels"!!!!!!! I have no personal knowledge other than SVT people here and one reliable source on this Site..............

Laughable! The car is very very nice, but are you seriously telling me that you think it will dyno 510rwhp STOCK? Perhaps you meant to type 410? Kids read this kind of stuff and then go spit it around to their friends and when the actual car comes out and doesn't dyno 510rwhp people are disappointed. I think a lot of people are getting too excited and doing a little too much surmising. 510rwhp and 3450lbs would be insanely awesome, but I think maybe 425rwhp and 3600-3700lbs is much more realistic, which is still awesome assuming it costs around 40k.

 

[EddieGT]

Laughable! The car is very very nice, but are you seriously telling me that you think it will dyno 510rwhp STOCK? Perhaps you meant to type 410? Kids read this kind of stuff and then go spit it around to their friends and when the actual car comes out and doesn't dyno 510rwhp people are disappointed. I think a lot of people are getting too excited and doing a little too much surmising. 510rwhp and 3450lbs would be insanely awesome, but I think maybe 425rwhp and 3600-3700lbs is much more realistic, which is still awesome assuming it costs around 40k.

amen

 

[Mr. Mach-ete]

I likey new Cobra. This car will be awsome to mod.

 

[Black96SVT]

they said that the new SHelby Cobra will be closer to the 500 but have at least 450hp at the crank, slap on a pulley and some simple bolt ones, you have a street eating machine

 

[capnkirk52]

I'm saying with full exhaust, CAI, pulley/tune, they will put out 700/700+rw.

its a wonderful time for power enthusiasts!!!! all the way round the spectrum, viper ($90,000), zo6 (65-$70,000), gt500(hopefully ~$40,000)...

 

[Captain Beyond]

I'm saying with full exhaust, CAI, pulley/tune, they will put out 700/700+rw.

These Shelbys will be underrated in hp by Ford. Terminators are underrated at 390, but everyone knows that they produce at least 425. Why wouldn't a larger cube engine with a more effcient twin screw S/C put out at least 500? Given the potential of these powerplants, I would have to agree with Fourcam330. :beer:

 

[big1inch]

AREN'T THESE NEW MOTORS SUPPOSED TO BE BASIC GT SUPERCAR MOTORS MAYBE DETUNED WITH LESS LIFT LIKE THE MARKv111. IF SO I BELIEVE THESE ARE 5.4 WITH COBRA R HEADS CHECK THE FLOW DATA ON THOSE AND ADD 20+ LBS. AND YOU HAVE 750+ CRANK HP. I JUST HOPE THEY DON'T SLIDE IN THE THREE VALVE ON US. IF THEY PRODUCE THE 4V 5.4 WITH A TWIN SCREW AND GOOD INTERNALS YOU WILL FORGET ALL ABOUT OUR BELOVED TERMINATORS. WE WILL CALL IT THE ANNHIALATOR.

 

[BillyGman]

AREN'T THESE NEW MOTORS SUPPOSED TO BE BASIC GT SUPERCAR MOTORS MAYBE DETUNED WITH LESS LIFT LIKE THE MARKv111. IF SO I BELIEVE THESE ARE 5.4 WITH COBRA R HEADS CHECK THE FLOW DATA ON THOSE AND ADD 20+ LBS. AND YOU HAVE 750+ CRANK HP. I JUST HOPE THEY DON'T SLIDE IN THE THREE VALVE ON US. IF THEY PRODUCE THE 4V 5.4 WITH A TWIN SCREW AND GOOD INTERNALS YOU WILL FORGET ALL ABOUT OUR BELOVED TERMINATORS. WE WILL CALL IT THE ANNHIALATOR.

No, no, and no.......

first let me say, that I share your enthusiasm for the GT500, and I'm thrilled that they're finally going to drop a 5.4L engine in a vehicle of the Mustang platform. I say it's about time. I'm also impressed that they're going to slap a twin screw S/cer on it!!!! But as far as the engine itself, it is NOT the 2005 Ford GT supercar engine at all. However, it will have the GT supercar cylinder heads (NOT the Cobra R heads). But the bottom end of the GT500 motor will be closer to the 03/04 Cobra motors. Iron block, forged steel crank, and forged pistons. The Ford GT supercar motor has a different bottom end which includes an aluminum block, a ten quart capacity dry sump oil system, and has different connecting rods than the GT500 will come with.

 

[Black2003Cobra]

The easiest way to estimate the power of the Shelby engine is to just scale from the ’03 numbers. They typically put down about 370 rwhp, which translates to an estimated 370/0.85 = 435 hp at the crank at 6,000 rpm (as mentioned above). After carefully reading that press kit release, it now appears that the Shelby will not only have the GT heads, but that it will also use the same cams. That said, there’s no good reason I can think of that VE won’t hold all the way up to redline of 6,000 rpm on the Shelby. So for the same boost pressure, and if we assume the same static compression ratio of the Shelby is the same 8.5:1 as the ‘03s, by neglecting the differences in blowers the Shelby engine would simply scale to ~435*5.4/4.6 = 510 hp at the crank. Note, the higher adiabatic efficiency of the twin-screw blower will result in less parasitic hp loss and a slightly denser air charge (at same Pboost), which would result in even more power. So yeah….450 is way under rated! But this is all just in fun!

 

[Formula51]

Probably a decent estimate, but be careful with linear relationships when talking about engines. There are many many variables in two completely different engines (5.4 and 4.6) which will almost certainly make the relationship between the two non-linear.

 

[Fourcam330]

The easiest way to estimate the power of the Shelby engine is to just scale from the ’03 numbers. They typically put down about 370 rwhp, which translates to an estimated 370/0.85 = 435 hp at the crank at 6,000 rpm (as mentioned above). After carefully reading that press kit release, it now appears that the Shelby will not only have the GT heads, but that it will also use the same cams. That said, there’s no good reason I can think of that VE won’t hold all the way up to redline of 6,000 rpm on the Shelby. So for the same boost pressure, and if we assume the same static compression ratio of the Shelby is the same 8.5:1 as the ‘03s, by neglecting the differences in blowers the Shelby engine would simply scale to ~435*5.4/4.6 = 510 hp at the crank. Note, the higher adiabatic efficiency of the twin-screw blower will result in less parasitic hp loss and a slightly denser air charge (at same Pboost), which would result in even more power. So yeah….450 is way under rated! But this is all just in fun!

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.