Cobra power, how much is enough?

[twin turbo]

On my car I have found 550-600 rwhp is the sweet spot (limit) for reasonable street driveability with fresh drag radial tires on good roads during warmer weather. If someone is having problem with spinning their tires at 70 mph running 500 flywheel hp (approx 420 rwhp), then it might be time to look at upgrading tires or checking suspension settings. When I first got my car I had 420 rwhp and had no tire spin in 1st when rolling into the throttle (I had 3.08 rearend gearing at the time). Cheers.

[olddog]

Originally Posted by tirod

It IS exactly why the big blocks were termed dangerous - don't forget, Shelby sold every 289 built, but it took 18 months longer to push the 427/428 off the lots. They were not considered user friendly. Bill Cosby shipped his back. Smart man.

Bill Cosby asked for a Cobra that could run over 200 mph. Shelby built two supercharged cars at about 900 Hp. One for Cosby the other Shelby kept for himself. Cosby did a comedy routine on the car. Cosby sold the car, and the 2nd owner died in a crash that destroyed the car. Shelby sold his a few years back at auction, fetching over $5,000,000.

Bill Cosby's car was not a typical 427 Cobra - apples to watermelon comparison.

Bill Cosby did not ship his car back.

I believe this is essentially correct, or at least what I remember reading.

[Obsessive]

Originally Posted by PHC1

What do you guys think is the "sweet spot" for powering a typical Cobra replica? If the car is to be enjoyed mostly on the streets and driven semi-aggressively on back roads, how much is enough to keep the car fun to drive and feel you have neither over-powered or under-powered the car with the choice of engine? Bragging rights aside, being realistic and keeping driveability in mind for your answer!

Horsepower is fun, especially when you can put it down! Driving a Nissan GT-R with 535HP and 0-60 of 2.8 sec with all wheel drive, dual clutch tranny and launch computer is nothing like driving a Cobra replica with the same HP! Of course the GT-R can't compare to the raw and exciting experience the Cobra brings either...

So then, would most agree that between 400-500HP is more than enough? Or do many feel between 500-600 is where the sweet spot is? Perhaps below 400 or above 600 for some???

This thread could go on forever. While there is a lot to address here to answer your question, I'll simply tell you what has worked for me. I've built a couple of these but never for racing. My first build was purely an experiment with a 428 FE. It went like stink but I never put it on a dyno to see the numbers. The 2nd build was a 427 that I stroked with a 428 crank. I really got carried away with the pursuit of high HP numbers and over did it. My current Cobra has a combination that feels perfect as I drive mine on the street and love to drive (too) fast. Here's what I find to be the best for me:

427 SO block, 428 crank, Ford "Sidewinder" dual plane intake manifold, custom grind cam shaft (.507 lift with 274/284 duration and 110 lobe separation), Edelbrock RPM Performer heads with 2.19 intake valves, Comp Cams roller rocker kit (with end posts), Holley 850 DP 4150 carb, Edelbrock water pump, Canton 8 qt oil pan, -12 oil cooler, Melling (non-HV) oil pump, ARP bolts and modified sidepipes.

I run a Lakewood bellhousing with a wide ratio toploader and 3.08 rear end gearing. The car sreams and I have never felt the need for more power. Even with the high gears, the car drives just a little faster than I can think but not so much that it scares me. Too much. I am still playing with the ingition so no advice from me on this.

Horsepower and torque numbers? Not sure but it feels like 500/550ish. With the modified pipes it sounds like even more.

Have fun.

[Silverback51]

Originally Posted by patrickt

Alright, it's yogurt for you for the rest of the summer. What was your final verdict on the corner weighting? Could you tell a difference in just normal, around town, type driving? Not autocrossing or racing, just regular stuff.

Okay, got to drive it a little yesterday and yes, I could tell a difference in L/H turns. Used to be that I could break it loose more easily in L/H than R/H turns.

And just for the record, I do not have a preference of L/H to R/H turns. The majority of drivers, or motorcycle riders have a preference and feel more comfortable one way or the other. That has never been an issue for me.

[patrickt]

Originally Posted by Silverback51

Okay, got to drive it a little yesterday and yes, I could tell a difference in L/H turns.

Excellent. Are you now going to go back to this thread: Best way to adjust rear coil overs for proper height on my SPF and report that Patrick and Jerry C. were indeed correct all along?

[Hydramada]

As much horsepower as your skills allow you to use effectively. I have seen Dennis Olthoff dominate with a 400HP Cobra against 600HP cars. My car has more horsepower than I can effectively use but I am smart enough to recognize that and respect my car.

[JBCOBRA]

Don't forget me

Originally Posted by patrickt

Excellent. Are you now going to go back to this thread: Best way to adjust rear coil overs for proper height on my SPF and report that Patrick and Jerry C. were indeed correct all along?

[Silverback51]

Originally Posted by patrickt

Excellent. Are you now going to go back to this thread: Best way to adjust rear coil overs for proper height on my SPF and report that Patrick and Jerry C. were indeed correct all along?

WHAT!!!!?

Admit that you were right about something?


Let me drink a few more beers and think about it.

[patrickt]

Originally Posted by Silverback51

WHAT!!!!?

Admit that you were right about something?

Let me drink a few more beers and think about it.

Uhhh, here... let me make it easy on you. Just copy and paste.

Guys, this is a follow-up to close out the thread and, for once and for all, put the issue of "corner weighting your street car" to rest. As you all know, Patrick can be a pompous ass at times, has an inflated opinion of himself, and, from time to time, is a rude jerk not only to me, but to others as well. But, when a man's right he's right... and this time Patrick was absolutely 100% dead nuts right. After corner weighting my car, it does indeed drive noticably better on the street, and I have no doubt it will do the same under more agressive scenarios. In fact, I wish I had listened to him and done the corner weighting long ago. All the nay-sayers on this thread are just plain wrong; Patrick is right, along with everyone else who echoed his sentiments. And, while it pains me to say it, I have now done just that.

[Silverback51]

Originally Posted by patrickt

Uhhh, here... let me make it easy on you. Just copy and paste.

Done.

And lord have mercy on my soul.

[Mdman352]

Not sure how much is too much but I have 480 HP and 580 TQ at the flywheel in a FE SO 454 inch motor with Avons and it did this with an off idle launch.......



In previous attempts with drag radials the results were a bit more dramatic.....

[patrickt]

Originally Posted by Mdman352

Not sure how much is too much... [/IMG]

Well, for those parts at least, I would say you did indeed stumble over the threshold of "too much."

[PHC1]

A lot of great replies with various viewpoints on this topic. Thanks!!! It is pretty obvious that choice of tires, suspension differences between the replicas as well as setup makes a big difference in how well any of these replicas can put the power down.

I originally asked the question because in my opinion and it is just my opinion, a replica car made of fiberglass with virtually zero safety measures built into it such as traction control, stability control, ABS, no airbags, virtually no protection from impacts on any side of it... etc... etc... should be powered in a way that would not break traction and result in wheel spin at the tip of the gas pedal in just about any gear.

Driving even semi aggressively on the back roads in performance cars with HP numbers in excess of 500HP and some 1,000+ lb difference over the Cobra replicas as well as running state of the art street tires, it is still NOT uncommon to see the traction control and stability control to be quite busy.... With them off, all hell breaks loose in a blink of an eye as well. That's in a modern performance car with chassis and suspension designed and built with the best of the current technology and engineering for street driven cars. I'm talking about cars that come from the best of the best from Germany and Italy as well as USA...

Yes, I've been on the track, yes, I drive with "enthusiasm", yes, I have experience with over 500HP cars and yet I'm thinking that somewhere in the range of 425HP or so would be more than enough for me in any of the Cobra replica.... If I am wrong, I will just have to live with a boring Cobra for a while!

Thanks for all the replies! Would be interesting to hear even more opinions on this!

[Silverback51]

Originally Posted by PHC1

I originally asked the question because in my opinion and it is just my opinion, a replica car made of fiberglass with virtually zero safety measures built into it such as traction control, stability control, ABS, no airbags, virtually no protection from impacts on any side of it... etc... etc... should be powered in a way that would not break traction and result in wheel spin at the tip of the gas pedal in just about any gear.

Sounds like maybe you better stick a little 120CI Chevy 4 popper in it and call it good.

It's been discussed a number of times, but these cars are flat out dangerous. And it can be argued as to whether a motorcycle or a Cobra is worse and both sides will have a good argument.

If you are looking for safety, consider looking a Corvette. And I don't mean that in a nasty way. There are lots of people that just have to have a Cobra, get one and then find out it's not for them.

[patrickt]

Originally Posted by Silverback51

There are lots of people that just have to have a Cobra, get one and then find out it's not for them.

John's right. The most recent debacle was Tin-Man's. That was just a few months ago, in fact. I think you should do some more research, let some time go by, and maybe reconsider the whole thing.

[RodKnock]

In your original post, you never mentioned whether you were thinking of building a SB or BB replica, but you ought to consider building a nice simple 302 like Tim built for his SB ERA.

ERA 2136 Build Log

SBF's are cheaper to build and make good power. I'm sure Tim's car scoots well. And someday if more power is desired, you can upgrade to a bigger SBF (stroked Windsor) or a BBF (385 or FE).

[rodneym]

Just saw Tin-Man's Cobra at the Shelby show in Pomona.

It's all sorted out and looks purdy. Just don't know who's gonna shell out $120k for it. There's another $120k SPF out there but I digress.

There's a lot of good advice here, PHC1. The horror stories usually start with wide eyed posts like yours...as they should.

Get as much seat time as possible.

[patrickt]

Originally Posted by rodneym

Just saw Tin-Man's Cobra at the Shelby show in Pomona.

Short of a funeral, that was about as sad a Cobra story as you're gonna get. He even managed to slingshot past RSIMOES, who I thought was going to be the polesitter for many, many years to come....

[RodKnock]

Originally Posted by patrickt

Short of a funeral, that was about as sad a Cobra story as you're gonna get. He even managed to slingshot past RSIMOES, who I thought was going to be the polesitter for many, many years to come....

Two sad stories, but only two. I'm sure there may have been some others, but the sad stories are few and far between to the best of my recollection.

I love the fact when someone is new to Cobras, we all suggest buying a Corvette instead. How about a Porsche, BMW, Mini Cooper, Mustang or a Miata?

Best Affordable Sports Cars Rankings | U.S. News Best Cars

[patrickt]

For half of what he will spend on a Cobra he can get a beautiful and fast 911 that will actually make sense to own.