horsepower

[Blue66]

Originally Posted by BossCER

You rarely hear guys guys with big h.p. complaining that it's too much or not streetable. In fact, it seems you always want a little more!

We run drag radials on all our cars here. You always need more power

[olddog]

The peak Hp number only tells you how it will accelerate at full throttle, when the engine rpm is near where the peak Hp is reached. The torque curve over the usable rpm range tells you "the rest of the story."

A high strung small displacement SB that peaks 450 Hp at 7500 rpm is only making 315 lb-ft of torque. Its peak torque might be 375-400 down around 5000 rpm. Below 3000 rpm it might be below 200 and off idle could only be 75 torque. Such an engine would be no fun to try to drive normally on the street. The fact that the torque is all over the place, depending on rpm, you never know what to expect, when you mash it.

On the other hand, it is not hard to have a large displacement BB that also makes 450 HP but at 5500 rpm. It might have a peak torque of 550 at 4000 rpm. It could have about 450 off idle and climb to near 550 by 2000 rpm, with a flat line to 4000 rpm. Then slowly drop off until the peak Hp.

Even though both engines have 450 Hp, the difference between them is night and day. The BB with a flat torque range, will feel like it has twice the power, every where other than flat out. It will have so much more throttle response everywhere and pretty much the same response everywhere. It would be much more fun on the street. Yet when geared properly both engines pretty much run the same time in quarter mile.

So again, Hp is not the question you should be asking.

[mikeinatlanta]

Originally Posted by olddog

The peak Hp number only tells you how it will accelerate at full throttle, when the engine rpm is near where the peak Hp is reached. The torque curve over the usable rpm range tells you "the rest of the story."

A high strung small displacement SB that peaks 450 Hp at 7500 rpm is only making 315 lb-ft of torque. Its peak torque might be 375-400 down around 5000 rpm. Below 3000 rpm it might be below 200 and off idle could only be 75 torque. Such an engine would be no fun to try to drive normally on the street. The fact that the torque is all over the place, depending on rpm, you never know what to expect, when you mash it.

On the other hand, it is not hard to have a large displacement BB that also makes 450 HP but at 5500 rpm. It might have a peak torque of 550 at 4000 rpm. It could have about 450 off idle and climb to near 550 by 2000 rpm, with a flat line to 4000 rpm. Then slowly drop off until the peak Hp.

Even though both engines have 450 Hp, the difference between them is night and day. The BB with a flat torque range, will feel like it has twice the power, every where other than flat out. It will have so much more throttle response everywhere and pretty much the same response everywhere. It would be much more fun on the street. Yet when geared properly both engines pretty much run the same time in quarter mile.

So again, Hp is not the question you should be asking.

And then there is the high strung, big displacement small block.

[cycleguy55]

Originally Posted by olddog

The peak Hp number only tells you how it will accelerate at full throttle, when the engine rpm is near where the peak Hp is reached. The torque curve over the usable rpm range tells you "the rest of the story."

A high strung small displacement SB that peaks 450 Hp at 7500 rpm is only making 315 lb-ft of torque. Its peak torque might be 375-400 down around 5000 rpm. Below 3000 rpm it might be below 200 and off idle could only be 75 torque. Such an engine would be no fun to try to drive normally on the street. The fact that the torque is all over the place, depending on rpm, you never know what to expect, when you mash it.

On the other hand, it is not hard to have a large displacement BB that also makes 450 HP but at 5500 rpm. It might have a peak torque of 550 at 4000 rpm. It could have about 450 off idle and climb to near 550 by 2000 rpm, with a flat line to 4000 rpm. Then slowly drop off until the peak Hp.

Even though both engines have 450 Hp, the difference between them is night and day. The BB with a flat torque range, will feel like it has twice the power, every where other than flat out. It will have so much more throttle response everywhere and pretty much the same response everywhere. It would be much more fun on the street. Yet when geared properly both engines pretty much run the same time in quarter mile.

So again, HP is not the question you should be asking.

Exactly. Paraphrased, it's less about where and how high the HP and torque curves peak than it is about the 'area under the curve' - particularly for street use. A rich, fat torque curve will not only make it more fun on the street, but will often out-perform a higher HP engine that's 'peaky'.

That fat torque curve will also allow you to keep the revs down and, hopefully, keep from drawing unwanted attention from the local gendarmes - they really seem to come out of nowhere when the revs get much above 4,000 RPM.

[SPF1061]

Originally Posted by ender2664

How much are most people running? I am deciding on an engine and am not sure how much power to put in given how light it is and have the car still be able to hook up.

Ender 2664,
The Cobra experience is not about being rational. I am going to guess that anything over about 300/325 is going to be a challenge hooking up. I am also going to guess that the AVERAGE Cobra hp is somewhere around 475. Regardless of how much hp you start off with, if you keep the car long enough eventually you will want more. You can take that as gospel.

[Joe's Garage]

Never knew that, seat time in a cobra makes your pecker shrink.
Joe

[cycleguy55]

Originally Posted by Joe's Garage

Never knew that, seat time in a cobra makes your pecker shrink.
Joe

Viagra, Cialis and Levitra are marketed to, uh, mature males - Cobra owners use higher HP and torque to achieve similar results. And yes, just like the little blue pills, I did talk to my doctor about my Cobra. I think he's itching for a ride - it's WAY better than his Jaguar.

p.s. Still waiting for the erection lasting longer than 4 hours...

[ender2664]

Blue 66, what size are your rims?

[kanuck]

Way back 20 plus years ago I witnessed a dyno run of a NOS 427 that came out of a crate,
it was suppose to be a 425HP version that was "under rated" no matter what carb or how much timing they put into it, the best they saw was 410 HP, so I really don't believe cobras had as much HP as we would like to believe they had, I figure it is just like anything else over the years the numbers just get bigger and bigger, every time the story is told.

Dean

[Blue66]

Originally Posted by kanuck

Way back 20 plus years ago I witnessed a dyno run of a NOS 427 that came out of a crate,
it was suppose to be a 425HP version that was "under rated" no matter what carb or how much timing they put into it, the best they saw was 410 HP, so I really don't believe cobras had as much HP as we would like to believe they had, I figure it is just like anything else over the years the numbers just get bigger and bigger, every time the story is told.

Dean

yup.... just listen to guys in the stands at the drags .. There best one is "My car dyno'd 600hp" . Then continued to run a high 12 @ 110 mph. Oh... "Track can't hold my power"

[Maricopa]

Way back 20 plus years ago I witnessed a dyno run of a NOS 427 that came out of a crate,
it was suppose to be a 425HP version that was "under rated" no matter what carb or how much timing they put into it, the best they saw was 410 HP, so I really don't believe cobras had as much HP as we would like to believe they had,

The majority of BB Cobras had pretty mild 428s making @ 355hp.The cars that won all the races had 12:1 comp, Weber-carbed 289s making less than 400 hp.

[Mother]

Goto "You Tube". Search "Bob's Cobra" Unit is a twin Turbo, small block 427. Mid Nines. Most interesting.

[jbcobra67]

Just watched Bob's Cobra. That is one fast car, let alone a cobra.
Very nice.

I've had one with a 347 that made 449 at the flywheel, super fun car. Now I have one with a BB 427, Not exactly sure of the HP, the builder in FL. pegged it between 450 and 460. But my what a different feel with the BB. Personal taste I would like to have a 408 stroker motor in mine.

[Arvin]

I am building a FFR roadster right now so I have a short understanding on this subject. I purchased a Kieth Craft 408 street/strip motor with TKO600 tranny. It dynod at 512 hp and 534 ft-lb on 91 octane gas. I am running FAST EFI. I just put the body on for the final time so I have about 150 construction miles on it. One sentence - TOO MUCH POWER. I plan on using mine for runs in the mountains and I would like 150-200 hp less. It's scary!!

[lovehamr]

Originally Posted by Arvin

I am building a FFR roadster right now so I have a short understanding on this subject. I purchased a Kieth Craft 408 street/strip motor with TKO600 tranny. It dynod at 512 hp and 534 ft-lb on 91 octane gas. I am running FAST EFI. I just put the body on for the final time so I have about 150 construction miles on it. One sentence - TOO MUCH POWER. I plan on using mine for runs in the mountains and I would like 150-200 hp less. It's scary!!

DEDENBEAR Throttle Stops-Baseplate Style

[Automan]

Hi, i put a 63 1/2 427 center oiler in my A&C with dual 650 CFM low riser. You respect the car and its power, it will respect you.

[Voyager]

My KC 408 dynoed at 515 hp & 531 tq. Probably 400ish at the wheels. About right for me. I bought this car to scare the crap out of me. It does.

Last time I floored it (about 3 years ago), I ended up in the grass.

Having said that, I had just as much fun in my old 125 hp 1st gen Miata. Besides, I don’t think ET is directly proportional to satisfaction in the world of sports cars.

[Detroit Bill]

Originally Posted by Voyager

My KC 408 dynoed at 515 hp & 531 tq. Probably 400ish at the wheels. About right for me. I bought this car to scare the crap out of me. It does.

Last time I floored it (about 3 years ago), I ended up in the grass.

Having said that, I had just as much fun in my old 125 hp 1st gen Miata. Besides, I don’t think ET is directly proportional to satisfaction in the world of sports cars.

Voyager, how did you get in the grass? What happened?
No matter how that happened I looked in your gallery and saw BFG Radial TA's.
That may have added to visit to the grass.

[landmass]

My Hurricane Motorsports first came with a 350 HP Ford 302 engine. It's my daily driver when the weather is good. The car weighs 2300 lbs with 1/2 tank of gas and me not in it. It was nice, but I wanted more power as I quickly became accustomed to it. I installed a Ford 347 with 480 crank HP, then added Fast EZ EFI, which I figured added another 20 HP. I do run mid 11's at the track all day long, with my best time at 11.3 at 121 mph with a short time of 1.55 with a T5 tranny. I run M/T 275-50/15 drag radials screwed to the wheels to prevent the wheels from spinning inside the tires and messing up the wheel balance(which happened). I've pulled the front wheels off the ground once(photo attached). It was totally unexpected, so my head flew back. Since then, I've been prepared in case it does it again! I've made 138 runs with the car and will be adding to that number this Friday night. 500 hp is OK on the street as a daily driver. That what this car is all about - raw, in your face, POWER.

[landmass]

Picture didn't work...try again...