Realistic horsepower for the street

[Mdman352]

The reason for this thread is for informational purposes and to confirm my setup.
I have a Jag rear with 3.55 gears with a Detroit locker. My new motor is a 454 FE with iron heads that have been port matched to the manifold and produces 470 HP and 580 FT. I told the builder I wanted a streetable motor with very little maintenance that I could drive everyday if I wanted to. I am running MT Street Drag radials. My car from a rolling start will spin the tires up to the rev limiter in 1st and about half through 2nd gear but then it gets interesting real quick. .
I don't know how someone with "regular" tires can get ANY traction.
I love the big numbers too but in the real world what good is it if it won't hook????

[Great Asp]

Originally Posted by Mdman352

The reason for this thread is for informational purposes and to confirm my setup.
I have a Jag rear with 3.55 gears with a Detroit locker. My new motor is a 454 FE with iron heads that have been port matched to the manifold and produces 470 HP and 580 FT. I told the builder I wanted a streetable motor with very little maintenance that I could drive everyday if I wanted to. I am running MT Street Drag radials. My car from a rolling start will spin the tires up to the rev limiter in 1st and about half through 2nd gear but then it gets interesting real quick. .
I don't know how someone with "regular" tires can get ANY traction.
I love the big numbers too but in the real world what good is it if it won't hook????

Hooking on the street is pointless, unless you were planning on drag racing from stop lights. The added power is seat of the pants feel when punching it from 40 mph.

[greg schroeder]

I don't see what the big deal is. My last Cobra was 475 to the ground, but I could see shooting for about 600 to the ground and it still being a nice street car on drag radials. You'd need to beef up the drive line a bit. I guess a 150 shot on my last Cobra would be about right and would put the car in the nines for the 1/4. How fun is that?

[patrickt]

Originally Posted by greg schroeder

I guess a 150 shot on my last Cobra would be about right and would put the car in the nines for the 1/4. How fun is that?

Even if you bolted rockets to my roll bars, I could not drive a nine second quarter in my Cobra.

[fkemmerer]

Just some thoughts on how much HP for the street is enough. I think the real question is how "streetable" is the power? I've think its possible to have an engine that produces 400 HP via high RPM torque that is not very much fun to drive anywhere other than a rece track. Its also possible to build a big engine or use a supercharger) to achieve a very flat torque curve that comes in at reasonable RPM (say 2,500 - 3,000) that makes 600HP or more and it will be a great street machine. Its true that it can be difficult to get a light car like a cobra to really hook up with a combination like this but with the right choice in tires and the selection of a gear ratio on the taller side, these combination can work quite well.

I am currently running a 482 ci stoked side oiler in my cobra and I find this combination to be very streetable. The engine was dyno'ed at 650 hp and 625 ft-lbs of torque. I am also running a blown and injected SBC in my vette. It made about 625 HP and 600 ft-lbs on the dyno. Both of these cars make their torque down low and have fairly flat torque curves. Both cars have rear end ratios on the taller side (the Vette has 3.31 gears, the cobra has 3.54 gears).

I will say that both of these cars need an extra measure of respect to be driven safely on the street but neither was overly difficult to master.

- Fred

[patrickt]

Originally Posted by Mdman352

I love the big numbers too but in the real world what good is it if it won't hook????

Even a Detroit Locker and full slicks are not going to stick with a 2500lb. car, 3.55 rear, and almost 600 ft/lbs of torque. It just ain't gonna happen. You could "de-tune" your engine a little by using a heavier spring to delay the vacuum secondaries a bit, and maybe a tad bit less timing. But what you have is simply "the nature of the beast."

[DAVID GAGNARD]

Years ago, maybe the early to mid 90's, not sure, I drove a very early FFR, number 46 or 47.....The owner built it by the manual,stock 225hp 302 GT motor with a 5 speed and 3.55 rear gears....While it was not earth shattering, it had planty of zip and would probably run the quarter mile in the mid 12's,maybe even low 12's, just my guess.....It was plenty fast enough for a novice and made an excellent weekend driver/cruiser car and got about 20+mpg.....would outrun 90% of the cars on the street at that time.......

I think too many people get caught up in the HP #'s game and thing the need 600+ hp to have fun, but those monsters require a lot of mantinance and some are very finicky about running hot in traffic....

Any decent motor with 400hp and 400 lb.ft. of torque will make a fun car to drive on the street and outrun most anything you come up against.....IMHO

Now racing is a whole different ball of wax.......

David