Horsepower in 427 cobra, what is too much?

[jerry mayer]

Has any one built a 427 cobra replica with too much horsepower?

[FWB]

i only can say i know when there is enough......

when your at the dragstrip, on your run and you have two burnout marks from the tree to the finishline, then you have enough........

[Mark Thompson]

I think the lowest power to weight of any sports car was the Porsche 917 which had well over 1000HP in 1300lb and was generally regarded as undriveable. That says you should stay under 2000HP.

[Excaliber]

I REDUCED my horse power from over 600 to around 500 and am very happy with the results. While it is possible to get 600 AND have decent street manners with the motor it's going to cost you, a lot. Getting 500 is fairly easy with a big block AND retain decent street manners. In addition I was surprised, I would say even astounded, to find there was no significant difference between 600 and 500. 1/4 mile ET was still within a hundreth of a second, you could not "feel" the difference, you had to measure it with electronic timing.

The reason, I believe, is traction limits. If you can only hookup 500 then anything over that is essentially a waste of time.

[FWB]

yep i agree, i cannot get all my horses to the ground. my mph at the dragstrip tells the tale. on drag radials i get damn close to breaking into the 10's and my mph is 140. if i could hook up i would be in the low tens. with 100 to 150 less HP i would still be at the same ET, my MPH would be lower but that doesn't matter.

[gsharapa]

That's a personal question as some will say never too much as it depends how far you push the gas pedal down!

[FWB]

when your tires break loose at 1\2 throttle, do you keep pressing on it? especially when the rear is coming around to greet you........heheheh.
the first time i staged the car at the dragstrip i left at 3500 rpm and the azz end went 90 degrees both ways before i had to get out of it to correct. you can have too much.
with a wheelbase of around 90 inches, its a little hairy....

[Excaliber]

FWB, good point about the trap speed. While my ET remained fairly consistent my TRAP SPEED was notably slower. The big horse power really shows itself at the top end, some where after you've gained enough traction to use it.

I dang near lost the car when the tires broke loose in 2nd gear, I was running Goodyear Bill Boards which have "decent" traction for a street application and not bad for a race application. They are going to be hard to beat when it comes to traction unless you move up to slicks.

[FWB]

i was using the mickey thompson drag radials, and they break loose in first and second unless i ease into the throttle, so i got a set of slicks. now i can't keep the front end down, for fear of putting the car on the rear bumper the slicks are not an option. besides my 9" traction lock will only take so many trips thru the water box before it gives up, i just stay with the drag radials, its more or less a safety valve for my rear to stay alive. with the NHRA rules i get thrown off most dragstrips after 2 passes anyway. too fast without 6 point cage. the only place i can race without catching a rash of BS is in canada. as long as i have a helmet they let ya race anything.

[mdross1]

It all depends what you want to do with the car.Too much,maybe trying to launch the car or in hard turns.Rollons would be an absolute thrill ride with too much hp/tq,provided the tires stay stuck!My car is in the 550hp range,the suspension is set up and scaled,a blast to drive.

[bobcowan]

Too much? I don't know. I only have 500'ish hp and gobs of torque, and still havn't hit the "Too Much" mark.

It's not about the power, it's about the control. 600 hp in a good chassis is much better than 350hp in a crappy chassis.

[undy]

I'll let you know after I install the 300 horse two stage fogger setup I'm getting ready to get with Mr. Jegs about. 900+ might be pushing the "too much" envelope though..

BTW.. I run the M/T ET drag radials (315/35/17s) on the car all the time. They allow the car to do a pretty good job with the 600 hp, v-e-r-y gratifying. Actually with the 35 aspect ratio and the real sticky compound it does pretty well in the twisties with them on too.

[Excaliber]

...300 horse two stage fogger setup

Yup. 600 streetable horse is gonna cost ya! There is no free lunch.

Another option for 600 streetable horse is a hydraulic roller cam and associated valve train geometry parts. That would be on the order of SEVERAL TIMES the cost of a flat tappet setup. Flat tappet, easy 500 horse with the right setup and easy on the wallet.

But hey, it's only money, you get more of it next month.

[Dwight]

Lainhart has a stroked 427 (487 c.i.) with 619 at the flywheel. 354 gears in a Jag rear end. Very streetable, very fast. You cannot just rev it up and drop it.

Get it rolling and easy into it.

Coach Mike has a stroked 428 (461 c.i.) with 601 flywheel hp. 325 gears in a 9" with MT street radial. FASSST.

600 hp is great for the street if you have the correct rear end gears and tires.

I've driven both Cobra and I love they way they cruise and the horsepower on TAP.

My small block makes 402 to the rear wheels. But we're talking about 427's
600 hp is what a Cobra needs! IMHO
Dwight

[twin turbo]

I know that Steve Berg in Spokane drives regularly on the street with over 800 rwhp, he says it pulls on crotch rockets just fine. I run between 550-600 rwhp (depending upon outside temperature), and it feels about perfect for me. Tire choice can make a huge difference.

[lovehamr]

In the words of Mark Donohue during the development of the 917-30 motor, the German Porsche engineers often asked Donohue if the motor finally had enough power. His tongue-in-cheek answer was "it will never have enough power until I can spin the wheels at the end of the straightaway in high gear."

I love that bit!

[blykins]

My view is that you should go for as much as you can without making the engine too fussy. After you drive the car for a couple years, you'll wish you had more, because you get used to the car.

For a big block or FE, you can get 600-625hp pretty easily and not have to run race gas, deal with radical camshafts, etc.

Of course the bigger the cubes, the more streetable power you can make. A 500hp 347 would be a little racy, where as a 500hp 489 FE would be a *****cat.

[Excaliber]

If I could drive like Mark Donahue, well dam, I want 800 horse (and slicks). But I'm no Donahue and slicks are problematic on the street.

[blykins]

What most people forget is that Cobras have gas pedals. You don't have to hold them wide open from the time you start them till the time you shut them off.

[lovehamr]

Originally Posted by blykins

What most people forget is that Cobras have gas pedals. You don't have to hold them wide open from the time you start them till the time you shut them off.

No, but imagine it could be kind of exhilarating!