how much HP

[ByronRACE]

Without making this sound like a "my penis is bigger" post, all I have to say is that in my 3000lb West Coast Cobra running Kumho V700 335's on the rear, 600rwhp is the most I can connect without getting sideways on the freeway starting at a 60mph roll. It's a big block/supercharger/efi combo, and the supercharger was pulled at an 80/30 ratio when I first tried to drive it. I've now pullyed it back to 80/40 and this traction problem still exists, so I run 19deg total advance to keep the power to a point where I can drive the car without breaking traction every time I feel the urge to step on the gas. Add 2deg of spark up top, and the tires do a pro-stock burnout starting at freeway speeds. So, if you have a lighter car and narrower tires with a less-sticky composition, you may want to give this a little thought unless you specifically are constructing a burnout/drifting machine. Yeah, it's cool to have a car that can do this sort of thing, but as far as I'm concerned, it lost its novelty and never improved my driving because I'm so nerve wracked to drive the thing that I find myself in "survival mode" instead of "drive mode" behind the wheel.

Byron

[LRcobradreamer]

I believe you Bryon. My Cobra has "only" 345 hp, but is very flat torque curve and it just hooks up and goes in second and up. I love it and feel very secure and not afraid to push it any time, well almost. I took it to autocross school and what a blast. With more HP it would have been more of a challenge to keep it on course.

Lee

[ByronRACE]

There are 2 or 3 posts missing from this thread that were there last night. Anyone else notice that?

Please disregard, I confused this thread with another one.

[patrickt]

Originally Posted by ByronRACE

... to keep the power to a point where I can drive the car without breaking traction every time I feel the urge to step on the gas. ... Yeah, it's cool to have a car that can do this sort of thing, but as far as I'm concerned, it lost its novelty and never improved my driving because I'm so nerve wracked to drive the thing that I find myself in "survival mode" instead of "drive mode" behind the wheel.

Byron's post ought to have a sticky on it that anyone who is building their first Cobra engine is required to read, and, for anyone that asks "Why are there so many 500+HP Cobras for sale on Cobra Country with less than 1000 miles on them."

[HI Cobra]

Heh heh - it may well be the "survival factor" is over-riding the "bragging
rights factor" for THOSE individuals who have decided to sell with "barely
broken in" mileage on their Cobras. Nothing wrong with that but it can be
an expensive decision.

[ByronRACE]

The only saving grace of my "eyes bigger than stomach" combo is that the power is tunable. NA, the engine will probably make close to 450-500rwhp. With timing retard, probably 400-450. So, with pulley changes and changes to the blow-off valve I can tune it to that level if so desired. Had I built a 1000hp NA engine, my options would have been far more limited.

One mistake I did make was cam. It's too big to cruise nicely under 2400rpm, and I find myself in 4th gear to stay there when I have a double overdrive 6spd available...so it's a bit of a waste. I'll be changing from a 242/256@.050 duration cam with .680 lift to something with about 10deg less duration and .080" less lift. It'll lose some lope and make peak power sooner (and less power) but will allow me to cruise under 2400rpm smoothly. I'll then tailor the power with boost once again until I'm at that traction limit. I like to be able to come out of corner exit, get it straight, mat it...and have it stick.

So, if you want something that has a real wide span of tunable power ranges without having to dig into the mill too deeply, you might want to consider a power adder EFI combo. You can do a lot with the keyboard instead of a wrench, and your option to change power further with easy to access surface parts (like pulleys) makes life easier.

That said, this entire exercise taught me that I probably would have been just as happy with the way the car drives had I put a 514 crate motor in it...and I would have been driving it 6+ years earlier. (I'm slow). One thing my car does have is additional wow factor when the hood is open. People just don't see that every day and for those that understand what they're looking at, it's a real conversation starter.

Byron

[FUNFER2]

Hey Byron, just thought I would mention the cam in mine.

600 lift, 252/260 duration @ .050 112 lobe sep.
It's perfect for me on the hwy & street, as I live outside the city.
It likes to idle at 1,000 -1,100rpm.

[mln385]

Okay just my 2 pennies here but the Roush 427 R's cam is not (in my opinion ) as street friendly.
What are you planning on doing with the car? If it is a street cruiser I would suggest the 427SR/Tw it is very well mannered for the street and the power comes on heavy at 3000 rpm!

I get 10-14 MPG with mine with the tko 600 5speed, if you find you want more HP later you can always upgrade to the injection set up for better throttle responce and roughly 40 more HP.

Marc

[ByronRACE]

Originally Posted by FUNFER2

Hey Byron, just thought I would mention the cam in mine.

600 lift, 252/260 duration @ .050 112 lobe sep.
It's perfect for me on the hwy & street, as I live outside the city.
It likes to idle at 1,000 -1,100rpm.

Thanks for that info, but can I get a little more? Is this a hydraulic roller, flat hydraulic, or mechanical flat? What is your engine displacement and cruise rpm? If it's 427 cubic inches, I'm surprised that you can cruise smoothly at 1800-2000rpm. That is really the best of both worlds if it works.

[mjmacqua]

Byron,

You may or not remember me, I had a lot of trouble cooling my 557, you offered a number of solutions. My engine had 650+HP and definetly had the pucker factor... With the cooling issue and the afore mentioned, I decided to rebuild it. I still wanted the big block, so stuck with the 428 starting point, when finished (almost) it will be a 514 with a mild cam. It will be, as most big blocks are, a torque monster, which is what really makes us go. Unfortunatley what sells cars is HP what makes them go is Torque. Hopefully none of us are racing on the street as we know that is illegal, but even more so, when the HP starts taking over, we are above 90-100MPH, another pucker factor in a go cart type vechile. (pardon the go cart reference I couldnt think of anything else to get the point across).
I think most of us love to DRIVE these cars and on occasion punch them out. They key is figuring out what you really want to do. You can spin the tires with a 302. And keep in mind the first 2 questions we are asked, is it real? and what's under the hood, 427? (two other selling points)