OK Chas, See If You Can Tell What's New...

[ERA Chas]

Originally Posted by RodKnock

...or less. Typical drivetrain HP loss is 15-20%. A 50 HP loss would only represent about a 10% loss.

Rod-he means the loss of FWHP on the engine dyno. A chassis dyno loses 15% (or more) from drivetrain friction and tire contact.

[patrickt]

Originally Posted by ERA Chas

Rod-he means the loss of FWHP on the engine dyno. A chassis dyno loses 15% (or more) from drivetrain friction and tire contact.

Yes, my true, honest, no-fibbing horsepower numbers are between 450 and 475 at the flywheel. I get a little extra for the Ersons and the fact that it is nicely broken in and carefully tuned. But still, when people ask, I tell them it has 450HP because that's the truth. BTW, my valve sizes are 2.09 and 1.66. You know, if I just wanted to test out a bonus 50 to 75 horsepower I could bolt on shorty straight-outs and then put on some ear plugs.

[ERA Chas]

Originally Posted by patrickt

You know, if I just wanted to test out a bonus 50 to 75 horsepower I could bolt on shorty straight-outs and then put on some ear plugs.

No you couldn't-they'd have to be tuned length around 37" plus a proper length collector.
Honesty is the best politics as Stanley used to say. A 447 that makes 475 is a rebuild-period. That's been my beef all along and it's a shame (even) you got hurt for a performance build price.
At least you know Brent and the current crop of builders won't hurt you on price and it's cake for them to deliver a pump gas, mild 1.3 engine these days.

[patrickt]

Originally Posted by ERA Chas

No you couldn't-they'd have to be tuned length around 37" plus a proper length collector.

I'm pretty sure we have a set of these at the local club. These would not work?

[ERA Chas]

Oh yes-pretty well. They're similar to mine but shorter.
Your 'shorty-straight-out' terminolgy threw me.
When I was a kid, that meant we welded 3" plumber pipe with a cap to the head pipe.

[Bernica]

Originally Posted by ERA Chas

That's why I'm hounding him (you) to do a Stage II, III or 1000 (), on them and get them near 300 cfm-at least. He never said valve sizes so that wouldn't hurt either. I think he has enough bore for 2.19s.
Maybe the BT dual plane is OK but the heads / cam don't work with it.

Yep. 325 CFM or so will do the trick.

[patrickt]

Chas, do you remember the erudite thread from Steve Sunshine a few years ago, that concluded, after a detailed and thoughtful analysis, that 535 flywheel horsepower was the maximum usable power in a Cobra under almost all conditions? Do you buy in to that?

[RodKnock]

I remember a Kirkham with a 720 HP engine doing 10's at a Las Vegas race track beating a Ferrari 458 Italia.

[patrickt]

Originally Posted by RodKnock

I remember a Kirkham with a 720 HP engine doing 10's at a Las Vegas race track beating a Ferrari 458 Italia.

But there are Cobras with much less power than that that run 10's as well.

[RodKnock]

Originally Posted by patrickt

But there are Cobras with much less power than that that run 10's as well.

Maybe, but as Chas pointed out, the good engine builders can fall out of bed and still build and engine that makes 1.3 HP per cube.

Again, my vote would be for a paint job.

[ERA Chas]

Originally Posted by patrickt

Chas, do you remember the erudite thread from Steve Sunshine a few years ago, that concluded, after a detailed and thoughtful analysis, that 535 flywheel horsepower was the maximum usable power in a Cobra under almost all conditions? Do you buy in to that?

Yes I do remember and NO I don't subscribe..
Speaking in absolutes is a fools errand in any context.
I always strove to maximize power and be smart enough to apply it effectively. Bruce's #3170 is an example and so is Morris' KMP. Both make well in excess or 535 HP. Those guys are light-years ahead of me certainly and 98% of the forum. But I go to school on their work.
Sunshine always wants to exude authority in the 'correctness' of his car and any pronouncements (such as your example) he makes. Lack of an open mind is like living in a dim room.

[patrickt]

I can't find his thread -- I think it got eaten during one of the server crashes. I do remember there were some pretty smart guys on both sides of the argument.

[ERA Chas]

We all have opinions based on our experiences. Some guys think theirs is the ONLY way...

[ERA Chas]

So-have you firmed-up a go / no-go plan for more power or new engine?
I'm sure Brent is making plans to leave the country...

[patrickt]

Originally Posted by ERA Chas

So-have you firmed-up a go / no-go plan for more power or new engine?

If I put a 600HP mill under my hood, bolted to my custom pipes, I would have a little over 500HP at the flywheel -- probably around 515 or so, if I'm lucky. Do I really want to pull my engine, box it up, and ship it off, for 40 horses?

[ERA Chas]

No-you want to get much more efficient pipes. Cut and flanged just like mine for track days...
Get 3" cores from Stainless. Learn to drive with ear plugs for steady state touring. You already have a 5 which lowers RPM and decibels at the same time. Call the haberdasher ahead of time and warn him...
That's the rationale for adding power-you need to improve the rest of the car to balance it. You can make serious improvements instead of make-work wheel colors and faux aircleaner doo-dads.

[patrickt]

Originally Posted by ERA Chas

No-you want to get much more efficient pipes.

I am reticent to do that. I really dislike ear-splitting pipes; I love my custom pipes, they're jussssstttt right. Uhhhh, you know, I could tuck a shot of nitrous between the carb and manifold....

[ERA Chas]

Originally Posted by patrickt

IUhhhh, you know, I could tuck a shot of nitrous between the carb and manifold....

Which would blow those crap heads right off the decks.
THINK man THINK...
I'll leave you alone about this-I have no traction to change your milquetoast preferences.

[patrickt]

Originally Posted by ERA Chas

Which would blow those crap heads right off the decks.
THINK man THINK...
I'll leave you alone about this-I have no traction to change your milquetoast preferences.

You know, 99.999% of the population could not tell you who Caspar Milquetoast was.

[blykins]

I don't believe Steve Sunshine for one nanosecond.

I've ridden in some 700hp Cobras that would catch traction and MOVE. Learning to drive a Cobra is part of the experience. Full throttle input with 300 hp will let you see what's behind you pretty quickly. Adding horsepower just means that you have to have more common sense and driving experience.

Ditch the girlie pipes.