Longevity & Reliability vs. Power

[patrickt]

Originally Posted by RodKnock

You're far more delusional that I thought if you think your 445 makes similar HP as my 482. Bigger cam, bigger cubes and weighs a lot less.

I would say "talk to the hand", but instead, I'll tell you to talk to Chas. He'll better explain it to you.

I conceded you have more. I would bet probably 75 more. I'm betting your 482 puts out about 525HP at the fly with the pipes and accessories all hooked up. Lykins, you agree with that?

[blykins]

Probably less.

I'd say you lose ~20% with drivetrain and exhaust losses on a Cobra.

How are you getting your own dyno numbers? On an engine dyno with Cobra headers and accessories running, or on a rear wheel dyno?

[patrickt]

Originally Posted by blykins

Probably less.

I'd say you lose ~20% with drivetrain and exhaust losses on a Cobra.

How are you getting your own dyno numbers? On an engine dyno with Cobra headers and accessories running, or on a rear wheel dyno?

I had mine broken in on the dyno and then measured with the pipes and accessories on it. I do not know what my rear HP numbers are, but I've always viewed dyno numbers on an engine that is being measured in a state that you're never going to see under the hood as being bogus. So you're in agreement that Rod's flywheel numbers with his pipes on and accessories on drop from 610 to below 525? Excellent. Take that, Rod.

[patrickt]

This seems to be a pretty authoritative post.

[CobraEd]

For just cruising around, the 408 will be torquier (sp?). But in a stoplight to stoplight race with a 500hp 347, you are going to shift at 7,000 rpm and beat the 450hp 408 every time. Especially in a 2,300 lb cobra where torque is not an issue.

If you are doing any kind of racing or performance driving you would bring that 347 up to 7,000 or why would you have built it in the first place. It will always win. But if you are going out to dinner or to pick up your dry cleaning, you obviously will drive it mildly and not have the lower end torque of the 408.


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[blykins]

Originally Posted by CobraEd

For just cruising around, the 408 will be torquier (sp?). But in a stoplight to stoplight race with a 500hp 347, you are going to shift at 7,000 rpm and beat the 450hp 408 every time. Especially in a 2,300 lb cobra where torque is not an issue.

If you are doing any kind of racing or performance driving you would bring that 347 up to 7,000 or why would you have built it in the first place. It will always win. But if you are going out to dinner or to pick up your dry cleaning, you obviously will drive it mildly and not have the lower end torque of the 408.


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Yeah, you're right. Horsepower is horsepower. 500 beats 450. However, if you re-read my statement, I stated that the 408 would FEEL stronger....and it would. You build an engine for a specified purpose. A 347 that peaks at 7000 isn't necessarily going to be street friendly. It all depends.