Feedback on Turn Key Crate Motors from the “Engine Factory” in New Jersey.

[undy]

Originally Posted by Excaliber

The flywheel and rear wheel h.p. may not be that far off, 446 to 326. IRS, for one thing, has more parasitic loss than a live axle. The parasitic loss in this case is about 27%. Anywhere from 18 to 25% is considered normal, so the numbers are in the ball park.

Wive's tale on the IRS having higher parasitic losses. The C6 Corvette is running around 11.5% drivetrain loss with it's IRS, less than Ford's latest Mustang 8.8" live axle.

I agree with CobraEd, everyone tends to juice their numbers, to one extent or another.

[Excaliber]

I wouldn't say it's wives tale because that would indicate ALL IRS systems are superior to live axle systems when it comes to parasitic losses. I don't believe that is the case. The new Vette may well be an exception to the rule as it's been tweaked in the last decade or so, like every other rotating component in cars, to reduce parasitic loss as much as possible.

I think the ERA FIA is running a classic Jaguar IRS.

[Mark O'Neal]

Originally Posted by Excaliber

I wouldn't say it's wives tale because that would indicate ALL IRS systems are superior to live axle systems when it comes to parasitic losses. I don't believe that is the case. The new Vette may well be an exception to the rule as it's been tweaked in the last decade or so, like every other rotating component in cars, to reduce parasitic loss as much as possible.

I think the ERA FIA is running a classic Jaguar IRS.

Depends on the deflection angle of the rear end. The lower it is the greater the loss.

[CobraEd]

Originally Posted by undy

I agree with CobraEd, everyone tends to juice their numbers, to one extent or another.

We have seen this for the builder referenced with people here in the DC area.


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[Jimbocobra]

Originally Posted by undy

I agree with CobraEd, everyone tends to juice their numbers, to one extent or another.

Not true at all. Ford Racing Performance Parts has a very "conservative rating strategy". See the 10 dyno tests from magazine articles and builders on the 392 I posted: Ford Crate 392 Stroker GT40 Heads Actual HP Documented in Magazine Articles Ford tends to underrate by 15hp - 30hp across the board on their crate motors. and it has been well documented.

I think some of the brand name guys like Roush and Keith Craft tend to be accurated with a proper tune as well. So many things affect the numbers, jetting, choke blade, temp., altitude, oil choice etc... So many guys spend $20 grand on an engine, but won't drop a couple hundred on a good dyno tune.

[Voyager]

I have a Keith Craft 408 street crate motor being built for my SPF. I’m sure I’ll do a follow-on dyno run at my buddy's shop later this year. I’ll post the numbers.

Bob