Quote:
Originally Posted by LGAFF
Time to get headers and a ported top end....
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That's the next step. My ultimate goal is to get 400rwhp. It looks like headers, porting the top end and good tune should get me there.
Quote:
Originally Posted by Paul Workman
Strong numbers, to be sure.
Researching dyno calibration specs a bit, it appears (cutting to the chase) that a 4% variance exists between STD & SAE correction factors, stemming from the fact that SAE normalizes to 77ºF whereas STD normalizes to 60ºF
Also, the SAE 1349 spec requires correction for torque, relative to the mechanical efficiency (ME), or estimated at 85% at peak torque ONLY.
It is still a little vague (to me) how ME is affected when the engine is producing other than peak torque, but intuition tells me as counter rotational force (drive train inertia) diminishes, ME increases. The result would be a reduction in calculated hp at those non-peak torque regions of the rpm band.
In any case, the dyno operator was obviously conditioned to lift when his ear told him he'd reached the limit of conventional pushrod motors. The sound of the LT5 screaming past 5500 on its way to 7k+ scares the crap outta some operators, and the unaccustomed as well.
Well...Now that the hook is set, it is time for some FBI top end porting...and then...and then... Yeah, speed is addicting! 
P. |
Good info Paul. I _think_ the Mustang dyno directly measures Torque and then "infers" HP from that.
I'm hoping Pete is still "for hire" when I want to get the porting done.
With 400 to the wheels, I think that puts the Z in line with the C7.
Quote:
Originally Posted by efnfast
Damn, the girls (at Mercruiser) built you a strong one. I had to do headers, K&N, exhaust and a chip to get to 353 RWHP on my 90.
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Yup, I wish I knew who to thank!
What we all wouldn't give to get our hands on the original runs for each of our engines!