[Skip Fix]

I think the point Slowbird is trying to make is all calculators and "math" have some bias in the formula or "programming". Plug the same data in different engine sim programs and see if you get the same answer. Some add different amounts for a solid vs a hydraulic vs a roller cam, some an exact amount of HP regardless of the motor. My higher end Dynomation wanted around a 118 LS for my 500 IA motor and I have all the flow numbers, port lengths etc added in. Don't think too many Pontiac guys running NA are using 118 LS on their motors.

If you ever used the old Quarter Jr. program there were lots of different tweaks in the program to try and get the estimate to match a real run.

My own car has run different 1/8 vs 1/4 where it it not the same multiplication factor to get the 1/4 mile et from the 1/8-so the math did "lie" if only one 1.52 or 1.55 is the "correct" one.

And lots of "generous" and "conservative" dynos out there-like flow benches. Few are really going to give the same exact numbers on the same engine even corrected for weather conditions. Ones that "run the number" are a little more to be believed-but unless it is your own how do you know. The Dyno my pump gas motor was run on was actually 25-40 HP less than the mph/hp calculators show. Some math is wrong there either the dynos or the calculators.

But as Aaron said all this is a slight side track to the original question-several folks out there have done multiple High Ports probably all different prices if price is a concern. Pick one you feel will match your engine and project goals and go for it.

[Stan Weiss]

Originally Posted by Skip Fix

I think the point Slowbird is trying to make is all calculators and "math" have some bias in the formula or "programming". Plug the same data in different engine sim programs and see if you get the same answer. Some add different amounts for a solid vs a hydraulic vs a roller cam, some an exact amount of HP regardless of the motor. My higher end Dynomation wanted around a 118 LS for my 500 IA motor and I have all the flow numbers, port lengths etc added in. Don't think too many Pontiac guys running NA are using 118 LS on their motors.

If you ever used the old Quarter Jr. program there were lots of different tweaks in the program to try and get the estimate to match a real run.

My own car has run different 1/8 vs 1/4 where it it not the same multiplication factor to get the 1/4 mile et from the 1/8-so the math did "lie" if only one 1.52 or 1.55 is the "correct" one.

And lots of "generous" and "conservative" dynos out there-like flow benches. Few are really going to give the same exact numbers on the same engine even corrected for weather conditions. Ones that "run the number" are a little more to be believed-but unless it is your own how do you know. The Dyno my pump gas motor was run on was actually 25-40 HP less than the mph/hp calculators show. Some math is wrong there either the dynos or the calculators.

But as Aaron said all this is a slight side track to the original question-several folks out there have done multiple High Ports probably all different prices if price is a concern. Pick one you feel will match your engine and project goals and go for it.

Skip,
Another reason et and MPH numbers do not match the dyno HP numbers is when someone is running a hood scoop. Who has dynoed with a fan blowing whatever MPH air they run into the carb(s)?

Stan

[mike leech]

Originally Posted by Stan Weiss

Skip,
Another reason et and MPH numbers do not match the dyno HP numbers is when someone is running a hood scoop. Who has dynoed with a fan blowing whatever MPH air they run into the carb(s)?

Stan

Or when you have this.....1 3/4"

[cosgrove]

Originally Posted by mike leech

Or when you have this.....1 3/4"

Mike,
You should have ran that thing with the hood off one time!

[mike leech]

Originally Posted by cosgrove

Mike,
You should have ran that thing with the hood off one time!

Prostockscoopttfmf! I'll have a scoop this year.

[Aaron Quinton]

Now that was funny. It should pick up quite a bit with more area above the carb. Was it like that on your best pass?

Originally Posted by mike leech

Prostockscoopttfmf! I'll have a scoop this year.

[mike leech]

Originally Posted by Aaron Quinton

Now that was funny. It should pick up quite a bit with more area above the carb. Was it like that on your best pass?

yup! been that way for years!