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Loss of HP and torque per every 1000 ft of elvation

J

Jharris

Active member
I don't know if this is the place to ask this Question but I will. Does anybody have info on Performance lost per every 1000 feet of elevation??
 
The true term is corrected altitude! Humidity has as much a part as elevation does. The higher the humidity the less power you can make just as the higher the elevation the less oxygen is present! There are rough formulas but the best way is to use a wet bulb and a weather station. This how most hard core bracket racers tune their cars!
 
j harris When I had my 502x502 Dyno it put out 415 hp at this elevation at sea level this motor is 522 hp. You will loss alot ,not to many 500 hp boats up there. What are you planning to put in you boat?
 
Jody I didn't realize it was you, tell me your altitude and your relative humidity and I can correct the dyno pull numbers on a 550HP motor which actually makes over 600HP on the dyno! Then I can give you a close horsepower number of what it will make at your altitude! I just ran your motor for about half an hour. I'm just waiting for the radiator! I will call you the minute I receive it so we can schedule shipping! I may just shoot a video of it on the breakin stand and put a link to it on a thread!
 
can you believe that little LS is still gonna have 100hp more than that 502/502 at altittude ???? shucks.................... :D
 
Hey Thunder, did Billy Wiggins get a hold of you. I turned him on to your motors. Is he getting one and which one if he is?
 
To be honest as far as I have seen, there is less loss with bigger stroke that with shorter stroke due to mechanical ability like our Cadillac engines (4.304") Air doesn't change as much (but it does) at altitude. This is one reason our engines are better bracket racing engines since change has to be forseen for the next run. Humidity costs HP, BUT it also allows the use of higher compression which, in turn, allows more power which is a wash w/o detonation. We are at 720 ft here, BUT we have 75% or more water all year round in the air. Humidity stops detonation period! What rattles here will rattle anywhere due to we have lots of humidity unless you are in NY on Long Island and they have a barometric pressure of 31 to our 27 plus. Find 4000 ft and 80% humidity and you can run 89 octane on 12-1 if you did the build correctly. Smooth edges and zero deck with the proper cam.
 
It's like I tell people I can build a 13to1 compression motor and run on junk gas with the right cam. Or build a 10to1 motor that will ping itself to death! There are a multitude of things you can do to prevent detonation!
 
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