Question about 1983 Mazda RX-7

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HP increase at elevation using a Dyno Jet Dyno?

Any experience or advice on Webber IDA downdraft carbed- Mazda rotary engines showing more HP at high elevations vs sea level?

We used a full size Dyno Jet dyno used at sea level and a portable dyno Jet equivalent approved unit at elevation (4400 ft), same model weather station equipment used at both locations.

(note when we first got to high elevation location dyno we were told we had 152 HP on the tune we started with which we figure at best was a mid 145-148 HP at sea level. How can this be...? We figured we would lose some HP not gain more?

At the end of the experience after detuning several times. we were told we now had 145 HP at 4400 ft elevation, then came back to sea level, two days later, similar weather conditions mid 80's low humitity, and the same tune up produced only 137 HP. Both numbers were adjusted figures.
Is it possible to make more HP either real or on paper at elevation due to volumetric eficiency of a rotary engine.

Can the operator of the dyno put in incorrect data thus making the numbers come out incorrectly.

Please add any additional information that help us understand this problem we and many other experienced.

Thank you,

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Same dyno? same operator? theres something wrong. the lower altitude the better, as far as I know. But someone thats smarter than me and has high altitude /dyno experience would be better to answer the question.

Posted on Oct 01, 2009


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