*Originally posted by John*

**So, my recommendation**

would be on any power number you read figure in 10% error and

if its a dynojet, subtract 20% for real world power.

John

would be on any power number you read figure in 10% error and

if its a dynojet, subtract 20% for real world power.

John

One thing to consider when looking at dyno numbers is which correction factor was used -- STD reads the highest numbers, while SAE numbers are a little more realistic (for example, 259 STD HP is equal to 248 SAE HP). Most people tend to post STD numbers.

I think John's 20% reduction on dynojet numbers is wrong. A good-running, stock-engined E30 M3 with a chip will generally record around 160 SAE RWHP on a Dynojet 248C. Using a 17% correction factor for flywheel HP, this yields about 193 HP, which is probably pretty close to correct.

Mustang dynos are great for tuning because you can lock the RPM to help tune load at given RPMs -- thus they are a great tuning tool. But, you can't compare Mustang numbers to Dynojet numbers (as I said above, you can't really even compare Dynojet numbers to Dynojet numbers).

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