Help, only dynoing 300RWHP

[rhipsher]

Originally Posted by Locobob

Here is a dyno of a 91 before and after porting, no headers. If you compare this to your dyno you will note that yours is down on power over the whole rpm range - not just at the top. So whatever issue you are having is effecting the whole curve, probably not a collapsing air duct as that usually just shows up at the higher rpms.

Hum! interesting to see the difference between Locobobs dyno results and my dyno results with top end porting an my totally stock exhaust. Bobs increase shows up at about 4200rpm,s. And the increase in my dyno shows up right from the beginning all the way up. Interesting to see how different they are. I'm not sure which results are more typical. I guess it all comes down to porting technique.