In the last few issues of Hot Rod, they have been working with the 5.7 hemi crate motor, which is identical to our engines except for the fuel system, which is either a carb or throttle body EFI. Thsi is becasue of the need to put the thing in older cars. Anyway, in the October issue, they changed the cam to a Competition Cams XFI273. While much stronger than the stock cam, it is far from a race cam. Anyway, Hot Rod could not find a way to over come the 5700 rpm limit of the Mopar PCM, so the used a Ford PCM on the hemi. The net result was 481 hp @ 6500 rpm and 415 ft/lb @ 5000 rpm. This was on a dyno running open headers.
Interestingly, the were able to get 401 hp out of a bone stock 5.7 hemi, by changing to the Ford PCM and reving the engine to 6000 rpm., again on a dyno with headers.
They tried the 6.1 SRT8 manifold on the engine, but actually produced less power due to the port size mismatch. Future tests will use this manifold with some port matching work to see if it will produce more power. Overall, it looks like there is a lot more power to be had from the 5.7 Hemi, once the after market figures out how to deal with the PCM
Phil
Interestingly, the were able to get 401 hp out of a bone stock 5.7 hemi, by changing to the Ford PCM and reving the engine to 6000 rpm., again on a dyno with headers.
They tried the 6.1 SRT8 manifold on the engine, but actually produced less power due to the port size mismatch. Future tests will use this manifold with some port matching work to see if it will produce more power. Overall, it looks like there is a lot more power to be had from the 5.7 Hemi, once the after market figures out how to deal with the PCM
Phil