[concobra]

To wtcobra

I find your comments on the blue thunder verses the peformer RPM very interesting and would like to further this dialog.

I went the direction of the performer RPM. I write this to identify where I am coming from for future dialog. I do not wish to present the image that I am defending my choice. I just wish to increase my knowledge base.

My choice for the RPM was based on investigation of dyno information supplied to my by a nationally recognized FE engine building company. (I cannot mention their name because I do not have their permission to do so. But I'm sure that you would know who they are if I would.) In their testing they found both the RPM and blue thunder to be equivalent to each other with a slight torqued advantage going to the RPM. This advantage is so small that any engine changes could easily effected this. Based on this information I went with the RPM as it seemed to be a good starting platform, easily available and less money than the blue thunder.

After dynoing the motor with the RPM we observed the that RPM does what Edelbrock claims. Good mid range, throttle response, good cylinder filling capabilities through the mid range. I attribute this to a good runner design. It did fall short on the top and I attribute this to plenum volume being quite small.

In looking at the Blue thunder it seems to use some of the normal runner length to create extra plenum area and may be able to continue to pull higher power readings on top. The shortfall being not as strong a signal in midrange and therefore softer on power there than the RPM.

Since the motor spends most of it's time between 2500 and 5500 RPM I felt the performer would be best. Since the top end charge, 5500 to 6000 occurs very quickly and will not advance the car that much faster.

What do you think?