I suppose that max hp drops down to the 5,000 - 5,500 range.Bill, Here you go. Remember this is only a simulation, but it does show a trend.
18" 3800-4300RPM
19" 3600-4100
20" 3500-3900
21" 3300-3700
Bill
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I suppose that max hp drops down to the 5,000 - 5,500 range.Bill, Here you go. Remember this is only a simulation, but it does show a trend.
18" 3800-4300RPM
19" 3600-4100
20" 3500-3900
21" 3300-3700
These are not 1/4 mile times, but the time to accelerate from 1600 rpm to 6500 rpm while in third gear, which equates to 20 mph to 80 mph. A fellow can present the argument that the area under the curve is the same, the times will be the same. The problem comes when you look at the times within the total, i.e., the time required to go from 20 mph to 30 mph. These times are amazingly consistent, not a full tenth of a second difference in any of them when comparing 19" runners to 22" runners.
Charles, imagine your surprise you discover that length seems to make no difference when you measure the output of you intake manifold that can be adjusted to various lengths.
Bill
I decided to see the real life impact of runner length, so put the car back together with a total runner length of 22". Resulted in a 20-80 time of 13.3 seconds with two people aboard. 22" is a maximum max, it made the air intake runner want to prop the hood open. So I shortened the runners to 21 1/2", a comfortable max. 20-80 time, unchanged. I then went for broke, shortened the runners to 19", the minimum they will go without cutting. 20-80 time, 13.4 sec. So the runners have been shortened 3" with no impact on performance. They are now at 20", but not tested. I fully expect no change, but I will do it so there is ho hole in the data. At that point, I will cut the runners so that the maximum length they will accommodate is 19" and see what happens as the runner length gets down into the 15" to 16" range. Right now I am pretty much dumbfounded that there is no difference between 19" and 22". How can that be?
Comments, especially explanations, welcomed.
Bill