Also I bet with a real UIM your HP figures would have skyrocketed. Running large
35mm valves with those tiny SH UIM ports.
Why would a larger lower suddenly make a big difference when the upper is the piece
already restricting the airflow? (I.E. If the lower is already larger then the upper. How
does making the lower larger help if the upper stays the same? It's (LIM) not
suddenly getting any more airflow.)
Demon, remember that the pre 99 LIM had 32mm butterflies. So, in the 98SVT the LIM was actually more of a restriction than the 31mm SH-UIM secondary runners. By going to the 34mm butterflies in 99, LIM flow area increased to near that of the 32mm DH-UIM, though is still slightly less.
Now in your case, since you have "delt" with the LIM, the UIM would be expected to flow less than your lower and so you may benifit from the extra X-Hone. And agree, David Z would have benifited ALOT with his setup. But the point was still, the UIM flowed to a level of 100 HP/L, as did the throttle body. Which suggests that with his cams and increased CR in a 2.5LSVT, with stock 98UIM and t.body and no AF-tuning the car would make 200FWHP. With a DH SVT upper and Apexi-i, probably more..
