At 04:49 PM 2/11/01 -0500, you wrote:
>I have 27.9" tires, and cross the line ~4500 as well (I never look, stuipid
>me) My Peak HP was ~4900RPM's and peak TQ was ~4100 RPM's with
>300ft/lbs+ from the start of the dyno at 3000RPM's to ~5000
>I'll be installing the MPI M1 when I get my truck back from AAMCO for
>loosing the weight on the torque converter... <SNIP>
>What do you think the M1 will do with me being SC'd? How do you feel my
>powerband will change?
>lemme know....Thanks, Tim Berry
Tim
Everything that I've read and personally experienced is that the MPI
will move peak hp and peak torque up the rpm scale. How much with
the SC, I don't know. On a NA engine, it would be about 300-500 rpms.
Also, everything that I read on the MPI says that it's at its best around
6000 rpm (maybe more) but this means that the powerband must be up
there. While more air can be brought in with the MPI, the limiting factors
getting this added air and fuel through the engine would be the heads and
cam. I know Bill Tierney is running low 14s with the MPI and a wilder cam
(higher powerband than mine), and he shifts at around 5800 rpm. Jon
Steiger ran 14.5s with stock cam and 3.55 but his '96 weighs a 2-3
hundred pounds less than mine.
If your peak hp is at around 4900 right now and you're going through the
traps at around 4500, you can better your ET by running a smaller diameter
tire or going to 3.92 or 4.10. Two years ago, before I put in the MPI, I was
going through the traps at 4000 rpm with 28" drag radials and 3.55 and was
running 15.1s. I felt my peak hp was near 4500 (I had not found a dyno
around as yet) so I switched to 26" drag radials. I was now going through
the traps at near 4500 rpms and ended the season with a PB of 14.91.
The next season, I put the MPI in and peak hp was now at 5000. I couldn't
go to 24" drag radials :-) so I switched from 3.55 to 3.92 (probably should
have opted for the 4.10 but there isn't a speedometer pinion gear out for
the 4.10).
Hope this helps.
Bob
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