Pictures of my extensive intake manifold work (56K Warning)

[Guest the_dj]

http://www.ls1.com/forums/showthread.php?s=&threadid=265761

[Sumo]

Nice work! But i think everyone wants more info on the .......................... Gumby shirt.

[grumpyvette]

having done similar mods and having dynoed the results (HERES A SIMILAR DYNO RUN) I can tell you that the results will be a loss in low rpm torque, below 5000rpm where your engine spends 90% of its time and a loss in volumetric cylinder filling efficiency below 5000rpm and a slight gain in hp over about 5000rpm due to the shorter runner length lower restriction to the air flow, (stock the TPI flows about 190cfm)

 

http://www.eecis.udel.edu/~davis/z28/winter01/dyno/dyno010511/webpage010511.html

 

notice the loss of 60 ft lbs of torque and the gain of only 10 hp! look 1/2 way down the page at the chart

 

now what would help would be porting just the upper 3 inches of the siamesed SLP runners and the PLENUM and useing an EDLEBROCK base with its bigger port size and straiter runners.

 

look the stock TPI has runners 15" long with about 3 more inches of runner in the cylinder heads , for a total of 18" of runner length, with that length runner both the 3rd and 4th harmonic wave help fill the cylinder WITHIN the ENGINES RPM RANGE

 

http://www.bgsoflex.com/cgi-bin/intakeln?length=18

 

BUT shorten the runner length to about 6" like you did by in effect extending the plenum volume down into the base of the intake bye making the runners for all intents just an extention of the plenum and you get this result

 

http://www.bgsoflex.com/cgi-bin/intakeln?length=6

 

all the benefits of intake harmonics WELL ABOVE THE RPM RANGE OF THE ENGINE

 

but look what just shortening the runners by 3" does

 

http://www.bgsoflex.com/cgi-bin/intakeln?length=15

 

now Im not saying you won,t get a gain in high rpms, but your low and mid range will cancel most of the gains

 

the HOLLEY STEALTH RAM has MUCH BETTER air flow (about 300cfm) and a cross sectional area that greatly improves the air flow at higher rpms and RUNNERS that are effectively about 11-12 inchs long measured from plenum roof to the back of the intake valve

 

http://www.bgsoflex.com/cgi-bin/intakeln?length=11

http://www.bgsoflex.com/cgi-bin/intakeln?length=12

[Guest the_dj]

 

notice the loss of 60 ft lbs of torque and the gain of only 10 hp!

 

Too small' date=' and a bit red. Torque curve isn't that flat either. At least the HP is on a good trend up and up.

 

 

Here you go

[img']http://www.eecis.udel.edu/~davis/z28/winter01/dyno/dyno010511/base-diff.jpg[/img]

[Guest the_dj]

AHHHHHHHHHHHHHHHHHHHHH!!!!!!!

 

http://www.ls1.com/forums/showthread.php?s=&threadid=266616