Shorter Runners for FAST Intake!!!
Well the results are in. These mid length runners on a stroker 418 were worth around 800 more rpm than the stock ls3 intake. We ran it up to just shy of 7300rpm and it didn't start falling on power until around 7250. Previous dyno with stock intake and solid roller cam was 480hp. The new hydraulic BTR cam and this intake yielded an additional 43hp and 20tq. Not too bad for all motor.
Thread Starter
TECH Fanatic
Joined: Aug 2009
Posts: 1,845
Likes: 255
From: Coast of San Mateo County Between Pacifica & HMB
Well the results are in. These mid length runners on a stroker 418 were worth around 800 more rpm than the stock ls3 intake. We ran it up to just shy of 7300rpm and it didn't start falling on power until around 7250. Previous dyno with stock intake and solid roller cam was 480hp. The new hydraulic BTR cam and this intake yielded an additional 43hp and 20tq. Not too bad for all motor.
Attachment 567705
Attachment 567705
The LLSR & the HR and the HP & Torque Peaks for
Each.
Hope to have Dyno Results this Friday with MAMOFIED
LSX with Mid Length Runners as well.
Cam specs were a bit different on the hydraulic. The LLSR was 238/246 .646/.629 115+4.
The BTR cam is 239/254 .624"/.595" 114+3.
The dyno sheet from the LLSR.
Attachment 567726
The BTR cam is 239/254 .624"/.595" 114+3.
The dyno sheet from the LLSR.
Attachment 567726
I would expect the new cam to carry higher. But nonetheless, a nice gain with a hydraulic roller. Would have liked to see a larger LLSR used with the mid-length runners. May have pulled even higher.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Does anyone know a tuner that has experience shortening the stock runners and reforming a bellmouth on them?
MJM
Thread Starter
TECH Fanatic
Joined: Aug 2009
Posts: 1,845
Likes: 255
From: Coast of San Mateo County Between Pacifica & HMB
Just went through your build thread for cylinder head & comp.
Data.
Was LLSR DYNO with 4.10:1 & 5th Gear VS
HR with 3.55:1 & 4th Gear? If so that is another variable
Perhaps 6-8 RWHP COST 5th gear VS 4th.
Also HR is considerably larger, LLSR translates to
Roughly 232/240 in HR adjusting for lash.
Looked like HP peak with stock LS3 ~6500 RPM
VS 6800 RPM for mid length FAST with better Carry
To 7300. Also going from 8* exhaust split to 15*
exhaust split is a HUGE Change IMO along with the
+ 7* Intake duration.
Data.
Was LLSR DYNO with 4.10:1 & 5th Gear VS
HR with 3.55:1 & 4th Gear? If so that is another variable
Perhaps 6-8 RWHP COST 5th gear VS 4th.
Also HR is considerably larger, LLSR translates to
Roughly 232/240 in HR adjusting for lash.
Looked like HP peak with stock LS3 ~6500 RPM
VS 6800 RPM for mid length FAST with better Carry
To 7300. Also going from 8* exhaust split to 15*
exhaust split is a HUGE Change IMO along with the
+ 7* Intake duration.
If you go back to my first post in here, we knew full well going into it that it would not be an apples to apples comparison. However, the mid length did its job, got the power up past 6400. I wish I had the $ to have done back to backs of each setup, but did not. Best way to see how it works, go buy one and test it on your setup 
Thread Starter
TECH Fanatic
Joined: Aug 2009
Posts: 1,845
Likes: 255
From: Coast of San Mateo County Between Pacifica & HMB
If you go back to my first post in here, we knew full well going into it that it would not be an apples to apples comparison. However, the mid length did its job, got the power up past 6400. I wish I had the $ to have done back to backs of each setup, but did not. Best way to see how it works, go buy one and test it on your setup
That's a bit more interesting(at least the long to mid comparison) than previous videos. I don't get why FAST doesn't sponsor a video like this where they really test the full gamut. At least 3 different cams with the three different runners on same engine. Then maybe same on a stroker.
Thread Starter
TECH Fanatic
Joined: Aug 2009
Posts: 1,845
Likes: 255
From: Coast of San Mateo County Between Pacifica & HMB
I spoke with Kip, driving back from So Cal after my results,
He shared some results on a 388" (destroked LS7, 3.622")
Mast 305s, 13.00:1 Comp with LLR ~262*/278*, .700"+
made peak torque 583 @ 7200 RPM (I made peak HP @ 7100-7300,
with mid length), peak HP 760+ ~ 8400-8600 RPM, Engine Dyno.
So... with peak power
@6500, shifting no higher then 7000 Long/Standard Runners.
@7000-7500, shifting 7500-8000 RPM = Mid-Length/HP Runners.
@8000+, shifting 8500+ RPM = Short/Race Runners.
He shared some results on a 388" (destroked LS7, 3.622")
Mast 305s, 13.00:1 Comp with LLR ~262*/278*, .700"+
made peak torque 583 @ 7200 RPM (I made peak HP @ 7100-7300,
with mid length), peak HP 760+ ~ 8400-8600 RPM, Engine Dyno.
So... with peak power
@6500, shifting no higher then 7000 Long/Standard Runners.
@7000-7500, shifting 7500-8000 RPM = Mid-Length/HP Runners.
@8000+, shifting 8500+ RPM = Short/Race Runners.
