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This is a graph from my Engine Dyno results.
Build details are in Dyno results section
Titled "396" DLRE,MMS,.....727 FWHP"
The Mid Length Runners, peaked 7100-7300 RPM, and carried
another 500 RPM only dropping 8 HP. The standard
long runners would have peaked 6600-6800 RPM and fallen of
a cliff 500 RPM later.
Had the opportunity to Speak with Richard Holdener
(King of the Dyno Testers) he was testing on the other
Dyno @ WesTech.
Mid Length Runners need Cam & Head Flow to Peak HP @ 7000-7500 RPM,
shifting 300-500 past peak HP.
Short Runners need 8000+ RPM HP peak.
Thought I would post some ideas for a killer street/strip
416". MMS LS3s, LLSR 249*/257* 114*+3* .670"/.640"
11.5-12.00:1 Comp, FAST LSXR, long runners for street
590-600 Lb Ft, shift @ ~6500, Mid Length for Track
725+ FWHP, shift @ 7500RPM+ with Vacuum Pump.
Good for Upper, Maybe Mid 9s full weight F Body,
with good suspension.
KW, That is correct long runners were not tested. The mid-length
runners were ported by Tony with the intake. I did not have the
Long runners ported as I did not want to pay to port those as
I do not intend to run them. At best I would have peaked 560
Lb ft perhaps 565 @ ~5000 RPM, but with earlier peak HP and
Much quicker roll over.
A longer stroke with more cam would show more significant
Differences with runner swaps from 6000-8000 RPM.
Last edited by NAVYBLUE210; 03-15-2017 at 09:11 PM.
Man, I really wish FAST would go and make mid length runners for the cathedral heads. I have MMS 235's on a 416 with all the supporting mods and I have been debating switching over to a Hi-Ram for more top end. Has anyone cut the factory runners and recreated a bellmouth on them!?
Man, I really wish FAST would go and make mid length runners for the cathedral heads. I have MMS 235's on a 416 with all the supporting mods and I have been debating switching over to a Hi-Ram for more top end. Has anyone cut the factory runners and recreated a bellmouth on them!?
Just get an MSD. They're more similar to a mid runner fast
man, i really wish fast would go and make mid length runners for the cathedral heads. I have mms 235's on a 416 with all the supporting mods and i have been debating switching over to a hi-ram for more top end. Has anyone cut the factory runners and recreated a bellmouth on them!?
Why not? There's enough requests for it then it will happen. I hear and read people asking about it. Sooner than later, it gets done IMO. It's only polymer plastic, should be easy enough. Licensing may be a factor.
Why not? There's enough requests for it then it will happen. I hear and read people asking about it. Sooner than later, it gets done IMO. It's only polymer plastic, should be easy enough. Licensing may be a factor.
Emailed FAST again today. The still have no plans of making the mid length for cathedral. I'll probably switch to MSD or modify my existing runners in the next few months.
02-25-2017, 05:28 PM
Fast 102 mid length runner results!!! 
