918 spring pressure loss?
well, something crazy is going on at 5100 and then again from 5300 RPM on up. I am not sure if the lil dip at 5100 is connected to the stuff happening at 5300 RPM or just a dip in the curev that is un related. Looks like something is breaking up above 5300 wether it is valve springs, spark plugs, plug wires, coil , opti, etc. Man, I have no idea the cause but I do see a problem.
I would start by testing spring pressure and making sure rockers are adjusted to 1/8 or 1/16 past zero lash.
Lloyd
I would start by testing spring pressure and making sure rockers are adjusted to 1/8 or 1/16 past zero lash.
Lloyd
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From: Carol Stream Il.
Thanks Lloyd. Kind of make me wonder how the hell this thing ran a couple of 11.9x's a few outings ago. The one dyno pull was done right before the high 11's.
check spring pressure now and see what they are, might check them all in case just a few are bad. Might even pull them to check them and re shim them to 1.720-1.730 as long as the pressure check good on all of them.
Also make sure the rockers are adjusted 1/8 to 1/16 past zero lash.
LOTS of things can screw up dyno #'s and track results on an LT1 and make sure no leaks betyween TB and MAF, amke sure the maf is clean, no exhaust leaks, compare left and right BLM's and O2's to make sure they are the same, gap plugs at .030-.035, bad plug wires, bad coil, bad opti, etc, etc.
Good luck but I would start with the mechanical side first (spring pressure and rocker adjustment) then move on the other things.
Lloyd
Also make sure the rockers are adjusted 1/8 to 1/16 past zero lash.
LOTS of things can screw up dyno #'s and track results on an LT1 and make sure no leaks betyween TB and MAF, amke sure the maf is clean, no exhaust leaks, compare left and right BLM's and O2's to make sure they are the same, gap plugs at .030-.035, bad plug wires, bad coil, bad opti, etc, etc.
Good luck but I would start with the mechanical side first (spring pressure and rocker adjustment) then move on the other things.
Lloyd
