Whats Up at 6200 ?
12-01-2007, 08:29 AM
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Whats Up at 6200 ? Got the tune in my LS1 GTO updated yesterday due to a FAST 90/90 (unported) and new catback install. Cam is TR224/224 with AFR 205s. Not unhappy with numbers....but tuner could not figure out whats happening at 6200 - and then we ran out of dyno time. He did 4 pulls on the Dynojet and they all looked about the same. He suspects maf issues - like not enough space / distance between filter and maf - or something. I did just change out to an delphi 85 mm truck maf (descreened) on my LS1 (casper harness) - and he did load new maf tables - but otherwise its an 05/06 oe gto maf / intake tube with a standard 05 lpe cai configuration - so why would insufficient space be an issue ?
Im not sure there is enough info here but anyway, anybody here have any suggestions on where to start looking ?
Im not sure there is enough info here but anyway, anybody here have any suggestions on where to start looking ?
Last edited by gtodude; 12-01-2007 at 09:51 AM.
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12-02-2007, 11:51 AM
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some sort of fuel or ignition cut-off was my first thought after the second and then the third pull showed power cutting off sharply and consistently pretty much at 6200 - 6250. I asked my tuner - and he said no - but worth following up on again.
12-09-2007, 02:12 PM
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i finally got my hands on an inch-pound torque wrench and found my best guess torque on the new fast 90 manifold was way short. I had maybe 50 inch pounds on the manifold bolts - was suppossed to be 89 inch-pounds. what kind of problems could that cause - could that be the source of my problem ?
12-09-2007, 09:16 PM
#15
I would think too much timing and a partial bad spark plug, or really lean or really rich and blowing out the spark.. Or some kind of restriction sucking up and plugging the air filter or VERY poor airflow going to the intake. Does it have a really harsh step going from the neck of the airfilter setup to the throttleblade?.
