Hamstrung LS7 - armchair diagnos this engine
02-19-2013, 04:12 PM
#1
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Hamstrung LS7 - armchair diagnos this engine I'm a bit of a newb at this but I bought a vehicle w/ the following
LS7 block
Mild Comp CAM (tuned for tq over hp)
L92 heads,
L92 intake,
truck manifolds
single 3" exhaust w/ Flowmaster 50 series
highflow cat
Dyno sheet from the previous owner says 389 hp, 426 tq at the rear wheels.
1) are those numbers what you'd expect? They seem low to me, even given the tuned for torque aspect of the engine.
2) Is there a particular item on the list above that stands out above another as an impediment to making more power?
BTW, it's not a dry sump. Thanks for the armchair quarterbacking!
LS7 block
Mild Comp CAM (tuned for tq over hp)
L92 heads,
L92 intake,
truck manifolds
single 3" exhaust w/ Flowmaster 50 series
highflow cat
Dyno sheet from the previous owner says 389 hp, 426 tq at the rear wheels.
1) are those numbers what you'd expect? They seem low to me, even given the tuned for torque aspect of the engine.
2) Is there a particular item on the list above that stands out above another as an impediment to making more power?
BTW, it's not a dry sump. Thanks for the armchair quarterbacking!
Last edited by fattirewilly; 02-19-2013 at 04:46 PM.
02-19-2013, 09:20 PM
#3
It's about a hundred horsepower off from what I'd expect it to do. You sure it's an LS7? 7.0? I bet if you investigate further you discover it to be much less than 7 liters. An LS7 Shortblock is worth 5-6k+ , I'd be surprised to see someone put that cheap intake on it.
02-19-2013, 09:33 PM
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Yep I agree with that. Your exhaust sucks from what I see in those pictures. You need headers and duals with an H or X pipe rather than that funky merge with 90 degree bends. That's probably costing you 40RWHP and TQ.
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02-20-2013, 08:44 AM
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It was built in 2008, so I don't think a FAST was an option for the L92 heads. What intake options should I look at??
The heads/intake and probably the oil pan were pulled from an LS2 that was in there prior. The previous owner spend a ton of money at a reputable race engine shop to meet whatever his goal with this thing was. The LS7 block was the third iteration.
Last edited by fattirewilly; 02-20-2013 at 09:08 AM.
02-20-2013, 09:14 AM
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09-03-2013, 07:58 PM
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