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Discussion Starter · #1 ·
Well was hoping to hit 400rwhp but I guess LS2/6 springs aren't ready for that.Heres the skinny.Baseline was 367hp-366tq with mods in sig. but no RR's on stock rims, no heat shield and fan blowing toward filter.Next dyno 9000miles later with 1.8RRs added 374rp 368tq with 18x9.5 thruxtons and 285-35-18 Nitto DRs which maybe a bit heavier and a heat shield over the CAI that blocked the fan from blowing at the filter so that may have taken the number down a little.The roller rockers did ad a pretty big SOTP gain regardless of the number, however above 6000rpms experienced nasty valve float that I thought I could feel when I would wind out the gears.I believe the springs can handle the lift but not the extra weight at the valve, not to mention the LS6 valves are lighter then the LS2's as well that might ad to problem.So final numbers with JBA shorties and wires, offroad pipes,Powerbond pulley,CAI,Magnaflows and X-pipe,1.8RRs,and tune.387rwhp 379rwtq.We will see if 1.75s weigh to much,or we will go back to stock.Guess you guys were right.
 

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What octane are you using? Number look impressive.
 

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Do you think with a Formato ported intake or FAST intake, ported TB, Elec. WP, maybe cutouts, and LT headers that 400RWHP would be obtainable? Nice #'s regardless!! that must feel nice to press the go pedal!
 

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jumbojet said:
Do you think with a Formato ported intake or FAST intake, ported TB, Elec. WP, maybe cutouts, and LT headers that 400RWHP would be obtainable? Nice #'s regardless!! that must feel nice to press the go pedal!
Think it would be close with a Formato tune. Don't wast money on FAST...Formato dose the same thing to a stock intake for much less. My guess would be mid to upper 380s.
 

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But on his car(hardcore4sure) do you think he'd gain 13rwhp from those additions. he's already at mid 380's!! The RR's is a nice mod. Other than the 3200stall/3.73 combo it was the most SOTP improvement on my LT1 IMPSS for sure and it gave me about 1-2 mph improvement.
 

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hardcore4sure said:
Well was hoping to hit 400rwhp but I guess LS2/6 springs aren't ready for that.Heres the skinny.Baseline was 367hp-366tq with mods in sig. but no RR's on stock rims, no heat shield and fan blowing toward filter.Next dyno 9000miles later with 1.8RRs added 374rp 368tq with 18x9.5 thruxtons and 285-35-18 Nitto DRs which maybe a bit heavier and a heat shield over the CAI that blocked the fan from blowing at the filter so that may have taken the number down a little.The roller rockers did ad a pretty big SOTP gain regardless of the number, however above 6000rpms experienced nasty valve float that I thought I could feel when I would wind out the gears.I believe the springs can handle the lift but not the extra weight at the valve, not to mention the LS6 valves are lighter then the LS2's as well that might ad to problem.So final numbers with JBA shorties and wires, offroad pipes,Powerbond pulley,CAI,Magnaflows and X-pipe,1.8RRs,and tune.387rwhp 379rwtq.We will see if 1.75s weigh to much,or we will go back to stock.Guess you guys were right.
On your dyno plot, did you show any TQ gain at 3000 or 4000 RPM?
 

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I ditched my 1.85 RRs for the same reason. Power and tq dropped off quickly above 5800 rpm (LS1 engine). 1.85 RRs are too much for stock valvetrain.
 

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Discussion Starter · #8 · (Edited)
Ok here goes,put the stock rockers on valve float appears to be gone.Weighed the stockers at the tip 5.8 grams,HarlandSharp 1.8, 18.1 grams.Oh yea 91 Cali CRAP OCTANE!A/F was 13.1-13.2 and my tuner didn't want to retune until float was fixed but did think adding fuel may lose a couple HP but would respond better on the street.
Like I thought the weight not the lift is the culprit.I did feel a noticeable loss down low but seems to pull all the way up top no float.I believe the main reason for the dyno # not showing the real gains was the extra weight of the bigger rims and tires,+the fan not blowing directly on the filter.I think a Formato ported intake and tune would have got me there if I either switched to 918s or put on SLP 1.85s due to the same weight however the lift (.571)would then max out the LS6 spring(.570) and possibly run into the same problem.Was going to try Comp 1.75s but my boy forgot them at the shop.Well I got some 1.8s HS for sale or trade for SLP 1.85s.SLED HEAD RICK do you still have yours?
 

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hardcore4sure said:
Well I got some 1.8s HS for sale or trade for SLP 1.85s.SLED HEAD RICK do you still have yours?
still got mine. they are for sale. sent you a pm...
 
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