Looking for more out of my LS3, ideas?
Motor is a hand built 377ci LS3. K1 rods, ARP2000 rod bolts, Clevite rod bearings, ACL main bearings, SRP 4032 pistons (5cc, .01 above deck), & 222/230 112+2 cam by PatG. My top end is FastToys Lid (I think it's an 85mm) > TSP 100mm MAF w/ screen > Nick Williams 92mm TB > stock LS3 intake > stock LS3 heads milled .020 with stock hardware except PAC 1518 springs. Only street tuned w/ mail order tune from Frost at this time. Static compression right around 10.8, I think DCR is around 8.2. Not interested in larger displacement, but I'm open to higher compression so long as it's compatible with 92-94 octane fuel.
Fuel system is stock LS3 injectors, Racetronix harness kit & Racetronix 255lph Walbro pump.
Exhaust is ARH 1.75" headers > ARH 3" catted Y-pipe > SLP dual-dual (with cutout). I don't like the sound of the exhaust without cat's.
Drivetrain is a T56 with basic upgrades, LS7 clutch with Fidanza 13.5lb flywheel, OEM AL driveshaft, OEM 10-bolt with 3.73 gears. I have considered going back to a 3.42 final drive if I could get the tip-in bucking resolved.
It's a daily driver which needs to remain reliable and low maintenance, don't want to worry about checking/replacing valvesprings, would like better fuel economy at cruise, max average torque between say 2500 & 6000. No drag racing, spirited street cruising, perhaps I'll get back into autocross or someday try my hand at a HPDE but I worry about the poor LS3 oil drain back for those activities.
I feel I lost some of the snappiness in the throttle when I switched from the LS1 to the LS3, and I've read that is a result of going from cathedral to wide rectangular intake ports. But I've also read that the there aren't any real gains (except a much lighter wallet) to be had with the Fast cathedral intake on a stock displacement LS3. Not interested in nitrous.
I was considering a BER or PeakSpeedShop ported LS3 intake and maybe better heads and a matched cam, but are there any other changes I could consider to raise my area under the curve in that RPM range and help with the other desires also?
Last edited by JimMueller; Sep 15, 2014 at 02:07 PM. Reason: Cam LSA is 112 (not 110), heads milled .020 (not .030)
Would there be such a thing as a complete boost solution (which includes all additional supporting mods) that meets my goals but would be maybe closer to $5K?
Last edited by JimMueller; Nov 15, 2013 at 12:23 PM.
Would there be such a thing as a complete boost solution (which includes all additional supporting mods) that meets my goals but would be maybe closer to $5K?
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Would there be such a thing as a complete boost solution (which includes all additional supporting mods) that meets my goals but would be maybe closer to $5K?
A&A also sometimes sell a "newsed" kit. A rebuilt blower with all new everything else. Those are usually around $4500 if they have some.
The Best V8 Stories One Small Block at Time
Rectangular:
TFS GenX 255, 255cc (12 degree)
Mast 510-202 (LS3 12 Degree 4.000" - 4.070" Medium Bore CNC), 255cc
PRC 199-265LS7SB LS3 (LS7x 265cc CNC Small Bore Heads), 250,255,260c
SDPC LS3 CNC Ported
???
Cathedral:
AFR 215/230/245cc Mongoose
Mast 215/245cc
PRC 237/247cc
TFS 235 - scratch that, needs min bore of 4.125
???
Last edited by JimMueller; Nov 18, 2013 at 10:32 AM.
Not getting my questions answered by PRC nor TFS.
Motor is a hand built 377ci LS3. K1 rods, ARP2000 rod bolts, Clevite rod bearings, ACL main bearings, SRP 4032 pistons (5cc, .01 above deck), & 222/230 110+2 cam by PatG. My top end is FastToys Lid (I think it's an 85mm) > TSP 100mm MAF w/ screen > Nick Williams 92mm TB > stock LS3 intake > stock LS3 heads milled .030 with stock hardware except PAC 1518 springs. Only street tuned w/ mail order tune from Frost at this time. Static compression right around 10.8, I think DCR is around 8.2. Not interested in larger displacement, but I'm open to higher compression so long as it's compatible with 92-94 octane fuel.
Fuel system is stock LS3 injectors, Racetronix harness kit & Racetronix 255lph Walbro pump.
Exhaust is ARH 1.75" headers > ARH 3" catted Y-pipe > SLP dual-dual (with cutout). I don't like the sound of the exhaust without cat's.
Drivetrain is a T56 with basic upgrades, LS7 clutch with Fidanza 13.5lb flywheel, OEM AL driveshaft, OEM 10-bolt with 3.73 gears. I have considered going back to a 3.42 final drive if I could get the tip-in bucking resolved.
It's a daily driver which needs to remain reliable and low maintenance, don't want to worry about checking/replacing valvesprings, would like better fuel economy at cruise, max average torque between say 2500 & 6000. No drag racing, spirited street cruising, perhaps I'll get back into autocross or someday try my hand at a HPDE but I worry about the poor LS3 oil drain back for those activities.
I feel I lost some of the snappiness in the throttle when I switched from the LS1 to the LS3, and I've read that is a result of going from cathedral to wide rectangular intake ports. But I've also read that the there aren't any real gains (except a much lighter wallet) to be had with the Fast cathedral intake on a stock displacement LS3. Not interested in nitrous.
I was considering a BER or PeakSpeedShop ported LS3 intake and maybe better heads and a matched cam, but are there any other changes I could consider to raise my area under the curve in that RPM range and help with the other desires also?
I'd say mill the heads some more to get around 11.5:1 compression.
Im running a 220/230 at .050, 108+4 cam in my stock GM crate LS3 and am right at 228 lbs of cranking compression. It likes pump 93 ok at 34* max timing, but I wouldn't want to push it any farther than that.
So I guess I'm interested in shifting my curve straight up as much as I can with the modified (not to be confused with ported) LS3 manifold, heads, valvetrain (higher lift rockers?) and matching cam. If I can get a bit better fuel economy below 2000 by shifting the curve to the right a bit I'd be all right with that.
Not sure how much I can mill before worrying about PTVC. Without a cam change, dropping to a 60cc chamber would put me at 11.5 SCR and 9.0 DCR with my current AIVC of 65.5. I'd need an AIVC of 70* or later to keep DCR around 8.7 or less.









