We test the best cams for your LS3
What are you driving? If you are a 2008-17 Camaro or Corvette person, the Summit Racing Stage Three 8710 camshaft we testedis the ticket to a solid 550 hp that is easy to live with.
If you want more power, Summit has the 8705 cam with a tighter 107-degree LSA, 234/277 duration at 0.050, and 0.595-lift using a stock 1.7:1 rocker ratio. It is a lot more aggressive and worth an additional 20 hp on top of the gains from the 8710 grind or 123 hp over a stock LS3 when combined with a stroker kit. Those numbers are N/A using a 91-octane California sluice-water gasoline tune.
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The 8705 requires piston clearance on the exhaust side to avoid piston-to-valve contact. Old man theory has proven that if you need to swap pistons, you should also add good rods. If you are going to add new rods, you should get a forged crank. What follows is buying a stroker kit that boosts the cubic inches to 415 and includes all three.
We took an LS3 from a 2012 Camaro to Custom Performance Racing (CPR) in Gardena, California, for the stroker install and the dyno tests. They have a CNC head program and several interesting supercharger options that we might try in the future.
Stock LS3: 470 HP and 484 LB-FT
The base LS3 is rated at 430 hp. The horsepower bump comes from the use of long-tube dyno headers, a larger throttle body, and usually, better fuel, and a more aggressive baseline tune.
Summit 8710 Stage Three Cam: 549 HP and 492 LB-FT
This simple cam and spring swap is worth 80 hp over the stock LS3, plus some additional revs in the rpm range. For a street car with a stock transmission and rear gears, this is the best cam you can get.
Summit Stroker 415 and 8710 Cam: 587 HP and 548 LB-FT
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The additional cubic inches come from the Pro LS 6.2L forged rotating assembly. The crank has a 4.000-inch stroke, the pistons are 4.065-inch, and the rods are 6.125-inch H-beams. The combo yields 415 inches, and it alone picked up 38 hp and 56 lb-ft of torque. More importantly, the torque peak moved from 5,100-5,500 rpm to a more usable 4,400-5,500. It makes more torque over a longer period of time. Great for drag racing or getting out of a corner on an autocross or road course.
Summit Stroker 415 and 8705 Cam: 607 HP and 539 LB-FT
With the larger cam and the extra cubic inches, the LS3 picked up an additional 20 hp at the same horsepower peak as the smaller cam, plus a rowdy idle. It dropped under 10 inches of vacuum at idle as narrow LSA long-duration cams tend to do. It also dropped some torque in the mid range. Brian Nutter at Summit mentioned the Stage Three is actually the more tunable option at the cost of a few horsepower at the top. We agree. If you want to have street cred and turn heads, get the 415/8705 combo. If you want to have a more tunable combo for a 2008-later LS3 powered street car that still has a nice idle chop, go for the smaller cam.
CPR 415-Inch LS Parts List
- 4x 3 bolt upper timing gear NAL-12586481
- Cam Retaining Plate SUM-150106
- Chevrolet Perf. LS9 gaskets (2) NAL-12622033
- Chevrolet Perf. Stage 3 direct copy cam SUM-8705
- HDR 7.425 in. 11/32 .120 pushrods SUM-14917425
- Pro LS Stage 3 Cam/Springs/Gaskets/Bolt Kit SUM-8710-2 DLSTL
- LS ARP Bolts and Studs 534-9805, 234-4345
- Summit LS2 spec timing chain SME-143012
- Summit Cam Locking Plate SUM-G1793
- TFS Steam Line Kit TFS-306SB601
- Trunnion Kit SME-143002
- Trunnion Kit tool SME-906011
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