Too much valve overlap can have a negative effect on clean running engine of the engine. I will be going very mild with a hydraulic cam with ~285/295 duration on a 110*LSA - probably not the most ideal choice but it will have a nice idle while still getting me over .500" lift. Founded in 1978, Cam Motion has a long history of helping racers win major championships at the highest levels of racing. - Super Chevy Magazine Begins Intake Event Sooner; Open Intake Valve Sooner; Builds More Low-End Torque; Decrease Piston-Intake Valve … “With an application like that we would use a hydraulic roller cam with 226 degrees (duration) at 0.050 inch on the intake, and 232 degrees (duration) at 0.050 inch on the exhaust, with something like a 0.544 to 0.559 (inch) max valve lift. It isn't overly aggressive, so drivability will be excellent. BTR PDS STAGE 2 CAMSHAFT 227/242 .614"/.592" 122+6 This is possibly the best overall camshaft in the performance aftermarket for GM LSA and LS9 engines. O = 70° cam overlap - 30 = 40, × 1% = .4: R = 750 × (14.7 + 10 + .4) = 1.63:1 (overdrive) ratio: 393 × 2 × 14.7: The supercharger turns 163% of the engine RPM, typical where the supercharger is fairly small, but safe at high RPM. Typically higher boost levels, and higher rpm, require more cam duration. Camshafts are a subject that all car guys love to talk about, and those who listen tend to roll their eyes at the staggering number of terms and numbers. It actually has 5* LESS overlap than my XE cam on a wider 114* LSA. (2) 0.028 in. Boosted engines don’t need a lot of duration or valve overlap to fill the cylinders because the turbocharger (or supercharger) does the pushing. Exhaust Valve Lash . Turbocharged engines have different camshaft requirements than naturally aspirated engines. (1) Get Results. Supercharged LS applications require very specific cam timing. For best performance with a … What kind of camshaft would I use on an 8.5:1 compression, Vortech VS-1A-supercharged 5.0L at 6 psi and 5-speed manual transmission? Will work great with any positive displacement supercharger on a 6.2 liter engine. The cam can (and most certainly does) make or break the car’s performance. Cam Motion provides superior quality, high performance camshafts and valve train components for the GM LS7 Engine. Camshaft duration is the measurement of the time one valve begins to open until it finishes closing, and it is measured in degrees of crankshaft rotation, not camshaft rotation. Interestingly, they said the cam timings are basically the same. “Supercharged and nitrous race engines typically benefit from a wider LSA because they don’t require as much overlap for exhaust scavenging as does the naturally aspirated engine,” continues Bolander. The overlap portion of the cam timing-curve, between intake and exhaust, is the most critical element for a supercharged or turbocharged engine. Don't be fooled though, when you strap a large blower to your LS3, this cam is capable of marching straight into 1000 horsepower-land and setting up a new home for patriots like yourself. How Camshaft Timing works. This camshaft's Performance Level varies by CID group. With a supercharger you don't need huge cams to make power - the overlap of a tight LSA would actually bleed off the pressure a bit - so a wider LSA would be better with the highest lift you can go. Perhaps a supercharger shouldn't want much overlap (due to wasted charge). Learn more about Camshaft Timing. The overlap portion is where the exhaust valve is just closing while the intake valve is just opening. Camshaft Usage . We took a L98 350 small block from a local wrecking yard and supercharged the Chevy Small-Bloc, but since we had it at our disposal, we decided to test and compare cams. To get the most out of your supercharged LS engine, choosing the proper camshaft is critical. (1) Get Results. $100-$250 (7) $250-$500 (5) Get Results. Effect Of Changes In Cam Timing And Lobe Separation Angle The following tables illustrate how variations in lobe separation angle and cam timing will effect the behavior of the engine in which the camshaft is installed. If you have a P1, D1, or Novi1500 sized blower, this camshaft will be a great pairing. Specs: 220/230 .581/.591 116+3 . COMP Cams Blower and Turbo Camshafts. A certain amount of valve overlap is beneficial, as without it the volumetric efficiency of the engine would be compromised. California EO Approved (1) Intake Valve Lash . For example, a 260-at-.050 cam has much more overlap than a 225-at-.050 cam, even if both are ground on a 112-degree LSA. Because of the negative effects of overlap on a supercharger car's performance, and especially in the case of high exhaust back pressure as is the case with most factory supercharged cars, we find that the optimal cam duration for the intake cam is typically 30-40* of duration less than a normally aspirated camshaft for the same peak power RPM. Additional duration, increasing overlap by opening the intake valve earlier and closing the exhaust valve later, is commonly found on performance camshafts. Camshaft tuning is an essential part of supercharger tuning. With only 5 degrees of overlap, this cam is docile enough to be used in daily driver applications. And it'll be plenty good for 5500 RPMs, where the blower is basically pooped-out anyway. O = 70° cam overlap - 30 = 40, × 1% = .4: R = 750 × (14.7 + 10 + .4) = 1.63:1 (overdrive) ratio: 393 × 2 × 14.7: The supercharger turns 163% of the engine RPM, typical where the supercharger is fairly small, but safe at high RPM. With no other changes to the motor I should be seeing a full 1 PSI increase in boost, and end up making the same peak HP but with more torque everywhere under the peak. However for optimum performance at higher rpms, a more aggressive camshaft will provide substantial power increases. Please see information specific to your CID group in the more detailed product description below. Quick view. Less valve overlap means better low-rpm torque and increased fuel efficiency --"fuel efficiency" being a relative term by 1960's standards. Add to Cart. With almost 0 degrees of overlap it has a definite camshaft sound, but still has a mild idle, yet makes the pow Will work great with any positive displacement supercharger on a 6.2 liter engine. 227/244 .618"/.604" 115+5. If you do not see exactly what you want, we can also make you a custom camshaft designed specifically for your vehicle. A supercharger can overcome inadequacies in a stock cam up to about 4,500-5,000 rpm. In fact the supercharger works better with a stock cam or only a very mild upgrade cam where you won't lose so much of the pressure charge to valve overlap between strokes. Just like carburetors, bigger is certainly NOT better! BTR CAMSHAFT - LS3 - CENTRIFUGAL SUPERCHARGED - 32744155R1. Supercharged engines generally benefit more from a wider LSA because they don’t require the scavenging effects that come with greater overlap. Currently my mind is in Cam Land thinking about an upgrade for my TNT heads/cam/headers 96 GTS with a 224/224 .550 lift 114 LSA cam. But even though there is pressure with a turbo in the exhaust manifold - the opposite of a supercharged engine - my sense of logic tells me that it's just as important to avoid overlap in turbos, simply because of backflow, as f1karting said. If you are uncertain as to which cam profile best suits your needs, please contact our technical support staff at 619-661-6477. Less valve overlap also helps a turbo spool up faster for less turbo lag when you floor it. When you are running nitrous or a supercharger, the rule of thumb is you usually want to stay away from cams with a lot of overlap and go with a cam that has a wider lobe separation. And the supercharged engine can be made to produce more power with lower compression ratio. Cam Motion has a wide range of camshafts listed for both positive displacement and centrifugal style supercharged LS engines. Since we’re using pressure to force fresh air and fuel into the cylinder, the overlap cycle (while still important) becomes less critical. Whether you have a Silverado or Sierra pickup truck that needs a little extra towing power, a Camaro or Corvette that needs a rowdy idle and quicker elapsed times, or a simple cruiser that's used for ice cream runs and burnouts, BTR has what you need! As a frame of reference, the similar but less-advanced RA-III used a cam with a 110-degree LSA, and the 1997 Firebird SLP's rollerized lifters allowed it to use a cam with a 115-degree LSA. (2) 0.028 in. There is a practical upper limit on combustion pressure before you run into detonation. Treat your LS7 with the respect it deserves and upgrade it with a Cam Motion camshaft that is designed specifically for LS7 engines. Level 3 camshafts are designed for moderately modified engines. This is known as valve overlap. Price Range . I think the key concept is NO overlap - you don't want to "short-circuit" the blower or allow the turbo back pressure to back flow. (2) 0.030 in. Camshafts orchestrate the valve opening and closing events in the engine and decide whether what comes out of our motor is beautiful high power music, or a mess of dysphonics. Emissions . The main difference between supercharged and turbo charged engines, is that turbo engines do not flow from the intake out the exhaust, at overlap, as easily as a supercharged engine, and therefore tend to open the intake valve earlier. However, gauging overlap solely by a cam’s LSA can be a bit deceptive. (2) 0.026 in. Camshaft Selection. May 19-20-21 Seminar Nascar Allstar Race Tailgate Party Themed Seminar We will have a drawing for 2 seats at the Allstar race Saturday afternoon {about 20 Miles away at Charlotte motor speedway} starts @6:00 pm For the rest of the attendee's we will watch the race on the projector screen while having a tailgate cookout party. A&A SUPERCHARGED CAM. You will typically find that performance with a blower will not be significantly enhanced below these speeds with a cam change. “Also, the wider LSA contributes to chassis stability in drag racing by avoiding the delivery of a ferocious blast of power that would break tire traction. If it is 260 degrees @ 0.050in on both intake and exhaust and with 114 LSA, it would probably generate sufficient vacuum. Advancing. With -10 degrees of overlap it has a … This camshaft works very well with small centrifugal blowers on 5.7-6.2L engines. Supercharged LS Camshafts. There’s lift and duration, overlap and lobe centers, lobe separation angles and so on, and all of them have numbers attached. Supercharged (11) Turbocharged (8) Street/Strip (1) Get Results. Typically the positive-displacement, supercharged cam profiles offer wide lobe separations and minimal (or negative) overlap. 0.020 in. A Brian Tooley Racing camshaft is the ultimate complement to your LS or LT powered vehicle. GM recognized this when they designed the LS9 cam for the factory supercharged 6.2L. View All Close. Related Products; Customers Also Viewed; Related Products. As duration increases, overlap increases, even if the LSA isn’t changed. EFFECTS OF ALTERING CAMSHAFT TIMING. BTR PDS STAGE 3 CAMSHAFT 231/248 .617"/.595" 120+5 This cam is on the upper end of aggressiveness for GM LSA and LS9 engines. 0.020 in. 10/15. Additional horsepower increases with the appropriate amount of overlap and can easily exceed output from a relatively identical camshaft with a wider lobe separation.