I am a new Corvette owner. Recently purchased a used 2008 C6 coupe with 6 speed, dual mode exh & Z51 performance package. I installed Kooks 1 3/4 headers and catted mid pipe and a CAI and did a dyno tune on the car. I want to go another step without getting to radical as this will remain a street only car for weekends and vacation trips. Looking at the Lingenfelter options without breaking my bank account the two obvious choices seem to be a set of CNC ported heads (L92CNC) and a camshaft. The suggested cam seems to be the GT11 with a set of 1.7 rocker arms, camshaft install kit (L200175307). Is this a good cam choice for a street car and should the valve springs and timing chain be replaced (upgraded) at the same time??
Lingenfelter CNC ported LS3 Cylinder heads, GT11 Camshaft 525+HP
The GT11 camshaft is an excellent choice for a daily driven C6 Corvette and offers good horsepower and torque with out compromising low RPM power. The GT11 is 215 / 231 duration @ .050 lift .631" / .644" valve lift with 1.7 ratio rocker arms and has a 118 centerline. This centerline produces a good idle that sounds great and very good drivability so the car is still nice and comfortable to drive. We use this camshaft in our 525 horsepower heads and cam package. This makes 439 rear wheel horsepower with stock exhaust manifolds and cats so with headers you should be doing even better.
Suggested cylinder head upgrades would be as follows:
Lingenfelter CNC ported cylinder heads
Reuse existing GM 2.165" hollow stem intake / 1.59" solid stem exhaust valves
Multi angle valve job, hand blending of valve seats
CC chambers, surface, set spring heights and assembly
Competition Cams 26918-16 ovate valve springs, GM seals with stock LS3 retainers
Another useful and cost effective upgrade would be port matching your intake manifold and porting and polishing your throttle body. These two items on this particular engine combination would work as well as any aftermarket intake and larger throttle body for a lot less money.
If you send your LS3 cylinder heads, intake manifold and throttle body here is a break down of the costs.
CNC Port cylinder heads complete as shown above - pair $1,253.95
Port match intake manifold & port & polish throttle body $345.00
Lingenfelter GT11 camshaft $386.95
Lingenfelter single bolt camshaft conversion kit $69.95
Head gasket, head bolts, exhaust gaskets & balancer bolt $164.95
While you have the engine apart you might want to consider a better timing chain we offer the IWIS upgraded chain $49.95 or the IWIS C5R Racing chain $168.95.
Here is a chassis dyno sheet from a C6 Corvette with manual transmission, stock exhaust manifolds & cats, built the same with Corsa cat back.
Other users of the GT11 cam on the Corvette Forum as well as other engine builders recommend using roller lifters with any LS cam with lift over .550".
I am doing the Lingenfelter LS3 heads, GT11 cam with Yella Terra roller lifters from New Era Performance in Rochester NY on my 05 LS2 . I ended up with 7.35" Comp Cam HiTech pushrods to get the .045" preload on my Morel lifters. I sould have it fired up in a few weeks.
The car sounds and drives great. I will dyno tune it in the morning.
Originally Posted by C6RAPTOR
I will let Tim know what the Dyno numbers are. I also installed a ARE dry sump system as part of this winter project. The car is used for street a HPDEs at The Glen, VIR,Mosport, etc.