Precision Race Components LS7 Cylinder Head Engine Dyno Results!!
We've finally got the opportunity to get the all new PRC CNC Ported LS-7 cylinder head installed on our dyno test LSx 454 engine! The engine was dyno tested with Texas Speed 254/260 camshaft, LS7 intake, Texas Speed all new 100mm MAF & 1 7/8" dyno headers!
about 615 or so at the tire I woudl guess! Did this have any "dyno tricks", like ewp (I assume not). Would there be any real power difference between this motor and a LS7 based 440 stroker? Is there any benefit to going with a bigger cam while using the LS7 intake?
What would the total price be for a complete engine (intake, TB, injectors, etc) using a LSx iron block or a LS7 440 stroker?
720 crank hp on a daily driver in a F body or vette would be nice. Probably get decent mileage too!
Jason.....are you going to have any exchange program of any kind with people that have LS7 heads already? I'm very interested in your heads but I'm kind've stuck because I have good heads, springs, and valves already. Traver
__________________ 2001 Trans Am 9.75 @139mph 1.40 60' 6.0 at 117 mph 1/8 mile High Comp 445 756/666 NA
Jason and most of the TSP guys are at the PRI show in Orlando, FL. I'll answer a few quick questions before I leave for the weekend myself, but unless Jason finds an internet connection, I wouldn't expect a response until late Sunday or Monday morning.
We ended up not using that Vacuum pump in the picture with our heads as it only made 3-4hp pulling 15 inches of vacuum on the crankcase, wasn't worth the hassle and belts were hard to keep in place. You can tell the vacuum pump was on the stock heads by looking at oil pressure, the more vacuum on the crankcase, the lower the indicated oil pressure. We were kinda surprised it didn't pick up more with the pump actually. May be a testament to how well the LSX block cylinders seal and the crankcase breathes!
All pulls were with a ported LS7 intake (look at the dyno notes in the sheet). We had swapped to that earlier on during the testing, but well before swapping heads. I don't remember exactly what the ported intake picked up (we were 3 days on the dyno) but I know it was around 8-9hp. The 100mm MAF picked up a little more than that by itself once tuned, that will likely have its own post.
The engine dyno facility we use only had 113 and 116 octane fuels, we used the 113 for all pulls. The static compression should be around 11.8-1 from what Jason said.
These were also not the final numbers (we tested quite a few setups), I'll let Jason post them up when he gets back. It was enough to not bother swapping to our biggest cam we took...
These graphes were the Cylinder Head swap alone, we probably made 20-25 pulls when we were finally finished with the other tests.
No dyno tricks...just no power steering, no air lid or air filter, EWP, underdrive pulley, no altenator so no need for a serpentine belt, 1 7/8" "dyno headers" which wouldnt fit an F-body or a corvette and are symmetrical for even flow...no dyno tricks at all!!! I wanna see this setup in a running, driveable vehicle, on a chassis dyno, with all enigine components hooked up and working, and with a serpentine belt, air lid, filter, etc. like it would actually be in someone's car...make good numbers then and I'll be impressed, as long as the numbers from TSP's chassis dyno equate to other comparable dynos, and are not "inflated".
I didnt mean b/c of the size of the primaries people...b/c of the shape of the primaries and how they run...how many sets of long tubes for f-bodies and corvettes are identical on each side and can stick out that far from the block and not hit something else in the engine compartment...Jesus Christ guys...I am not a complete dumbass!! Just mostly a dumbass...HAHAHA! Those headers will outflow and and outperform any aftermarket LS-style header on the market b/c of how they are designed! Really, I just wanted to light a fire under their *** to get this motor in a car and give us some real world numbers! i am interested to see what kind of RWHP this setup can produce!!
Am I the only one that looks at this as they only gained 27hp and 5-20 ft/lbs of torque through out the rpm band over stock heads? That tells me that the factory ls7 heads are pretty badass from the factory. And those gains might not be as large once the motor gets bolted up in a car with real world accesories and exhaust / intake.
Again, I'm not knocking, just amazed at how well the factory heads work with the larger cam and all of the intake/exhaust work.