On my zz502 i used a combo dynoed by sallee chevy. Hyd or solid roller cam roller rockers larger throttle body and ecu upgrade would be a good start.
Gm Performance Parts Pirate4x4 Com
502 ram jet upgrades. The unique ram jet fuel injection system stands 11 inches tall at its highest point and consists of a two piece manifoldplenum. The ram jet 502 blends the legendary torque and performance of the big block with a modern port fuel injection system and tunnel ram style high rise intake manifold. Looking for a good drop in upgrade cam for a un modified zz502 crate engine with about 4000 miles. Of torque in a visually stunning presentation. You might want to play with the ecu to increase fuel etc with these mods to take full advantage. These newer ram jets tend to run better than the older generation mefi 3 equipped ramjets but still have their problems.
I bought all the parts to make it a gmpp ramjet 502 with some upgrades. Its a combination that offers uncompromising performance in a visually stunning presentation. Upgrades included mildbasic porting on factory heads matching to intake and crane 168731 cam springs and roller lifters. The ram jet 502 blends the legendary torque and performance of the big block with a modern port fuel injection system and tunnel ram style high rise intake manifold. Asm offers calibration of the ecu to correct overly rich running condition on mefi 3 ecus and toggle on these features and provide the o2 sensor upgrade. Ramjet ecu upgrade for 305502 crate engines.
I added new gmpp upper and lower intake manifolds all new sensors iac valve gmpp computer controlled distributor 42 lbhr injectors with a gm fuel rail and regulator a holley dual 58mm 1000 cfm throtlle body msd coil and a holley commander 950 pro with a wideband o2 kit. Running in a 70 nova with t400 w about 3k stall and 373 gears. 12499121 502 hp at 5300 rpm. The ram jet 502 blends the legendary torque and performance of the big block with a modern port fuel injection system and tunnel ram style high rise intake manifold. Headers and 3 exhaust. Upgrade ideas needed 07 30 06 0823 am post 973202 in response to xsoonersx i think your best bang for the buck would be bolt ons and upgrades.
Running power disc brakes but will eventually add electric vacuum pump about 4 6 months. If you have modified your mefi equipped ramjet engine or are using a ramjet intake and mefi ecm system on a custom built motor you could benefit greatly from a custom tune for your engine. Mefi 3 equipped models had no o2 sensor feed back for closed loop operation or air temperature compenstaion. The newer ramjet 350 and 502 engines run a mefi 4a ecm with a single narrowband o2 sensor and are set up to run in closed loop operation from the factory. New member from az. These engines ran very rich fuel fouling spark plugs and as a result poor fuel economy.
This kit consists of a mefi 4 controller a wire harness an intake air temp sensor and a heated oxygen. For owners of ram jet engines with the old mefi 3 controller gmpp offers an upgrade kit. 552 hp at 5500 rpm and 572 lb ft at 4500 rpm. Its a combination that offers uncompromising performance including 502 hp and 568 lb ft.
Gallery of 502 Ram Jet Upgrades
