I'm not sure where people keep finding all these "60" lb injectors. The only ones everyone else uses for the LSJ are Siemens 64 lb.
And you can run 42s on a 2.8 just fine. If you actually tune the car to not run like pig rich 10.8 afr and have some cooling mods and good airflow, you won't be past 85% DC.
RSG Offroad
Jeeps. Jeeps. And more Jeeps. Oh and Jeeps too.
I'll be looking at the injectors closely.
RSG Offroad
Jeeps. Jeeps. And more Jeeps. Oh and Jeeps too.
Question, Based on the info below, wouldn't the tuning be off anyway because Cobalts run 62 PSI fuel pressure and these injectors are rated at 43.5 PSI?
Isn't the LSJ injector offset based on an injector that flows X at 62 PSI Pressure?
I max out the injector offset on an LSJ when using these injectors and have to trim alot out of the Maf Curve to get it to run right.
Racetronix Part # L107FM Part # 107961 (Siemens FI114961 - Mototron INJ-GAS-006 - Accel 74620L - MSD/Edge 2030)
All tests run with n-Heptane (0.6855g/mL) @ 20oC (+/-1oC), 3.0 Bar (+/-0.01 Bar) (43.5PSI) , 14VDC (+/-0.05VDC), saturated driver. Engineering data specifies a flow ratio of apx. 1.035:1 when converting to gas.
Static Flow Rate: 60.56 lb/hr = 668 cc/min = 458 g/min (+/-6%)
Dynamic Flow Rate 2.5ms PW @ 100Hz @ 600KPa: 19.5 mg/pulse (+/-6%)
Coil Resistance: 12 Ohms (This high-impedance injector will work with all factory ECM/PCM injector drivers)
Gain: 0.11ms/mg
Offset: 0.055ms
Turn on time @ 14VDC: 1.14ms
Turn off time: 0.85ms @ 600KPa
Spray Pattern: Cone (4-Hole)
Connector: Minitimer (Bosch EV1)
> Click here for dimensions <
Factory fitted with Viton upper and lower o-rings.
Grease supplied to lubricate o-rings prior to installation.
Dynamically flowed and grouped to within 1% tolerance using Racetronix custom injector flow bench
Note: Injector flow rates are based on testing with n-Heptane test solvent (0.6855 g/ml). U.S. EPA emission test gasoline 40CFR86.113 (0.735g/ml) flows in most common injector designs at about a 3 to 4% higher rate than n-Heptane. A ratio of 1.035:1 can be used when converting the flow specifications above.
Which is why in the LSJ you tune them for 64lbs......
And you should be doing your calculations at around 59psi, that is a more steady state pressure when asking for that much fuel.
RSG Offroad
Jeeps. Jeeps. And more Jeeps. Oh and Jeeps too.
Actually, I tuned the injectors for what ever the flow apparatus at my old shop said they were. And I know it's not 60lb/hr... and it's not 64lb/hr either.
If you want to get all technical on the subject, you should call them "59-66lb/hr depending on which end of the tolerance you got" injectors...
I've seen the Siemens Deka injectors have a very large difference in flow from one to the other. At least most retailers try to match them up the best they can.
Either way... in the event that someone did put "60lb/hr" in the injector field, you do realize that they can account for it everywhere else in the tuning process, right? (assuming they didn't half ass the tune) The V8 guys do it on purpose all the time.
Tyler