mowton
September 23rd, 2013, 10:40 PM
Based on the above, I am experiencing a rather weird situation. So we updated this SC corvette about 2 years or so ago to E85 and the E40 Custom OS. At the time, the 2005 Corvette calibration did not have the ability to set the Stoichiometric value so we used the embedded 14.7 and tuned accordingly. Actual used a bit of lambda for grins and giggles :). Car ran like a champ (made 750 rwhp and torque to burn) and customer was very happy. As a result of this project, I asked EFILive if they could add the Stoich table to the E40 calibration and you guys obliged with the new B3671 table.
Segway to 4 weeks ago when the customer returned and wanted to replace his tired Ls2 with a beefed up 427. So after the install we strapped her to the dyno and away we went. Being smarter today than I was when we first tuned her to E85, and having the new table, I set the Stoich to 9.8 (as well as the LM2) and off we went. Well it wasn't long before we experienced what we first thought was "running out of injector" when we entered into the BOOST VE table because no matter how large we made the VE (until we actually maxed to the 500) it just wouldn't supply enough fuel per the BEN results. It seemed to be good going to 105 Kpa, but as soon as we entered Boost/PE, it just wouldn't fuel correctly. As a note the injpw was 20-21 ms. so we were close.
Of note, the Build was 240 that I was using at the time. Today I just updated to 242.
So we pulled the fuel system, saw some dirt/sputtering, so we replaced the pumps (3) and installed a new set of 2000cc injectors as we were at 21 ms and still needed more to go.
Low and behold last night after getting her back together, we saw the exact same scenario. Boost just couldn't get to the right fueling no matter what value we set the Boost VE to. I even cut the inj/ve relationship by 50% to get away from what I had once read was a 139 VE hard limit in the E40 but same results.
So finally with no other answer or way to go, I reloaded the file that the car came in with (remember, pre B3671 days) and to my amazement she fueled correctly (after some VE tuning) and hit my target PE AFR of 11.0 (based on the 14.7 stoich which we reset the LM2 to.
Does anyone else ever experience this with setting the Stoich to 9.8 in the E40 PCM?
sorry so long but any insight would greatly help
Ed M
Segway to 4 weeks ago when the customer returned and wanted to replace his tired Ls2 with a beefed up 427. So after the install we strapped her to the dyno and away we went. Being smarter today than I was when we first tuned her to E85, and having the new table, I set the Stoich to 9.8 (as well as the LM2) and off we went. Well it wasn't long before we experienced what we first thought was "running out of injector" when we entered into the BOOST VE table because no matter how large we made the VE (until we actually maxed to the 500) it just wouldn't supply enough fuel per the BEN results. It seemed to be good going to 105 Kpa, but as soon as we entered Boost/PE, it just wouldn't fuel correctly. As a note the injpw was 20-21 ms. so we were close.
Of note, the Build was 240 that I was using at the time. Today I just updated to 242.
So we pulled the fuel system, saw some dirt/sputtering, so we replaced the pumps (3) and installed a new set of 2000cc injectors as we were at 21 ms and still needed more to go.
Low and behold last night after getting her back together, we saw the exact same scenario. Boost just couldn't get to the right fueling no matter what value we set the Boost VE to. I even cut the inj/ve relationship by 50% to get away from what I had once read was a 139 VE hard limit in the E40 but same results.
So finally with no other answer or way to go, I reloaded the file that the car came in with (remember, pre B3671 days) and to my amazement she fueled correctly (after some VE tuning) and hit my target PE AFR of 11.0 (based on the 14.7 stoich which we reset the LM2 to.
Does anyone else ever experience this with setting the Stoich to 9.8 in the E40 PCM?
sorry so long but any insight would greatly help
Ed M