E85 Conversion

[Hog]

Just to see what GM is doing with their new engines on the Flex-Fuel front.
I do see that the newer K2XX trucks from 2014+ are running the new GEN-V SBC with direct injected Ecotec-3 engines, some are flexfuel like the L83 5.3 and the LV3 4.3 liter V6. I included the L86 6.2, even though it isn't a Flexfuel engine just to show how well these newer Durect Injected engines do.
L83-5.3 355hp @ 5600rpm/383 lb·ft @ 4100rpm on gas
376hp @ 5600rpm/416 lb·ft @ 4000rpm on E85
21hp/33 lb/ft torque gains in SAE ratings using E85 the L83 5.3 uses an 11:1 compression ratio

L86-6.2 420hp @ 5600rpm/460lb·ft @ 4100rpm
The L86 6.2 liter/376cid runs a 11.5:1 compression ratio, this is the truck version of the C-7 Stingray's engine. They are both GEN-5 SBC's.


Even the LV3 V6 does better on E85. This V6 has an 11.0:1 c/r.
285hp @ 5300rpm/305lb·ft @ 3900 rpm
297hp @ 5300rpm/ 330 lb·ft @ 3900 rpm on E85Gains of 12hp @5300rpm/25 lb/ft torque @3900rpm on E85.

With these truck engines, I'd bet that there is some ECM tuning funny business at play here. GM supplies vehicles with Flexfuel engines to make the Gov happy, and then tunes them slightly more aggressive when E85 is in the tank so that folks will buy them and then choose to burn E85. This keeps the farmers happy to supply the ethanol plants. The Gov. then backs off on corn subsidies.


As to Todds response, agreed in a true N/A E85 to gas compare with ECM tuning optimized for BOTH gas and E85, the E85 should show less power. To see a power advantage while running E85 in a N/A setup would require an increase in compression. In doing so, your engine would from that point forward be a race gasoline or alcohol/E85 only engine due to the increase in compression.