Something BIG is missing from the LS9...

**dmd** · 08-13-08, 03:19 PM

Been poring over the tech articles on the LS9 and there is a glaring omission: Direct Fuel Injection. It hasn't been mentioned at all. There hasn't been an application larger than the 3.6 V6 yet so far, but they must've tried it. Did the Corvette team merely set themselves up for a coup in a couple years to pull another 100hp out of the DFI hat, or did it just not work with boost? Are the DFI injectors incapable of overcoming the pressure of a boosted engine?

DaveD

**Hib Halverson** · 08-13-08, 03:47 PM

Direct injection for V8s is under development at GM Powertrain.

When it arrives it will be mainly a fuel econonomy enhancement and not a power enhancement.

DFI injectors will be able to overcome the pressure of a boosted engine. That task will be no more difficult that overcoming the pressure where the injectors are now.

Remember gasoline DI is not the same as diesel injection. The fuel is still injected during the intake stroke, it's just not injected in the intake port.

With a diesel, the fuel injection comes during the compression stroke.

**dmd** · 08-13-08, 04:30 PM

Thanks, Hib. I see now that the primary advantage of DFI is a higher compression ratio on regular fuel, which would be negated in a boosted engine. But it would still be a hell of a coup if a DFI ZR1 ran on 87.

**Hib Halverson** · 08-13-08, 05:11 PM

Don't assume that DI allows both high CR and running on 87-octane. It's more like one or the other.

Even if the LS9 is fitted with DI, I doubt a DI LS9 will also run on 87 octane gas.

**motorman** · 08-13-08, 06:43 PM

DI will come later so the 2009 buyers will have a reason to move up. you can't give all the goodies at one time or you will have no repeat buyers. i know as i have owned 11 new corvettes and if there had been no improvements i would still be driving my first one.