Old_Yeller

I have a 67 camaro RS with a 355 sbc, D1SC procharger, 4l80e. The setup runs great, but I have recently decided I would like to drive the car more. Problem with that is my fuel mileage is not so great, even with the 4L80E. And I know some of you are saying, why are you worried about mpg with a hot rod, but it is nice not to break the bank just to make a cruise.

So lately I have been trying to decide if I should keep the setup i have and invest in Holley's HP EFI to increase driveability.

My second option would be to do an LS swap. If I were to do this I am not really interested in using the procharger. Just a stout n/a LS motor. Looking at used engines and maybe swapping cam, intake, and maybe heads.

I am having a tough time deciding what to do. The procharger would be hard to give up, and if you've ever driven a supercharged car you know what I mean. But I also know the LS motors are potent.

If anyone has used the Holley HP EFI, please let me know the effects it made on your car.

I would like some opinions from you guys about this, just to be sure I have thought everything out before I make a decision.

Thanks

Oh I attached a picture of my ride. Maybe it worked.

futureuser

iTrader: (1)

The problem I see is if you do the ls swap you could loose power, since your current setup runs well. I think the LS swap is a good alternative to purchasing aftermaket efi. Why not procharge the ls instead of spending the money on heads, and have the best of both worlds?

Pop N Wood

iTrader: (1)

What rear gearing are you running?

LS motors with the right gears get good mileage. My carb'd LS2 Datsun gets the best mpg of my 3 vehicles, over 25 mpg if I drive it right. I'm running a TKO with a 0.64 fifth gear and 3.55 rear gears. I imagine the Camaro weights in about the same 2500#, so a stock cam 6.0L should do the same in yours.

I suppose nothing blown is going to turn out good mileage. Maybe consider selling the procharger and going NA?

BTW, from what I can tell EFI and a well set up carb get about the same mileage. People like to argue that point, but the facts remain. Most carb guys with wideband tunes are turning in similar numbers to EFI cars. Maybe the blower changes that equation, but I would imagine you won't see a huge increase in MPG by just going EFI.

Old_Yeller

I am running a 3:55 gear. I had thought about putting the procharger on an LS motor, but sometimes I think it would be nice not to have the complexity of a supercharger, worrying about proper afr , timing, etc.. I do think going to efi would make it easier to tune and more of a pleasure to drive.

speedtigger

iTrader: (16)

When I built my car I could have went any way I wanted. But, I chose a strong N/A motor with as much pump gas compression as possible. I did this for simplicity, cost, feel and efficiency. I just like the way a high compression v8 drives. High compression is also the most efficient of any of your choices, so it has far greater potential for fuel economy than any other set up. Now whether or not you will ever get your conversion money back in fuel consumption is another question altogether.