5.3 flex fuel mods

**jimmyz454** · 05-23-2014, 01:40 PM

Im new here so be gentle! Got a 2008 Tahoe and I want to be different but need advise. I want to cam the motor with stock heads with an intake exhaust and a tune for starters. Can anybody suggest a cam/springs that works well. Has anybody done this or knows of someone who has modded this generation engine. Thanks any help would be appreciated.

**pajeff02** · 05-23-2014, 02:34 PM

Welcome to the site!

We're a friendly bunch here -- go ahead and ask anything and ask often.

Do you have a DOD engine? The 5.3 is a strong runner - we have an '07 Suburban with a Flex Fuel 5.3 and I use it to haul our enclosed race trailer up and down the hills of Pennsylvania.

**jimmyz454** · 05-23-2014, 04:11 PM

Originally Posted by pajeff02

Welcome to the site!

We're a friendly bunch here -- go ahead and ask anything and ask often.

Do you have a DOD engine? The 5.3 is a strong runner - we have an '07 Suburban with a Flex Fuel 5.3 and I use it to haul our enclosed race trailer up and down the hills of Pennsylvania.

- - - Updated - - -

Sorry whats DOD?

**pajeff02** · 05-23-2014, 04:46 PM

Displacement on Demand -- switches between 8 and 4 cylinders depending upon engine load. The system works by controlling oil to the lifters, effectively shutting down half the engine. Our Suburban has the DOD setup -- my understanding is that to mod the engine this has to be removed and replaced with conventional parts.

**jimmyz454** · 05-24-2014, 12:33 AM

Originally Posted by pajeff02

Displacement on Demand -- switches between 8 and 4 cylinders depending upon engine load. The system works by controlling oil to the lifters, effectively shutting down half the engine. Our Suburban has the DOD setup -- my understanding is that to mod the engine this has to be removed and replaced with conventional parts.

**jimmyz454** · 05-24-2014, 12:39 AM

Ok understood yes I do have dod. I will look up that procedure. Will I have to also delete the VVT to upgrade cam. After doing these adjustments I assume a change is needed in the cpu to compensate for the changes, correct?

**pajeff02** · 05-24-2014, 03:58 AM

Best bet would be to check with an engine builder who is familiar with the necessary upgrades. I know GMHTP has discussed this in more than one article -- here is one that I found with a quick search on their site (for an L99 engine, but the principles are the same): Camshaft Upgrade - Too Fine L99 - GM High-Tech Performance Magazine

**bigrondownhiller** · 05-27-2014, 02:20 PM

I have seen articles in Super Chevy also on a 5th gen Camaro. Mast motorsports is a company I see in the magazines. I think you only have to disable the DOD. Remember you are doing a heavy truck. Torque is your friend.