So, I go yesterday to buy my walbro 255 pump from my buddy that owns Lightning Motorsports in Baton Rouge. He asks me what vehilce im putting it in and I say 09 GMC CC. He calls his friend who is one of the engineers at Walbro, and this guy says we have a variable voltage pump system on our trucks and their pump wont work unless its hard wired in. Is this true? Im trying to get my fuel system done before my turbo kit comes in and Im trying to see if I will need to do a return style system with this pump and hard wire it in or not. I would rather not for the time being. Anyone got any info on this or if this is true??

 

Yes, he is correct, you will not be able to use that pump on the stock fuel system. I've tried it lol... What are the specs on your setup? The stock pump is pretty strong. I'm still running the stock pump and fuel lines, and I see a bit of a pressure drop at WOT but haven't gone lean yet. The new operating systems on the GMT900s its very versatile is far as fueling is concerned.

 

Im going to be running a Trick front mount Non-Intercooled kit, and a LS2 cam with 60lb injectors. Will the stocker be enough to keep up for a while with the 60s?

 

He only recommends running his intercooled kits up to about 7psi because of the high IAT issue, so at that boost level you'll be fine with the stock pump.

 

well thats good news then. that just cut out alot of extra work i was thinking would need to be done before i put the kit on. upgrading the fuel pump and system can wait until i get the front mount for the kit later on. Thanks for the info man!!

 

Its a bit late and im still working but having a beer or three so if im worng dont shoot me.

That said it has something to do with the flexfuel ethanol capacity. Ethanol requires a LOT more fuel volume than gasoline so the fuel pumps are variable for this reason. The good news is they do flow a boat load of fuel so yeah sounds like your okay with the stocker. At least i think thats how it is

Dunno for sure... getting old...er sucks