I have a question about upgrading fuel system. I am building a FI project. The short block is built with forged pistons and rods. I want to get a high flow pump, return system kit and high flow injectors. My question is do I need to have it tuned with this upgrade, or can the stock ecu adjust for the difference? I will be adding high flow cats and a spacer soon and don’t want to run lean.

 

You will definitely need a tune unless by some miracle the flow rate of the injectors is perfectly matched to what the forced induction setup will consume, technically it's mathematically POSSIBLE but I've never seen it happen.

Most tuners can give you a baseline tune that will get the car to start so you can check for leaks and stuff, but you should throw the car on a flatbed and tow it to the tuner unless you can drive at low speed with low throttle down to the shop.

You can always watch A/F yourself via OBD2.

 

[QUOTE=cleric670@gmail;7167700]You will definitely need a tune unless by some miracle the flow rate of the injectors is perfectly matched to what the forced induction setup will consume, technically it's mathematically POSSIBLE but I've never seen it happen.

Most tuners can give you a baseline tune that will get the car to start so you can check for leaks and stuff, but you should throw the car on a flatbed and tow it to the tuner unless you can drive at low speed with low throttle down to the shop.

You can always watch A/F yourself via OBD2.
Ok just curious I do have a scanner and can watch short term and long term. I don’t want to have to pay for tuning until I have all my mods done. I plan on driving it daily while I am building it.

 

You're probably fine with the spacer and cats. When you start to mess with FI, injectors, pumps, etc then you'll definitely need a tune.

 

You will absolutely need a tune if you change injector size. The car is tuned for a specific flow rate, and opens the injectors a specific amount of time. Larger injectors will dump more fuel for the same amount of time open. The ecu can't compensate for such a change and will just throw codes while your car is running stupidly rich.

Change everything at once, then get it tuned. Or work with an e-tuner that will adjust the tune whenever you change parts.

 

So if for now I just want to upgrade the Fuel system and do a couple mods like a spacer and high flow cats/ exhaust how much would it cost to get it tuned and how much HP do you think I could get NA

 

Don't do the fuel system changes, save them until you're ready to install the FI. The rest of those mods (spacer, hfc, exhaust, tune) will net you about 40whp. Stock injectors and pump are more than capable of handling delivery of those mods.

 

^^^ what he said.

PM member seymore4 on here about a tune. Basic Uprev tune should run about $500. He'll give you specifics though, I'm just ball parking it.