I'm currently working on an lt1 swap for my 98 s10. I have a pull out engine from a 96 impala. For my build I have already purchased the 280xfi k-kit and ultra pro-magnum 1.6 rockers, meziere electric water pump and zex wet n2o kit which I eventually plan on jetting at 125hp (using a mallory 685 to retard timing). I plan on doing some cleanup work on the factory intake/heads as well as having installing 52mm t/b, I have 1 1/2 primary shorty headers as longtubes are a total pita to use with a 4l60e and an 8.5 wide front wheel. I am curious as to what size injectors I need to purchase, or if my stock injectors will suffice.

 

Take your extimated flywheel HP and multiply it times .07 to get a good estimate on what your N/A injector requirements will be.

 

What would you calculate for? Somewhere around 350-370hp?

 

Stock injectors will be good at 45psi for a hydrolic cam only lt1. When you start messing with heads youll be out of injector. If your doing a swap just turn the pressure up to 60psi and youll get some more power from them.

 

Seriously?

 

A good fuel calculator:

http://www.rceng.com/technical.aspx

(Bottom of the page)

 

I've also got a wideband so I can watch a/f, I just figured before I went ahead and swapped the motor, I would put the right injectors in it. I have an adjustable fuel pressure regulator as well. I'm just trying to get some help from people with similar setups and maybe learn from their successes/mistakes. I just want this thing to be right.

 

Your first mistake is using an adjustable fuel pressure regulator. They are overkill (and unnecessary) for 95% of builds, and can sometimes be a hazard (some have been known to leak). I have a stock FPR on my car and don't ever plan on changing to an AFPR. For your setup, 30#-36# injectors will suffice (approx. 400 crank HP).

 

^^ This. I removed my adj. FPR day before yesterday due to a massive leak. If you HAVE to have more than 43-45 psi to accomodate spray, get something other than an Aeromotive. I hate to call out a manufacturer, but their adjustment method is **** and prone to leak without constant attention. And the location does NOT lend itself to constant attention.

 

I purchased it because I got a great deal. My plan was to adjust it to factory pressures as I have read from many tuners not to deviate from factory pressures. I'm just working on putting together a good running motor so I can have some fun cruising it around. I've thoroughly enjoyed the lt1 in my 97 z28 so I figured putting one in my s10 would be twice as fun. Thanks everyone for the advice and I guess I'll look to score me some ~ 30lb injectors to slap in it so when I get the ecu flashed it'll be closer the first time.

 

Out of curiosity, what brand is the regulator?

 

There's no reason NOT to run an adjustable FPR. I like having full control over fuel pressure, especially given the fact that I'm going to be running 2 walbro pumps...

A lot of injectors are designed to run at 4 bar.... Its nice to be able to bump the fuel pressure and get more out of the injectors rather than having to upgrade.

 

Not everyone knows how to use them properly, which makes them one of the most misunderstood and improperly used mods for the LT1 motor. IMO, it's safer and more certain to use a properly sized injector and have the tuning done within the PCM. Persons like you are the remaining 5% that I spoke of earlier.

 

Some redtops should work just fine

 

The fuel pressure regulator is from FAST. It looks similar to the factory regulator except for the adjusting screw and lock nut. As far as who produces it for them, idk.