Hello, I'm wondering if anyone can provide a recommendation for a shop that can machine my SP3 for fuel injectors. I'm not sure on which injectors I want to use yet, mostly looking for pricing. The one place I found online, Wilson Manifolds, charges $950 which seems a bit high to me considering the SP3 already has injector pads cast in. They provide the machining, rails, and rail mounting. Anyone here had this done? I'm trying to figure out the total cost of MPFI vs TBFI! I don't have access to a mill or I'd consider doing it myself, but it's probably better to have a pro it to avoid any possible alignment or depth issues.
you can buy the bungs and Rails and bring it to a Alu welder they can drill and weld the bungs in make sure they are vertical mounted Do you know waht inj. you use? i recommend the typical LS styles https://www.amazon.com/JEGS-Performance-Products-14710-Injector/dp/B078WK6N63
Thanks for the tip! I was looking at the materials, one thing that confuses me is: Do you need bungs if you already have pads on your intake? I thought the pads would just get drilled out to the proper size(s) for the injectors?
Kevin Thompson of Hot Rod Solutions did my SP3 intake in 2016. Not sure if they are still around or not though https://v8buick.com/index.php?threads/ta-performance-sp3-injector-install.305405/
I applaud both of you for using and considering “TRUE” fuel injection, not the barbaric TBI that all the carb. companies push as being fuel injection…… TBI, worse than a carburetor
TA used to offer the service on their new manifolds but I don't see it on their website any more. I had my SP1 done by a place out of Miami but they seem to be out of business now. There's a lot to the placement of the injectors (depth, position, etc.) so I'd make sure that a knowledgeable shop does the work. But also $950 seems excessive (unless that includes the price of the injectors too or something like that). -Bob C.
It just seems like there's a huge jump in cost and difficulty from the TBI to MPFI. For me the draw of MPFI is also running each cylinder closed loop, with its own AFR/injector and tune to account for variances. Here's my rough breakdown, assuming one already has the upgraded fuel supply sorted: -Machine Intake/Fuel Rails -$500-1000 -Holley Throttle body: $500 -Holley Terminator ECU - $1300 -Holley Fuel Injectors -$500 For Individual Cylinder AFR: -Holley 8 Input Add On Module - $500 -Cam Sensor - ??? (GN unit is ~$300, or could try sensor on fuel pump eccentric) -Crank Sensor - ??? (Could maybe use $800 Holley Hyperspark Ignition for crank signal) -8x AFR controllers/sensors or EGT setup - $1000 I still think TBI probably makes the most sense for me right now as an easy way to boost the motor without a special carb or tuning knowledge? I still want to have the thing dyno tuned but don't want to have to mess with a carb endlessly. I still can't figure out if the Terminator ECU can even handle the 8 AFR sensors, it might have to be something like a BigStuff ECU ($$$).
You might end up messing with the TBI also. There’s just some thing Wal Marty about aftermarket fuel injection ESPECIALLY the TBI, it seems they throw parts together just for the sake of fuel injection and then sell it.
I used a company called imagine injection,inc in California. Top notch I would highly recommend them. They did my SPX manifold. I believe the man’s name was Bob. They supplied the plate that is sandwiched between the throttlebody and the intake flange there by eliminating the need to weld brackets to hold the fuel rails in place. He also supplied the fuel rails see pictures attached.
I remember correctly it was not that bad. It sure beats having somebody weld brackets on your intake.
That plate between the TB and intake is one of those "why didn't I think of that?" moments. That's pretty slick.
