I tried doing a search and I wasn't able to find a clear answer. I am installing a remote turbo (a few topics down). I'm still not clear about the fueling. The conditions for now is getting my LB9 to run as good as possible. Its a stock LB9 with full boltons but do not plan on using the nitrous with the turbo on this engine... I also have an adjustable fuel pressure regulator. I need to know what are the components needed to make this car run right based on your experience. The engine is a 1987 305 Tuned Port. I don't plan on running anything over 7psi on this engine. I don't plan on leaving room to grow on this engine since once I get this running I plan building a fully forged 350 with a properly tuned computer (730) and wide ban afr and such. Should I go with 24lbs injectors and 10:1 FMU? or 24lbs with 8:1 FMU? or 30lbs injectors? I'm not sure. I plan on getting new stuff for the new build so these would be "1 time use" components. I'd like to keep my idle as steady as possible and this is also my DD so MPG would be considered. The turbo I'm using is .60cold, .63hot... thanks for the info guys!

 

Not really sure about the FMU, but I'm planning to install a PT51 or PT61 under the hood of my elcamino (5.7 TPI) and was also wondering which FMU to get. My friend has an almost new set of ford motorsport 24# injectors that I'm going to use. Not planning on using an intercooler, but will put on a Methanol kit and shoot for 12#. Thinking I'll end up having to use a MSD timing controller. I was actually thinking a 4:1 FMU would be about right (That with the added fueling of the methanol), but I can't find a straight answer.

 

same here, I'm not sure about the FMU, imo I think 10:1 and 8:1 sounds too high and I do not want to run rich, then again, I don't to run lean either... So I'm not sure what would be a good combo...

 

I had looked at the vortec supercharger kits, but they don't list what size the FMU is that comes with their 3rd gen kits. It almost looks like having to just buy one and then see if it's too rich/lean and go from there with their recalibration kits. Thing that really confuses me is, I have an '87 GN and from the factory it's FPR is a 1:1, I have 60# injectors in it and with methanol I'm pushing 28# of boost (makes the L98 in the elky seem slow, hence the need for a turbo!). IMO as you get larger injectors, the ratio of FMU should go down. After looking around some more, I'm leaning towards a 3:1 since I want 12#, the 4:1 would max out the injectors, and then if it's too lean I'll just add more meth. I've just started getting a list of necessary parts together, so maybe you'll get to the tuning part before I do

 

that does make sense, let me know what you find out... the reason I'm afraid of the 30lbs injectors is the possible idle issue...

 

Are you going to have your chip reburned for the new injectors? If so, it really shouldn't matter how big of injectors you get. It would be nice if there were as many choices of chips around for the 3rdgens as much as there is for the TurboBuicks (the 60# injectors in my GN idle better than factory, passes emissions, and will go deep into the 10's). I used to have a simple programmer for the GN and would burn my own chips. But, for the TPI I'd rather not even have to learn to burn my own and eventually go with DFI. I have sent my Hypertech to a guy at tpichips.com to have tweaked before, so that's where I'm going to send it back once I get a little closer on the turbo project, I just hope his fuel mapping is correct for whichever ones I chose (24# if I can get them from my friend cheap enough, lol)

 

no, I'm not planning to burn another chip, thats why I want to know if I can go with a smaller injector than 30 and be alright. I plan on building another engine that will be turbo specific so I can turn up the boost to about 12-13psi...

 

I don't know, it would seem like you'd have to really drop the idle fuel pressure down low to get a somewhat smooth idle with having larger injectors than the ecm "thinks" you have. My friend went from a 305 to a 350 and swapped injectors from 19 to 22 without reburning the chip, still seemed to idle a little funny, but he also had a large non-computer specfic cam. You'd probably get a away with 24 to 26 pounders, but much more than that, IMO the idle will suffer. It'll be a fine line of getting large enough injectors to cover your 7psi but still small enough to idle and still get around the 75psi (or whatever it is around there) where the injectors shut off using the FMU.

Originally I put the TPI in the elcamino for reliability and always knowing it would start. All of this turbo stuff would be sooooo much easier had I just put a carb on it

 

I'm gonna look for LT1 injectors at the junkyard but if for some reason I can't find 24lb injectors and have to purchase them online, then I'll just look for 30lbs and turn the fuel pressure low for the idle, the FMU would take care of the rest...