Anyone using one of the after market throttle body fuel injection systems? The prices have dropped a lot of the last couple of years to make it an option for me to consider when the time comes. There are kits available from Summit, Holly, and FiTech; all under $1000.

I’ve actually install a lot of them we use the fitech system they work really good the hand held programmer has options for stock to wild cams and multiple engine sizes
You can even set some things yourself
Comes as a kit with external or an in the tank fuel pump
Sensors everything you need to install
we’ve never had one fail yet

I have the Holley Sniper installed on my bird. I had some quality control issues with it to start off but since then everything seems to be working well now. I really like it. I think it has a few more features than the FITech and I think the price point might be a bit lower too.

Hey Bob, What's that brace you have going from fender to fender, is that a Firemustang?

Ha. Not funny.
It's Hotchkis( I think ) design. They call them handle bars. It's a bracing system for the front subframe. Connects from the upper control arm mounts to the firewall and that cross brace keeps them from flexing out or in when weight transfer changes on the front subframe. Believe it or not they make a big difference in how rigid that front end feels. You don't realize how much flex you get up there until it's gone. Everything just kinda floats normally but with the bracing it's stiff enough to knock you teeth loose every time you hit a bump. YAY!

I replaced my Holley 4150 with the Holley Terminator Stealth EFI.

Is that a bolt on item? Did you make it yourself or buy the Hotchkiss? I've seen the ones welded to the front subframe then up to the firewall with a cross bar and strut braces but not this.Ever think when you first got into racing you'd end up modifying your car that much?

I think I saw one of those steal EFIs for sale the other day. The "carb" part was pretty normal but OMG the wiring that went with it was insane!

Those are bolt-ons. And yes, home made. I can't afford Hotchkis prices.
Well yeah since these cars were made for the general public street use it kinda makes sense that if you are going to abuse it on the track that there will be a multitude of improvements that will have to be made. 40 years and counting,a little bit at a time, so far...

So to install one of these you have to have an electric fuel pump and a return line to your tank? Do you nee to change the size of your fuel line or is that determined by the ki you buy?

You can get the kits with a cheap external fuel pump that will include the filters and fuel lines. My 69 has a factory return I used. The size of the standard line they send you should be fine, or use 3/8 for higher HP applications.

Some of these units require a return and some don't. My car didn't come with a return so I installed one before i went FI. I used stock 5/16 steel line. If I had planned ahead I would've used 3/8 instead. Better if the return line at least matches the feed.

Great! I'll just run 2 3/8" lines to the tank when the time comes.

Should be fine up to about 600hp. Over that you might want to think bigger. Although the line coming out of the pickup might not be any bigger. I'm not completely sure how that comes into play. Kinda seems like filling a 55gal drum thru a straw to me but what do I know?

Apparently, you know quite a bit.

Not only the size of the pickup but the sock that goes over the end to keep lumps out of the fuel system can restrict flow. I was suffering from fuel starvation a couple years back. Very frustrating, and embarrassing, when doing a burnout leaving the ferry boat on the way down to a car show and having the car sputter to a stop. Not only was the sock on the pickup restricting flow but it was also disintegrating and the particles of mesh caught up in my fuel pump. Managed to get to the show and home but had to behave myself driving. I put an open 1/2" pickup in the tank and installed a large filter in the fuel line right where it comes out of the tank. I took the pump apart and cleaned the valves but it was never rights so I had to buy a new one.

Return line does not need to be the same as the feed line, and doing so provides no benefit.
Up to 600hp: 3/8" feed and 5/16" return
Above 600hp: 1/2" feed and 3/8" return

On general principle I would agree except for the fact that my pressure regulator is supposed to be factory set at 59.5psi and it idles at 72psi on the feed side. Could be its not because of the smaller return but it's been suggested that is the reason. IThe return only runs about 3-5psi back to the tank so I'm not sure why it might have that effect other than it leaves the throttle body through a 3/8" line and is necked down to 5/16" steel down at the frame. I'm no expert, I just listen to what they say.

With only 3-5psi on the return that's not the problem. Either your gage is not reading correctly, or the regulator was not set correctly, or it was damaged and there's too much pre-load on the regulator diaphragm spring.

For example, installation of the regulator by pressing on the top of it can deform the body enough to increase pressure. Although being almost a perfect 1bar (manufacturers use metric units), it's more likely it was set on the production line to the wrong specification.

Or, one more thing to check, is your tool measuring in “gauge” pressure or “absolute?” That would also account for a 1 bar delta.

I don't know which type of pressure my gauge is reading. I guess I didn't know there was more than one type of fuel pressure. It is totally possible that the function of the regulator is not running at the précise spec it's supposed to. I did source a replacement but Holley assured me that there shouldn't be an issue unless it reached 90 psi( again, not sure which type) so I never did swap out the regulator. It does seem fine so I'm not going to sweat it. Also I would agree that a 3/8 feed and 5/16 return should be fine ( it's what I have so I know it works) but if I were going to do it again I think I would do a 3/8 return instead.

Well you're right, there is only one pressure, but can be called different things. Yours will be gauge pressure. With the pump off and pressure bled off it will be zero, atmospheric pressure is read as zero on a gauge pressure, pressure gauge. A standard day atmospheric pressure is 14,7 psi. So if you were to measure your fuel pressure in absolute pressure it would be your 59.5 plus 14.7 for 74.2. But normally we measure the pressure of fuel, air in your tires, oxygen in your tank, MIG gas in your welding equipment, what you run your air tools at etc. at gauge pressure. When the power goes out and your impact wrench drains the compressor tank, or you run over a plow blade and your tractor tire loses air the pressure on your compressor gauge or your tire pressure gauge will be zero. Even though all around us the air pressure is 14.7psi. When someone tells you to fill your tires to 32 pis it's just automatically meant 32psi on your tire gauge, 32psi higher than atmospheric, not 32psi absolute. 32psi gauge is the same as 46.7 absolute, but called two different things.

Hey Bob, getting ready to install fuel lines on my GTO for EFI. It sounds like you reused your main line. If so, did you use the factory barb fitting or change it.

Yes I didn't do anything to the orig line. It's got the orig bubble flare on it. The only thing I did different is use the full band clamps designed for FI applications and used FI hose for the flex connections.

Thank you, that is exactly what I was planning to do. I did take your advice and ordered two 3/8 fuel lines, one for feed and one for return.

Where did you order the lines? I was looking for new pre-made lines when I was adding mine and the price of the line wasn’t bad but I remember the shipping was more than the part and drove the cost higher up than I was willing to pay. I ended up going to twilight zone and buying two straight pieces of steel line and bending my own. There is a junction where they meet that I was a little worried about but it’s never so much as had a drip. I would liked to have had some of that spring protector on it for the exposed areas but I think I used something else(can’t remember now). Came out perfect if I do say so and only cost me about $16 IIRC.

I have to install a return on the 67 because it was a 326 car and never had one but it’s got the 400 now and will need one now. I’ll probably do the same thing again unless I can find a screaming deal on pre-bent cheap enough.

I bought mine through Inline tube, but I had a big order ($1K) so the shipping was free. It included lines, disc brake conversion, emergency cables, etc. They are nice, so I may do the same on my Firebird. For the bird, I bought a roll of 3/8 and was going to attempt bending myself first.

I checked summit yesterday and they have right stuff 3/8" lines for $69(+an extra $10 for oversize). They don't offer a 3/8" return so I'd have to buy 2 feed lines but the return line is supposed to go over the crossover and travel along the front of the frame so I'd have to rework it anyway. Pretty sure I wouldn't be happy with it. All the while I'd be thinking I could make it for 1/10 of the money. I'm just hating on the aftermarket right now, don't mind me.

Interesting I just checked Summit, nothing listed. I did go to the Right Stuff website and they have 3/8" main lines for $64 and free shipping over $99. That's a bargain, I may buy 2 as well. Question for you, when they say 2 piece, are they basically saying the second piece is the crossmember piece. I am not that familiar with the V8 fuel lines. I was wondering if the main fuel line from the tank ends near the front right frame rail like it does on my car.

All I've seen end behind the crossmember then a rubber connector to the piece that runs under the motor to the driver's side. I imagine the second piece is the crossover piece but don't know for sure.