I did a post a few days ago wanting to know if anyone might know a way to identify some grey injectors that I got given to me. It was thought that they might be 24lb injectors. They were suppose to have been in a 99 Cobra that had supercharger on it.
I had a flow test done at a local shop and found out that they flowed 93cc for 30 seconds. I was wondering if I did the right math for the conversion to lbs.
I did the following conversion to come up with them being 70lb injectors; 2x93=186(one minute) 186x4=744cc 744/10.5=70.86lb Did I do this conversion correctly?
The 99 Cobra's came through stock with 24lb. injectors. In order for those injectors to be 70lb., that 99 Cobra must have been putting out some serious horsepower. What did it have for a fuel system, and what supercharger was on the car. Usually by rule of thumb, there's a chart for injector size and when you need to go bigger. For example: 19lb. injectors are usually good to 245 HP., and 24lb., are good to 310 HP., 30lb., to 385 HP., 36lb., up to 460 HP, skip 42lb./hr, and go to 48lb./hr., are good to 615 HP. So if those were 70lb./hr they would be good to around 800 HP./hr. And for what you have, that would be a very large over kill. Depending on the Manufacturer of the injectors, would also differ in the color of the injector. Another thing in this Cobra's fuel system, what did it have for fuel pumps. It would take some serious pumps to handle 70lb./hr injectors. That much I can tell you, my 70 BOSS which now is fuel injected has 90lb./hr, fuel injectors with some serious fuel system to feed the 71 429 SCJ with an F2 Pro-Charger that puts down 1050RWHP and 980RWTQ. And you don't want to know how much money is invested, in this 9 year build that I've owned now for 38 years and is street legal. I would contact a reputable performance shop, and tell them the same thing. They might be able to tell you exactly what you have, Mike. SCT Tuner.
I do not know anything about the car these injectors came out of. I know it had a supercharger and it was a real nice looking 99 Cobra. I was about to leave the tune shop that I used to custom tune the 07 Stang and stopped and talked to the guy about his car. He was there to get new injectors installed and have a tune done. He just bought the car and the injectors that he gave me came loose in a box with the car.
I will try to find out more about the car next time I go to the shop.
That is part of the problem there is no part number on these injectors. I do know that the one injector that we flow tested flowed 93cc at 30 seconds. Fuel pressure was set at 40lbs.
Correct conversion for injectors? 
