Tune/Injector Question

[corsair231]

Have the intake off my Sy at the moment and considering an injector upgrade while it's apart. I've got a set of MSD 50#'s that were used for a little while in a GN originally. Way back in the day the 50's were pretty popular in the Buick world but now everybody seems to have forgotten them. I know that Turbotweak does make chips for them but he doesn't sell a 50# injector set. (He skips from 42's to 60's.) I was wondering what kind of reputation the MSD's had in these trucks. Drivability, idle, hard to tune, etc.? Still a good combo or do modern injectors just out shine them? Or do I really even need upgraded injectors?

At what level does the stock injectors start to max out,especially if I add alky injection? Not intending on a drag star but just a good running street truck. I'm just thinking about some future work savings by upgrading the things I really need to while it's apart.

[Aeroking]

The chip/tune needs to be calibrated to your particular injectors. There were several manufacturers of the 42s, 50s, and 60# injectors, and they all have slightly different characteristics. That is why you will find the chip suppliers like TurboTweak will sell a matched set of injectors with their chip. You may still be able to find an older style chip that is set up for 50# injectors. If you use an older chip, you would need to make fuel corrections with the fuel pressure regulator.

The reason for the switch over to 60s is because injector technology is always improving. 50# injectors were only a slight upgrade from the 42s, but there wasnt anything else available at that time, without making a large jump to 75#, using a modified driver. Where the modern 60/65# injectors offer a better spray and a lot more headroom for future engine upgrades. As the technology continues to improve, you will see larger sized fuel injectors available in high-impedance (which is compatible with the stock ECU).

Adding alky injection will aid with undersized fuel injectors, since you are injecting the additional fuel that you need, through the alky nozzles. Many people use the alky injection as a band-aid for an undersized fuel system, although it is very risky for your engine's health. If you ever have a problem with the alky system, your engine will run lean and be damage.

[corsair231]

Eric (Turbotweak) burns modern chips for 50's but apparently his injector supplier doesn't make a 50# injector and you are right, when they were popular, 50's were about the biggest High Z injectors you could get but when the 60's came out it seems the 50's sort of fell out of favor.

I know that 60's will flow more than I will ever need and the chips are adjustable so over fueling will not be a problem but it's sort of like having a size ten foot but buying a size 15 shoe. Hate to buy all that extra that I will never use especially when I've already got a pair that fits . Either way I'm still going to have to buy a chip with a secondary alky tune and a 3 bar map so if I could use the 50's it would save me some dough. The stockers may even work for my goals but I'm thinking of the age and wear on them plus if I ever upgrade the turbo I would like a little more of a safety margin but even then with alky I probably will not need the fuel that 60's can flow. (I can see my tuning files now. Injector duty cycle at wot - 63% ) Saving dough is nice but running right is a must so if there are drivability/tuning issues with the 50's then I will bite the bullet and get a new set but then the question becomes 42's or 60's?