I’m hoping to get some input on installing an underdrive pulley on my alternator so that while The engine is high rpm, I maintain correct voltage. I’ve read, but found very little, that stock alt don’t perform well at high rpms for any extended period. What concerns me is that while I’m flogging the engine down the track, my fuel pumps will not be getting the correct amount of voltage, thus loosing fuel pressure and then running lean. My engine ended up with a toasted number 7 piston. Which 7 is the last cylinder to get fuel before the fpr.

 

The #7 piston thing is not a fuel issue, its a coolant issue. but most guys put the fattest injector there to help anyway. A simple fuel pressure gauge will tell you if you are loosing pressure. If you are, then you need to do something, but if you arent then the fuel system is fine.

 

This is something that I keep posting, my first 60 lb injector tune had incomplete data as far as the voltage vs offset (offset?). So with a higher hour alternator, it would go lean at like 5000 rpm. The brushes were bouncing, the voltage dropped to 12ish, and that was in the area of bad data. A new alternator fixed that, and I have since changed injectors with ones that have complete data.

So like in the previous post, check pressure, but also monitor voltage to see that if the pressure drops does it coincide with a voltage drop.

If so, see about getting better brushes before slowing the alternator.

 

I will also add to this that the "big 3" upgrade will help you get everything that alternator is putting out. I did the upgrade and from a performance/idle perspective it " feels" more stable.

 

I’m also currently looking for better injectors. Data is priority before any purchase. Anyone here have experience with Fic injectors? Also is the data complete, meaning is it something I can just transfer into hp tubers? I was running deka 80s. I’ve moved onto ethanol blends, so maxing them out is not far away.

understanding voltage and amps has never been my strong suite. I just want to make sure I’m setup correctly On the fuel system. Current setup is two walbro 450s merged to single -8 Feed. and -6 return. Stock 2002 Silverado alternator. Ive upgraded to bigger wiring as well.

 

The 450s can draw almost 30 amps each, you definitely need to upgrade to the 145a or larger alternator.