I was wondering about the ATI ProCharger for a 99 Sierra with the D-1SC upgrade & 3 core intercooler. Is this the best supercharger for my truck and what are the gains for it? thanks

 

Run a search on this subject, I beleive not to long ago this was discussed. Most guys go for the radix for the practicality of everyday driving, fun factor, completeness of the kit and all around great product. I know there are a couple guys running ati's around here

 

ATI makes a excellent product, most on here like the Radix cause they make a very complete excellent product. Now ATI I consider more for race applications, there was a Procharged 5.3 RCSB with locker and 3000 stall that ran a 7.8 in the 1/8th. As far as the D1 goes I have been told different things, I heard the D1 is too big, yet I heard upgrade now becasue the price of upgrading later is insane. With the P1 a 3.6 pulley will make around 11psi which is all I want to make in my truck. I am though getting the 3 core intercooler becasue the 2 core doesnt flow that well. What I like about the ATI is it comes with the FMU that utilizes the stock injectors and the pump they give you in the kit. With the FMU 5.3 make around 365rwhp theres a 99 4.8 with custom tune that makes 348 rwhp! So with the longtubes and a custom tune I think 400 rwhp is acceptable in a 5.3. But you will still have to buy a larger fuel pump and injectors in you want to run a smaller pulley and more timing.

 

Definately do a search. This one has been gone over in depth many times.

 

I have the ATI and like it, but I believe that the bigger injectors and a custom tune are a must. The FMU is just too inconsistent and very hard to tune with. The advantage of the Radix is that it is a very complete kit and is plug and play.

As far as P1 or D1, I went with P1 because it comes with a CARB #. I don't know how important that is to you though. Most people here will tell you to go with the D1 if you can. Also, get the 3 core. I wish I had it, but they didn't offer it when I bought my kit.

 

I ran my truck on a dyno with the FMU and Stock injectors, the A:F ratio was all over the place 11:1-15:1, I ran my truck for about 8 months on FMU and Stock injectors, but after seeing that dyno run I ordered 43# injectors, ditched the FMU, and got a better inline pump and tune. Night and day difference and piece of mind.