I already have s/c pulley kleeman headers, header flanges and straight pipe, and also cooling done now I'm hungry for more power my question is I'm planning on doing a bigger throttle body and maybe intake system do you think I should also upgrade my fuel system ? Should I also do a looped fuel rail and bigger injectors with the bigger throttle body ? Thanks in advance.

 

I'd did the 550s and looped rail at the same time I did 168 pulley and 82mm tb. I got a 172 pulley shortly after for a good deal but decided it wasnt a big enough improvement over the 168 to justify the work. So I still have if interested.

I would definitely do the tb and injectors at the same time.

 

I'm running stock injectors with all those mods you mentioned..and my Eurocharged canned tune feels great and my wideband shows the A/F looks great. That being said, while I was installing the 82mm TB I put in NEW factory fuel pumps and filter, and had the stock injectors sent out to be cleaned and flow tested, replaced the fuel pump relay and fuse... That way I've got my stock fuel system at 100%. From what I understand bigger injectors aren't mandatory until you start running higher boost like a 180mm+ crank pulley. The smaller S/C pulley isn't enough to matter.

 

good info guys thanks a lot i appreciate it helped a lot.