I have a 13 GT with a Roush supercharger with a 79mm pully. I'm playing on installing billet OPG and wanting to install smaller pully. If anyone has any info on this and will share, I will really appreciate it. Thanks
Not sure what boost your running but would not go above say 9 lbs with a stock motor, and that assumes a good tune. I know some will say higher, but for the street 9 is fine. And any pulley change will require a new tune. Sray safe my friend!
From what I've read the above info is correct. I'm still running the 82 pulley to be safe. 79 would be the smallest "safe" size as far as I know on stock motor. I'm sure a tune could be written to keep it safe but then your not getting the full benefit of the added boost so why bother?