L99 ~ LSA conversion, lower pulley swap safe ? - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

Sweet15 · 07-15-2015, 11:55 AM

Need some advice from all you brothers that did the LSA conversion. I've been considering changing either the upper to 2.5 and/or the crank pulley (9.5 / 10), but concerned about the risk on the engine by raising the boost level. There are a lot of post doing this on ZL1s but can't find any on the SS L99s. Currently have the LSA with ported snout and 2.85 upper (switched to metco during install so it would be easy to swap without removing snout later), BTR stage 2, Kooks LT, SW retro exhaust, DW 90lb and BMR suspension upgrades. Boost is at 8.5 and making 580/516 with just the ZL1 fuel bump. I know I would have to add a BAP and was looking at the Kenne Bell. I was considering ported heads, but the pulley change would get more RWHP for about half the cost. I DD her and she runs great, but just looking for a little more. So safe/reliable to go to about 11-12 boost ?

Juice2SS · 07-15-2015, 12:18 PM

I stayed with the stock crank pulley. Are you switching all the accessories also for the larger belt? I ran the stock pulley and adjusted the blower pulley. Depending on what you do with the heads, you can get up a little more on the boost. There are a few running 11-12 pounds with the LSA.

Sweet15 · 07-16-2015, 10:49 AM

I am really just thinking about changing the blower pulley down to a 2.50, which I believe will only need a belt change and in my set up a BAP. Not sure what other accessories need to be changed ? Going to keep my heads stock for now until I reach about 20K miles, that way I'll upgrade the springs etc all at once.

07-15-2015, 11:55 AM	#1
Sweet15 Drives: 2018 2SS HBM Vert Join Date: Dec 2014 Location: WPB, FL Posts: 91	L99 ~ LSA conversion, lower pulley swap safe ? Need some advice from all you brothers that did the LSA conversion. I've been considering changing either the upper to 2.5 and/or the crank pulley (9.5 / 10), but concerned about the risk on the engine by raising the boost level. There are a lot of post doing this on ZL1s but can't find any on the SS L99s. Currently have the LSA with ported snout and 2.85 upper (switched to metco during install so it would be easy to swap without removing snout later), BTR stage 2, Kooks LT, SW retro exhaust, DW 90lb and BMR suspension upgrades. Boost is at 8.5 and making 580/516 with just the ZL1 fuel bump. I know I would have to add a BAP and was looking at the Kenne Bell. I was considering ported heads, but the pulley change would get more RWHP for about half the cost. I DD her and she runs great, but just looking for a little more. So safe/reliable to go to about 11-12 boost ?

07-15-2015, 12:18 PM	#2
Juice2SS Drives: 2011 2SS Join Date: Jan 2013 Location: DFW, TX Posts: 931	I stayed with the stock crank pulley. Are you switching all the accessories also for the larger belt? I ran the stock pulley and adjusted the blower pulley. Depending on what you do with the heads, you can get up a little more on the boost. There are a few running 11-12 pounds with the LSA.

07-16-2015, 10:49 AM	#3
Sweet15 Drives: 2018 2SS HBM Vert Join Date: Dec 2014 Location: WPB, FL Posts: 91	I am really just thinking about changing the blower pulley down to a 2.50, which I believe will only need a belt change and in my set up a BAP. Not sure what other accessories need to be changed ? Going to keep my heads stock for now until I reach about 20K miles, that way I'll upgrade the springs etc all at once.