[ChadSZL1]

Currently I have 2017 ZL1 with BTR stage 2 cam, 8.66 lower, stock upper, 2” long tubes, no cats, awe back, 95mm TB, standard rotor fab, JMS voltage booster, flex sensor and tuned on E60 with a trans tune also. I am adding jorkerzs full tilt port with a 2.45 upper, DSX aux pump, 103 TB, and big gulp. Car made 10.8 pounds of peek boost with the current setup. My question is should I leave the 8.66 lower with the new ported blower having a 2.45 upper, or change to the 9.17 lower/2.45 upper? It’s mainly a street car but does see the track a few times a year. This next spring I will install a trunk tank for cooling. Thoughts?

[ZLRob]

A ported blower will increase boost all else being left as is. There is no sense in raising boost further when what you're doing will additionally add naturally.

[ChadSZL1]

I just want to make sure I maximize all the mods with the best pulley combo for power and not produce a crap ton of heat soak.

[ZLRob]

Well you have some space left to go. You could probably bump up another 1.2- 1.5 lbs of boost before you are outside of the blowers efficiency range and coating the engine more power to drive the blower. You want to keep the blower ratio at or right under 2.0, but you don't want to go over that at all. If you have HPTuners you can add a PID on there which will show you the current pressure ratio as you are logging.

[SOCAL.M6.ZLE]

Originally Posted by ChadSZL1

Currently I have 2017 ZL1 with BTR stage 2 cam, 8.66 lower, stock upper, 2” long tubes, no cats, awe back, 95mm TB, standard rotor fab, JMS voltage booster, flex sensor and tuned on E60 with a trans tune also. I am adding jorkerzs full tilt port with a 2.45 upper, DSX aux pump, 103 TB, and big gulp. Car made 10.8 pounds of peek boost with the current setup. My question is should I leave the 8.66 lower with the new ported blower having a 2.45 upper, or change to the 9.17 lower/2.45 upper? It’s mainly a street car but does see the track a few times a year. This next spring I will install a trunk tank for cooling. Thoughts?

Great question, and I found myself in the same crossroad. I suggest leaving you pulleys as is, and trying to tune to maximum E content first. Once your tune and fueling is sorted, if you have room for more boost, and have some cooling mods lined up, then perhaps go to a 9.17" lower. If i was tracking the car, i'd prioritize E over boost.

[KingLT1]

You will more than likely hit the fuel system limits if you touch the pulleys.

[ZLRob]

Originally Posted by SOCAL.M6.ZLE

Great question, and I found myself in the same crossroad. I suggest leaving you pulleys as is, and trying to tune to maximum E content first. Once your tune and fueling is sorted, if you have room for more boost, and have some cooling mods lined up, then perhaps go to a 9.17" lower. If i was tracking the car, i'd prioritize E over boost.

Originally Posted by KingLT1

You will more than likely hit the fuel system limits if you touch the pulleys.

I agree with these guys my dude. Get the maximum amount of E content first. The primary goal is to be able to just fill up fully at the pump without having to mix. Once you have achieved that, if you have space left on the fueling THEN you can and should touch more boost.

Sometimes less on the mods is more.

[ChadSZL1]

So with my 8.66 lower (10)% and the 2.45 It will be like running a 9.17 lower and stock upper correct? So close to 15% overdrive with my 38% cam lobe, jms booster and the DSX aux kit. I am good with mixing E as my gauge show live E content.