[kttxz06]

Originally Posted by Can'tHave2MuchHP

Why piece it together and have doubts...Just order a pair of Headers and connection pipes. Once you're past the Headers + Primary cats, the rest doesn't matter nearly as much, hence why running a stock cat-back is standard procedure on these cars even when highly modified. Cat-backs do essentially nothing for your engine's needs. A secondary cat delete or even a primary cat delete does not replace the job of Headers/Catless or GESI cats.

Thanks. After I spent $1200 on a Corsa exhaust. haha.

[Can'tHave2MuchHP]

Originally Posted by kttxz06

Thanks. After I spent $1200 on a Corsa exhaust. haha.

I mean sound wise, Corsa is an improvement, will probably be my first mod. I'd say your Corsa is worth MAYBE 5-10 HP, likely 5 or less though.

[Evolvedx27]

I wonder what the power difference is on these cars going from 200 cell hfc to catless... I wonder what sound level difference is too...

[Sharp Shifter]

Originally Posted by Can'tHave2MuchHP

Why piece it together and have doubts...Just order a pair of Headers and connection pipes. Once you're past the Headers + Primary cats, the rest doesn't matter nearly as much, hence why running a stock cat-back is standard procedure on these cars even when highly modified. Cat-backs do essentially nothing for your engine's needs. A secondary cat delete or even a primary cat delete does not replace the job of Headers/Catless or GESI cats.

Only reason I haven't done headers yet is because power gain to cost didn't seem worth it..... But if there will be to much heat I'll either not do a pulley or just order headers. I was waiting to do headers the same time as a cam swap later after saving up some cash.

Cat back I know does do anything, just like the sound of stainless works on these cars.... Open to suggestions guys

[Beto6.2]

Originally Posted by WEAPON-X

Here is an LT4 pulley combo chart for you guys to peruse for some general info. We've done an insane amount of these across all platforms and our LSA chart helped a lot of people over the years, so I put this together a couple of weeks ago too:

https://weaponxmotorsports.com/blogs...ng-mods-needed

There are a few factors that come into play. The lower pulley being replaced reduces the rotating mass on the front of the crankshaft; however, when going to a larger diameter of rotation, this affects the MOI (moment of inertia) as you're essentially moving some mass (albeit less) further out from the vertex of the crankshaft.

The upper pulley we can go all the way to a 15% increase aka 2.175", but the snout needs machined with anything less than a 9% aka 2.3" upper. We offer the snout machining, porting, and pressing a pulley on and can ship back. Our Griptec pulleys eliminate the static slip that occurs when the crank taxes the upper pulley, so "the lower is always better" thought process is gone.

https://weaponxmotorsports.com/produ...-zl1-gen-6-lt4



Doing the lower, you can actually go up much further with over-driving the supercharger, but anything over a 15% really needs headers anyway to get rid of the restrictive cats which hold in heat. You can run up to a 25% lower with heads/cam/headers etc for that high 700whp range though.

IW lower kit goes up to 31% lower:
https://weaponxmotorsports.com/produ...-zl1-gen-6-lt4


ATI lower kit goes up to a 25% lower:
https://weaponxmotorsports.com/produ...ts-v-gen-3-lt4


Belt choices for various combos:
https://weaponxmotorsports.com/produ...ts-v-gen-3-lt4

How come 9.17 isn't on the list??