[LesBaer]

Originally Posted by jessrayo

Thanks for the back-up. I'm really neglecting that Camaro5 board since I got this 2016. I'm planning on running the ZL1 at the Texas mile next month if I can get it to come together.



I'm definitely with you on being one of the first into the game with forced induction on a LT1 Camaro. I'm quite sure I'm the first non-shop owner to have turbos on a 2016. Mine is back in the shop getting a broken weld fixed right now. The first run at a new system always has some issues. I'm fine with that. Now AGP is machining bolt together parts rather than welding for any future kits....

I guess my whole point on this discussion of the LT4 kit is that the LT1 motor is much different than anything in the old Gen5 Camaro LS series. All of the LS motors could make a boatload of power on the dyno if you could get more air into the motor. Air was always what limited your power on a Gen5 LS motor. Yeah you had to change injectors to keep up but buying a bigger injector was pretty easy. Since this LT1 (and to a certain degree the LT4) came out very few builders are running out of air. And fuel upgrades on these direct injection motors are more complex and expensive than simply adding injectors. On the really crazy builds the fuel is not atomizing well due to the volume sprayed over such a short duration and the injectors are struggling to get the amount of fuel into the cylinder over a fraction of the time the old port injectors had to administer a pulse.

The second issue with the LT1 motor is it comes from the factory with 11.5 to 1 compression ratio. The closest thing GM has produced before this to a high compression V8 was the LS7 at 11 to 1. Generally more compression means more power and this new LT1 is extremely efficient with no boost. It is pretty close to being maximized on pump gas. And what that means to the aftermarket is as you put more air into the cylinder with forced induction you have to roll the timing back out of optimal efficiency range to prevent detonation. Yes you can get more air in the engine but because of the timing adjustment you have less efficiency. The more you boost it... the farther it falls out of the optimal range. You really are getting diminishing returns with more boost on a stock LT1. Conversely the LT4 has 10 to 1 compression ratio stock and can go up to about 15 pounds of boost before it even hits peak efficiency. If I change the bottom on my car I would not run the same compression pistons, I would reduce to at least 10.5.

That is my point on this LT4 supercharger kit thread. The LT4 supercharger is probably the most efficient blower you are going to be able to put on the stock LT1 motor. It can even handle fuel updates to over 700 whp. With the previous generation GM motors more air capacity was always useful and it was easy to build into it. This LT1 engine is not really that way. It has to be completely reworked to the tune of probably $20K at least to be able to use any more air capacity available from the larger FI systems.

I got some pretty expensive turbos on my 2016 thinking I was going to start out with 750+ whp but as we started working through the issues I describe above here I realized I was going to need a completely new bottom end to hit that kind of power numbers. I kind of think I'm with the majority of people that want to mod the car without completely rebuilding a perfectly good engine.

Sorry I'm still not seeing what makes it a better SC if the E-force and Hearbeat can create more power, run cooler and don't take the same hits at the top end as the LT4 SC. Callway, Jannetty, Redline, Lingefelter, etc., the list goes on - they all focus their SC builds off of similar, larger TVS2300 superchargers. I haven't come across anything, anywhere that puts the LT4 SC at the head of the class for any car, whether it's running the LT1 or LT4 engine. I appreciate your input and experience, but you're literally the only person that I've ever heard say that the LT4 is the most efficient SC for our cars.

I agree that the majority of people won't go beyond adding the blower and other bolt-ons, but if we're going to rationalize this by what most people do, how many people do you see picking the LT4 SC over the offerings available? Maybe I missed it, but I haven't seen a single person here add the LT4 to their Camaro. I even see more people with Pro Chargers than I do with LT4's and we both know the LT4 is probably more reliable even if it does come from a GM parts bin.

I'm not sure where you're getting $20k in re-work being needed to the motor either, that's insane.