LT4 mods without a tune
 

What mods can be done in the LT4 without requiring a tune? CAI, headers? Small od% Pulley? Etc

Same size CAI and that’s about it.

Maybe some go fast stickers.

yea I agree with the above. Too many computer systems on new cars to not get a tune with even headers. You could get away with it on the LS1s but now, its just a requirement when doing anything that deals with the combustion process.

CAI and thats about it.

I ran regular Rotofab CAI, Soler ported TB and AWE catback with PLPs and secondary cat delete. Didn’t tune until I added flex fuel and headers.

What the others said. Since you are in California, you should probably leave it stock. Aren't aftermarket exhausts illegal there now?

If you are looking for real performance improvement, there's not really anything that is guaranteed. It seems to me that there's little room in the OEM to grow much, if any, consistent power above stock. Unless you upgrade to a CARB-legal mod', which would modify and adjust some torque modeling, you could potentially the stock torque management system by driving in cool-dry weather at sea level with a completely stock car.

It seems, to guarantee any improvement, you have to crack the ECM open. And at this time, in CA, when it comes time to smog, they, apparently, can see a non-OEM tune file and fail you. If you're not concerned about that, get a tune and enjoy all the available power all the time, and optimize your set-up.

JMO...

Not many mods you can do without a tune except for a CAI and a few other things as others have replied.

IF it matters in this discussion - no CARB-legal CAIs I've noticed yet... Again - if it matters in this context :happy0180:

It doesn’t stop people from putting them on out in California but what do I know? Doesn’t matter to me anyway as I don’t live there.��

From what I read, in CA, you can tune the but before you smog, you need to put the stock tune back on and drive the car so all the monitors are ready.

It is easy to put a stock intake back on, but if you have a cam or something more difficult to put back to stock, with a stock tune, you will likely get codes and fail regardless of you failing visual.

Yeah its new, it popped up on one of my feeds.... What a joke...


Here's a good reminder to anyone running a tuned car out in California: As of today, July 19, the state's notoriously strict smog testing will automatically fail any car when it detects modified software onboard, aka, a tuned ECU.

Certain CAI’s and a ported TB. Made a noticeable difference on my ZL1 and the same when I did it to the C7Z. Both responded well. This is a state where 93octane is available. I wouldn’t do any mods in a 91 octane state unless it could be tuned. Too easy for these engines to detonate on lower grade fuels.

From whats I've seen and done, axle/cat back exhaust (as long as you keep both sets of cats), ported stock TB, and a CAI (as long as it not a big gulp or any other 5" CAI).