[19Nasty1le]

Has anyone ran a ported LT4 (non blackwing different ECM i guess) on stock tune? Curious if i can port my blower now and keep a 2.5" pulley (OEM size) and drive it without issues until i do the rest of my mods and tune it. Been getting Yes and No answers from different sources. CSP might actually do a video on this after talking to Andrew. Currently only have a RotoFab Dry and Corsa Extreme+ catback

[Rapid_blue_zl1_22]

Yes, you can. These cars run a little on the rich side stock, so they can handle a little extra air. I ran my Kong X-port for almost a year with no tune (Stock pulley size). Not only is it doable, but the car ran phenomenal.

I didn't dyno it, but it felt stronger, and the whine was amazing. I track my car on road course, so it wasn't driven softly for that year. I installed a wideband gauge whenever I did it because I had my concerns as well, but Lambda was perfect. My car is tuned now, but at the time it was 100% stock besides the X-Port and Corsa intake/axleback exhaust.

[19Nasty1le]

Awesome info thank you! I don’t have a wideband and was worried about this as I was told the DI engines are ok lean but rich can damage apparently? I’ve been told yes by the manufacture companies and no by tuners lol. Jokerz has the porting on sale plus a discount for July 4 so wanted to grab it while I could!

[Z OH 6]

Originally Posted by 19Nasty1le

Awesome info thank you! I don’t have a wideband and was worried about this as I was told the DI engines are ok lean but rich can damage apparently? I’ve been told yes by the manufacture companies and no by tuners lol. Jokerz has the porting on sale plus a discount for July 4 so wanted to grab it while I could!

Somewhat rich isn't likely to damage anything. That being said, forced inductions engines need to be richer than NA engines.

[Rapid_blue_zl1_22]

Originally Posted by 19Nasty1le

Awesome info thank you! I don’t have a wideband and was worried about this as I was told the DI engines are ok lean but rich can damage apparently? I’ve been told yes by the manufacture companies and no by tuners lol. Jokerz has the porting on sale plus a discount for July 4 so wanted to grab it while I could!

There is a big difference between optimized and safe. Tuners say no because it is not optimized to make max power possible, but that doesn't mean it isn't safe. They just want you to spend $1k on their tune.

Lean is bad, a little rich is ok. These cars run pretty rich from the factory, so leaning them out a bit is still fine.

[KingLT1]

Imo ZL1's don't run rich. They target 12.4 afr on a gas scale.

The only vehicles that I would run the stock tune on with modifications are cars with factory widebands that can self-correct.

Another friendly reminder since this hasn't been mentioned for a while is that these ECU's are torque based with preset torque limits in place. You start trying to add power and the ECU will close throttle in attempt to keep torque under its programmed limit unless you adjust this in the tune.

[19Nasty1le]

I’ll be keeping OEM size pulley on it, and won’t be driving it much / beating on it until I get to my tuner to get Cam Headers etc installed just getting the lead time on the porting out of the way. Gonna grab up a DSX lid too I think

[SJFGTO]

If you are minimizing driving and keeping your toe out of the throttle I doubt you will have a problem. But absent a tune, your car wont be able to efficiently use the increased air flow from the porting. Since this is a temporary measure, that is not a concern I’d guess.

[radz28]

Originally Posted by KingLT1

Imo ZL1's don't run rich. They target 12.4 afr on a gas scale.

The only vehicles that I would run the stock tune on with modifications are cars with factory widebands that can self-correct.

Another friendly reminder since this hasn't been mentioned for a while is that these ECU's are torque based with preset torque limits in place. You start trying to add power and the ECU will close throttle in attempt to keep torque under its programmed limit unless you adjust this in the tune.

Aren't they known to do this, even with a standard RF, for example?

[Megahurtz]

The car won't blow up without a tune. But you won't be making the best use of the extra air without a tune. The car will feel sluggish in the lower RPM range.