[gilgamesh]

SO, I am reading about a cat on a FB group that, supposidly, did a tune on his '17 ZL1 WITH NO OTHER MODS and picked up around 35rwhp and 40rwtq. Basically reporting that from the factory the car is very rich and lacking on any timing.

Anyone else had an experience with doing JUST a tune and what were your results?

[ZL1 1LE]

Originally Posted by gilgamesh

SO, I am reading about a cat on a FB group that, supposidly, did a tune on his '17 ZL1 WITH NO OTHER MODS and picked up around 35rwhp and 40rwtq. Basically reporting that from the factory the car is very rich and lacking on any timing.

Anyone else had an experience with doing JUST a tune and what were your results?

I'm considering doing this after the warranty is up.

[Quicksilver64]

I agree that is probably the case but to echo the second post, when warranty is up I will try as well.

[IneedAZ]

Probably 40hp gain at the crank. Hope he runs at the track prior to any other mods. I am sure a lot of people want to know if the tune not only gave him the HP/TQ bump but were they successful in the posted TQ management hold back from the other thread.

[BoostedX2]

So dumb question--why so rich from the factory? I would think they would have optimized the tune....

[Evolvedx27]

Originally Posted by BoostedX2

So dumb question--why so rich from the factory? I would think they would have optimized the tune....

You will never get a car from the factory that doesn't run rich. Pretty sure it's a warranty issue. I could be wrong.

[travislambert]

35 rwhp and 40 rwtq sounds right for a very conservative tune and a little low from what's achievable by leaning out the engine.

In my '16 SS I made 605 rwhp and 633 rwtq (SAE) with a 100% stock LT4 crate motor (stock exhaust, airbox, etc..). That was simply from a K&N stock replacement air filter and dialing in the MAF. (The tune was a mostly stock values from a '17 ZL1, but used the '16 SS Operating System (of course) and variable camshaft settings from a '16 CTS-V.)

I had a couple pulls with rwhp above 610 and rwtq above 650 while the car was running a touch lean.

[travislambert]

Originally Posted by BoostedX2

So dumb question--why so rich from the factory? I would think they would have optimized the tune....

Lean fuel conditions can cause detonation and potentially destroy an engine. By running the engine a little rich it helps guard against poor quality/low-octane gasoline and aftermarket mods such as cold-air-intakes. If GM knew nobody would ever mod their car and nobody would ever use poor quality gas, there wouldn't be a need for them to tune them to run rich.

(Many cold air intakes simply increase the diameter of the air tube going to the engine which throws off MAF reading. In other words, more air enters then engine than what is measured. This causes the engine to run leaner and therefore produce more power (at the increased risk of detonation)... This is where almost all of the power increase comes from... not the increase in airflow. There are a couple exceptions. Manufacturers of quality aftermarket intakes, such as Rotofab, will provide a dyno graph which includes air to fuel ratio readings. If the A to F ratios are close to stock and horsepower is improved, this proves their intake actually works and isn't just a MAF hack.)

[NicD]

GM runs the car a bit rich for safety but then you also have cat overtemp that kicks in and drops the a/f ratio down into the 10s to protect the cats for long pulls. This doesn't mean that the tune has not been optimized, just that there is more to it than just raw horsepower.

Outside of fueling the only thing left that can make more power is timing and I can guarantee that you will not be adding timing in a tune on a stock LT4 seeing as how they generally knock a bit with the factory tables on 93 octane let alone 91 octane.

Getting rid of the cat overtemp and rich condition at WOT is NOT worth 35 rwhp no matter what somebody is trying to sell you. I've done that test MANY times and at best it's worth 15-20 rwhp at the expense of POSSIBLY hurting your cats.

[travislambert]

Originally Posted by NicD

GM runs the car a bit rich for safety but then you also have cat overtemp that kicks in and drops the a/f ratio down into the 10s to protect the cats for long pulls. This doesn't mean that the tune has not been optimized, just that there is more to it than just raw horsepower.

Outside of fueling the only thing left that can make more power is timing and I can guarantee that you will not be adding timing in a tune on a stock LT4 seeing as how they generally knock a bit with the factory tables on 93 octane let alone 91 octane.

Getting rid of the cat overtemp and rich condition at WOT is NOT worth 35 rwhp no matter what somebody is trying to sell you. I've done that test MANY times and at best it's worth 15-20 rwhp at the expense of POSSIBLY hurting your cats.

You're absolutely right about adding timing. There's not much room to add on the LT4 tune. On my tune I actually pulled the timing back from stock a little and the difference was negligible.

Also, the stock air filter on the ZL1 is very restrictive. So much so that there have been cases of the filters collapsing under vacuum. I'm sure the K&N stock replacement filter helped the airflow (and horsepower) quite a bit, but I didn't get a chance to test with the stock filter to see how much of the horsepower gain was attributed directly to the air filter swap.

I can tell you with certainty though, by just dialing in the MAF and a stock replacement K&N filter 35+ rwhp is easy to achieve. There's no need to disable COT protection or run the car leaner than it's designed to run to get it.

[gilgamesh]

Great info, all. Thank you.

I am looking forward to seeing what a simple CAI and Tune can open up on this car. It seems like it came pretty nerfed from the factory.

[NicD]

Originally Posted by travislambert

Also, the stock air filter on the ZL1 is very restrictive. So much so that there have been cases of the filters collapsing under vacuum. I'm sure the K&N stock replacement filter helped the airflow (and horsepower) quite a bit, but I didn't get a chance to test with the stock filter to see how much of the horsepower gain was attributed directly to the air filter swap.

I can tell you with certainty though, by just dialing in the MAF and a stock replacement K&N filter 35+ rwhp is easy to achieve. There's no need to disable COT protection or run the car leaner than it's designed to run to get it.

The title of the thread and the OPs post specifically said tune with no other changes. We have tested this ad finem on the Z06s over the years and found a tune only to be worth around 15-20 rwhp on average and that's really just from leaning it out from the pretty rich 10 AFRs since you can't really add timing on pump gas with these motors. Since the motor is the same and the timing tables in the WOT regions are pretty much the same...

[travislambert]

Originally Posted by NicD

The title of the thread and the OPs post specifically said tune with no other changes. We have tested this ad finem on the Z06s over the years and found a tune only to be worth around 15-20 rwhp on average and that's really just from leaning it out from the pretty rich 10 AFRs since you can't really add timing on pump gas with these motors. Since the motor is the same and the timing tables in the WOT regions are pretty much the same...

I can read. It also says ZL1 in the post.

On the Z06...the tune is quite a bit different, the air box is not the same, etc.

Given that the air box is completely different on the Z06 I don't see how you can give me shit about providing feedback on a camaro with a stock replacement air filter.

...Just trying to help the same as you.

[NicD]

Originally Posted by travislambert

I can read. It also says ZL1 in the post.

A stock ZL1 with a TUNE ONLY, not an air filter, not a single other mod besides a tune.

Originally Posted by travislambert

On the Z06...the tune is quite a bit different

No it's not, it has minor differences and the timing tables are nearly the same which tells me you don't know what you are talking about.

Originally Posted by travislambert

the air box is not the same, etc.

Of course it's different, but since we aren't talking about changing anything mechanically and only doing a tune it is irrelevant.

Originally Posted by travislambert

Given that the air box is completely different on the Z06 I don't see how you can give me shit about providing feedback on a camaro with a stock replacement air filter.

Because the air box or air filter doesn't matter when you don't change it. This is TUNE ONLY, not tune with a different air box or air filter which will add power and then it is no longer TUNE ONLY.