Tuning a stock car, worth it?
 

08 manual trans, completely stock down to the paper air filter. Would It be worth it to get a custom tune? Did GM leave some power or responsiveness on the table?

yes, but supporting mods help, alot.

If you are satisfied with the car then there's no harm at all in leaving it alone. However, a tune can certainly add a lot to the day to day driving enjoyment even on an M6. Sure, some power was left on the table. What was really left on the table was throttle response, which I found really bland. A lot of people address this with a hardware throttle controller, but it can also be done via software. I was more comfortable with the software approach based on many years of positive experience with it on European cars. With an ECM software upgrade you can get some more power, better throttle response, get rid of skip shift, and more. Lots of potential benefits even on an otherwise stock car. Probably best to first think about what your goals are, because the modification game can have no end once you start and you might end up on a talk show ;-)

Thanks guys, I’ve always played with Mustangs and forced induction. I’ve always built them to the point of unreliability and don’t want to do this with my Corvette. I’m thinking at most a cold air kit and a tune but am seeing mixed responses on the cold air kits on the LS3. I do want better throttle response and it feels sluggish at low rpms but considering my last car was an ‘03 Cobra with a roots style blower maybe this is just normal. I want reliable power so I can drive it like I stole it and not break stuff.

oh, ok. So you already know the drill. I should have been tipped off by your screen name. You can do very well with an intake and a tune, which is what I did. It will be fun and reliable. There are some recent threads where I posted my experience. Your throttle is probably normal, but you don’t have to live with it.

Yes, if reasonable cost.
You'll be "dialing in your" air fuel ratios and throttle pedal to throttle body response.

Otherwise if you are currently happy the way it drives....your call.

HAHAHAHA reminds me of an alcoholic that just wants to take the "occasional sip"..... I feel you pain brotha but it's hard to step away from the mods!!!! Good luck to ya though I certainly support the effort!!

ON my 20018 base LS3 with less than 900 miles I went from 375 rwhp to 400 rwhp with a tune only. The tq went from 383 to 400.

I thought it was worth it but then I had some $$ burning a hole in my pocket.

Really depends on your driving skill level.

As noted, GM used TM to hold some instant power back to protect the drive line. Hell same goes for the clutch, and it meant slightly slip during high RPM shifts to save the drive line from shock as well.
Also, the throttle mapping curve response is really to soccer mom the car to keep you out of trouble to a degree as well.

So just these TM not hobbling the motor and sharper throttle mapping re-tuned will make a huge different in the seat of pants feeling of the car. Hence your only going to pick up around 15hp with the re-tune, but since the bigger one of TM not holding power back from reaching the tire, makes a world of difference.

As for throttle remapping, if you are treating the gas pedal like an on/off switch, instead of rolling and out of the throttle, the would not remap the throttle.
Truth is, with the throttle remapped to be linear between pedal position and TB vain opening rate like say a 70's carb car with the same amount OEM HP, the C6 would be dam near UN-drivable in most hands since every time you breathed heaver on the gas pedal, it would break the rear tires loose.

When my 08 was OEM I kicked the tune idea around. I took it for a dyno tune and was
really pleased with the outcome. That was 3 years ago and still pleased that I had it done

Absolutely go for it.....provided there is a reputable tuner in your area. The OEM tune is conservative by design & yes, a custom tune will yield some additional hp. While you're at it, consider adding headers & an aftermarket exhaust. Doing so will give you most advantage with a tune without spending crazy $$$.

Diablosport In tuner 3 is it a good alternative?
 

Would the Diablosport In tuner 3 works just as well?

I have a 2008 manual as well. Mine dyno'd 450 WHP @ 4540 RPM with just an air intake, headers, exhaust, and the tune of course. The correction factor was set to 1.18 so that number might add a few horsepower.
Hope this helps.

I am thinking about doing a stock tune as well. Seems like it would be worth it!

Any benefit to keeping CAGS even with a tune? I kind of like the system...

Is the power limited in first and second gear in manual cars, too?

if you like CAGS, a tune can be set up to keep it. However, you might be the only one to do that. Most people don’t like it. The only power limit in 1st and 2nd that I’m aware of is traction :)

Stock Engine/CAI tune benefits:

Cags can be eliminated.
A tune will remove most or all torque management which will unleash toque which is where you will feel most gains.
Most tuners will recommend a lower t-stat and adjust the fan program to lower engine coolant temps, then if possible adjust timing table.
If a CAI was installed the MAF tables will be adjusted to account for any additional air at part throttle cruise.
The power enrichment will most likely be leaned out a bit to pick up some power at WOT. The stock tune is on the rich side at WOT.
Some timing adder tables may be adjusted.
Auto Trans - shifting adjustments for firmer and quicker shifts.

Can you explain just a bit more on what "traction power limit" means?

Yeah...too subtle humor. Tire traction is going to ultimately limit how much power you can actually use.

Ah I see now...

So there is no software power limit??

Of course there are software power limits given the general nature of the question. There is a great deal of software in these cars. One can argue that traction and stability control is a type of software power limit. Redline cut is a form of software power limit. Timing adjustments based on conditions could be argued the same. What's underlying your concern about power limits?

I know of European cars that are significantly power limited in first and second gear (torque limited to be more specific). After a tune they can still end up with the same limits, which means the tune only does something when you hit third gear. If that's your concern I don't see anything like this going on in the C6 M6 cars.