Using HP Tuners or EFI Live to modify the parameters programmed into the car from the factory - adjust spark, fueling, reduce torque management features built into the factory tune, etc.

Remember the factory tunes them with emissions and warranty in mind. There is power to be had if you are willing to be a little more risky with the parameters.

There are those that will tell you a tune will void your powertrain warranty, and it likely will. The dealer can check to see if you have a non-factory calibration in your computer and will sometimes use it for an excuse to deny warranty coverage. And sometimes rightly so, if you get a beginner tuner who screws up and sets your A/F ratio to 16:1 WOT by fat fingering the table that does that and the engine blows, well, then they are right to deny warranty coverage.

Most dealers won't deny warranty coverage for, say a power window motor because you have a tune. But in between those two examples is a lot of gray area.

I tuned my car right away myself, as I wanted the add'l performance a tune gives me and I am a big boy, I don't have warranties on most of my stuff.

 

A tune basically changes the parameters in the computer control that were set by the factory. The most significant items are fuel and timing.

In the past, fuel was changed with jet sizes and timing by rotating the distributor. Now it's all much more precisely done with computers that can be reprogrammed.

The best tuners will make changes to suit your particular car, any mods you make, and your driving style. Since you have no information in your profile about your location, it's impossible to guide you to a good tuner. It's much better to deal with a local tuner, so that any problems or updates are handled on a personal basis and can be checked on a dyno or by driving.

Be fully aware that a tune can void parts of your warranty where failures can be directly traced to changes in the parameters. It does not mean your entire warranty is gone.

 

If this is your intended future use of the car I suggest you leave it stock and forget the idea of getting a Z06. How many times have you planted your foot to the floor for a minute at a time? How many times have you planted your foot to the floor for 15 seconds? If you haven't done those kinds of things on a regular basis you just aren't going to get your money's worth except in bragging rights.

No matter how much money you invest in mods you just will not notice them except in the cost of fuel. There is almost no highway in that part of the country where you can actually open the throttle to wide open for more than a couple of seconds. That isn't really long enough to notice any difference.

Bill

 

OK, new to the forum, so just updated my profile a bit to state that I am in central Missouri. A decent track is a couple hours away, so that's not going to happen very often. I don't intend to race the car, per se, but bragging rights are always good. I'd love to have the car to the point that I could run it on a track, when the opportunity presents here and there, and I suppose that's a big factor in my consideration... our car is a convertible. So, a hardtop or even targa top is a factor I'm considering for handling, safety, etc.
I appreciate all the good comments; thanks very much.

 

There is a substantial difference in power going from LS3 to LS7...raw power substantial.

 

There is a lot of validity to this response.

I would like to add my 2c on the topic. Some mods are useful even for going to car shows or cruising.

Case in point:

A set of 4.10 gears will make the car feel (and be) substantially quicker than it does with 3.42 gears. Anyone interested can look at my thread linked above where I show my car and another with the same power but different gear sets. You are giving the engine a longer lever to work with and you feel that.

The sound of a cam is not to be denied, if you like such things. Even though there is a fuel mileage penalty in town, I still get combined 21 mpg in my car with 4.10 gears and a nice cam.

QTP cutouts are another of my favorite mods. Quiet for most of the time, DEEP and LOUD when I want it to be.

This gets attention and makes me smile every time I start it. The sound of the car is important to some folks, like me.

 

There is also nothing like a boosted LS3.

 

http://www.magnacharger.com/p-113-co...arger-kit.aspx

 

There's also the fact that a ls3 can be made into a 427.
Or forged and boosted.

 

As you imply it is all about perception but perceptions don't have to be based on truth. There is another way to get the same thing. We used to call it badging a car. Put stickers and badges on the car, put some signatures on the valve covers, use a couple of iffy spark plug wires to get an engine misfire at idle and you pay a lot less money for the same effect.

As for the gears do you really accelerate harder than you would normally do so? If you used a certain amount of throttle opening to accelerate before the gear swap do you still use same amount afterwards? Or do you actually use less throttle and end up accelerating at the same G force you did before the gears. A lot of times it is the limitation of the individual drivers and the areas where they are operating their cars that limit performance Vs the car being the limit. Again, it is a perception issue and false perceptions can cost needless money.

Bill

 

I would not say putting in a cam is is tantamount to putting SS stickers on your Malibu. I would argue that even on the street fooling around you do feel the benefits of a cam, which tend to "come on" at 4500 RPM.

As to whether you feel gears on the street vs pressing the gas harder, the answer is you absolutely do feel the difference with gears. Best way I can describe it is that it feels like the car lost 500 lbs...and it's because at any given road speed in high gear, you are producing more HP than you would be with regular gears.

I don't want to take the time to debate this with you any further, as I'm guessing you don't have a set of 4.10 gears in your car so you are arguing from a disadvantage.

And one more thing I disagree with you about - you absolutely can benefit from mods even if you don't go to the track. Since I grew up in Missouri I happen to know the OP has some excellent Ozark Mountain backroads close to him that you certainly can benefit from mods, including tires.

You don't have to go to the track every weekend like I used to do to enjoy some mods on your car, particularly the non-npp exhaust. Chevy should be ashamed of themselves for Corvette exhaust, it's way too quiet for a performance car. Cavaliers z24's used to have more bark than a Vette.

 

It doesn't make any difference what gears you're using, it requires the same HP to move at any given speed. You don't automatically gain or lose HP with a gear change. You simply change the RPM to where that HP exists.

BTW You can thank your local rep to Congress for the quiet stock exhaust. It's not GM's fault that the gov't lowered the sound limitations. At least for the Vette they got around the requirement by offering the bi-mode system to pass federal regulations.

 

Ok my friend Tom, for you will spend some time to hopefully show how this matters.

I know you won't argue that a longer lever gives add'l mechanical advantage to a given torque. That's all a set of lower gears is giving you, a longer lever. 1/2 ratchet will get a bolt out easier than a 3/8 if you have room. The tradeoff is do you have room. In a car, room is the operating range of the engine and the fuel mileage associated therewith.

In the old days when 1:1 was top gear, a 3.90 gearset caused the car to be a gas hog (my Hurst/Olds got 7 mpg with 3.90's and my 3.23 geared 442 got 12) and top speed was limited to 110 or so vs 130 or so (not that I really enjoyed either car past 90 mph with their lousy suspension).

Now that we have a double overdrive six speeds, you can have the best of both worlds. My 4.10 equipped Vette gets 1.4 60 foots, 74,000 miles and 494 launches to date...the reason my clutch lives through that is the lever of my 4.10 gears and 2.97 first gear.

And the car goes 185 mph at the top of 5th with my 345/30/19 street tires.

And it gets 21 combined mileage in my daily drive. You know I've got videos and a spreadsheet of every gallon put in the car since I bought it to prove these facts.

Best of both worlds I say. Long lever to get me off the line and tall overdrive for top speed and mileage.

The long lever also makes the car feel a lot peppier. Here's why.


On the topic if exhaust, I disagree. How come new Mustangs sound so great and the Vette sounds like a Prius? They are the same federal standards. Chevy did a bad job with the standard Vette mufflers from a sound standpoint. Having tested them on the dyno with my cutouts however, they are quite efficient, only giving up 6 rwhp at the 450 rwhp level (none at 386 rwhp level).

 

I had this same issue. Do I trade up to a 427 Vert or mod my '13 GS Coupe? I got a rude awakening when I tried to market my car. It is much cheaper to mod my GS than it is to own a 427. I purchased a complete Z exhaust, a Z intake and thermo swap. I want to add a BIG cam some day. However, I can't afford to lose the engine warranty so I will be adding better gears next. In the end, all I really want is the quickness. A few bolt-ons and some new gears will give me all the neck snap I need and be easier on my wallet.

 

Joe, I thought your other car WAS a Prius!!!

 

It is!! I speak about things I know about, you know that!

My latest tank.....10.237 gallons to go 605 miles...59 MPG. And I ride free in the express lanes, saving from $10 to $14 every day.

Of course on a chamber of commerce day like today...it's top down motoring in the Vette.

 

Well, it appears we A6 guys don't benefit much from gear swaps so I guess I'll get boosted instead.

I've enjoyed this thread though. The next round is on me.

 

tires - sport cups?!?
brakes - pads alone first
sway bars
shocks
seat / harness
coil overs?
engine: tune/header/cai
engine: cam
engine: FI


All in that order, to improve your vette (on MO backroads) (or HPDE)..

imho, just off the top of my head.


I've put over 10K$ into my Z06 for tracking (wear and improvement) and still haven't gotten to anything driveline related except air filter! Still stock tune. I don't regret that.

 

But Joe, I wasn't talking about acceleration and neither were you. It was in direct response to your statement where you said gears produce more HP at a steady speed. Only engines produce HP. The gears merely transfer that power to the wheels at a rate that takes advantage of the power range of the engine.

Let's assume it takes 60 HP to maintain a steady 40 MPH in your car. You can do that in any gear from 1st through 6th. The HP never changed because the difference was the RPM of the engine. The load (i.e. move the car 40 MPH) the engine had placed upon it was identical in each gear. The ability of the engine to produce 60 HP is far easier in the higher RPM of 1st gear than the low RPM of 6th.

 

Yep. Having about 150 more RWHP than a Z06 made me get over my 427 envy.

Not that I wouldn't take a little extra displacement. Could happen.