BJ67

Thinking of buying a 2009 3000 mile auto trans Z51 corvette. Any issues with these cars? I assume they are easy to tune, what do they respond to as far as bolt ons, how rugged is the 6 speed automatic? Am thinking of making this car into a high 11 sec runner.
The car is a 1LT so its as light as possible and has the Z51 2.73 gear ratio, are these rears easy to mod to a 3.42 gear?

Any input is appreciated no matter how small

LMB-Z

No issues with these cars...easy to tune if you know what you are doing and have the proper equipment...they respond to any and all bolt-ons, auto trans is very rugged...rear can be modded if you know what you are doing

919cw313

Here you go: https://www.corvetteforum.com/forums...questions.html

BJ67

Thanks bud, I have not been on C6 forum for some time, have a 15 base manual stingray that I bought new so the C7 forum is where I am at. Before the C7 I had a 08 Z06, but I didnt follow the non Z06 cars. It seems the LS3 combo with the 6 speed auto with some gear or boltons will get me in the high 11's easily.

HOXXOH

I'm running high 10's with just boltons. High 11's are easy. What's your budget?

BJ67

Its not a budget issue, I have a goal for a high 11 sec daily driver. Got to be comfortable, good looking, and a pure pleasure to drive in any conditions.


Thanks for asking.

subfloor@centurytrans

High 11's are achievable with nothing more than a tune and some drag radials.

BJ67

Thanks again, I had a hunch it wouldn't take much.

BJ67

How do these cars launch with the auto trans and the 2.73 Z51 gear ? do they launch hard, any torque management issues? should torque management be tuned out for harder shifts at redline ? do these cars shift at redline at WOT or do they typically shift early.

subfloor@centurytrans

Bone stock they're a dog off the line as the PCM is designed to pull timing when you stab the throttle. Basically what happens is the PCM sees the sudden influx of air and thinks "Look out, we're gonna see engine knock so let's pull out tons of timing to save the engine!" I've actually see timing go negative on a stock car but fortunately this can be tuned out fairly easily.

You can also pick up around 3/10ths by simply turning off torque management across the board.

Garry in AZ

I have a Grand Sport with manual trans, headers, high flow cats, Kooks Xpipe, sticky Mickey's and a good tune. I ran 11.62 @ 114 on my first pass. Yup, 11's are no problem especially with an automatic.

BJ67

Even with a steady diet of 93 octane and rarely sensing spark knock, the PCM still takes out timing? if I lower the stat and keep everything as cool as possible, along with a good cold air intake, it will still pull timing? The C7's are set up to pull timing early and easy because of IAT and water temp and realize the PCM is tuned much different on the C7. Your info is good to know, especially on the timing retarding that much. I like a lot of timing when snapping the throttle for lively launch. Will turning off torque management make for shifts too harsh or just quick and firm?

BJ67

I like that, the car is quick, not fast. 11.6 is a nice ET with a low MPH says to me a very quick car and driver not relying on horsepower for a great ET.
Last car I had that did that was auto trans 69 chevelle big block with 3.73 gear, 11.48 at 116.7 mph...... quick not fast LOL.
For a comparison, my 08 Z06 with a tune only on factory runflat's ran a best of 11.5 @ 125 mph speed shifting only and a high 1.89 60ft

FAUEE

The weak link in the cars is that they're IRS, and tend to wheel hop as they're set up from a suspension standpoint for corners more than drag races. If you keep that in mind and allow for the needed buffer because of it, they can be very reliable. But guys dont fo that and break stuff.

I will maintain forever that if you just want to run after a drag strip time in the most boneheaded way possible, the camaro is more robust for that. It takes a bit more restraint to keep a vette together than a camaro. It's cheaper to do a camaro too, as they're cheaper to buy, parts are cheaper, and you can slap them together with less care.

The corvette is BY FAR the better car, but you just have to recognize what its designed for and act accordingly.

subfloor@centurytrans

Yeah, the PCM will do that no matter what fuel is in it or how cool it is.

I've found that turning TM off still makes it very streetable. It's when you start messing with line pressures and shift times that it can become less fun to drive if you get carried away with changing the settings.

BJ67

I hear ya and understand what your saying. That's why I will be using a auto trans car and keeping at the upper 11 sec range. Auto trans cars are more gentile on the IRS. I usually strive and drive for a no spin launch, hence no wheel hop issues. I have never been one to launch anything as hard as possible, I feel for bite and then get it to floor.

HOXXOH

Your best bang for the buck, which also keeps the car very docile and drivable, while making the biggest single difference in ET, is a higher stall converter. My best 60' with a Vararam, Z06 exhaust manifolds, a tune, and DR's was 1.89 and an 11.98 ET while using the stock converter. It took all that to go from a 12.41 when bone stock. Then I swapped to to a 3200 stall Yank and immediately had 60' times in the 1.7x area and my ET's dipped into 11.6x. with no other changes. Best 60' was 1.70 and best ET was 11.49 with that setup. Wheel hop never happened with the 3200 stall, since the converter absorbs most of the shock.
A 3200, tune, and DR's will put you in the 11.7-11.8 range no problem and nothing visible except the tires.

BJ67

Got it, I do believe in a higher stall converter. Did you replace it yourself or have a shop do it? its a big job that requires the rear suspension to be lowered so the trans and diff can be pulled back.

HOXXOH

I did the 3200 and 3600 myself and had a friend help with the 4000. The first time was slow,due to the learning curve and the last time was slow, due to all the frequent BSing. I'm old, retired, and not in a hurry except when driving. All three were done in my garage on jackstands. I'm guessing, based on shop ads, that shops can change it in about 3 hours.

subfloor@centurytrans

It's not that hard to do and I have a How To guide I can email you.