Hello everyone! I recently joined the ranks of Corvette ownership. I purchased a used 1 owner 2007 C6 with 46,500 miles on it.

I LOVE the car. It has every option I wanted - Yellow, Nav, T top, Z51, etc...

Anyway, the reason I am posting is because although it has a TON of power, it doesn't quite seem to be "Corvette fast". (Or at least how fast I anticipated a 400HP/400tq car to be)

I have done some basic maintenance on it (Replaced front tires (rear were ok), oil change, new air filters, checked tranny fluid, new brake pads) The only basic component that I haven't checked is the spark plugs, but again the car is a completely stock LS2 and only has 46,500 miles - so I didn't think it should need it.

The car had no DTC codes stored when I bought it and had not tripped any since driving it about 500 miles.

However my problem is that it still seems a little light on power for what I expected a Corvette to be. Even with traction control turned completely OFF, the tires don't break loose at all. I don't ever rev the engine while holding the break before launching (it's auto, so I can't dump the clutch) but I would think that the car would have enough power to spin the tires even from a 2-3 MPH crawl launch with traction control turned off.

I have not been to the track with it, but I have had a chance to use the "Dynolicious" app for the iPhone. I know that these things can be slightly inaccurate, but from what I hear they are usually accurate to within +/- 5%.

My Dynolicious numbers are:
0-60: 5.4 sec
Max acceleration: 0.66G's
Even with 0% drivetrain loss, it estimates the car to only have about 280HP

To me between those numbers, and the tires not ever breaking loose even with traction off, it would seem as though something is wrong. Any thoughts? What should I check next? I don't really want to pay for an official dyno yet since I'm pretty sure it will just confirm the low numbers, and I'll still have to hunt down the problem anyway.


Just for reference, here is a short video clip of me punching it at WOT:
http://www.youtube.com/watch?v=ZpGeGNoANXM


Thanks for your help! Again - I love the car, I use want to make sure I'm getting the "full Corvette experience" :-)


*****UPDATE*****
I replaced the spark plugs. That helped some, but not much. I'm starting to think that between the z-51 package, relatively new tires, and the hot conditions that I live in, this is how the car is supposed to perform. Like I said, I absolutely love the car - I just wanted to make sure it is operating as it should.


*****UPDATE #2*****
I finally got it to the track. Track conditions: appx 82 degrees & humid, appx sea level. Bone stock - no tune, Auto in D mode, minimal wheel spin.
I was able to post a 13.45 @ 107. Is that normal for automatics with no tune in this kind of heat? I've heard the fastest stock time on this forum is around a 12.4-12.5. That may have been a MN6 with a tune though... Is 13.45 off the mark for my car specs in those conditions?

 

where are you located? have it put on a chasis dyno. uselly around $75 to $150 for 2 or 3 pulls



take it to your local speed shop and dyno it. i would but your probally ok. if your phone thing said 280hp i bet you put it on the dyno youd see around 330 hp at rear wheels (sae correction)


just for referance drivetrain loss are estimated as

15% manuals
20% autos

 

Sounds like headers, CAI, and tune are in order!!
If you are so insistant on a dyno, go for it. Depending on the dyno, you will see between 330-350 stock rwhp as mentioned above. I wouldn't put much into that though. If you want it faster, than you will need to mod it a bit.

 

Bone stock LS2s should be putting out about 330-340 horspower to the rear wheels. Are you sure your car is bone stock first of all? If someone changed the rear end or the stall, I could see where it would be harder to break em loose from a roll.

As for your spark plugs, if you aren't getting a misfire, replacing them won't help you.

 

100% sure it is a bone stock LS2. I have a friend who has one as well and his dyne's right in that range (appx 330 HP). I am pretty sure I am making under 300 at the wheels.

Agreed on the spark plugs. I just don't know what else to check.

 

It's not a matter of wanting faster really - it's more a matter of wanting to make sure there is nothing wrong with the car since it's making an estimated 40+ HP below other C6's. I'm fine keeping it stock as long as it performs like other stock C6's.

I just wanted to ask other C6 owners if they can easily spin the tires when they turn traction off.

Thanks for the reply!

 

I'm in the Tampa, FL area.

The reason I put in 0% drivetrain loss is because that shows you what it's making at the wheels. So it's only making an estimated 260-280 at the wheels. When I use a 20% loss, it's estimating the HP at the flywheel and then the numbers are 305-325hp.

Either way, it's still way less than I would have expected. I'm just wondering what mechanically I should check, BEFORE having it dyno'd because I don't really want to pay to have it dyno tuned only to find out I have to replace something mechanical and then have to get it re-dyno'd after everything is working.

 

Something is weird. It should burn the tires off if you stomp it from a dead stop.

 

That's what I was thinking. Any guesses what I should be checking?

 

checked the air filters ? autos are really prone to lag with dirty filters. if it's stock, just get a set of K&N replacement filters for the stock air box. a CAI for an LS2 is, in most cases, a bigger risk than reward. If you do toss it on a dyno, you should see about 320-330 at the wheels with the auto.

 

One of the first things I did was buy new air filters... wasn't the problem :-/

 

Making a statement like that based on a phone app is pure crap. Do not put a lot stock into it. If you really want to see, pay for a dyno test.

You know, the Vette has a great suspension setup. It gives you all kinds of grip. Is your friend's C6 an automatic? Is it stock? Does it spin the rear tires given the same environment?

 

I agree that until I take it to the track, I can't give out accurate numbers, but it's a combination of what I'm feeling and what the phone's sensors are picking up.

As for the suspension - yes. Especially since I have the Z51 package, it really does handle well. However my buddy has pretty much the same vette (z51, LS2, etc...) and he is able to break the tires loose with ease. He had a dyne tune, but I don't think that would explain the significant differences we are getting. Maybe it would though... I'm just looking to see what other LS2 owners experience.

Thanks for the help!

 

the next thing that might be worth checking is if you burned a plug wire on a header pipe... if it's grounding out, you'd lose power but likely not throw any codes...

 

I know this is a shot in the dark but. could you have a brake caliper dragging? Or maybe the e brake? Consider what you paid for my suggestions, that's what they're worth.

Good luck

 

There is a possibility that 1 or both of your cat. converters have melted or broke apart restricting exhaust flow. Some on this forum have had it happen and I've seen it happen. Good luck.

 

I appreciate the suggestion, but that's not it either. I tried to check the spark plugs, but couldn't get the plug wires off :-/. I didn't want to pull too hard for fear of breaking the boot. None of the wires were burnt though. They disconnected from the coils with not too much effort, but the end that attaches to the plug wouldn't come off. :-( I've never worked on a vette before so I need to read up on how to change the plugs... Not sure if there is something special to it or not.

 

Interesting idea... I would think the car would pull to one side if that was the case though... Plus I just had the brakes done, so I don't know if that's it. Additionally when I'm at a stop and just let my foot off the brake, it crawls forward with ease.

Good ideas though. Thank you for the suggestions - just not sure if that's the issue.

 

That's an interesting idea... I didn't think of that! Do you think that's really possible at 46k miles though?

How would I check for that? Do I need to pull the exhaust off to look at the cat's, or is there a way to tell just by looking?

 

A tune can be huge and just taking out torque management alone can make a large difference. Tuning the auto transmission shift points makes a big difference too from what I have read. How good are your tires compared to your buddy's and what size rear tires are on the car? Have you tried with just traction control OFF and AH on? I have an MN6 '08 ... but I cant imagine that stomping the gas from a stop with TC off wouldn't break the tires loose in an auto LS2...... something does seem odd.