Power?

[vettegirl]

I love my C5, but it has never seemed to have the "get up and go" that my 96 had, even though it is a higher horsepower engine. I never thought much about it, but my husband just drove a friend's C5 (which is basically the same as mine - auto, convertible, etc. - mine's a 98 and friend's is a 99), and he says it is waaay more powerful off the line than mine. What could be wrong with mine? I have no codes showing, what else could be wrong???

Thanks!

 

[Gorgon]

I'm betting the friend's C5 had the performance rear-end while you have the stock axle. That will make a large difference.

Leon

 

[vettegirl]

I hope it's that simple..

I'd hate to think my car's a dog!! I'll have him look at it, he and the friend's car are at the Corvette Shop as we speak (type??)..

 

[c4c5specialist]

HI there,
As long as the mileage is the same, I would suggest that you have the 2.73 rear axle ratio, and your friend has the 3.15.
It does make a difference.
Allthebest, c4c5

 

[vettegirl]

Thanks c4c5...

I went through last night and changed some things that I thought might be effecting the performance. I noticed my battery volts were only between 12.5 and 13.1, so I replaced the battery with an Optima. I changed the air filter and PCV valve, and wanted to replace the fuel filter but it seems I need to special-order one. It actually seems a little better this morning (not that it's bad at all, it's just not throwing me back in my seat when I accellerate, and my husband thinks this is a problem!)



Anyway, while looking for the PCV valve (before I noticed the diagram on the inner fender!), I found a valve on the driver's side intake up by the firewall. It looks similar to a PCV valve and has a 90-degree rubber hose thing coming off the top of it. The hose is cracked - what is this thing, and could it be robbing power? Do I need to replace the whole assembly, or just the hose part?

Thanks so much for your time (and patience!)...

Lauren

 

[Gorgon]

Before you throw a bunch of money at it, did you verify if there was a difference in axle ratios? The RPO for the performance axle is G92.

Leon

 

[Bugster57]

Look on the glove box door for the option list. If you have the performance axle (3:15) it will have G92 listed among the RPO codes.

 

[hawaii-5-lo]

hey vette girl,
what octane gas are you putting in?we only have 91 in hawaii,if i go to the track with that alone,my car will go into a low octane table,and it will be a pig until i put 10 gals of gas to reset the computer,i use octane boost at the track,it prevents this from happening and the cars a rocket ship.i have the 3:15 rear,i would imagine that the 2:73s feel like caca.
i tend to agree with the others on the gears in your car,im just thowing out another option.does the car feel same as when you got it?or has it gotten worse?how fat is the cracked hose your talking about?good luck,Todd.

 

[vettegirl]

Thanks for the info, guys..

I get off in 15 minutes, and can't ait to go look at my RPO codes (I am learning so much here!!!).

Todd, I only use 93 octane but I have never tired using an octane boost - does this help for regualr street driving? I want to say this problem has come in the last week or so - when I re-set the code I shouldn't have and got the "reduced engine power" condition it's like it never all came back! I have cleared all my codes (they're all "H" codes this time), and I'm going to stop for an oil change on the way home to see if that helps.

The hose that comes off of the valve-thing is maybe 3/8 to 1/2" o.d. It is about 4 inches long, but with a 90-degree turn, and it's black. I thought this was the PCV valve at first since the PCV valve on my '96 had a hose that looked like this.

I really appreciate all the input - I really want to get to know my car, I hate being "helpless".

Have a great holiday weekend! I think tomorrow we're going to drop the top and cruise over to Daytona Beach, there is one of those vintage car cross country races ending at the Daytona bandshell, and some of the cars listed I have never heard of. Should be interesting - supposed to be a 1966 GT40 coming in - never seen one of those in person!

Lauren

 

[hawaii-5-lo]

hey vette girl,
i dont use the octane on the street because even though it says cat and sensor safe,its probably a little hard on the plugs and o2 sensors,i will just replace them more often.my car is more sluggish around town with the 91 octane.at the track i ran without octane to see what would happen,the car knocked the timing retarted and my times got worse too.i have since did a decarbonization recomended by c4/c5 spec,and the car has got alot of power back,but the octane still makes a difference.
maybe the hose your looking at is the vacuum for the brakes,does it have a little check valve in it?good luck,Todd.

 

[c4c5specialist]

HI there,
Please reference the following diagram.
This, I believe, is what you are seeing.
Yes, this would create a drivability concern.
It is your PCV recovering hose.
I would also add a fuel system cleaner, 12345515 to the tank, and see how you make out after this.
Allthebest, c4c5

 

[vettegirl]

That's it!

Now that I can explain the part I need to the dealer I will replace it.

Something I did, or a combination of things, has made a real difference. The car is driving great again, although I think you are right about me not having the performance gear (I did not see RPO sticker in glovebox or center console - might it be somewhere else?). Once the cracked hose is replaced, and the fuel system cleaner run through the system, I will feel much better!

I think this car is much more high-maintenance than my '96 - but high-maintenance is not necessarily a bad thing...

 

[vette-dude]

but high-maintenance is not necessarily a bad thing...

I could say somehting here but I won't.

Randy

 

[Blade]

Try releasing the parking brake

 

[vettegirl]

Thanks, that worked!!!!

Try releasing the parking brake

 

[DRTH VTR]

RPO codes

Aren't the RPO codes on the bottom of the center storage area hatch lid?

 

[tomls1]

vettegirl,

i have a 98 and the rpo codes are on the left hand storage lid. remove it, flip it over and you should see your codes.

 

[vettegirl]

Thanks sig!

I was thinking the last owner was more neurotic than me and removed the "sticker"! I'll look there as soon as I can sneak out of my office!

Lauren

 

[Blade]

SEQ#: It can be found on a sticker on the underside of the right hand compartment cover in your trunk.


VIN#: The VIN# is located on the identification tag on the left side of the dashboard.


RPO Codes: They are listed on the sticker inside the glove compartment.

 

[cruzer99]

Fuel Filter.......Fuel Filter.........Fuel Filter......Replace it. It will make a big differance.