I am searching for vette specialist shop in indianapolis area but couldnt find any.
I dont mind paying money to fix it but even after paying money my local chevy dealer wont fix it. I took my brand new chevy suv (which is under factory warrenty) to resurface the rotors bcoz streering wheels was shaking while applying brakes. but dealer couldnt reproduce problems. i had to pay $200 to resurface rotors at other shop

Does GM dealer have that Tuner software? can i go to local chevy dealerhship?

It doesnt bog down in second gear. it goes upto 5500 rpm in second gear.

I am not very familair with the automatic transmission so i am kinda scared to change to 3rd gear while cruising on highway.
I tried driving with TC off. it still shifts at 3000 if i floor it. if i gradually apply gas then only it goes up to 5500

 

shifting to third is what you want to do when you want to speed up, it is MUCH better for the car than hammering the gas and letting it down shift to second on it's own. ( which is what it's going to do unless your doing 80+ in most cases)

i could go into a long description about how the OD gears turn an opposite direction. and all that but It's easier with pictures. when really racing/getting on it in the street letting off the gass and putting it in 3rd is what should be done ( the car will still use 1&2 when it needs to it just won't go into Over Drive)

 

There serveral great shops in Indy that specalize in vetts. Do a vender search for shops in your area. Indy has some of the best performance shops in midwest. Your lucky there

 

Well you need to address that before you look any further. Without a difference in the height of the tire/wheel combo between the front and the rear you will have issues with the AH/TC modifying your control inputs. These cars are "drive by wire", there is no physical connection between the gas pedal and the throttle. Your input at the pedal is read by the system and the throttle is opened or closed by the PCM. The amount of open/close can be effected by other factors as in if the wheel speed sensors report that your rear wheels are turning at the same speed as your front wheels (which would be the case if the front and rear wheels were the same overall height, as on your car) the programming see's this as the rear wheels must be loosing traction (because if they were different sizes, as designed, the front wheels would always be turning faster than the rears because they are smaller).

Sooo . . .when it see's this, and thinks the rears are slipping, it reduces power ( I was under the impression it did this by retarding the ignition, not sure about reducing the throttle opening, but either way) rpms drop....as you are seeing.

What people do when they want to run the same size rims all around is that they choose a tire sidewall height that results in the required difference between the overall height of the front tire/wheel combo and the rear (you want about an inch difference). So basically with 20's all around with the same sidewall you are going to need to change one set of tires. Either a smaller sidewall on the front tires or a larger one on the rears.

Review this post for a better explanation

http://forums.corvetteforum.com/c5-g...ah-issues.html

You may have more than one thing going on, but Im pretty confident that "there will be no peace in the valley" until you address the wheel/tire set up you have.

Dont get nutz over this Yes, the car isnt performing as designed, but it was modified out of design. If you are driving it like a regular car (not like a vette) you probably are not hurting anything until you can get it fixed.

We went over the TC system retarding the ignition when it thinks there is wheel spin, but the AH system is also in play in any situation other than direct straight line movement when it senses wheel speed differences, lateral G's, yaw values and steering wheel position (yes, its monitoring this stuff all the time) that dont fit in the values stored in the table it will attempt to correct your line (the path of the vehicle) by differential braking of each wheel independently (think of skid control....on steroids).

So if you were in a left hand turn and it saw high lateral G, and excessive left yaw it might apply just the left front and/or rear brakes to different degrees in an attempt to get the vehicle back into controlled configuration.

Why mention all of this? well just to answer the "can I hurt anything by using it this way" question. Other than loosing control from a malfunctioning AH system due to the altered data going in because of the wheel problems above, you may also be experiencing uneven brake wear if your driving it hard in your present configuration. Regular driving, probably isnt hurting anything.

 

what if i turn off AH/TC before i start driving? i dont drive it in rain or bad weather.

 

Can you tell me how can i do vendor search in indianapolis? I tried but didnt return any results. I went to chevy dealerhisp and mechenics there told me that car is normal and wheel size is just fine. He even told me not to change those wheels because they look nice.

 

P.s i am getting used 98 c5 coupe wheels from craigslist. do you think they will fit in my 2001 coupe?

 

"YES" They will fit. Hope this fixes your problem.

 

Yes they will fit and yes the Chevy guy is right. Your overall tire height is the right ratio for your car. This is NOT the source of your problem.

 

I was basing what I said on his statement of all the wheels and sidewalls being the same size. Did you see something I didnt ? Or where you able to calc that they were sufficiently staggered (wrong term I know but you know what I mean) to not cause AH/TC problems?

And believe me, Im not challenging you here Im here to learn, what do you think is going on?

 

Ok on the left side of the page. Look down until you see venders and click on it, Then enter your state. I know RPM performance is close to Indy. And there Is a tuner that just moved to indy and opened a nice shop. Hope this helps

 

In post #13 the OP states the actual tire sizes. Yes they have the same wheel diameter (20) and the same aspect ratio (30). However they have different tread widths. Since aspect ratio is a percentage of the width (30%), the actual tire height is different for the front and rear. If you calculate the actual tire heights, you can calculate the ratio or front height to rear height. The ratio is VERY close to the original ratio. You are allowed about 1.2% difference from the stock ratio while the OP is only 0.3% off from the original ratio. The are dozens of tire size options working just fine that have a bigger % than this.

Hope this makes sense to you and helps.

 

I dont know if this is relevant to my current problem.
I noticed whistling sound on idle coming from underhood. It sounds more like a cold air intake. I also have throttle response lag around 1/2 second.

 

It is really hard to say what your trouble is, You are not being very discriptive at all, I would say take it to the dealer and have them check it out. I am sure they can find the prob with your car. People have tried to help you, But seem like you don't know much about cars. Just take it to someone and be done with it.

 

Well it was a nice theory anyway

Slim....Im out...sorry guy

Thanks Doje