Like 95 slvr said 8.7 seconds is still really slow for a Z28. My V6 has no problem running in the 7s and thats in the summer heat & humidity.

You should do some regular tune up stuff. I recomend you replace the air filter ASAP. You can buy a new one at pretty much any auto store (NAPA, Autozone, discount auto) or even at walmart. A regular filter is only about $10 - $15. Or if you want you could pick up a K&N filter, which will let the engine breath more & it is reusable so you will never have to buy another filter for the car. They go for about $70 new.

I would also replace all the Spark plugs & wires. If you are having a misfire this could fix it and even if you arnt it will probly still help. You can buy all the sparkplugs & wires at a local auto store like NAPA or autozone.

I dont know when the last time you changed your engines oil, but it may need to be changed again. Dont go with cheap oil either. The oil you put in your engine is everything. make sure you check it often and keep it at the correct level.

Also it should be said that the luanch has a big deal to do with 0-60 times. How are you luanching it? or are you luanching it at all?

You may just be getting a bad start and not giving it enough power off the line. Or you could be giving it too much power & your getting alot of wheel spin.

Do you feel the tranmition sliping at all?

There are alot of factors that come into play, including the climate & weather.

Next time you test you 0-60. Turn off the engine before you time your run and let the engine & transmition cool down. If you are an automatic you do not want your tourq converter to be too hot when you are doing timed runs. One trick for cooling the engine down faster is to buy a can of air that is used for cleaning out keyboards. Turn it upside down & spray it on the engine & under the car on the tranny. Dont spray it into the intake as the air is all Co2 and the engine needs oxygen. This should cool everything down alot faster.

If you do everything here you should see your times fall a bit. But there are probly still some other factors in play. If you replace your air filter, spark plugs & wires and are still not getting times under 7 seconds you should probly have a mechanic take a look at it. Most places will diagnose problems for free.

Good luck!

 

You said that it tends to run like crap when warm....this may also be from a bad head gasket. Not sure of the mileage on the car but i had that happen in my old T-bird. Check to see if you are losing any coolant.

Also, check you filters and do a complete tuneup: wires, plugs, cap rotor, pcv valve, fuel filter, air filter, and throw in a fuel njection cleaner.

That should give you a good start

 

thank you all very much for the helpful replies. i will do all my tune up needs in the next couple of weeks. but anyways seeing thatmy car makes me very depressedi decidedto go out and find answers and do some comparrisons. today i raced about 3 other lt14th gen f-bodies. come to find out..... i beat all of them from first gear but....... once i hit second they started to catch me and then pull away
does anyone know y that is? it really pisses me off. by the way its an auto with a shift kit and it was just rebuilt so i dont think the tranny is the problem.

 

so today a friend stopped by with this gadget. its called a "g" something i dont know. but we stuck it to my windsheild and started the testing. my results were 0-60 in 7.1 sec. and the 1/4 mile in 15.35 at 90 mph. does that sound pretty bad? later on today we checked my spark plugs and wires and we found out that 3 spark plugs were ononly finger tight. so we fixed that and it didnt seem to make a huge difference

 

You are spending too much time road testing, instead of fixing or diagnosing the problem. Pushing a bad running engine creates more damage. Tune up the car first as everyone explained. If it still runs bad after that, you need to go to a good repair shop before you create more damage. Have the car scanned for trouble codes, have all the sensors tested with the scanner,check the exhaustfor excessive back pressure, have the coolant tested for combustion gases, if gases are present do a leakdown and compression test. Check fuel pressure and regulator,and make sure the air filter and fuel filter are clean.