I purchased a 1998 Z28 from the origional owner with 80000 miles on the car. She seldom drove the car but did drive it every month. Now that I bought the car it is driven on the weekends and to the local drag strip. This is where the turd factor comes in. It runs from 13.90s to 14.20s on the same night. I bought new goodyear F1s along with a comple tune-up. Would a SLP intake and exhaust improve the preformance that much?

 

yes, it would improve alot, needs some cleaning out i'm sure, but 12's, nah! Gonna need more than intake and exhaust for that one to run 12's, and definitely will depend on location, weather, traction, driver, 6speed or automatic, just too many more factors i didn't even list that you didn't mention

 

Thats what they run dude

 

That is incorrect. Stock ones, even with high mileage have run 13.4-.5's and thats for the autos.

Lots of things could be up here, location and weather would help in diagnosing if there are any problems.

 

You just said that he was incorrect and correct in the same post.

Like 1998Z28LOADED and UCABlackChevy both said, those very well might be normal times, but we need location and weather.

What was included in your "tune up?" You say you got new tires; were you spinning a lot?

 

He implied that ALL stock LS1's run 13.9-14.2 which is incorrect, I corrected him and implied weather/location is the only thing that can cause a tuned-up stock LS1 to run that slow. Thanks

 

Weather/Transmission/Altitude!!!

 

what were your 60' times?

where are you from?

like everyone else said there are big variables that can change the times your running...

when i first ran mine it was mid 14s......then i found out the rear was broke, and when i had it apart for the rear i found a cracked spark plug.....

once the rear was fixed and it got new plugs and wires it was running low 13s and hasnt looked back since

 

That is correct because mine stock ran between 14.02-14.1 all day. (40k)

My friends car ran 14.1 (Its a 98), and Ive seen basically every stock 98z runs between 13.8-14.2. (Unless they have tires)

You can google search for what 1998 z28s run and you'll find 13.9 everywhere.

 

Not "ALL" but 95%

 

A friend of mine has a 1998 z28, only mods were a tune up, which consisted of spark plugs, wires, air filter(paper), fuel filter, oil change, he managed to get a 13.3 out of it and its a M6 car, over 100,000 miles.......

 

Evidently he doesn't care, he has yet to say if auto or stick. or tell us where he ran the car. oh well, tried to help

 

Sorry I have been on vacation. It is an automatic with a new tuneup. I race at gateway in St. Louis with high heat and humidity. 60 fts 2.134 2.097 2.113 2.122 It looses it at different ends of the track. I would just like it to run in the 13.90s and consistant.

 

Well your 60's are pretty bad good thing is it's easy to fix with that auto. First and I cannot stress it enough GET TIRES. those F1's are great street tires but not good drag tires they are too hard and don;t let you grip the track. Look into some drap radials or even ET streets with thoes tires you should be getting consitant 2.0's maybe 1.9's next look into a good Torque converter look for something around the 3400 stall speed next go after some lower gears 3.73s seem to be the prefered in autos with all 3 your 60's should be more like 1.7s or so

You don't need more horsepower yet. you need to get the horsepower your already making to the ground and then work on getting more. with those 3 mods stall,gears. and tires you should be able to drop a good .5 off that time and I have seen some people dropping close to a full second with them

Hopes this helps

 

Thanks !!!!!!!!!!

 

My 98 Z28 was a factory 2:73 geared car A4 and ran almost the exact same times when totally stock. I think that is fairly normal, especially under less then ideal conditions. I had 110K miles on the car the first time I took it to the track, I had purchased it with 98K miles on it. I knew that it felt like a low 14-high13 sec car, and sure enough its first pass was 14.15 @100mph 2.18 60ft.

Now with some good bolt-ons but still internally stock and 120K miles it has run a best of 12.18 @ 109.72 w/1.663 60ft and actually pulled the left front wheel about 1 1/2-2" on that launch. I say that 98s are'nt necessarily turds, when given the same mods they can run just as good. My car is still not full bolt-ons, there's still a few that I have not don yet.

Do some research and buy the right parts combination and your car will surprise you on how well it can run. I have knocked off two full seconds off of what my car originally ran bone stock. Oh, and by the way, I bought everything used except for my MTI clear lid. I bought everything off of LS1tech and spent less than $2000.00.

Good luck with your car!

 

Probably heat soaked.

 

i had a 98 z-28 w/64,000,lid,lca,mac off road y-pipe,free mods,nittos555s and ran 13.19@106 w/ a4 .

 

my 98 went 13.20 @ 108mph with just a muffler. Driver and weather are the biggest influences. I cut a 2.05 on street tires and I am m6. My track was real close to sea level and humidity was low so that cars breathe good down here...

 

not bad, i hit 13.4