theses are the mods I have.Flowmaster exhaust no cat.
LT4 KM,52mm throttlebody,160 degree thermostat,KN cold air intake,Hypertech power programer111,new MSD wires with AC delco platium plugs,BBK underdrive pullies,And drag radials on the rear.I was hoping that this would be a mid to low 13s car this year,But to my suprise I cant get it below 14s.Last year I had a best run of 13.9.This winter I done the tuneup LT4 km,Pullies and put the drag radials on.I was wondering if you guys could help me out and maybe tell me what could be the problem with this thing.Thanks for the help I appreciate it much.

 

What year car?Miles? Transmission?
What was involved in your tune-up?

 

Can we see a timeslip?

 

First of all, if you have the hypertech power tuning on your car, get rid of it. In fact sell the whole damn thing and get in touch with madz28 and you will come out much better. Need more info on car

 

its a 95 z28 with an automatic trans.it has 96,000 miles on it. The only tuneup I done is the plugs and wires.

 

Time Slip

R/t .104

60' 2.033

330 5.844

1/8 8.995

Mph 75.23

1000 11.696

1/4 14.001

Mph 96.16

That Was My Best Run.i Hope That Helps.

 

I would assume you have roller rockers because you put in an LT4 KM. You should be in the 13's. Not to kick you in the nutz but I was running 13.7 all day with less than that years ago. Does it feel okay while your going down the track. Does it feel sluggish or anything unusual

 

wow theres something holding u back. you should be in low 13s easy. i ran my car and it only has some small bolt ons, nothign major at all, and i managed a 14.1 at 99 with a 2.2 60' . you should get a good tune and go from there.

 

Um low 13s not a chance..he has a catback ,cold air and minor mods. No big power mods ,I dont' even see gears or stall.
Also what altitude track are you at. What is your raceweight.Buddy with simlar mods on his 94z got best of 13.8 with 2.0 60ft on old bfg drags. I can't see you getting under a 2.0 without gear and stall. We are at 1700 feet.
Altitude and temp and bar pressure and wind all make a difference ,humidity too.
Raceweight makes a difference. You are so close try running 1/4 tank,no tire or spare maybe even take out back seat ,front passenger seat,mis stuff,mats,cds..sub box whatever.

But seriously if you expect 13s and especially low 13s you need some power mods..get some headers.macs or long tubes..get a nice 2800 or 3200 or so stall. Gears helped me going from 2.73 to 3.42 knocked off three tenths or so.

Get a cutout for the track that is usually good for a tenth. Headers and stall should put you way down in the 13s..
Your mph is a bit low too..this could be tune related or altitude or weight etc. Your mph is close to my heavy 3800 raceweight vert with simlar mods.
And again am at 1700 feet. I had headwind last time I ran. Got 14.3 at near 96 with a 2.18 on nittos track prep sucked that day and track isn't the best.
Mods at the time were 3.42s,tb bypass,magnaflow catback,slp fan switch,hpp tuning out,maft ,thats about it.
This season so far have added 2800 vig and asp underdrive balancer and have some old bfg drags sold the nittos. Hoping for a mid thirteen this year and if the above don't do it have 1.6 pro mags,CC305 and zex wet to throw on.

 

Your 60s sux for drag radial. I can pull 1.9 all day on street tires and that was before the 373s. HPPIII,try running +3 on all your shift points and see if that helps, it it did for me but then again thaere are a lot variables in 1-2 tenths. Also your 52mm tb is not giving you anymore than the stock tb, if i remember correctly the stock tb is good up to 450hp at the fly. And i think the pullies are only giving you maybe 5-10hp. research your mod wants better to get more bang for your buck, if I would have researched better I'd have a low 12 sec instead of a low 13 sec. Not trying to sound like a dick just trying to help

 

My best time last year was a 13.9 at i believe 98-99 MPH somewhere around there.So this winter I put the plugs and wires ,under pullies,LT4 km, drag radiels on there.Plus I got a fiberglass SS hood whichs weighs less than the stock hood.Thats why Im confused on why I cant seem to get it to run the way I think that it should.

 

Seeing that most of your mods dont really add any power I dont think that times are that bad at all..Seeing that LT1's are generally low 14 second cars stock. Flowmaster is one of the most undesired catbacks for our cars because there lack to really flow well...Id continue w/ my mods I wouldnt be too concerned...If you can cut a 1.9 60 w/ the dr's a 13.7-8 is in your near future

 

That car will never go low 13's as it sits. What gear does it have? If it's 2.73 that might explain some of this. If it's 3.23 your MPH looks sluggish. You should be around 78 mph in the 1/8, and 99-100 in the 1/4.

Has the fuel filter been replaced?

 

Ive seen a 2.73 car go 13.4 stock except a vortech muffler. Its possible

 

your mph is way low, stock lt1's in good tune should run 98-100