I have 92 z28 5.7 liter running in 16's!!!
the car is not stock
350 tpi w/superchip
shift kit
exhaust cut out
plenty of suspension mods

any ideas why its starting to lag at 70mph? seems like computer wont let it get to high, there is no rev limiter

 

Hows the 60ft. I bought a chip back in the day and was the biggest pos I ever bought. I made less power with it than the stock one. The chip put the max amount of fuel in the mixture. After I had it custom tuned I gained 40 more horse. Oh yeah are you going through the gears individually or just putting it in drive. My car wants to shift itself at 4900 rpm. I shift it around 5700

 

i shift it manually, strange that it is making such numbers. could it be a speed sensor that the ecm wont allow it to go over the 110 speedo? from a dig its great but top end is horrible.. any suggestions??

 

Do you have an aldl cable to hook to the cars ecm and a laptop to dattalog and see whats going on.It could be alot of things.How are your 60` times?What mph is it running in the 16`s.Is it a custom chip?How many miles on engine?Had a recent tune up?Speed limier in chip maybe,but I dont think tpi had speed limiter.Has the engine ever been rebuilt or been into?What gears and stall?

 

TPI isn't mean to have good top end, so naturally the top end will be horrible. But that chip is probably hurting you much more than it's helping. Try switching back and see how it runs.

 

TPI isnt meant to have good top end but it should do better than 16 sec 1/4.Mine doesnt loose power at 70 or even 110.It may not be as fast as other intakes in the upper rpm`s but it still goes from 70-130 fairly quick.I dont think the tpi caused the 16 seconds.Chip prolly had a lot to do with it,but still really dont have enough info to tell anything else

 

Woops..I forgot to say that just because of it's top end not being so great, it should still be better than 16s. My 305 when it wouldn't idle with only exhaust ran in the mid 15s.

 

Wow...

I agree, hook it up and scan it to see what's going on. And, I think I'd even do a leak down test. I've had 305 auto cars with the peanut cam run better than that w/ just free mods.

 

ill take it to the track saturday and ill get some 1/4 and 60 times for everyone as it is. anyone know a good place to get a ecm burn??

 

H ow did you comr up with the 16 sec onds?Was that not on a track?If thats all the mods you have in your first post your original 350 chip should be fine.Check out the DIY prom board.First thing i`d do is get an aldl cable and dattalogg.I have been useing Harris performance/tbichips.A mail order tune wont be as good,but brian is working with me.I dattalogg and send the info in an email he makes changes to try to get everything dialed in properly.They say it`s not hard to tune I just havent had the time to get into it.

 

those are official track times. will post after saturday night with new times. where can i order that cable to reformat my chip?

 

You can get the cable at aldl cables .com for like 50 bucks I think.But that only lets you hook to a laptop and dattalog.To change anything in the chip you need more equipment.Its all in the stickies on the DIY prom board right here on tgo.Check it out

 

thats odd...i have a mostly stock 305 tpi and it ran a 14.9 with the 3:42 gears. are you running the stock rearend?

 

you might want too look at dates before you post.

 

That's too funny. I know I shouldn't laugh, but can't help it.

 

Pull out the garbage Superchip and use the stock MEmcal instead.

Pay close attention to your base timing setting, keep it stock or 2 deg more.

Get a fuel pressure gauge on it as well.

If that all pans out get a temp sensor and check the cat(s) out, should see a roughly 100 temp difference from frt to back.

 

Doubt the guy still has the car let alone the chip at this point!