I just tore all of that stock crap out of there, all the heads back. I replaced it with some SLP 1 5/8" shorties, a 3" catco cat, and a Hooker 3" Catback. I ran it at the track and was VERY dissapointed. I only shaved off 1/10th of my previous best time. That's right, 16.499. I ran it last night again to see if maybe it was a fluke, and I ran a 16.405. Still very dissapointed about spending about $900 after it was all said and done and all I got was bullsh*t. Now my question is, would I have to up the fuel pressure to compensate for the headers? I wouldn't think so, but I dunno.

I'm running an open element also, only TBI mod.

 

With headers and an open element, you now have more potential to flow more air.

To ensure you make good use of that potential, you can do some really simple mods to help you out.

Increase fuel pressure, very simple mod to do our TBI's come with a FPR with the injectors. Use a multimeter to measure the voltage of the O2 sensor under load, odds are you'll probably need more fuel since you have improved flow characteristics.

Since you're flowing more air and adding more fuel, you'll need to ensure your able to brun that fuel. Good plugs, wires cap and rotor will do nicely, but an added touch is a coil to ensure even though you can flow more spark energy, that you have that energy available to you at higher rpm.

The more in depth free stuff I'd do is ultimate TBI mods, I personally haven't done them yet but have gone adifferent route to improve times on my car.

Tips on track,

Drop rear tire air pressure to like 24 PSI.
Shift manually at 5500 RPM (I'm still header restricted so I'm actually shifting aroun 5300-5400 RPM)

Post more details about your run, mph, 60 and 330 ft stats...
Also notes on whether you felt like it was struggling or not
Weather, tires, elevation how you shift...

There are many factors that go into et's engine power alone will not give you great times, a lot rests on driver and the rest of the car's setup.

 

damn that $ucks how many mph did u increase

 

Well, I've got a new cap as of early this year, some Taylor Spiro Pros, and some Accel header plugs (went on same day the headers did) I may need a better coil, It's very likely that my fuel filter badly needs to be changed. But I'll check the 02 and the other things, and I'll post my fastest timeslip for you all to see.

 

My fuel filter was full of shiat and was seriously hampening my performance. I would just go with a cheap one, and would not spend an arseload of cash on it.

As far as dropping the tire pressure; unless you only race at the track or drive around all the time at 24 psi, I don't agree with that. That's a false number in my book. Just my opinion though.

P.S.- Try bumping up the timing some.

 

I run 24 PSI only on track.. daily driving I use 30 PSI in the back.

I bumped timing advanced 2 degrees at track only, but found engine ran better so kept it.

With the 24 PSI I improved my 60 ft times to 2.2-2.25 range from 2.4.

With the 2 degrees advanced, I improved my times from a flat 16 to a 15.8 consistent.

Those are just track tips.

Fuel filters tend to go and performance suffers a lot... I change mine now once every year and a half to keep it working great, I also use 94 octane fuel and run a cleaner every oil change to keep things neat as possible on the inside.

With a header/cut out install I'm gunning for low 15's maybe break into 14's... we'll see on the 14th how I do.

 

The thing is, I completely took off the air filter and ran it open twice to see if that made any difference. nope, ran a 16.6 and a 16.7. Bah. I'll post my slip in a minute.

 

Alright, here it is:

R/T .667
60' 2.417
330' 6.911
1/8 10.596
MPH 66.98
1000' 13.748
1/4 16.405
MPH 84.89

analyze away if you may.

 

I might add, before the exhaust stuff, I was running 16.5-6 at 79 MPH in the traps.

 

you gained 6 mph in the quarter.

 

you run 30 psi of fuel daily???

 

Yeah, I know, but I only picked up 1/10th in the quarter.

 

mph is what determines HP, not ET

 

Dude you're spinning to all hell outa the hole. 2.4' 60 is a bad thing. Get that man a posi unit right now

 

what kinda quarter mile time is an 84 mph worth? say he got a 2.0,2.1 60 foot 1/4 =?

 

depends on the car. tons of stuff go into that.

 

The thing is, I'm not spinning at all. I have never spun them off the line for sheer lack of power off the line in my opinion.

 

how do you launch?

 

remember what schumacher said.... its not the mods u have...its how well the mods u have work together. sure u got free flowing exhaust now and everything but what heads are u running? stock i take it? u didnt need 3 inch pipes and everything. u just set urself up to run a better breathing engine. dont be so disappointed because as soon as u do some motor work that exhaust will probably show lower et's that stock...more that a tenth of a second. relax

 

Rev it right before the wheels start spinning, then go. Don't spin. Most of the time just from a dead stop.

 

Your mph should be good for a low 16. I ran a 15.9 @ 85.05 with an open element and the AFPR and timing advanced. The timing and afpr mod goes well together since your supplying more fuel so you need more spark to go with it. Try those two mods since theyre free. Headers are going to help more at the top end then at the bottom end, thats why you got a 6mph gain and not much et gain.

 

Well, gaining 6mph in the 1/4 translates to around 30rwhp. So the exhaust defiantly helped you. With an 84-85mph trap speed you should be around 15.9-16.1. How many times have you been to the track on the new setup? When I got my full exhaust I noticed a decrease in torque from idle to 2000rpm so a set of 3.42 gears would probably help a lot.

 

been to the track twice. I think I need to do some tuning then.

 

I'm running 15.8 with a 89 trap speed, I don't think 84-85mph trap speeds is good for sub 16 times unless your car hooks like glue to the track.

My fuel pressure is just around 12 psi, I don't really mess with the fuel psi, rather I tune fp via o2 readings. I make sure that at wot in 3rd gear my o2 sensor reads around 0.875 mV. This makes sure that I'm running just enough pressure for WOT and 3rd gear load.

Its my tire pressure I dropped to 24 psi, not the fuel.

That drop from 30 psi to 24 psi gained me 0.3 sec on my 60 ft times.

For launches I deep stage at the lights, start in 1st gearm manually shift at 5200 rpm and do a brake pedal slip to gas launch.

For ET I do a deep stage, for trap speed I do a shallow stage. A shallow stage is worth almost a mile in trap speed, and a deep stage is worth half a tenth in time...

 

You know, that's a weird thing, I can't keep the transmission in first, it likes to shift for me. the shfter is all messed up. maybe I need a new one. won't even go down into first.

 

hey slade u ran a 15.8 at 89 but this guy ran a

1987 Z/28 305 tpi
slp air foil, bfg comp t/a,kn filter, march pulleys, brake hose, pads and rotors, new plugs, and MSD blaster coil
NEW:best times
1/4- 15.3@88.2mph
RT-.918
60'-2.161

so i definitly think u can run high 15s with an 85 trap

 

I know I could do better, key is traction and weather conditions too.

I did my runs on a freaking hot humid day as well.

I was slipping in first and 2nd shifts oddly enough wheels chirp.

Lastly, someone recently told me the track we did our runs at is a generally slow track.

Recall you said that time was for a TPI, they usually have a better rpm power band than the TBI's do. Spend less time in the midrange than we do when doing the 1/4 mile thanks to the extra power.

 

I have a tbi and I do the 1/4 in 15.34 at 89.xx so its possible for a tbi

 

Like everyone has said, you've gained 6 MPH in the 1/4, and that's what matters.

ET is all about the 60'. If you pull a crappy 60', forget your time...it'll suck. If you cut your 60' down from that horrible 2.4 to a 2.0 or so you should cut a 15.9x easily. Usually it seems that for every tenth you cut off your 60' you cut 1.5 or so off your 1/4 ET.

I did the same thing, full exhaust, and my car was still slow as *****. It ended up not paying for itself and I was sick of running 16s like some Honda. So she went bye-bye. Maybe it's time for a 350 crate?

 

Well today, I went to HS drags. VERY pleased

Only thing I changed since the last run was the Shifter cable, only out of necessity because it snapped and left me at school in park.

anyways, I pulled a 16.063
a 2.37 60'
85 MPH

I'm going off of memory, so my numbers may be a little off. But I am very happy. For some reason now, the car seems to have new life, I could not keep any traction off the line, even with 22 Lbs of pressure in the tires with a burnout. Made me happy because I actually never lost a race today.

 

And it makes me happy because I dialed in at 16.1 and broke out and ran a 16.091 when the car was pretty warm. Gotta love that.

 

nice.... does ure car have the limited slip option or does only one tire spin

 

never lost with a low 16 sec timeslip, DAMN

 

bracket racing

one wheel peel baby, but I could've sworn that they were both squealing off the line. it's still got 2.73's in it.