LT1 383, running 12.06 1/4 mile, help me make 11s
 

My car is a pretty decent home built setup. I'd like to see just a little more out of her though. Some advice on where to point my $$$$ for future mods would be helpful. I'll list a basic rundown of the car w/o going into ridiculous detail

94 trans am
383 LT1, scat 9000 crank, speed pro hyper pistons (flat)
12:1 compression
gm 847 cam
Cc pro mag 1.52 rr
Supporting valve parts.
Manley race-flo valves 2.0 & 1.56
OE head and intake castings - professionally ported
58mm TB
Ported intake
36lb SVO injectors
pacesetter LTs 3" ORY - Borla wide open
MSD blaster coil / wires
Underdrive pulley

SPEC stage 3 clutch

Stock T-56

Moser 12 bolt, 4.11 gears
E/T DOT street drag 26x10.5x16

Tubular bmr torque arm
bmr rear LCA
Tubular Panhard
Large rear sway bar
polygraphite bushings throughout front and rear
Alston weld in SFCs
STOCK springs and shocks

Full interior car... with ac and power seats.... etc. No weight reduction.

The car is very close to an 11 second pass. I know the car could do it now, but it's human error that I can't seem to improve past right now.

Here is my best time slip

60'........ 1.670
330....... 4.996
1/8....... 7.721
MPH...... 89.33
1000..... 10.983
1/4....... 12.068
Mph...... 115.xx

It seems like similar cars are about 95mph in the 1/8th and finishing around 120ish at about 11.60s. this is where I think the car should be. Maybe it's just because it's a 6 speed car and not an auto. Not sure.

I've played with tire pressure, 15ish seems to be the best.
I know I could benefit from some pizza cutters in front, maybe an electric water pump, some 1.6 roller rockers. 28" tires instead of the26s I currently have. And some springs and shocks.

I've experimented with launch rpm, from 3500 to 6500.
I get a decent launch, maybe a little wheel spin, not much (the M/ts are at least 10 years old so that doesn't help., I'm finishing the race at about 6200 rpm and it feels like the power just isn't there quite at the end.

We are near Chicago, I think about 600 or 700 ebove sea level. And my last track time was in cool evening weather probably mid 60s.

I'd like to see at least 11.80s with the car I guess. I'm not going to start stripping things out for weight savings.
Maybe I should just be happy with it the way it is.
I just hate that my friends cars are ls1 cars, heads, cam, bolt ons, and they do low 11s...
If I was building this car now, I would have done an ls1 car, but I built it 10 years ago when ls1 cars were still fairly expensive.

Please advise.
Thanks!

Re: LT1 383, running 12.06 1/4 mile, help me make 11s
 

We have a very close set up.and. we are having 02 problems. Runs great for about a week. Then idels going all over the place. We found a bigger 02 with a extra ground wire .is that the fix? Are the just getting too hot.

Re: LT1 383, running 12.06 1/4 mile, help me make 11s
 

Pump the front tires to 50lbs. Rear tires should be as much air that still allows you to hook. 1/4 tank of gas but make sure you bring some fuel, the track has gas, or there is a station open when you leave the track.

Stage as shallow as possible (make the bottom bulb blink) and try to get as far to the outside wall as possible while still staying in the grove. As you make your pass angle from the start to finish line to cross as close to the center wall as safe. This will take advantage of any (if at all) crown in the track (for water drainage).

You can mount an upside shark fin under the front bumper. Plastic sign works well down to 2" above the surface. This will break the beam with your nose rather than the tires and pick up a little ET. This doesn't effect the starting line as the timer starts when the back of your front tire leave the beam.

Re: LT1 383, running 12.06 1/4 mile, help me make 11s
 

Are you running skinnies up front and i picked up from switching off the cooling fans when I pre-stage. Just dont forget to switch them back on at the end of the pass.
Good Luck,

Re: LT1 383, running 12.06 1/4 mile, help me make 11s
 

Have you tried a 28" tall tire?

What does your set up look like from the air filter to the throttle body?

Re: LT1 383, running 12.06 1/4 mile, help me make 11s
 

Thanks for the replies... I mighat try some of that this spring. Not running skinnies up front, probably a good idea also.
As for my air intake, I can't get a picture of it because the car is away in storage for the winter. I'll describe it. I have an LS1 air cleaner assembly, leading into a stock MAF, then a smooth rubber adapter gping from the maf to the 58 mm throttle body. It's round on one end and oval on the other side.
Thx for the input this far