formula383

I have the LT4 conversion with all the mods listed in my sig. I went to the track on Friday, it was very hot ond humid. But anyway here is what the car ran

1st run
1.76 60ft.
5.18 330 ft
8.077 1/8 mile at 84.349
12.717 1/4 mile at 105.730

Adjusted fuel pressure after that run
1.82 60ft
5.22 330 ft.
8.11 1/8 mile at 84.385
12.745 1/4 mile at 106.051


On the first run, the car got towards the end of the track and actually stopped pulling. I mean the rpm stayed the same and everything.

Anyway , what I want to know is how can I make it faster. Do I have something wrong?
Do I need some little something? What mods will help me the most from here??

Thanks

joeSS97

If you used the LT4 springs,I would upgrade.They might be the reason your car stop pulling.Your times are nice tho.

formula383

It only did it on the first run though It felt like it was pulling fine on the other runs.

I will keep that in mind though.

Thanks

Bobby

Injuneer

I'm no expert in the LT4 conversion, but the MPH looks low. And, based on the comparison of the 1/8th MPH to the 1/4 MPH, the problem exists all the way down the track. My calculator says 106MPH in a 3,650# car (my assumption) is about 340-345flywheelHP. I hear about people pulling 400flywheel and better with that setup, and that would show up as 111MPH.

bradpreece95z28

But, did you buy your car off shawn at Mccoy Motorsports???
If so ...I know that car lol.
I live in Mingo county, West Virginia.
Did you run at Clay City?
That is a moderately slow track anyways.
Shoot me a pm man.

TheHeadFL

Based on his fuel pressure comment, and the fact that he got faster by (presumably) raising the fuel pressure, its possible that he is actually running so lean at the end of the run that its almost like he is hitting a 'rev limiter/fuel cut' if its even possible.

Injuneer

Not sure which way he adjusted it.

What is the elevation of the track? Do you have the temp, barometric pressure and humidity, so we can convert to "standard" conditions?

94formulabz

is this bone stock lt4 heads? Is it a 383 bottom end?

Antz97ZNJ

your mph's are low, bolt on LT1's cut those traps...but i can see how the heat n humidity would kill that

formula383

The fuel pressure was way low, and I adjusted it up.

The car has stock LT4 heads and a stock LT1 bottom end.

I thought the mph was low too. That is why I need a little help. A little later in the evening I ran a 107 pass though.

I don't know what the elevation is, or any of the other things.

More help please.