Which Gear

[fourtenposi]

Hello,

I have a 74 nova, 3200 pounds with me in it.
Footbraked, launch at 3000 rpms
powerglide with 180 first gear,
5800 converter,
SBC 406 600 hp at 6600 rpms,
Best et shifitng at 7200 rpms.
29 inch tire
4.10 gears.
best to date, 6.42@106.5 in 1/8, 10.15@130 in 1/4
Sixty foot was a 1.44.

I feel that the sixty is soft for what the car runs,I am considering sticking in a 4.56 gear to help it on the line more. Most car I see running this et are in the mid 1.3xs Any thoughs or opinions.

Thanks

[supernova]

What tire are you running? Is it spinning off the line? If it's spinning try launching at a higher rpm like 4500 instead of 3000 rpm's. it won't hit the tires so hard and may hook better.

I would try a 4.30 gear before I put 4.56's in it. The 1.80 low gear set may be hurting it some.

[fourtenposi]

It dead hooks, tire is a 29x9 hoosier slick crossing at 7200 rpms for that pass.

I agree with the 4.30s, but unfortunitley they don't make that gear set for my rear.

Car works pretty good, just playing so if I can't find a little more.

[supernova]

Does it pull the front wheels up and how far does it carry them?

[supernova]

What kind of rear traction system do you have?

[fourtenposi]

I have the caltracs on there. It pulls the wheels 2-3 inches and carries them 4-5 feet.

[monzaz]

What rear do you have under the car?

5800 stall??? Humm...What is the converter? How old? Sounds like that might not be working correctly. That thing should flash stall all the way to 5000 at least.

Have you tried to just mash the gas off the line instead of preloading the converter? See what happens on the sixty foot. Just testing the converter there.

What are the cam specs? duration lift etc. Pistons? (flat pop-up how much?
Head chamber volume, (64 58 70 76???) valve size?

INTAKE type?

The 60 foot is off BUT the stall should have taken care of that. ???

Jim

[John_Heard]

If it's hooking like that and carrying them out there a ways, then there may be some to gain by tightening things up (front shocks extension, rear shocks extension, more air pressure in the tire. Obviously keep notes so you can go back to where you were before when trying things. Maybe a stiff sidewall tire also would show improvements.

[Craig W.]

I'd go with 4.56 or maybe 4.88. My last 383 ran best with 4.88s. I like going through the traps close to my shift rpm.

[monzaz]

I am not trying to be critical...But how can any of you figure what parts to use when you just going by the size (cubes) of a motor. Your cam profile is what makes the engines characteristics... Generalization of any 350 400 383 454 etc. is a big mistake in picking comparable parts for your performance. If you have a small duration cam in a long stroke 383 motor you will need less stall because all the torque will hit a lower rPM range (2000- 6000) compared to a longer duration cam which have its torque and power band higher in the rpm range (3500-7500)
Then we have compression of the motor, size of valves, Intake...ALL this MUST be taken into the equation or your just plain guessing and blowing money out the window on a guess....

Plus knowing what the car/truck will be doing for it owner will also have to fit the equation of the parts to pick again.

Good luck until there is more info on the table to figure this out.

[Craig W.]

I am not trying to be critical...But how can any of you figure what parts to use when you just going by the size (cubes) of a motor. Your cam profile is what makes the engines characteristics... Generalization of any 350 400 383 454 etc. is a big mistake in picking comparable parts for your performance. If you have a small duration cam in a long stroke 383 motor you will need less stall because all the torque will hit a lower rPM range (2000- 6000) compared to a longer duration cam which have its torque and power band higher in the rpm range (3500-7500)
Then we have compression of the motor, size of valves, Intake...ALL this MUST be taken into the equation or your just plain guessing and blowing money out the window on a guess....

Plus knowing what the car/truck will be doing for it owner will also have to fit the equation of the parts to pick again.

Good luck until there is more info on the table to figure this out.

Sounds critical to me.

You missed the part where he said it liked to be shifted at 7200. In my experience, that tells me quite a bit.