Shake Zula

LB9 went from 15.8 with 2.73's to 15.3 with 3.42's.
But 60fts didnt change. 2.3's with either gear ratios. I think Im spinnin with the 3.42's, but cant tell cuz its so loud at the track.

Thats it for the year. If I decide to keep the car Ill do headers, custom tune, afpr, and nitrous next year, and hopefully be in the mid 13's (at a good track)

Shake Zula

And another guy that was there with an 89 Firebird 350 would keep his passenger side headlight cracked open like 2 inches. he said it lets more air into the intake. Makes sense to me, but dose anyone know if it actually makes a difference?

AlkyIROC

The deeper gears got the engine into a higher rpm range quicker for the better et. The deeper gears also increased the torque multiplication to the tires. More torque normally means quicker accelleration however the tires need to grip the pavement. To drop that 60' time down which will also lower the ET, you're going to have to invest in some sticky tires.

Shake Zula

I have a set of DR's, but there 28"tall. It will be like having 3.08 rear gears. But Im done for this year. $20 to get 3 runs in just aint worth it.

Time for the famous saying: "Just wait till next year"

AlkyIROC

A taller tire makes a bigger footprint from front to rear. This is better for traction than just a wider tire. Going to a taller tire also means going to deeper gears to bring the engine rpm back up to where the cam makes it's power.

The 28" tall tires should have 3.73 or maybe even 4.10/4.11 gears to move the rpm into the sweet spot although what you have now will be good for highway cruising.

Look at magazine articles for pro street cars. 32-34" tall tires and 3.73 or 4.11 gears. With tires that tall, those are highway gears. My tires are 29.5" tall and I run 4.56 gears. I'm also shifting at 7000 rpm.

The best source for information on tire height and gear ratio is 4x4's. They know that putting a tall tire on means using a deeper gear ratio to compensate.