i just wanted to know if anyone can tell me what kind of gains in my 60 foot and 1/4 miles times i should expect from doing this gear swap.times and mods in sig.thanks!

 

About a month ago I swapped out my 1 wheel wonder 2.73 and installed a 3.42 with posi, track was'nt open as it opens this coming Saturday so no hard numbers, but I can tell you seat of the pants was great! The car used to do a pretty good burn out in first then fall on it's face in second, now with the new gear, the car pulls through every gear, to say the least I was impressed. Right now I'm just screwing around with what came with the car and for no more than I have in it she runs pretty good-for a street car-I know when I go to the track Sat. I'll probably only see mid 15's though, but what do you expect for 122,000 on a 305.

 

There is a rule of thumb equation from doing gear swaps but I forget it, I would say look for .4-.6 at the most.

 

I just swapped from 2.77 (9 bolt) to a 3.45 gear.

Before
60 ft 2.126
1/4 mile 15.477 @ 85.33 mph

After
60ft 2.066
1/4 mile 15.539 @ 86.92

I wasn't excited to see that my 1/4 mile times actualy got worse but there was a great improvement in my 60 ft times. I'm guessing that the engine setup that I have in there right now just doens't support ANY top end power. If your setup has more top end power I'm sure that you'll make gains in the 1/4. I wouldn't expect more that .3 though.

 

I was just gonna say you might actually slow down but someone just proved my point. The 305 is a low end torque motor that is quicker when pulling through a lower gear ratio.

 

This is a perfect example of what I have been trying to tell some people that didn't believe me to match your cam to your gears, which I failed to realize at first and I didn't gain any time either , that was using a G-Tech. I'm going to bookmark this page.

 

As long as we're talking about performance gains, when I did the 3.42 swap I could roast tires forever 26"ers, that was with factory single exhaust, performer dual plane intake & Holley 600. Yesterday I got my car back from the exhaust shop, they put on a set of Heddman long tube headers, and true dual exhaust 2.5", blowing through "Flowmaster knock offs", as of yesterday I lost all torque, could barely power brake, now I don't know yet if they got the distributor a tooth off or what they had to pull off A/C condensor, brake booster, & distributor for header install, (I am trying to get line locks, driveshaft loop, tach hooked up before Sat, plus still has to go back to exhaust shop for H-pipe, and fine tuning) so I got to play around a little more. Maybe the carb needs adjusted as it went from 50 degrees outside to 85-91degrees in the past 3 days.