gear swap.. performance increase?

[RedGTS]

A lower (higher numerically) gear ratio will increase performance by multiplying the available torque at a higher rate. Gears are tremendously helpful on cars that don't make much torque at low rpms, such as a 4v Mustang Cobra. Vipers are torque monsters to begin with, but even still, the general consensus seems to be that a moderate increase to 3.45 or 3.55 is a very worthwhile investment, assuming the car is stock or has mild bolt-ons. Very high hp Vipers usually have serious traction problems to deal with that are only made worse by more gear.

Ronnie

 

[Eddie N]

i thought the whole theory behind a gear swap was to put you deeper into the powerband more often thus giving you more power? in another thread i swear i read something stating that the gears do nothing for performance, just more SOTP grunt? is this the case?

just curious.

- eddie -

 

[toddt]

Every time I see this topic I look in, hoping to get some hard performance numbers at some point.

Still waiting.

 

[GONABITE]

I will give some hard number on the swap soon my car runs 11.7's with the stock gear I am changeing them Thursday to 3:45's and head to the track next week.

 

[varanus]

My 2 cents.
It only makes sense that lower gears will accelerate harder and faster. Muscle cars have done that for years. The variable has to be
1. Traction-lower gear only quicker if you can hook as well as you did with the higher gear.

2. Your measurement standards. If its 0-30 with no shift, lower gears should win. But on a measured distance such as the 1/4 mile all kinds of things come into play. Extra shifts to reach the 1/4 mile mark, especially if you have mods to make you have to do the extra shift because of the higher trap speeds.

I think it is like road racing. There is no optimal gears for every use. Pick your battle, then choose the gear/power combo that best suits it.

 

[varanus]

BTW with warmed up Kuhmos on the street I was able to do 4500 rpm lauches with the nitrous kicking in at the end of first at 80 hp and full 200 in 2nd. Traction was excellent. My buddy was running a 200 shot on his viper with 3.07. We both agreed the acceleration was quicker with 3.54 but the shifts were coming up very quickly.

 

[Motor City Mad Man]

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:</font><HR>Originally posted by toddt:
Every time I see this topic I look in, hoping to get some hard performance numbers at some point.

Still waiting.

<HR></BLOCKQUOTE>

Here are some numbers for you. I had the stock gear and 3.45 gear swapped. No other changes. With the 3.45 gear I got a best of 12.25 @ 120 mph in the 1/4 at the drag strip. With the stock gear I got 12.3 @ 118. Also, using a G-tech to measure 0-60 mph with the 3.45 gears I got a best of 4.09 and with the stock 3.07 gear I got 4.29. Take it for what it's worth. The 1/4 mile times were done a month apart on the same track and the 0-60 times were done on the street in the same spot. But it takes some getting used to in how to launch with the 2 different gears. I can launch at around 3,000 rpm with the stock gear but only about 2,600 with the 3.45 gears without spinning like mad.

 

[WESTCOAST JASON]

I drive in between Vegas and San Diego usually 5-7 times a month. When I went from 3.07 to 3.55 I was tickled since I could actually feel better using 6th gear. 2000RPM in 6th is 100mph on stock gearing. 2450 is now 100mph with 3.55 - May not seem like much of a difference, but besides the better rpm
(IMHO) on the freeway, the car is also 'quicker feeling' and feels like it shed some weight. Traction problems are about the same for me, (mid level mods), depending on how the car is clutched I can make it grip or spin with either gear. I may be wishing I had the 3.07's back though as my car is going to Axis for a twin turbo gitup. Anyone looking for 3.55, email me first, maybe we can swap or something.....

Jason www.speedstuff.com