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Auto Racing/Gears in the differential

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Question
I'm a little confused about the gears. One of The cars i'm looking at has 3.55 gears in the back. And it's labeled the "performance package". but also another car is equipped with a "track pack" with a set of 3.73 gears in the back. From what i understand one car is gonna launch faster than the other. What are the disadvantages of the one that launches faster than the other?

Answer
The higher numerical gear (3.73) is going to raise your engine rpm higher than the 3.55. This can be annoying if driving on the highway at a constant speed like 60mph. The higher ratio increases the torque multiplication as it is apploed to the rear wheels. It will give a better stoplight to stoplight performance. Increased wheel spin may result if performance tires ane not used. If you have an overdrive transmission you may be able to use the higher gear on the highway due to the reduction by the overdrive ratio.

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Matt Lyons

Expertise

I am considered an expert in drag race chassis construction and tuning. I also have general knowledge of performance engines with small block chevies being my specialty.

Experience

I have worked in the automotive aftermarket as a builder, designer and seller of race components. I worked for Moroso Performance for seven years as an engineer and product manager. I currently am the owner of Lyons Performance LLC, a shop that specializes in American manufactured race products.

Organizations
NHRA, IHRA, SEMA,ASE, Alpha Omega Theta Fraternity

Publications
Muscle Mustangs and Fast Fords

Education/Credentials
BFA-New York Institute of Technology, Marketing

Awards and Honors
1998 SEMA best new product Award -Racing Vacuum Pump

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