What effect(s) would switching from the stock 2.73 gears to 3.42's or ??? have on my '01 Z28 A4 coupe? I noticed on the HyperTech PPIII that I can program it for different rear gear ratios, so that part seems easy enough. Will different gears affect passing smog test? mpg? What gains in performance would I see going to 3.42's vs. the 2.73's?

What brands are best for my car? You guys know, all the "usual" questions.... LOL...

Thanks,
Daryl

 

I swapped my 2.73's for an entire rear out of an M6 car. Very pleased with the results. If you go this route make sure both cars have TCS/don't have TCS - they need to be the same. If you're just doing gears consider 3.73's too. Gear changes won't effect smog tests, but will hurt your gas mileage some. To see what RPM's you'll be running with different gears check out www.f-body.org/gears/

 

wont he have to change carriers if he wants to go 3.73s, or do they make 3.73's for those 2 series carriers(They are 2 series right?)

 

3.23 or higher gears require the 3 series carrier (about $100). A few manufacturers make higher gears for the 2 series but its better to go with 3 series gears. That's why I bought a 3.42 rear from someone upgrading to a Strange - good price, easy install, no whining, etc.