Just ordered the Ford Racing 4.10's from Mustang Tuning

$275, added the install kit “carrier shims and new pinion bearing" as suggested by this thread. Will stop by Ford and pickup the Gear Lube & Limited Slip Additive.


Can't Wait, and Thanks Again For The Great Advice.

 

i would just like to add that on top of using your horsepower more efficiently, the torque multiplication that is a huge player in improved acceleration actually provides you with a great deal more real world torque to the ground AT A GIVEN SPEED (power at rpms wont change, but just as tightening that bolt with the end of the wrench is much easier than holding it near the tip). this means that you in essence have extra torque at the rear wheels to overcome the air and mechanical drag more effectively, thus increasing your top speed (NOT you "top end" which is a generic term for the "geared out" top speed were you to have the power to get there). the reason for faster acceleration is a combination of this increased rwtq (and yes, dyno's do have to be adjusted for your gearing/tire size to give more accurate hp readings) at any given mph relative to the ground, and the more efficient use of the engines available power.

a good experiment is to get an 18 or 21spd bicycle and try taking off from a stop in different gears. notice that in the lower gears (not nec the "lowest" gears, but closer to that spectrum), you will accelerate to about 10mph MUCH faster than putting it in the equally high gears to start. notice also that you will be able to reach a higher sustained top speed around gear 3/5 than in gear 3/7 because of the extra torque that your wheel puts to the ground, making it easier to sustain and increase pedal speed. notice finally that while gear 2/3 will accelerate from a stop MUCH faster than gear 3/7, it will max out and someone who started next to you at the same time in gear 3/7 will eventually pass you given the fact he/she has enough leg power to overcome the gearing. its a balance between effective use of the increased torque (aka TRACTION), engine life (too much revving high will put more mechanical wear on parts), top speed (least important part of equation), acceleration, and for drag racers most of all: what gear/rpm/speed you cross the 1/4mile line. for most of us, 4.10s or 4.30s are what compromise all those in the most enjoyable and productive way.

hop this was accurate/helpful
-Geoff

 

I live in Southern California and I'm wondering what I could expect to pay to have gears installed and the names of a good shop to do it. Anybody have ideas?
Thanks
Greg

 

Wow! Dude. www.ebay.com

 

I know, guess the over excitement got to me ! Did call MustangTuning, and they dropped it down $20.

They also offer free shipping.


Thanks Again

 

Didnt I read somewhere the ecu must be programmed to the new gears? It knows you should be only going XX mph at XX rpm's, and with new gears it will be off, causing a limp mode?

 

I've also found Amsoil synthetic gear lube at $7.55 per quart. Good or Bad experience with Amsoil?

Synthetic Gear Lube SAE 80W-90 (AGL) Is this the correct viscosity?

https://www.amsoil.com/storefront/Se...?CategoryID=39

 

Jus tinstalled 4.10's about 4 days ago... I love them. I have a GT 5 speed... the increase on the highway in RPM was very minimal way less than i expected. Sometimes i think i should have gone with 4.30's. I drive the car daily in the summer and so far i love these 4.10's...

 

If you have an SCT X-CAL2 you can retune it yourself, it's one of the parameters in the tuner. I'm about to pull the trigger on 3.90s myself (I have an automatic) and asked the same question before I order them.

 

Can't speak for Amsoil, but the factory calls for 75/90 synthetic. I have a Diablo prgrammer and it took all of 5 minutes to change the parameter in my custon tune and reload it. Piece of cake.