I want low end grunt AND I want a fairly QUIET set-up. I don't race the 1/4 mile, so I don't need the absolute STRONGEST set, just a replacement that is as strong and quiet as the 3:55s that are in there from Ford. I drive on the hwy at about 80 mph (ATL) so I don't want to be above 3500rpms in 5th. Do you guys have any suggestions/recommendations/experiences that you would share with me please- Thanks in advance- Doug

 

I think the 4.30's would be too much.....My 4.10's turn like 3k rpm at 80 as it is and I certainly wouldn't want more revs or noise then I already have.....If you want the grunt but don't want insane revs or rear end noise I'd say 4.10 is your best bet as you aren't planning to track it or make it a quarter mile car strictly......

John

 

r22tech, Just a quick calculation: 007swingle says he turns around 3k at 80, and he has 4.10s. The final drive in 5th of the auto is .75:1 and fifth in the manual is .67:1. That is around 10 to 11 percent slower for the manual. The difference in the gears, on the other hand is around 5%, so my assumption is that, even if you got the 4.30:1 gear set up, you would still turn about 5% lower revs at 80 than John.[I] Someone more knowledgable correct me if I'm wrong.

 

On the other hand, I'm not sure you'd notice that much difference between 4:10 and 4:30 gears. Also, if you are concernced about driveability and noise, then more moderate is almost always better. Good luck.

 

If your only requirement is to turn less than 3500 RPMs at 80, then you can install any gear less than 5.20 with a P235/55/R17 tire.

You can calculate RPMs for a given gear here.

 

Since it seems you have the 4.10s AND a manual tranny: How do you like the setup? Noise level compared to stock(I'm talking about rear end noise not noise associated with higher RPM)? Did you need a speedo recalibration? Do you feel it was worth the $500+/-? Should I be significantly concerned about the installer, or is the job a no brainer for a Ford tech? Any and all input is appreciated...I haven't EVER changed gears on a car so I don't know what to expect. Thanks-Doug

 

Go with a set of Ford Racing 4.10s they are a good quality part for a good price.

 

You will need a speedo recalibration for sure.....any tranny or Ford shop should be able to take care of you....same rear ends and gears they've been installing for years so no concerns there.....as far as being worth the 500, it was WELL worth it....woke up the car so much with just the gear change and no performance mods...you'll be pleased.....later!

John

 

I like my 4.10s. I notice a big difference in 3rd and 4th. I can't tell any difference in noise at all. It cost me $189 for the Ford Racing gears and $300 for the install. I was told it was important who did the swap so I took it to a hot rod shop about an hour away. Before I took it in, I called my Ford deal and they told me they could adjust the speedo. When I took it to the Ford dealer they told me their software would not allow them to input anything higher than 3.57 into the computer. The service manager said it was not "approved" by the EPA probably.

I'm waiting for the DiabloSport Predator to be released next week so I can reset the speedo and install a tune.

 

Xcalibrator should help you out with the speedo...not to mention many other things about the car present and future.

 

4.30s are not too much for this car if you see a lot of track time. 4.10s should be about the perfect street/strip gear. 4.10s are perfect on the 2V cars, and the 3V motor is a tad more rev-happy, so it should be even nicer. Plus the wheel diameter differences mean that 4.10s on a 2005 GT are the equivalent of a 3.99 ratio on a 99-04 car, so it won't be quite as much gear as on the previous cars.

Just get the 4.10s and enjoy!

 

OK. I am sold on 4.10's...searching for stores as soon as I get done typing here.

 

 

I've never upgrade the gears on my car, how exactly do you recalibrate the speedo? Im not sure what you all mean when you talk about a speedcal, wouldnt this be something that has to be changed in the computer/tune to keep everything accurate? (odo, mpg meter, etc).

 

SCT Xcalibrator does this with a couple clicks of the mouse and reflash

 

Since it seems you have the 4.10s AND a manual tranny: How do you like the setup? Noise level compared to stock(I'm talking about rear end noise not noise associated with higher RPM)? Did you need a speedo recalibration? Do you feel it was worth the $500+/-? Should I be significantly concerned about the installer, or is the job a no brainer for a Ford tech? Any and all input is appreciated...I haven't EVER changed gears on a car so I don't know what to expect. Thanks-Doug
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NO, this is not a no brainer install threy must be shimed in for the correct track ( MESH)and stay away from super low price on the gears.If you are going to install FMC gears I would have them install them and get your computer flashed by someone else. Any Ford part they install is covered by the warranty

 

If your State does dyno emission vs tailpipe tests the lower gears could cause you to fail a smog inspection. I may be wrong but I would ask a really sharp smog tech. Increased RPM vs MPH it's worth checking out!

KC

 

Hey Doug.... the gears that come stock are Richmond, as are Ford Racing parts. It's all part of the Dana corporation and Ford has been working with them forever. The Ford Racing gears will hold all the HP you can throw at them.

Here's a Gear/MPH Calculator that you can use to play with tire size and gear ratios.... I don't ever want to do the math myself, so I keep this handy. Perhaps one of our boys (moderators) can make a sticky with this link.... I've posted it several times before.

By the way, here's your stock gear ratios so you don't have to look it up.

1st: 3.38
2nd: 2.0
3rd: 1.32
4th: 1.0
5th: .67

axle ratio: 3.55

tire size 255/50/17

 

I think the stock tire size is 235/55/17. :scratch:

 

I say go with the 4.10s, but if you plan on putting boost or nitrous to the engine then stay with 3.55 to 3.91 because your added hp will be able to "pull" the taller gears and allow you to have lower RPMs during daily driving. Short gears are good for short races and help engines low on hp.