Canadian Manual Gt's come standard with 3.55 rear axle. We have the option for 3.73 for $500. Is it worth it? Will you notice anything? Or should I just buy aftermarket 4.10 gears?

I know the U.S Gt manual comes with 3.31 as standard. I would imagine a switch to 3.73 would be more noticiable than our option. Any input would be appreciated...

 

can't quantify if it's worth it, it's your money
for me with this car at this time i went for the most performance, i.e. 3.73s

here is from a thread i made called speed in gears about the mph/100rpm in each rear gear ratio/tire size/trans

so I input the various ratios available for the 2 transmissions offered into a gearing/mph calculator to give an idea of the speed@1000 rpm.

pick your motor, trans., tire size and ratio to see what rpm's you will be turning at any given speed.

MUSTANG GT
235/50/18 tires
MT ratio rpm 1st 2nd 3rd 4th 5th 6th
3.31 1000 7 10 14 19 24 38
3.55 1000 6 9 14 17 23 35
3.73 1000 6 9 13 16 22 33

245/45/19 tires
MT ratio rpm 1st 2nd 3rd 4th 5th 6th
3.31 1000 7 10 15 19 25 38
3.55 1000 6 10 14 18 23 36
3.73 1000 6 9 13 17 22 34

255/40/19 tires
MT ratio rpm 1st 2nd 3rd 4th 5th 6th
3.31 1000 7 10 14 18 24 37
3.55 1000 6 9 13 17 23 35
3.73 1000 6 9 13 16 22 33

235/50/18 tires
AT ratio rpm 1st 2nd 3rd 4th 5th 6th
3.15 1000 6 11 17 23 30 37
3.31 1000 6 10 16 21 28 35

245/45/19 tires
AT ratio rpm 1st 2nd 3rd 4th 5th 6th
3.15 1000 6 11 17 23 30 38
3.31 1000 6 11 16 22 29 36

Given the 7000 rpm redline:
MANUAL TRANS cars will cross the 1/4 mile in 4th gear.
AUTO TRANS cars will cross the 1/4 mile in 3rd gear unless it can exceed a 112mph trap speed.

 

Thank you for the information...

 

I was building my GT yesterday with the salesman and he made it seem like you had to choose the 3.55 or 3.73. Isn't the 3.31 standard? What code do you put in?

 

if you are going with the standard rear end ratio nothing is put in only the transmission you are going with

 

3.31 is the standard equipment gear with a manual trans at least in the U.S. cars.

Verts have no optional gear.

A 4.10 gear will be overkill unless drag racing is all you want to do since the 6 speed has such a short first gear.

Going from a 3.55 gear to a 3.73 is such a small change as to be almost un-noticeable.

 

My SVO has 3.73 gears, while the GT has 3.55's. Can I feel the difference? yes, but I don't think that it's enough of a difference to justify the cost.

IMO? From 3.31 to 3.55, yes. From 3.55 to 3.90, yes. 3.55 to 3.73, no...

 

Thank you!

I want the 3.73s, but in my circumstances for what I will use the car for and what I can afford, skipping the 3.73s and the brembo package is the smart thing to do...

 

Can't compare the SVO to the GT, the 1st gear on the SVO is like 4.24:1 vs. a 3.35:1 and not to mention the torque curve of these motors are so different.

I agree though..3.55's to 3.73's are not worth the expense.

Dave

 

Don't skip the Brembo package, heck that's really the only package at a minimum I would get.

Dave

 

Thank you for all your comments. You helped with my decision...Joseph...

 

But Dave, my car will probably never see any road course or autox duty. I really only wanted the brembos for the wider tires, that way I could switch to the GT500 wheels with ease. The 245/45/19's won't fit the 19x9.5 wheels...

 

dropped .3 in the 1/4 plus gained 4mph with my 95GT

 

If you are getting 3.55 gears standard I wouldn't make the switch. For US owners it's worth it to get the 3.73s over the 3.55 since it's the same price for both.

 

I was thinking the same so i am going to stick with 3.55's since they are standard here in Canada.

 

There was more to it than the gear swap from 3.55's to 3.73's, I'm not disputing your numbers but you will be lucky if going from a 3.31 to a 3.73 will get you .3 or 4mph in the 1320.

Dave

 

Oh I totally understand, its just I would still get it.

 

I had the dealer I bought my 2010 from re-spec their 2011 GTs. They were getting 3.55 gears but they changed them to 3.73 based on my recommendations.

 

Well I'm really thinking about it now. Since the dealer agreed to invoice+holdback, its only a $609 difference between the brembo pkg and the regular 19"s ...... ........

 

nope JUST a GEAR swap.. ran average 12.7's @ 108 with 3.55's 3 weeks later same track and conditions 3.73's ran a average 12.40 @ 112

NOTHING ELSE WAS CHANGED