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3.73 and auto trans question

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Old 06-23-2011, 01:18 PM   #1
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Default 3.73 and auto trans question

Ok, I'm pretty close to pulling the trigger on 3.73 gears for my auto convertible. I've found a good shop to do it and have a reasonable price. I drive about 20K a year, with about 15K of that on the highway. However, about 50% of my time in the car is spent in city driving. Atlanta traffic sucks. People drive aggressively here, and there are constant merges, hills, lane changes, etc.

I know that the 3.73 gears will improve my acceleration at the cost of a lower top speed. There are lots of threads on that. My question is a little different. I'm really not trying to improve my 0-40 mph acceleration per se. With the CAI and 93 tune, the car is pretty quick off the mark as it is. I am not going to race the car. The real issue for me is that the after reaching about 40 mph, the car reaches its tall gears and loses all torque. The engine lugs when I have to accelerate, pass or go uphill. Compared to many other cars I've owned, the Ford transmission is very bad about recognizing that it needs to downshift. I tend to drive around town with one hand on the overdrive lockout.

So my question is for those of you who have an auto trans and have changed to new gears. Do they improve your improve the overall drivability of the car, esp in the 40-60 mph cruising range? Do you get faster response and more torque when you need it?


2008 V6 auto convertible. Go: GT duals/custom H pipe, front and rear GT sways/poly bushings, Brenspeed tune and CAI. Show: Blackout panel, painted mirror caps, 17" Bullitt rims and Pirelli Pzeros, GT front bumper.
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Old 06-23-2011, 08:10 PM   #2
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I had 3.73's at one time in my automatic convertible, and do a lot of highway driving. I don't recall it being an issue in the 40-60 range or making quick lane changes on the highway.

But, I will say that the worst modding decision I ever made was trying to build a 7.5 with tlok and gears. It would have been cheaper to simply swap the rear end for an 8.8 by the time I was done - after paying for the parts and the installation. And then I didn't learn I guess and ended up taking it elsewhere to try to get rid of the whine.

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Old 06-24-2011, 07:31 PM   #3
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Ihave a 8.8 3.73 setup in my convertible with 93 tune. Only thingextra is i have a aluminum driveshaft. The gears made a huge difference for me, i drive mostly highway.. love the car, its damn quick for a v6 mustang, i have no problems with the aggressive drivers and idiots of memphis.
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Old 06-25-2011, 05:09 PM   #4
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That loss of torque feel will dramatically be reduced with 373s. It'll still be there, but not as bad. Yeah, no fun flooring it and it's taking its sweet time to get accelerating in 3rd or 4th gear.
Mike - 2005 Stroked/Forged/Cammed V8 (5.0L.); twin-turbos . [previous: 2.6 KB, in sig pic]
- 2006 4.0 V6 with PH Turbo and TR6060
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Old 06-27-2011, 09:44 AM   #5
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I never once regret going with a 3.73, in fact at times I wish I would have went with a 4.10. Most of my driving is around town but I still take it on the highway occasionally, over 100mph, and don't notice any limit in the top end other than the craptastic factory driveshaft. Definitely go for it!
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Old 07-04-2011, 09:30 PM   #6
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I have heard that the rule of thumb is: Automatic go with 4.10's, Manual go with 3.73's.
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Old 07-05-2011, 09:44 PM   #7
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I went 4.10's and am perfectly happy with them, yeah it revs a little higher on the highway but to be honest, I dont really even notice it. The improved acceleration is well worth it to me. Auto here by the way.
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