I know nothing on gear ratios

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I know nothing on gear ratios

July 04, 2011, 05:17:16 AM

so looking around a bit, supposedly my car has a 2.73 gear ratio in the rear axle by what the VIN sticker and tag on the rear axle say...... stock '88 cougar 302/aod

how does the ratio i have compare to some of the other ratios (the good one, not so great ratio, the so-so ratio ..... is it like the economy ratio because i can't seem to fathom its the neck breaker ratio

to me so far, i'm loving when i can push 26-30 mpg highway but then again, kinda wish it had just that little bit more get up-n-go :burnout:

I know nothing on gear ratios

Reply #1 – July 04, 2011, 09:47:53 AM

Despite the standard output 5.0's measly 150 horsepower and dreadfully limited powerband throughout the rpm range, better gearing will help it, and any vehicle for that matter. My friend had an 89 Grand Marquis. I have an 87 Crown Vic. Mine has 2.73s and that simply is ridiculous for a 4000 lb whale. That 89 seemed to wanna get right up and go, the RPM's in each gear went by quicker with fewer MPH, it clearly had 3.08s or 3.27s....I dont know what options were available in those cars. But it wasnt screaming at highway speed either...thank the AOD's good overdrive for that. At 0.67:1, with even 3.73s youre doing abut 2700 at 80 mph, which isnt too bad. I think 3.27s would be good for you. An even better compromise, and with the stock powerplant, throwing a drag gear like 3.73s or 4.10s wouldn't be worth your time. Something higher like that would be fun if you did the H.O. conversion or something even more powerful, but 3.27s would make it keep up with traffic better and require less out of your right foot just to putt around.

I know nothing on gear ratios

Reply #2 – July 04, 2011, 10:02:45 AM

I've been really happy with the 3.55's I have. I think they're a great "all around" gear. Decent gas mileage, great performance, rpm's are kept down. Nice.

I know nothing on gear ratios

Reply #3 – July 04, 2011, 12:54:43 PM

I'm with Vinnie, my f150 has 3.55 gears, as does my Sport. Snappy, but not too much so...I can't say on the mileage, as I've never drove mine for more than 20 miles, here and there...
If I was running a little taller tire out back, I'd keep 3.73s a consideration, however.

Get yourself a 3.55 gearset...you'll never regret it. :)

I know nothing on gear ratios

Reply #4 – July 04, 2011, 01:12:57 PM

You also have a 7.5 rear, 3.45 gears would be a nice improvement. A plus is there is a sale on a trac loc dif. in the for sale section,that is a good buy.

I know nothing on gear ratios

Reply #5 – July 04, 2011, 02:40:30 PM

Thanks for the input....I've tried to learn about this kinda thing but didn't have the time or ambition, altho I have not given up just yet.

As for buying today will have to wait only cause the transmission replacement is first on the list but at least I can decide what I want to get and start looking into the swap hopefully by the end of summer, for a winter project maybe

I know nothing on gear ratios

Reply #6 – July 05, 2011, 04:46:18 PM

Basically the car is falling on its face with a high gear ratio in the 300 range. I would use a minimum of 3.45 or a recommended 3.73. Here is a comparison of an 8.8 i just did.

This is the pinion gears side by side 2.73 Versus 3.73 8.8

http://i740.photobucket.com/albums/xx46/proguns/005-4.jpg

Available ratios for the 7.5 DIFF 2.73 3.08 3.27 3.45 3.73 4.11 4.56 5.13

I personally would use a 3.73 Final Ratio The 302 is low on HP and torque and its a heavy car. In my opinion for whatever it is worth a 3.73 is dead nuts.

I know nothing on gear ratios

Reply #7 – July 05, 2011, 05:07:53 PM

Available ratios on the 8.8 DIFF

2.73 3.08 3.27 3.31 3.55 3.73 3.90 4.11 4.30 4.56 4.88 5.13 5.71 6.14

I know nothing on gear ratios

Reply #8 – July 05, 2011, 05:22:45 PM

My vote is for 3.55 for a daily (had them in my Pig of a 92 Tbird SC and loved them). If its more of a weekend car I would recommend the 3.73s. Anything below that is going to be obnoxious to commute in.

I wonder what 6.14s would be like. I have to imagine you would be into the redline before your pants caught up with you.

I know nothing on gear ratios

Reply #9 – July 05, 2011, 06:27:53 PM

Well if he has a 7.5 3.55 is not available. Remember he is OD + LOCKUP. The TC came stock with 3.73 with Auto and it is equivalent to the 5.0 in many ways. That is HP and Torque. The 3.73 was chosen for the auto for its first gear overall ratio. The 5 Speeder came with the 3.55 but the later coupes were 8.8 My recommendation is 3.73 for whatever its worth. But going from a 2.73 to a 3.45 is like night and day. Thanks

I know nothing on gear ratios

Reply #10 – July 05, 2011, 06:30:06 PM

The 1/8 mile guys run the 6 series gears 88. I had 5.13 in one of my cars years ago. It was interesting for sure. !!!!!!!!!!!!! No problem pulling the wheels off the GROUND HONEST!!

Here is a photo taken by my brother many many years ago. Look at the left front wheel its off the ground. This car was HEAVY . I pulled the wheel up and my brother snapped the photo. That was 1971. But with an elephant under the hood built by me it was outrageous. Everyone egged me on to pull the wheels off the ground. EVERY DAY And i Obliged WILLINGLY

http://i740.photobucket.com/albums/xx46/proguns/017.jpg

I know nothing on gear ratios

Reply #11 – July 05, 2011, 07:08:04 PM

Something to keep in mind when dealing with an 87/88 Automatic TCs is the fact that many owners complained that they were horribly gutless. The fix for that was 4:11 gearing. I've come across a few in the salvage yards with 4:11 gears in them. Too bad those gears turn the TC T5 in a four speed.

I know nothing on gear ratios

Reply #12 – July 05, 2011, 08:44:19 PM

NUMBERS

4 speeder 1-1 high gear 3000 RPM 26" TIRE 1.00 forth gear Diff 4.11 = 56.5 MPH
5 SPEEDER in fifth 3000 RPM 26" TIRE .78 FIFTH GEAR DIFF 4.11 = 72.4 MPH

Automatic with .67 High gear if applicable I am going to assume this is correct i do not know.

3000 RPM 26" Tire 3.45 rear axle =100.4 MPH
3000 RPM 26" Tire 3.73 rear axle = 92.9 MPH

MY Camaro with 6 Speeder 6000 RPM Diff 4.11 sixth gear .5 Tire 26"= 225.8 MPH

I hope my math is correct YIKES!!!!!!!!! Thanks

I know nothing on gear ratios

Reply #13 – July 05, 2011, 09:11:29 PM

"I personally would use a 3.73 Final Ratio The 302 is low on HP and torque and its a heavy car. In my opinion for whatever it is worth a 3.73 is dead nuts." I just did this to mine and it made a world of difference. The guys at trans shop tried to get me to go 4.11 but I thought it would be to much, now I think it would have been fine. I can drive 70 and not buss the motor at all.

I know nothing on gear ratios

Reply #14 – July 05, 2011, 09:32:27 PM

Randynten Not much difference between 3.73 and 4.11 either is ok as far as i am concerned. If you have a 4 SPEEDER 3.55 is about all i can take. Randy when i use the word dead nuts thats GOOD. I did not mean using 3.73 gears was nuts. I hope i did not confuse you or me. Thanks. By the way the most common gear change i do in fords is whatever to 3.73 for autos and 5 speeds. On 6 speeders its 4.56. Most ford guys shy away from the 4.11 for some reason. I presonally like them depending on the final drive in the tranny. Theirs an old saying i use in the shop all the time to my guys. PERFORMANCE IS ALL IN THE GEARS. Thanks