Drivetrain Sorry For Bludgeoning A Dead Horse...

Dave Garber

Member
Apr 2, 2016
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... but I've been digging around and can't find a concise answer to this oft asked question:

I'm putting my 90 LX 'vert together with the goal of running mid 13's, maybe low 13's. It's primarily a sunny day cruiser that I'll 'play' with from time to time (I'll go with the stock block, Comp Cams XE270HR, TFS 170 heads, GT40 intake - pretty basic).

Anyway, it's got the 2.73 rear gear set. I was all set to order a Ford Racing 3.73 gear set, but before I pulled the trigger I figured I'd do one more round of research and came across some topics concerning the effect on first gear with 3.35's, vs 2.95. Seems that my car's 3.35, combined with 3.73's, would make 1st pretty much useless (like a pickup truck granny gear). This is something I never once considered, and now I'm not sure what to do. I see guys running this gear all the time, and I'm wondering if they're running a 2.95 1st, or just dealing with the steep 1st ratio.

For my purposes - mostly cruising around, occasional stoplight stuff, and a few trips to the track, what do you folks suggest?

Again, sorry for bringing this up again, especially as a first post. I guess my goal here is to get some feedback from those running this type of setup to help me decide.

Thanks!
 
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First gear becomes very steep after anything over 3.27. I have 3.55 in mine and I can hold it in first for a bit, but it's really just to get the car moving. In comparison my friends 95 with 4.10s is basically out of gear by the time you let the clutch pedal out. It's a very quick shift into 2ND and 3rd is where you you can start to wind it out.
 
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Thank's for the reply. Interestingly, I found an article from Hot Rod Magazine where the author feels that a total first gear ratio of anything over 9.5 is overkill for anything other than a dedicated track car. He's essentially saying that my 2.73's are almost perfect as they work out to 9.14.

I'm starting to think I might change tactics and look for an entire rear axle out of an SN95 with the 3.27's and see how it goes. What to do, what to do.

Thanks again for the reply!
 
See below - this chart uses stock tire size and stock T5 gear ratios.

gear-ratio-charts-jpg.553834
 

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For your car a 3.73 would be fine and the minimum i'd choose. If it were me i'd do 4.10 as it would compliment your mods great and get that heavy vert moving. I have 4.30's in my streeter and 1st isn't useless.
 
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With your mods....3.55 at a minimum. You need a little gear for that cam,intended use,etc. 73's would be my recommendation. And :bs:
On the "useless" 1st gear debate. Track car=3.73 or 4.10's---Street=3.27-3.73 and just a daily driver/commuter =stock(and buy a Prius if youre so worried about gas mileage).

Hell I'm old enough to remember non overdrive transmissions. Nothing like 3400rpms at 55mph(4 speed with 4.10 gears) to suck in the mpg category lol.
 
Thanks for the great replies, guys! It's very much appreciated.

Just to be clear, I'm not the slightest bit concerned about fuel economy. This car is my toy and only ever see's dry, sunny days. This is from the HotRod Magazine article that led me to this post to begin with:

"We started out with a broken T5 purchased from a friend for $25. Then we contacted Don Walsh at D&D Performance to find out what we had. This is a case of doing it backward-we should have done our research first, but the price was right. "You have one of the crappy 3.35 boxes," Walsh told us. "The best way to go is to rebuild it with one of our 2.95 low gearsets. Then you'd have a nice trans." That's what we did

If your Mustang has a 3.35 First gear and a 3.55 rear gear, the overall First-gear ratio is 3.35 x 3.55 = 11.89. Anything greater than 9.5 could be considered overkill for the street. Ever driven a Mustang with a 3.35 First-gear trans and a 3.73 rear? First gear is virtually useless, since the overall ratio is 12.49. This is why a 2.95 First-gear T5 or the Tremec 600 2.87 trans is far more desirable if your plans include deep rear gears."


It was that article that started me digging and where I first came across concerns related to first gear being overly steep. Final drive ratio is of zero concern to me as well - I was just concerned about having a first gear that would be little more than drop clutch/shift into second.

Based on the excellent chart jrichker posted, along with what you guys are saying, I'll probably go with the 3.73's I originally intended to go with.
 
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I agree that first year is useless with the 3.35 first and 3.73's.

Honestly, I'm not a big fan of the 3.73's since I love to do a lot of highway cruising. Typical highway crusing speed for me is 75-80MPH (that's flow of traffic believe it or not) and with 3.73's, that's around 3K RPM in 5th I actually prefer to cruise around 2K RPM, so in my case, I'm really eyeing a change to 3.08's or 3.27's.

I drag race, or do 0-80MPH runs very rarely. Most of my driving is done 40-80MPH.
 
:dead:
I mean really guys? With a title like that nobody added the guy bludgeoning a dead horse?
#disappointed
Hey! He's like me asking about my mini-tubbing. He knows he wants to do it, just wants someone else to help point out how smart he is for choosing to do it!:nice:

I got 3.73's, now if my car were just at the stage to be running......
 
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Just relearned some of this! I put an S10 four cylinder T5 in my Chevelle a couple years back, with 336 gears. First was just like a friggin dump truck. Now has a tko and 373s, perfect.

Two weeks ago I put a 91 Mustang T5 in my 89 2.3 coupe, in place of the A4LD. It has 373 gears, and first gets going easily but needs to be shifted quickly. Does not seem as bad as the Chev, but I see why Ford put 355s in the 2.3 stick cars. Its worth paying attention to.