Anybody hear running around with other than stock gears? I was thinking about maybe 4.1, but then at the same time I think is that gonna be enough of a change in gearing to even worry about? but then I cant really go 4.444 and stay streetable because id be doing 5000RPM on the interstate... what are some of you guys running? also incase anyone maybe wants to see some numbers on gears, i did a quick calculation of speeds in each gear at 8000rpm on 20'' diameter tires (approx. 13'' wheel with 60/ tires) if someone might find it helpful, no since in it going to waste lol

Stock 3.909 gears

1st= 33
2nd= 55
3rd= 85
4th= 122
5th= 148

4.1 gears

1st= 32
2nd= 53
3rd= 81
4th= 116
5th= 140

4.444 gears

1st= 29
2nd= 49
3rd= 75
4th= 107
5th= 130

so final word. anyone besides me think it would be a waste of my money to go 4.1 gears vs my stock 3.909?

 

Since you have an 83, the in-between years, I dont know exactly what you have: small or large axle. I ran 4.10 for many years with no problem. Better launcher than a 3.90 and good for cruising as well.

If you want a 4.10, find a GSL-SE, early miata and front diffy out of MPV van 4x4. Grab the ring and pinion.

 

why? something better? or just tryin to maybe save me money?

 

I have a set of 4.444 for my gsl. Haven't installed them yet but i do most of my driving on the 1/4 mile and very little street driving.

 

'83 is a "small" axle (ironically stronger, due to the housing) with a large companion flange (like 84/85). Axle size is irrelevant for gears, presuming you are installing them in your existing pumpkin. You only have to worry about it if you are grabbing a whole pumpkin from another vehicle.

I have tens of thousands of miles on 4.88 (aka 4.875) gears, as well as many more in 3.909s and 4.08s and 4.30s. My favorite is the 4.88, but it does make driving seem a little like work when you aren't flogging it. The mid-4s (4.3, 4.44, etc.) are really nice compromises. 4.1 is okay, but it doesn't get me all excited. Don't forget that the only important thing is the overal gear ratio, which is determined by the transmission gear ratios, the rear end ratio and the tire diameter.

Many years ago, I did an RPM/Gear calculator in Excel that I still use today. You can insert four "cases" for side-to-side comparison. All the reference data is there for copying and pasting, too. Here is a screen shot of it. If y ou want a copy, shoot me an email. It is over the upload limit here.

 

well my main issue was the cruise rpm on interstate being so high, and the fact that redline in 5th gear only shows a difference in 8mph for the 4.1 gears. to me thats just not enough of a change in gearing for 500+ dollars. and if i go 4.444 i think itll be hardo n the car on the interstate (i cruise in the 80mph range) so itll be over 5k rpm in 5th gear. and also like 500 bucks. and whats this with the "pumpkin"? will the gears from racing beat not fit a stock diff housing? or is there something else better i dont know about? im going for cheap and easy

 

actually 83 could have large or small axle, something like 7-83 and later build date
have the large axle, im pretty sure there is a vin # around here somewhere where it tells the date/#. it should be in the 1st gen archives if it is not already. this question comes up all the time.

 

you guys are crazy hahaha. i'm trying to fab up a 3.08 rear so i can have MORE gear

 

Thats what i was thinking...hahaha

 

if i had more than 150hp i would too, i love gear, only when i can pull it. later when (and if) i do the t2 swap ive been planning, ill proabably go stock gear or try for something more

 

I would very much like to know how you came by this information. Every single *stock* '83 I have every owned or seen had the small axles with the large companion flange (which confuses people who equate the large companion flange to the large axle size). I have never seen a reference to a large axle '83 in any reliable material and cannot imagine them doing that. It certainly is not in the Mazda Electronic Parts Catalog (EPC) and I confirmed this with Rob Golden, who was a Mazda dealer shop foreman. I've owned both early and late '83s and worked on many more. The usual confusion is that people hear that it was an "inbetween" year or similar phrase...and they are right: Mazda changed from the small companion flange to the large companion flange while keeping the small axle for one more year. But I am quite certain, from my own experience, that there were no large axle '83 cars, other than those that have been changed by a previous owner. This usually happens because the later cars are the only ones with the proper sized companion flange, so it was the easier swap.

 

perhaps it is because the later built 83 cars are titled as 84's?
i know for fact a 10-83 car i found in a junkyard had the large axle because i swapped it in my 84.

 

Now, I'm going to share a couple facts with ya all.

FACT # 1: The small axle rearends have a bearing outside housing diameter just behind the backing plate of 2 7/8 inch.

FACT # 2: The large axle rearends have a bearing outside houising diameter just behind the backing plate of 3 1/4 inch.

FACT # 3: Now please quit your going to get sore.

 

Yeah, it sounds like you got it from an 84 model year car, which would have had a large axle. There were no mid-year changes to the axle size, just one complete year that was a 'tweener with large companion flange and small axle.

 

Facts #1 and #2 are correct, which is the most reliable way to distinguish between the axles. Anyway, all the complete rear ends interchange just fine with the caveate that you also need the approriate driveshaft if you mix between 79-82 and 83-85...or you can swap flanges, if you are capable of it. If you are mixing and matching PARTS, it is critical to know the differences and similarities. Fact #3 is clearly erroneous. I am a professional.

 

***or you can swap flanges, if you are capable of it.***

This ^ would sound likea slam from a PROFESSIONAL.

 

Huh? Swapping the companion flange involves a bit more than the average enthusiast is likely to want to get into. Not tough, but it is a can of worms. Besides, swapping the driveshaft is waaaaaaaay easier.

I don't know if you were just being facecious (no smilies, unlike my post) or seriously accusing me of being arrogant, but I do happen to be a professional and tend to want to warn people before they go tearing into things they may not be ready for...particularly if there is an easier option.