i was wondering wish one is better. it seems that the se is better then the gsl hp diff and so on but all i see is videos of the 12a model being modified and not the 13b why is that? is it because the 12a gsl is better then the 13b gsl se?

 

Which one is better?....I can't wait to hear the responses.
I think you'll hear meatballs from both sides claiming whichever car they own is hands down the better car.
In reality it depends on how much time, money, and skill you have, and what it is that you like.

I can almost feel the flames coming!

 

Well I'm an owner of a gsl-se but it's not fuel injected. The Se has the better suspention, disk brakes in rear, LSD (which is a BIG plus) & comes with the fuel injected 13B. Gsl owners often get Se suspention swapped into their rides bc the 4x114.3 fitment allows for a greater wheel selection opposed to the 4x100 & it's a stonger set up. I'm a Fan of the good ol' carb & feel in the long run it means less headaches. @ the end of the day the facts shows the SE is the better of the 2.....

 

I've got a GSL, but the SE is definitely the "better" car. In the case of how it's equipped anyway. It's got more power at the expense of very little extra weight and a much more common bolt pattern. The brakes aren't really that much better, GSL's have discs all around too as well as an LSD. However the GSL is probably a little easier to work on since there isn't as much electrical equipment. Aside from that they are fairly similar. Both have sunroofs, power windows and mirrors. The SE trans has a taller 5th gear so you cruise on the highway at a lower RPM, thus saving a bit on gas. My car now has a Sterling carbed 4 port 13B with an SE transmission, but still 12A spec suspension, albeit heavily modified.

The reason you see more modified 12A's is simply a matter of numbers. The RX-7 came with a 12A from 78-85. The 13B was only offered in 84 and 85. There are just way more 12A powered first gens out there. A lot of people stick with what they have or go with a TII swap. A lot don't bother with swapping a 13B that only has 35 more HP.

 

ok i see so its still better to modify the 13b right... 35hp is 35hp u can feel them but the engine has more feature or its just the same. both will hit the same times in a strip?

 

My prefered GSL-SE engine mods:


RB intake with edelbrock 600, RB header, GM HEI ignition mod, and e-fan. Ugly car, but runs rather good.
Ignore the throttle return spring, that pic was from the former owner. I've made a few minor changes since then.

I've also got a 12a car, as seen in my avatar.

 

Premixing??

 

Of course. The OMP is gone, as is everything associated with it. Car came with a 1/2 full gallon jug of MMO.

 

i love the driveability and the reilability of the stock GSL-SE engine. its much smoother and more fuel efficient than the 12A, not to mention more powerful. though both engines are extremely reliable and powerful in their own regard. the SE is the "better" overall car due to not only the larger brakes and larger wheels, but the cloth seats are marvelous and nicer overall than the the S and GS seats. the GSL seats are identical to the SE's seats in function but they have a soild velour on the upper and lower bolsters that opposes the striped pattern. it really comes down to preference though because some people prefer less equipment and favor the carburetor on the 12A over the EGI (electronic gas injection) of the SE. i personally prefer the EGI 13B, so i swapped the 13B EGI engine into my 85 GS and retained the fuel injection. its basically an SE without the wheels and brakes.

 

the GSL-SE is one of the best overall cars Mazda had ever built, #2 is the 90-97 miata. Both of these make excellent daily drivers, fun, practical.

#3 might be the rx8, but it's a little soon to tell, we used to see 300,000mile GSL-SE's all the time on the factory engine, the rx8 is fun just like the SE though...

 

Keep in mind that while both GSL's, and SE's both had disk brakes;
The SE's are larger and VENTED on all four corners.
The GSL's where solid disk in the rear.
The SE' also has a better rear end ratio of approx 4.09 vs
the GSL's 3.9.

There's more, and I am sure we could SEARCH to find it,
it's been a while since I actually thought about it.

Truth is, most FB's are somewhat modifed at this point in their life,
so the line between the two is significantly blurred.

Only time to really care is if you are "comparing stock to stock."
or shopping for aftermarket rims.

 

there is a vin split, only the early 84's are 4.09, mid 84 on is 3.9. its hardly noticeable actually, it really only makes up the difference between the gsl's 13" tire and the gsl-se's 14's

 

Where are you getting this information from?

US SPEC MAZDA DRIVELINE RATIOS

*** FIRST GENERATION ***
……………………………………………………………….…….………………………………..AXLE..FINAL.TIRE......TIRE..ENGINE
VEH.. YEAR. 1ST.. 2ND...3RD.. 4TH...5TH...RATIO RATIO SIZE……....RPM...RPM @ 60 MPH
RX-7. 79-83 3.674 2.218 1.433 1.000 0.825 3.909 3.227 185/70-13 892...2878
RX-7. 83-83 3.674 2.218 1.433 1.000 0.825 3.909 3.227 195/60-14 891...2875
AUTO. 84-84 2.458 1.458 1.000 0.720 N/A...3.909 3.909 185/70-13 892...3487
GSLSE 84-84 3.622 2.186 1.419 1.000 0.758 4.083 3.097 205/60-14 878...2719
RX-7. 84-84 3.622 2.186 1.419 1.000 0.807 3.933 3.175 185/70-13 892...2832
RX-7. 85-85 3.622 2.186 1.419 1.000 0.807 3.909 3.156 185/70-13 892...2815
GSLSE 85-85 3.622 2.186 1.419 1.000 0.715 4.077 2.914 205/60-14 851...2480
RX-7. 85-85 3.622 2.186 1.419 1.000 0.697 4.444 3.099 205/55-14 910...2820

84's had a 4.083
85's has a 4.077

SE's never came with the 3.909 gears.

 

I looked in the parts catalog, the GSL-SE has a different part number for the r&p for 84 than it switches to the 12a part.

I've also taken a couple apart and verified it, the part number is stamped on the gear

 

the info that i've found on the 84 vs 85 GSL-SE rear axle ratio was found in the factory brochure's and the owners manual for the 84 and 85 RX-7. the 84 lists the ratio at 4.076 and the 85 is listed at 4.076 as well.

the difference i've seen between 84 vs 85 axle ratios are that in 84 the non SE is 3.933 (regardless of limited slip or not) and in 85 the non SE was 3.909. in looking through the parts manual it shows a different part number for the SE's rear axle through Nov 84 production and from Dec 84 production. it does not list a specific gear ratio as it does for the other non SE trim levels. the parts manual does list a 3.909 rear end availability for the SE from the Dec 84 production, though that part could be a misprint. you guys can download the manual from SgtFox's website and verify as well.

 

So are you guys saying that some early 84 SE's could have come with the 3.9 rears?

 

based on the parts manual, yes. i guess the only way to find out is to find someone with an early SE and pull the diff part and count the teeth on the ring gear, lol. my SE is a 2/84 build.

 

per the parts fische.... see 27-110, gear set final? i guess actually december 1984 makes it early in the 1985 model year....

 

That seems like a misprint or an error of some kind.

It says the gears are 4.076 though to Nov '84.
Then Later
From Dec 84' and on (until the next manual) it's 3.909

The way it's written, - SE's from 12/84 an on would have a 3.909.

We know the 85's had 4.10ish gears - so I am still leaning on misprint here.

Perhaps they they meant regular GSL's?
Both gears (3.909 / 4.076) are interchangeable in the pumpkin, aren't they?

 

I'm with DF here, gotta be a misprint.

 

i've found in taking a couple apart, that the ring gear is stamped, it'll have the "m090" on it. it makes it pretty easy to tell that the parts catalog is actually correct.

 

Hahahaha I am on my phone and I was like I know that car. the good ole days

 

"M090" are listed as GSL-SE's only. (4.076.)

 

Yeah, you know that car. Might have been a couple years since you saw it, but it's still much the same as it was back then, for now......