What does it take to run the F trans?? (DOHC MX-3)

[av8ter]

I have decided that I want to use the Dohc Mx-3 engine for my festiva but I am wondering about the Mx-3 transmission. How is this trans different than the G25mr? (gearing? Size? footprint?) From what I guessed, I would have to run axles from an capri xr2 or 323 gt, and make all new mounts, modify the cross member, and make new shift linkages. Any one know for sure?

It just seems like I should use the trans cause I am looking for about 120hp to wheels, and I wand the hydro clutch.

Any input???


Kevin

[nonamekid]

The F series tranny will require axles from a pre-90 323 or from a non-turbo capri. G-series axles WILL NOT FIT. The output splines on the F-series are different from the G-series. In this respect the F-series are easier to get axles for. The F-series is the same basic footprint as the G-series and uses the same mounts. The F-series is just not as strong. The F-series tranny can be found in an car that has a B-series engine but does not have the E or G-series tranny .

[Safety Guy]

Does anyone know if the F-series is lighter than the Gs?

If so, might be the way to go for engines with less than 140-150 hp or so.

I figure the stock tranny should handle up to 100 to 120 hp.

The G-series would be for top end power.

What can the F-series handle? Even if it weighs the same as the G it should be an easier job since you don't need the intermediate shaft. Am I right?

Karl

[av8ter]

Could I use stock festiva axles?

I really want to run this trans so I wont have to baby the car once I get 120 hp.


Kevin

[nonamekid]

http://www.fordfestiva.com/forum/viewtopic.php?t=13743

read this post. This question has been asked a few times. I keep asking to get this stickied. But it never gets done. I am not upset at you, but rather that we have all the information on here, it is just spread out so it can be tough to find. If we had a sticky about the F-series transmission, it would make it easier for people. Also people have alot of questions about axles, but the information has been posted a couple of times. Good luck on your project.

The festiva axles will not work, in case you did not want to read that other topic.

I believe the F-series weighs about the same as the G-series. It may be a little lighter but not enough to make a difference. The F-series tranny is easier to swap because the axles are easier to find. There is no intermediate shaft, and even if there is one, how many pre-90 323s have you seen? There are still plenty out there. And the capri non-turbo are not too tough to find either.

With an F-series tranny I would not go more than about 140hp in the festiva with it. You are going to have problems with the tranny if you launch hard also. Matter of fact, you will have problems with almost any tranny if you launch it hard. That HP number varies also on how hard you drive the car. But if you have that much power in a festiva, why wouldn't you beat on it?!?!

[av8ter]

I'll probably stay 120ish hp assuming miata cams, header, 2,1/4 exhaust, and a new intake gets me there, and if i decide to turbo later on, I'll swap in a g trans.

Do you know how the gearing compares between the mx3 trans(hydro) and a hydro g trans?


Kevin

[nonamekid]

That information I don't have. But I did some reading and the mounts for the G-series are slightly different than the mounts for the F series. Also the F-series uses a 20-tooth input shaft spline, while a G-series uses a 22-tooth input shaft spline. This means the clutches do not interchange and neither do the flywheels. And when it comes to F-series trannies, I read that the protege has a more fuel economic final gear ratio than the mx-3. This would be a protege with a B8, not the BP because they had a G-series trannies. I don't know what tranny is mated to the B5 that is in the later proteges. Here is the gear ratio for one car I was able to find. Not all G-series cars have the same gear ratio.

1998 Mazda Protégé 1.8L/G-series
First Gear Ratio (:1) : 3.416
Second Gear Ratio (:1) : 1.842
Third Gear Ratio (:1) : 1.290
Fourth Gear Rato (:1) : 1.028
Fifth Gear Ratio (:1) : 0.775
Reverse Ratio (:1) : 3.214

[nonamekid]

This was taken from a Ford site. The 1st, 3rd, and 5th are G-series, the 2nd is E-series, and the 4th is F-series.

Trans Model First Second Third Fourth Fifth
G5M 3.31 1.83 1.31 0.97 0.750 (Probe2.5L/Escort ZX2 2.0L)
M5 3.45 1.94 1.28 0.86 0.69 (Tracer 2.5L, Festiva)
M5 3.3 1.83 1.31 1.03 0.79 (Escort/Tracer 1.8L)
MTX 3.416 1.842 1.29 1.028 0.820 (Capri Non-Turbo)
MTX G 3.307 1.833 1.233 0.97 0.795 (Capri Turbo)

[av8ter]

I guess I'll be shifting frequently!

[shorestiva]

I had a non turbo capri motor with a f series hydro trans. It had the same gear ratios as a hydro g series. I just used capri axles. You do shift alot but I liked it better than my turbo trans.

[av8ter]

I saw your vids, and cardomain site and was wondering what hp you are putting down? How does the capri gearing compare to stock trans? What size tires are you running?


Kevin

[Damkid]

i have an f-series trans in my car with a BP attached to it

[shorestiva]

hp was probly between 100 and 115 at the flywheel. Its been a while since I drove a festy with a stock trans so I can't really remember how it compares. I know a n/a capri has a 4.10 final and I think a festy has something like a 3.83 final. All my track passes were on 175/60/13

[av8ter]

Cool, thanks.


kevin