Ctrl

Greetings.

I'm a relatively new 7 owner. I've had a 85 GSL automatic for about 6 months now and have lurked here long enough to understand the basic concepts of the rotary engine and it's performance tweeks....but I still have many questions.

Last weekend my automatic tranny went kaput.

N=1st gear, but if you back of the gas, true nuetral appears.
R= locked in "park" but engine working against torque converter, hence in gear. WOT moves it nowhere, but engine struggles at max 2500 rpm....going nowhere.
P= same as R with roughly half the engine load.
1st, 2nd, D & O/D work as normal.

My linkage upon visual inspection appears fine, so I think something internally is messed up in my auto-tranny.

Anyhow, I never liked automatics to begin with so I'm going to pull a 12a (my engine) 5 spd tomorrow at the boneyard, and the related hydrualics, pedals and cylinders to go with it

I know it's a big job, and thanks to the advice of darkfrost who's done it before, I want to fix this myself.

Here's my dilema and where my questions begin.....

I have a 12a now and there's a 12a in the boneyard ready to have it's gearbox yanked..... if I want to upgrade this winter to a 13b turbo, will I still be able to use this tranny with it. How about the same drive shaft with it?

Also, my GSL has the LSD, does the flange on the rear end's input shaft meet up with the various engine/driveshaft combos?

I don't want to fix a tranny , especially the hard way with an auto-2-5spd swap only to find I can't use it later with a 13b.


TIA

inuissus_cendi

from what I know (not experience, just reading alot on this forum) you CAN use a 12a 5-speed transmission with a 13b, but its not going to hold up very well. There are a few modifications I think you would have to make also. If I were you I'd stick a Turbo II transmission in there now. You'll need a custom driveshaft and some mounts to hook it up, but it can also hook up to a 12a, it has higher gears, and it will hold up to all the torque when you stick your 13bt in there. Many people stick in the Turbo II tranny when they turbo a 12a, so you can find some help with that on here.

hornbm

all rotayrs have had the same tansmission bolt pattern since 1974. THe only exception is the FD auto, which had one extra bolt hole, but still had the required bolt holes for the manual tranny.

Ctrl

I was hoping I could get away with a weaker rear end if I refrained from jack rabbit starts and gently eased up to cruising speed.

I don't want a dragstrip 13 second racer..... I want a road racer..... think I still need to upgrade?

Ctrl

Best news I heard all day.... thx

Ctrl

Well I took the day off work today and snagged a 12a gearbox from the boneyard, both cylinders, both pedals etc. etc. ....every single thing except for the shifter ****.

Should I bother getting the tranny rebuilt or would simply changing the input and output seals keep me going for a few years?

IOW, if it was your money, would you chance it and just do the seals?

Oh yeah.... does anybody have the dimensions of RB's lightened steel flywheel?

I'd rather machine it to the same specs than pay their outrageous price for a 15 minute job on a milling machine.

Ctrl

It's been colder than a witches tit since I grabbed my parts, and I lost my ambition to fix my car as cold at as it.

I've taken it to the local shop. rx7 specialties for this swap over of transmissions.

I've been thinking that since I'm already paying for the tranny/engine separation, now's probably an opportune time to get my 12a street ported.

Here's my question... If I hold off due to budget, for a better carb and exhaust headers can I still expect some increase off the porting or am I just pissing gas out my exahaust pipe?

T_Racer

iTrader: (1)

just my .02, but you are putting off the inevitable. 12a's can be made much more powerful with just header, ignition, and carb so they are an obvious restriction, so I would do those first, get the tranny in, get the suspension and all sorted and then go after the SP and/or turbo setup.

Also, get a GSL-SE rear end. stronger, larger axles, better bolt pattern, of course will need to change the front to match, but better all around. And cheap too. Not sure about the flange dimensions, though may be the same. Broke about 2-3, then ran out of supply on our race car, Auto-X/Solo I/Hillclimb, went to GSL SE rear end, have 12" slicks and not broken yet, with Two aggressive drivers.

Though on a side note, it is fun watching peoples face when the car is on sticker tires. will lift the inside front tire about 2-3" off the ground, and if you left foot brake in a sweeper, will just carry it. I know, less front roll stiffness, but it hooks like hell now, and is fun!!!

Cheers,
Travis

Siraniko

iTrader: (13)

nah. Dont believe everything you read. Lots of them are bullshit. The 12-A tranny is fine for N/A application.

Ctrl

Okay.... I've got what I've been told is an LSD and I've got 4 wheel disk. If it means drums in back I'd rather not.

What's the story?

rotornoob

iTrader: (2)

well, from what i have read and judging by the 4 wheel disk, either you have a GSL-SE rear end already, or someone has upgraded the brakes to a 4 wheel disk setup. at least, that is if my understandings of what i have read are correct

Paradox

iTrader: (1)

gsls have the lsd rear end with discs.

sounds like you blew your auto valve body to ****. getting that repaired may be cheaper than a 5spd swap. but half as much fun