So I’m rebuilding my 12a and considering a street port or even possibly a half bridge BUT I have an auto transmission. Can that transmission handle the power? And are there any downsides?

 

Generally speaking, the bigger you port it the higher the powerband shifts, and the less driveable it is at lower rpm's. The auto's try to keep the rpm's low-ish, so I'd be worried you'd be stuck in the low-mid range and never get to that new-found power.

 

**** well does anyone have a kit I can buy to do a manual swap on it then?

 

there used to be places that modded the auto trans, Level 10 here in the USA, probably long dead.
its been done, but probably not in ~20 years

 

there is no kit. u will need to source all the parts needed to do the swap. check the classifieds for a trans and pedal assembly. u already have the counterweight sp a lightweight flywheel and clutch setup can be gotten new as well as the clutch master, slave, and lines.

 

The "manual swap" would be you buying -
*Manual tranny for the same year range
*Lightweight steel flywheel (will mount to your existing counterweight) or used cast iron flywheel.
*New clutch kit
*Replacement pedal assembly w/clutch pedal
*New clutch Master and slave cylinders
*Manual shifter surround (easy to get new or used)

 

Nobody makes a kit for the auto to manual conversion. The ease of doing the swap depends on what year your RX-7. I would not put anything other then a stock port in an auto. The auto is a dog and can't even take advantage of the high revving rotary engine.

The 1979-1983 is pretty easy. Just need the comment stuff like trans/flywheel/clutch/master and slave hydraulics/hoses/clutch and brake peddle and hardware/etc.

The 1984-1985 require all the above plus welding in new trans cross-member body mounts. I've done this swap on my 1985 so I can offer some help.

 

I have an 85 if you could help me please I would really appreciate it this is my first time doing a tranny conversion and I would like all the help I could get please

 

Handy thread: https://www.rx7club.com/1st-gen-gene...tions-1120671/

The first step is to gather all the parts.

1. 1984/1985 transmission with shifter
2. 225mm clutch/pressure plate/throw out bearing/pilot bearing
3. 1984/1985 clutch and brake pedal with long through bolt and it's spacers.
4. Clutch master/slave cylinders
5. 1984/1985 clutch master to slave hard line
6. Stainless steal slave hose.
7. Shifter dash plastic/boots
8. 1984/1986 manual trans cross member with bolts
9. Manual trans isolator
10. 1984/1985 Manual trans driveshaft. Might think about concerting the staked U-joints to replaceable ones. A good driveshaft shop can do this for about $120.
11. Trans body mounts from a 1984/1985 manual body. I have the ones in this pic I can sell after I remove them. Will require welding them to your body. I can get pics of what I did.
12. I'm sure I've missed something.



Here are some pics of what mine looked like after welding and before seam sealer/paint/undercoating. The ones with black wrinkle powder coating are the manual trans ones I added.

 

You need a modified auto trans with modded gear ratios to take full advantage. I have a modded auto trans, it revs higher before shifting ( 5.5 k ) and 1/2 gear is incredibly close together. The thing is my trans was modded back in the early 80's.and has cut gears that are noisier than stock.
As KCR said, , auto trans effectively strip your car of power by no allowing you to rip to 7, a neat trick is to put the car in 2 and drive it around like that. the car shifts at around 3.5 but will never shift to third gear and you will get to 7 K at around 60 mph . In 1 you will rip right to 6,5 at 40 mph, but letting go of the pedal slows you down bigtime.
Also, a common misconception many of you guys have is that the auto trans shifts at the same low RPM, wrong, it has a solenoid that detects how far your food is on the pedal, past halfway point you hear a click and the trans effectively delays its shifts up to 5.5k ( 5 k bone stock) . Also +1 it keeps your engine in better shape,