foghead

The car - a mint condition 1983 GSL with a newer limited slip rear from an 84, all new bushings and a 12a that was rebuilt with about 55k on it (157k on the body). Zero bondo and 100% straight body-wise. Not certain if it was done up with new rotor housings or not when it was done, but either way, it runs perfect.





My options -

1 - leave it the hell alone and 100% stock
2 - keep the 12a, throw a racing beat exh on it, maybe ditch the rats nest and basically do a light mod to the car and switch to pre-mix
3 - sell the 12a as an excellent runner and grab a 13b to swap into the car to get a little more to play with or...
4 - pure sacrilege - lose the rotary and go with a 4.3 or SBC and be done with it totally. Hell, I can get everything I need from a donor car for the price of the 12a RB exhaust!!

My main hesitation regarding any mods is that the car is genuinely THAT nice. Runs/starts/drives 100%... but I kinda would like to make it 100% without worrying about some oddball emissions failure or the death of the 12a.

I'm kinda leaning towards a cross between #3 and #4 just due to the financial aspect of building a 13b... but everything is on the table here. As a side note, I REALLY like the way the rotary delivers the power!! Insanely smooth and deceptively fast!! A 13b would be my choice if $$$$'s weren't such a concern. Financially right now, #1 is where it stays due to being broke!

Chime in and let me know what the thoughts are!!!

85rotarypower

The decision is ultimately yours to make but my choice would probably be #3 with a twist. Stock S4 13bt with a free flowing exhaust and standard 2nd gen mods for a small power increase. 220hp at the flywheel is not hard to obtain out of that engine and it wont likely grenade your drivetrain like a V8 swap would. Keeping the engine close to stock will also net you excellent drivability with a smooth power delivery similar to stock 12a.

Im not totally against piston swaps but when it comes to reliability of the stock rear axle a v8 is not what you want to do. Much more than 250 ft lbs torque i think the rear axle will snap like a twig with grippy tires. The small bearing early 1st gen axle is even less than that.

82FanTC

iTrader: (9)

Wow that looks pretty nice! I would do one of two things. Remove emissions equipment, add a racing beat exhaust, and mod your stock carb and be done.

Or sell it as is and buy one that already has a 13b/bt swapped in. You will save big bucks in the end

Sgt.Stinkfist

iTrader: (6)

hmmm, I say Cosmo S5 13B, NA, street port AND semi-P port

DreamInRotary

iTrader: (49)

I'm considering similar options for my car as well. I'm leaning towards keeping my 12a, heavy bridge porting it, block off emissions and OMP and go to premix, and DLDFIS (I think that's the correct acronym..) as well.

j9fd3s

iTrader: (3)

#1, maybe i'd put headers on it

foghead

Thanks! I have to allow for at least an extra 20 minutes everytime I take it out as I almost always get locked into a conversation about the car by someone that starts off with, "I haven't seen one this nice in AGES!" Buffalo weather/winters killed a lot of these off...

I'm looking at #2 as the most likely scenario for now, and that's only because the thing runs so well that I'm thinking (knocks on wood here) that it's easily a 100k mile motor. Atkins did the build and the previous owner was pretty good about changing the oil... all in all, it's a VERY strong car as it is.

foghead

A 4.3 would be too torquey? Wasn't there a heavier fist gen axle from the later years? The axle in this has disks, a lsd and was either out of an 84 or an 85...

t_g_farrell

iTrader: (1)

I'd replace the beehive with a FMOC first.

Enjoy the stock everythng until it becomes a pain in the butt to maintain.

Then get the RB SP Full Exhaust setup. Then replace the nikki with a nice big Dell or Weber
DCOE. Do eletric fans and a better ignition setup and enjoy a 12a with 50% more
power without breaking the keg.

Save up for a new 13B engine for a few decades when the 12A finally blows.

foghead

I've used the search feature on here many times to see if I could find a how-to for replacing that beehive. Can you possibly help me here with a link that has complete instructions? Right now, I don't have any access to a used 2nd gen oil cooler either. I kinda wanted to get that replaced as well as get some electric fans on it in the immediate future... link for fans too possibly?

foghead

Also for anyone that might be able to shed some light on this idea, I have an intake mani from a 79 or 80 that doesn't have the shutter valve on it. Is it a better manifold than the 83 unit? Would it be a wise thing to replace it possibly? I also have the Nikki from that mani, but it's in pretty rough shape... now I'm up to 3 extra carbs...

Jeff20B

iTrader: (13)

Search "ACV port" and "quicksteel"

KansasCityREPU

iTrader: (9)

replacing the beehive is a good idea. I'm in the process of going to a FMOC in my 1985 GSL and here are my thoughts.

If you have the money ($500) you can go the route I did. I would not recommend going completely aftermarket unless it something you really want.

Here is a thread with my setup: https://www.rx7club.com/1st-generati...ooler-1011061/

* Rotary-Works 10 row -10an FMOC
* Steal braided hoses
* Custom fabbed mounting braket
* Earl's oil temperature regulator
* RE-Speed oil pedistal
* Oil temp and oil presure gauges
* Endlink bushing kit to isolate vibration

My suggestion would be to get an GSL-SE oil cooler or even a 2nd gen cooler and have a hydrolic shop make up some hoses with the factory fittings. You will also need either a non beehive oil pedistal or get the Re-Speed one.

mazdaverx713b

iTrader: (91)

i would not touch a thing personally. unmolested 7's are getting harder and harder to find and when completely stock, they get decent mileage, are reliable, and are very enjoyable to drive. i find that more issues will arise in the future with modded cars.. not saying a recing beat exhaust and removing the emission equipment will necessarily harm anything, its that you may end up missing the bone stock classic.

foghead

Looks like the oil cooler mod will be it for now... That and maybe a racing beat exhaust, minus the header. Anything to help get the heat out of the motor and give it a running chance at a longer lifespan....

85rotarypower

Im not saying the 4.3 is too torquey. The v8's generally are. The later 1st gen axles are stronger but can still be broken with about 250ft lbs. That seems to be about the limit if you want to run slightly sticky tires from what i have read.

84stock

iTrader: (5)

I would go with the bonez cat repalcement pipe. It's only $75, heavy duty, sounds great and a lot cheaper than a whole new exhaust.

Worked great on my low mileage 83.

Rotary Performance | SA Exhaust

KansasCityREPU

iTrader: (9)

If you go this route, do you have to delete the air pump?

tasty danish

iTrader: (5)

I wouldn't touch a damn thing till it broke.

Though I do PASSIONATELY hate the stock header (if you can even call it that) and would do a full exhaust with header, and maybe a FMOC because hives are just crap.

But with the shape it's in, you may consider plastic wrapping anything you do take off...

foghead

DUDE! That is EXACTLY what I was trying to find!! Thank you!!! This and the RB muffler will probably tie it up for me!

Plus, the cash I get back from selling the convertor will offset it's cost. I love it when a plan comes together!!

foghead

Yeah... the cat delete pipe is a certainty, and the oil cooler will also be tagged and bagged over this winter. This car is nice enough to try and preserve.

tasty danish

iTrader: (5)

The stock exhaust header is a boat anchor and flows exhaust through it about as well as a boat anchor would... just saying

foghead

Understood for certain. It'll disappear eventually, but for now though, it comes down to 80 or so for the delete pipe or 800 or so for the full system. Besides, preservation is the name of my game. The header will/would be nice, but worrying about extra hp from the 12a just isn't in the best interests of the motor, seeing as how parts have dried up pretty badly. It'd likely help hot gasses to escape faster than the iron blob but once again, just not in the budget at the moment.

DivinDriver

iTrader: (15)

Beautiful restoration candidate; you can either restore it to original condition (mainly some replating and cleaning from what can be seen) and preserve it's value, or you can start modding it to your taste with the realization that every dollar you spend on non-stock mods will be reducing the value of the car by several dollars.

Just a sad fact; with very rare exception, nobody wants somebody else's mods. So figure out what you'll enjoy most before you start.

foghead

Also a good point. As it stands right now, I'm going with the cat delete pipe and RB muffler. Will be removing the air pump (and storing it) and going to a double pulley on the alternator. Already also have the OMP adapter that allows for a separate tank of 2 cycle oil to be fed into the motor.

Those mods will likely be about it. All suspension bushings are new urethane, springs are all new, struts/shocks too. Nothing else is on the radar at this point in time. I'm going towards restored/preserved with tasteful and logical mods done.