I just picked up a 74 coupe and wanted to build up a little.I had a rx-4 years ago ('85-'95) and always regretted selling it.Well I picked up a '74 coupe -a/c,p/s,a/t fixer upper car and was considering going with a efi turbo motor rather than the ported/holley setup I used to have.I am looking for maybe 225-300 hp realistically with stock rear end,and am going to leave the jatco a/t in (will build up a little).Any suggestions.A friend recommended getting a S5 (89'-91') motor ,and go with aftermarket ecm.I also was considering a '93-'95 Rx7 motor or even the cosmo 13b turbo motor.I've been out of the loop for a while and saw some pretty radical setups at the japanese classic car show in Long Beach saturday .I don't want to spend 25k and don't need to run 11's.just want a decent running car that retains the p/s,a/c and looks good under the hood.I own an auto shop so I do know how to do things just not really what to do in this case.any help appreciated ----Thanks Mike

 

An S4 TII swap is probably the easiest, both on install and finding parts. With minor mods, the S4 can hit 220-240 hp. Past that you will be looking at turbo, fuel and ecu/management upgrades. If you decide to go with the S5, Steve84GS, in the 1st gen section has one of the best swaps, 300 hp and passes Cali emissions.

 

Acually smog is no longer an issue on pre '76 cars here in CA.I had an '87 tII and an '89.The '89 ran much smoother.What is wrong with the later('89-'90) TII setup? Is it just not avaliable or is it that much more complex?My '87 with RB exhaust ,K&N and manual boost controller had about 240-250 I suspect(according to RB)

 

I put a Cosmo 13B-RE motor in my '73 RX3. The intake ports are just so big I could resist. It went in pretty easy. The only real trick was that I used a 1st gen front cover and a '88 TII waterpump (Extra stud in block at the DD). I had to relieve the front cover and waterpump about a 16th of an inch each in one spot to get the housing to seat.

I just got it running with a Microtech. I currently am running NA, but when I trust the ECU I will reinstall the turbo. I am also looking for a huge high quality intercooler to upgrade with. I was using a Volvo 760 cooler.

 

The S5s have an electronic mop that must be hooked up to the ecu, and working, otherwise the ecu goes into limp mode. The 12A or SE front cover will take some modding to mount the mop. It's not a big deal, just another step in the puzzle. The S5 throttle body also has no provision for a mechanical mop rod if one goes standalone, that usually means means pre-mixing or more fabbing.

 

Thanks guys.So by what I see , the MOP I am assuming is the oil injection correct?I knew the 3rd gen was electric but didn't know the 89-91 was like that.
................Also I have seen a lot of large air-to-air intercoolers installed in older/newer cars.Very bulky at 2'X2.5'X3"to4" thick . Why doesn't anybody install water-to-air coolers? They are more compact and efficient.The Lotus esprit 89-95 4cyl cars used them and put out 280-300 hp w/13-15psi (mechanically driven off of crank)and the syclone/typhoon trucks also used them(electric pump). All you need is a small 5"X5"X12" box near the throttle body, a water(coolant) pump and a heat ransfer ( lotus uses basically a modified A/C condenser).Just curious.Mike

 

thet is--- heat transfer--- on that last message.sorry

 

Found it -Metering Oil Pump-thanks mike

 

The main problem I have with water-air is that it has more complexity than the air-air. And this usually means it is more likely to break. If you lost water or water flow you would be screwed. I would recommend a pressure activated saftey warning light at minimum if you chose this type of system.

Water to air has good quialites. Less pressure drop, because less surface area is require. Can be mounted where ever you want. This allows for the shortest connection between turbo and throttle body and less turbo lag. A large volume of water and some ice is a nice feature for a drag car.

Another bad thing is that you will never be able to get your water to cool down to ambient again while running. You will always be cooling with water that is a bit warmer that the air you use to cool it. You would have to stop and wait for it to cool down again to get peak power.

If you look at who uses what. Road racers use Air-Air and Drag racers use Water-Air sometimes.