REMAGIK

so im debating on what engine to get.. i know 13t can put out way more power much easier.. or so iv been told.. i do not intend to custome make the turbo for the 12A .. the engine i seen for sale is the actiuall 12At from jap.... but iv heard the 12A is waay more reliable.. and puts out a cleaner tone on the exhaust.. iuno... help

perfect_circle

youve got alot of misconceptions. a 12a can make almost as much as a 13b, with similar mods. as far as reliability, if your keeping them stock, i would say the 13b, seen as how so many more where produced. the 13b also has a larger aftermarket, but i think overall a 12at would cost less to build. and as far as the exhaust note, that all depends on turbo, mufflers, wastegate.

Alex-7

12A turbo.

Leave 2mm apex seals for those 2nd gen suckers.

perfect_circle

lol, i forgot about that!!

DriftFB

I am always torn between the 3 myself, the factory 12at, making your own 12at or the S5 13B, I can never make up my mind. Right now I think I am leaning twords the do it yourself 12at or a supercharged 12a. mmm... 12asc

Naegleria_Fowleri

I personally say it will be near impossible to find a jdm 12at, and if you don't want to custom fab all the parts for a 12a turbo then go with the 13bt.

mckinneyml

I've got a JDM 12AT rebuilt by www.PineappleRacing.com

http://www.corksport.com/store/categ...c_engines.html also has them listed for sale.

Mine's still in the break-in period awating tuning. Looking good so far. I can't compare it to a 13BT though because I've never driven one.

PaulFitzwarryne

For the same modification a 13BT makes 8% more power than the 12AT. The difference stock of 24% [182hp v 147hp] was due to a more aggressive turbo set-up, sports car as against fast sedan with lowdown power.

To rebuild and modify a 12AT is more expensive than a 13BT, you will need an intercooler, an aftermarket ecu, and upgraded turbo. For equivalent modified power, installing four injectors[800 and 550cc], and larger ports are esssential. If you are dropping the 12AT into a late FB then I suggest a new oil cooler and SA style radiator.

I agree there is no difference in noise, the main factor is muffler design.

DriftFB

^Which engine came out of a fast sedan? If memory does me justice both the 13B and 12At come out of Rx-7s. And saying with similar modifications they make a 8% differance in power is making a lot of assumptions. Also how does the 12At make up 16% of power when modified?

PaulFitzwarryne

The 12AT first came out as options for the Cosmo and Luce.The Cosmo sedan was then the fastest Japanese production car. The 82 RX-7 still only came with the 12A 6p with about 114hp. When sales of the RX-7 slumped in Japan, the 12AT engine was made on option on the 1984 model RX-7 GT, GT-X and SE Limited models. The 85 model Limited Version was the only RX-7 model which only came out with the 12AT. All Rx-7s came out with the later second series 12ATengine with a slightly different Hitachi turbo and around 4hp more.

The Cosmo and Luce also were available with the 13B years before the RX-7 got it with the GSL-SE. The 13B was variously upgraded, finally becoming available as the 13BT. While it was available in the Cosmo[which finally in 92 also used the 20B in its top model], the FC was the prime target for the 13BT engine as the new faster Skyline had killed Cosmo sales. The FC needed the extra power as it had become a heavy 944 look-a-like. The 13BT in its final 93 REW format had different twin turbo set-ups for the FD and Cosmo.

A 12AT can be modified in the same way as a 13BT. While still retaining streetability, the engine can be modified up to 400rwhp.The route is FMIC, porting,increased boost, larger turbo, digital ecu, 4 injectors[800cc and 550cc are just adequate], upgraded header and exhaust upgrades, performance fuel system. My daily driver is primarily bolt-on moded and gives 224rwhp at 12psi. My wife's 85 SE-Ltd spec fast shopping cart will be more powerful at 300rwhp with enlarged ports and 4 injectors.