Disclaimer: I searched around and couldn't find what I was looking for... possibly because I can suck at searching sometimes, LOL, but I searched for awhile before making the post (I always try, since I hate rehashing topics). So apologies if this has been discussed a thousand times...

I am picking up a roller FD tomorrow morning. Pretty excited, as this is my first RX7/Mazda/Rotary, and have been a fan since I was a kid. Anyways, I want to keep the car a rotary, and I don't have the budget for a 20B, so I wanted to put in a factory 13B-REW drivetrain. With a modest goal of 350whp (give or take a bit), is there any specific advantage from USDM to JDM or early FD engine vs "JDM only" later years? What should I expect to pay for a good quality used engine? Should I go new? What are some the best resources to find engines besides this forum and local classifieds?

I've read a bit about the factory transmissions having issues right around the power level I'm looking at, so would it be advantageous to go for a CD009 Nissan transmission swap instead? I've been into Nissans for a long time, so it's what comes to mind as a popular transmission upgrade for a lot of other cars. I run an RB25 transmission in my SR powered S14 due to better parts availability than the CD transmission, but that's my race car, where as the FD will be more of a weekend toy for me, so a factory transmission should be fine. I don't know, just postulating, so looking for experienced advice. Reason why I bring this all up is if I should look for an engine only and get a separate transmission instead of an entire drivetrain set.

I have a lot more questions of course, but I'll start with this. Thanks in advance!

 

You'll get different opinions on the motor. Mine is to buy new since you have nothing right now. They're $4,600 from most vendors but you'll want to have it opened up and change the seals at the very least. There are cheaper paths, but I don't think many would argue that going new provides the best peace of mind.

A factory FD trans in good condition shouldn't give you any trouble at that power level. 400+ is when a third gear pull might have consequences.

 

IRP sells new Mazda short block, personally I would go that route. The stock trans is fine for that power, mine is doing fine street driving it for years at a little North of that number.

 

Thanks for the response guys! I would think the biggest issue with the new route is that I have nothing that goes around the engine. No accessories, ecu, harness, etc etc. I would need an entire crate engine and transmission. I would think that would get rather expensive ha ha.

 

It will add to the cost for sure, but this is the part where you don't want to take chances. If you want to go used then I would suggest find someone with a full pull out engine and trans that has a proper compression test.

 

Yeah, I could see going all new could cost me well over 10K after everything is said and done. My initial plan was to try to get a "JDM swap" and then do a refresh on the engine before install. But I figured I'd ask around and do some research while I have the time in case that wasn't the best option. I'm assuming doing a turbo Renesis would not be ideal? I honestly don't know much about those engines other than a few small bits of info I've read so far.

 

Don't even think about Renesis for the fd.. There are two things to take into count here.
1. Knowledge about the car to complete you future project.
2. Have the $$$ to get someone to check/rebuild an used engine for you, if you go that route.

New engine will save you a lot of headaches, such as chacing good housing, rotors, shaft that an used engine could have problems with.. then buy the required parts to get up and runing.

If you buy an used engine, you will have to send it to someone to rebuild it most likely. It might cost you feom $2500- $4000 + what you paid for that engine assumming it is a good core.

I would go used, just make sure you ask for compression test numbers like was said above.
Be carefull where you get your used engine from.
Good luck and congrats on the new project.

 

Thanks! I'm new to the platform, but I've been working on cars my whole life and understand the theory, etc on rotaries (which is one reason why I've wanted one). I like to figure things out myself as well as learn from more experienced people, but most of the work that is done on my cars, I do myself (I don't do machine work or paint). If I buy used (new is still attractive if I can figure out the rest of the parts on a budget), I will definitely do my best to ensure everything checks out. It's one reason why I asked for reputable sources on engines. The importer I used to get all of my Nissan engines from retired and sold out, so I'm back to square one there unfortunately.

 

late engine is better, since you have nothing the JDM engine route is probably the way to go. you get the harness/turbo/manifolds all that. Mazda sells new engines now, which is great, but if you need all the stuff on top too its probably cost prohibitive (plan C, buy a JDM engine, sell the engine, keep the junk on top, buy new engine from Mazda, or whomever, lot of work, but you'd end up with a new engine)

trans is completely fine at 350hp. learning curve is steep enough to put the car together that a trans swap, even if it was needed is probably too complicated.

Nissans and Mazda's are fundamentally differently, the Nissans are built like legos, they pick the engine, suspension, design subframes, and done! if they want a different engine, they just put it in, easy peasy.
Mazda's are more like a Ferrari, the FD particularly. the FD shares very few parts with any other car. even the Rx8. to put an Rx8 engine in an FD would be a HUGE amount of work, an LS engine would be easier.

TL;DR? put the FD together as close to stock as you can, and then its a very clear mod path to get to 320hp

 

The easiest way to get all the major parts you need would be to buy a JDM long block. Typically you get the transmission, all the manifolds, wiring, etc. Prices have been going up on these and I'm not sure how much they run at this point.

Stock trans is good until you start moving into 500hp. I would probably start with the stock trans and get the car running and going then look at changing it out down the road. There are options for using other transmissions but they aren't in common use, it's going to be a big job. You're probably better off starting out stock.

If going with a JDM long block I would definitely budget in getting the short block rebuilt. A fresh engine with upgraded apex seals will go a long way.

Another option could be buying a wrecked car with a good drivetrain in it but that can be much harder to find than just finding a JDM engine.

The core engines themselves are fundamentally the same 92-2002. 99's added the better turbos, but you'd probably pay a premium for a 99 long block and you probably won't be using those turbos. I would just find a 93-95 engine.

Wiring harness can work with some modification. Or, there are some aftermarket harnesses out there especially if you are going single turbo that work really well.

Dale