Hey everyone,

I'm sort of knew to this subforum . I've read through threads here and there before, but since I was never in the market for a 20B I had no use in posting. Well, things have changed. I'm looking into doing a 20B swap into my FD over the winter and was just trying to price out everything. I was hoping some of the more experienced members would be able to help me out a little.

Here's what I'm working with:

My car was setup for a 2-rotor single turbo with everything taken care of to put down 450-500 rwhp. Now, recently I decided to go in a different direction and that direction is the 3-rotor 20B engine. For the time being I plan on running it with stock turbos nonsequentially.

Here's a list of mods already done that I plan on keeping for the 20B swap:

550cc primaries and 1680cc secondary Injectors
Supra TT fuel Pump
Aeromotive FPR
Greddy FMIC
Koyo Radiator
4" exhaust from the downpipe back
Tial BOV
HKS Twinpower Ignition
Spec Stage 2 or 3 clutch (Can't remember at the moment)
Greddy Type S boost controller
Bunch of other guages, and items related to the single-turbo

Here's what I believe I need to purchase:

1- 20B longblock

2- New standalone ECU (I already have a Microtech LT8s, but I would like to change it for something else I have in mind)

3- 20B subframe (Either Pettit, Hinson, or something similar)

4- New engine mounts? (I've heard I'll need to change these, but I'm not totally sure. Could someone please tell me what needs to be done? If I need to change them what engine mounts would be recommended? Any and all details are appreciated!)

5- New oil pan? (Also, not sure if this will need to be changed? Please enlighten me .)


Now, what I'd like to know is how much should I expect to pay for the things I listed above and IF there is anything else I forgot please let me know. Also, please don't flood this thread with useless remarks saying "If I need to ask, don't consider it." I will have ALL the labor performed at my own shop so that will NOT be an additional cost.

I'm expecting to pay anywhere from $10-15K for EVERYTHING I need to complete this project. Does that seem like it should be reasonable?

Thanks in advance for reading through all this and for providing any advice/input,

Rizwan

 

around 10K on top of what you have.
the HKS DLI will not work.
Get a Haltech E11V2, Microtech LTZ12, or AEM EMS.

 

Definitely need that.

The Lt8 will not work for ignition anyway. A Lt-12s or haltech E11V2 as already posted.

Those will work, and uses the stock 20B mounts, and the stock pan, and stock intake. The downside? Moves the steering rack 2-3" down. Which then you need a bumpsteer correction, ect ect. If you want to avoid all that (like I did) then you may want to look into what I have to offer. My 20B conversion kit leaves the STOCK subframe entirely. No cutting or anything to it. And a stock subframe means even the rack is not moved in the slightest way, the way mazda intended it. The down side? You have to chop and re-weld the 20B intake 1.75" for clearance. A very small price to pay for a perfect handling car.

With my kit, they are custom and included, and extra beefy. The others use the stock 20B mounts

No if using the other kits. If you go with mine, its sent in to me and modified. This is included in the conversion kit cost.

The conversion kit I offer is $1,550.00 for everything you need. Link for pics- https://www.rx7club.com/20b-forum-95/first-look-production-fd-20b-conversion-kit-583378/

Yep.

Hope I helped a little!

 

If you're worried about trusting someone from the forum compared to dealing with a somwhat well established company, DO NOT HESITATE to do business with Logan (GTORX7)

He is a stand-up guy that will NEVER keep you in the dark, and his product is VERY high quality.

For what it's worth, I would (and do) use his kit.

ryan

 

Thanks for the help guys. I have a few more questions:

1- I was already planning on ditching the LT8s and going with an Autronic SM2. Will this work for the conversion? Do you guys know of anyone else running this ECU on a 3-rotor?

2- I had already looked in to GTORX7's kit, but I was also debating whether to go with this subframe:

The 2nd one is a brand new RX7 Specialty with bump steer correction kit. The price is $1700+shipping. It's a complete new unit, not a modified 3rd gen subframe so it's much stronger. The bumper steer correction kit does not require modifying the steering spindle.





Any comments/suggestions regarding the latter subframe?

3- I'm trying to figure out which direction I should take on purchasing the longblock. Here are my options:

---- Ebay = I'm not sure what type of motor I will be getting. I haven't yet emailed any of the companies selling the motors, but they claim that they will provide compression numbers. Also, I'm not sure if they know or would even tell me what type of motor it is i.e. A, B, C, or D code motor.

---- Forum Member = Sounds like a great motor. 20B three rotor ( number D507), great compression ( 85-90psi cold with a jumper battery and regular, not mazda gauge). The engine is complete with turbos and harness. I pulled the turbos to inspect the apex seals and housings. everything is great.

---- Another forum member = https://www.rx7club.com/showthread.p...&highlight=20B. This fully built 20B motor. I don't plan on running anything more than the stock twins for now so I wouldn't purchase the turbo or the ECU or anything else additional I don't need. However, would this be a good route to take?

Ideally, I'd like to have a great, strong running motor that will not give me more hassles than expected. Would the fully built 20B have issues I'd need to address frequently with it? I'm almost positive somewhere down the line I will put in a single turbo so would this be the way to go?

Thanks in advance everyone,

Rizwan

 

hows it going to cost 10-15k if you do the labor yourself and can find complete 20b's for 4k and all the conversion stuff for 2k? i dont see where all this extra money is going it didnt cost my friend nearly that much.

 

Hey,

You may have, but you might want to double check on the SM2 running a 20b. I was looking at using the SM4 for mine, but they do require use of the multiplexor.... which is several hundred dollars ($500-$900 I'm guessing?). Also, I heard recently there were some problems perhaps with it and running a 20b.... just check into it. This is unconfirmed information.

As far as running a built 20b, I think the biggest advantage you get is knowing that the parts are new. As for the "built" motor that you posted, I'd have a few concerns about that. First it has the 9.7:1 compression rotors.... Personally, I'm not sold on the high compression rotor/boosted applicaion issue. You can come to your own conclusions on that as I"m not here to sell one way or the other. Also, his mention of the nitride coating stuff and it smoking. I had a buddy coat all his internal engine parts on a 13bt. AFAIK it never stopped smoked and eventually blew up. Don't know if there is any correlation but do some homework. As that seller mentioned, it might just be a breakin thing.

As for the subframe. I haven't seen anyone saying they've broken the stock subframe... so I'm not sure stronger is better/necessary. Also, I didn't look into it, but IMO... ANYTHING.... that requires ANY sort of bump steer correction is sub par.... no matter what that correction requires. Again, this is my opinion. Dunno if that helps any

I think the biggest thing is to be honest with yourself on your goals for the car and go from there.

Good Luck.

-Chris

 

I've been wondering that for years...

 

would you stick a completely stock 20b in your car? stock, tiny exhaust ports and all? You'll want to re-build it and port it. A good, full rebuild kit will cost you ~3k for a 20b. so 2k for ecu, 2k for install kit, 1.5k for clutch, 4k for 20b, 3k for rebuild, 2k for various unseen expenses, you're looking at 15.5k right there.

 

Regarding ECU's for 20B-I would like to suggest a REAL solution-Electromotive's TEC3R-used it on my 20B engine and it performs flawlessly. Used for over a year before car was destroyed last yr. We/I do a lot of ECU tuning including PFC,Haltech, even Motec-the TEC3 solves ignition problems and the sophistication of the software,auxiliary outputs, datalogging that makes sensable tuning easy, and tuneability is unsurpassed-even have MAPS already developed= 535RWHP @10psi with T78 turbo (small for 3-rotors) and power accesories are functional.
Bryan
Rotorsports Racing Inc.