LiveWire's 13B-REW build thread
 

Hello Everyone!

Yes, it is what you think it is and what you dread. Another 20B thread. My reason for starting this is simple: I need help. BUT WAIT! Before you express your negativity (although you are free to do so) I do have intention to see the project through to the end. And by that I mean I probably have something near the income to pay for the build. One way or another, I would like more power (more reliable than a turbo renesis) so some sort of a swap is in order eventually. I would like to start accumulating a stock pile of parts and info (yes I have started the info already).

To prove this (poorly) I found the most "helpful" links to be:

https://www.rx8club.com/series-i-maj...-rx-8-a-89065/

20b FAQ and Links - RX7Club.com

Many of the links are broken, and much is out of context, and I need your help! Feel free to PM me with any info you feel could be relevant. Post names of members who would be willing to invest some time helping me with this build! I've tried contacting a forum member and 2 outside 20b owners to no avail. Any and all info would be appreciated. Most searches end in threads of "search noob" and out of many hours searching, little good info seems to come about. It seems I cannot gain access to all the inmportant information on my own.

On to the important part, the initial parts questions.
1) To allow for a 13brew conversion if funds become a problem, what ECU would suit both a 20b and 13brew swap? Is the Haltech E11v2 suitable? I have heard a few negative reviews on this ECU, does anyone recommend anything different?

2) Is there anyone who knows how to make/has experience making custom engine mounts for the rx8/20b swap? Price quotes?

3) Are the S2 oil coolers suitable for cooling to 20b? No, idle airflow needed

4) Can the rx8 s2 front cover be used?

5) Is the gasket kit found at:

Mazda 20B 20 B Cosmo 3 Rotor Factory Engine Gasket Kit | eBay

a decent price? That seems to be the only gasket kit I can find. N/A, Rx7store engine

6) Is there any good/available rotary E-tuner?

7) Will the stock cosmo twin turbo setup fit in the engine bay? Is there a major reason most do not keep them? Room, Limited airflow and power

8) Is the ACT stage 3, 6 puck clutch a good option? I have heard some negativity on that front too. Dual Disc Clutch

9) I think I saw someone say the 20b bolts up to the rx8 tranny with maybe different clutch housing? Can anyone clarify?

10) What are the major body modification to expect? I know of the (not entitled to the details however) steer rack relocation, the crossmember relocation, and the custom engine mounts. Am I missing anything?

And with that it is getting late. I may come back with more questions. I don't fully understand all the issues (obviously aside from the often quoted cost). Please try to restrain yourself from throwing pointless negativity (unless it is accompanied with information!) into the thread. The plan is to buy most of the parts within the next year to space out the cost of the build as much as possible. If you have a parts list of a 20b build, please send it my way. If you decide to read all this and help, blessed be your soul. Godspeed and thanks for your time.

One hopefully and positive guy,

Alex

These links provide the closet thing I can find to a parts list for the swap, however they lack important information, such as radiator and intercooler size, etc.

KMR Formula D 20b Mazda RX8 Technical Specifications | Kyle Mohan Racing Blog

3 Rotor RX8 P.R. - NoPistons -Mazda Rx7 & Rx8 Rotary Forum

Something like this is tempting. Anyone have more info on this?

Rotary Engine

Regarding oil coolers, it's possible that the s2 coolers will be sufficient, but their major downfall is that their stock locations get no airflow when the vehicle is not moving. Another is that their ridiculous piping arrangement seriously drops the overall flow through them.

However, the stock FC oil cooler (~$50) is used for 20B swaps fairly often, and when sandwiched with the stock radiator they can use the airflow from those fans. Contrary to popular belief an oil cooler/radiator/anything sandwich does not effect the cooling capabilities of anything on said sandwich.

I wish all posts were that helpful, thank you. Is any FC oil cooler sufficient, or should I look into one from a Turbo II model?

If anyone knows dimensions or either Fluidyne Aluminum Radiator or Spearco Intercooler that I could use that would be a great help!

I believe they're all the same, as long as they come from an FC, if they are different then I'd assume that the turbo variant would be more capable.

Upon talking with some people, I plan on taking a well more reliable route.

JDM Mazda RX7 FD 1993 1 3 13B Twin Turbo Engine 5 Speed Transmission | eBay

I was wondering if anyone has bought a used motor from the supplier above (JDM Midwest Motor Depot). I am planning on rebuilding the engine, so frankly as long as it is has not detonated I think it should be able to be rebuilt without oodles of money.

One community benefit of this build is that I will be testing the strength of the stock S2 transmission, as I plan on mating that to the block. Hopefully any of the information I have gathered thus far will help other members as well.

All suggestions are welcome.

Here is a file containing what I currently have planned for the build. The parts list is about 90% complete.

You will not want to use the RX-8 tranny...it will not survive over 400whp unless you drive like a grandma

You have so much fabricating to do...fitting radiators and oil coolers will be the least of your worries

You need an exhaust manifold, and cold side charge tubes, intercooler placemen,t battery relocation, fuel pump upgrades, ECU wiring, coil mounting...the list goes on :-)

Did you take a look at the attached spreadsheet? That already lists the prefilter, afterfilter, and dual 044 pumps & bracket, etc.

I heard (can't remember which thread on this site) that the S2 transmission is (unclear as to how much) beefier than the S1 transmission, and since the S2 hasn't seen much FI due to a lack of tuning options the community really doesn't have info on how it holds up to FI. Since the engine I linked above comes with an FD transmission, I figured I should at least try to gather so info on the S2 tranny strength while I have a backup available. I would say its simply a person preference. This is one of those things I would like to try rather than go by hearsay.

I can tell you a lot based on experience. ...I have basically what you are doing sitting in the driveway waiting for the parts to swap in another tranny. The S1 tranny lasted 10 minutes at a detuned @425whp. Not sure i would expect the S2 to be much stronger considering it's roots.

The S1 transmission is prone to failure when raced hard, particularly 4th gear. The S2 transmission IS stronger....at stock power levels..

You won't be anywhere near that. What is a significant improvement at 200whp is negligible at 400. If all Mazda did was make the strength limit 250whp instead of 200whp, that does nothing for you despite being stronger. You may want to read through angeljoelv's threads to see what all he keeps breaking. It will save you a lot to apply what he has learned.

LOL...yep...4th gear... big bang and a lot of really nasty grinding :-)

4th and 6th gone. ... as long as i go slow the rest work unless they pickup gear bits :-)

First off, very useful info thanks guys. Despite however arrogant or naive my posts sound the info is much appreciated.

I thought Angel's 20b was ultimately the source of all the clutch/transmission issues?

There was also a 20b PR thread several years while back that said by replacing bearings and 2nd gear synchro + crown solved the transmission issues. Is that just simply incorrect?

In the worst case scenario I could use the FD tranny that comes with the above purchase. Is the shifter placement the only issue that needs attention in the transmission swap?

Not precisely. He certainly broke plenty of those, but he broke a whole lot of other stuff too. I think 3 different axles last time I looked, as another example.

I don't recall ever seeing that one.

I can't help with that question, sorry. I would personally just start with the FD transmission to begin with, since they seem to take your kind of power without issue.

Here's the thread that I was referencing. I tried PMing rgonza but I never got a reply, so I can't say if his solution worked well or not.


https://www.rx8club.com/series-i-maj...ranking-78088/

There are so many things involved in fitting a 20b in an 8.
Questions you should ask yourself and start learning/researching are;
NA or turbo? If turbo, what power goal do you want for your application examples are street car or track car? The series 1 and 2 trannies are of no use for a powerful 20b period. As RGonza discovered after strengthening some interior components of these transmissions, they bust, period. He upgraded transmission(s). Look at Joel blue 8, how he fitted a t56 with a variety of clutches. I recommend first look at your budget and income to find this project aside from life expenses, then ask yourself with numbers infront of you think this is possible for your in a realistic manner. Take into consideration the cost of the engine, the rebuild expense, the price of the ECU you choose. Also look at fuel rail costs, fuel injectors cost, fittings and lines, fuel pumps, surge tank, fiel pressure regulator, turbo manifold materials and fabrication costs, radiator, oil coolers, alternator, air condition or not, exhaust materials and cost. This is just some of the bunch needed to get it running then you have to strengthen the driveline, to include tranny, driveshaft, half shafts, rear end, brakes, etc. then think about the fact that you have to support something giving out like rotor housings and breakable parts.. Can you support this project? Think about that, research the 20b threads here even sinfidelity's and research all the components and their way of function. I can give you all the info I have on the above and more but first ask yourself it you can do it... Or do like me and blind yourself of the total cost and take the plunge haha :-) good luck man let is know how we can help.

Thanks again, I suppose I should clarify the plan is to swap a 13brew in rather than a 20b, mostly due to the fact that 600rwhp or more is hard to daily drive as well as track (especially coming from my ~180 whp.) I luckily do have the funds for the project as I am an engineer, living at home 5 minutes from work, single, and have little school loan debt left. I figure that now is the time that I will be able to afford heavily modding a car (before paying for a house, etc.) My plan atm is to accumulate a large amount of the parts needed for a swap and take my car to slick motor sports. In my area they build most of the cars around that last. On black friday weekend I am planning to drop around $5k on parts, which will become around 4 with the savings and drop the overall cost of the build by $1k. Its not a ton considering the total cost of all the parts I am planning for, but it is something.

On the subject of parts, Legot mentioned the FC oil cooler for the 20b swap. Since the 13brew swap is less powerful, what oil cooler setup should I consider? I see most swaps (pictures) with dual coolers below the headlights. Not sure if this still has a problem with idle airflow. Comments on this?

https://www.rx8club.com/series-i-maj...setups-225750/

Found a Transmission solution. Is the above link the easiest solution to mate the FD transmission to the car?

By the end of the week I will be able to tell you more......the bellhousing on the 5MT looks like a T2 bellhousing...with a slightly different starter bolt pattern....the tailshaft is about 4" shorter...and the PPF mounts are in the correct place to use the RX-8 PPF


I'm opening a box on Friday and will compare to a FD box.....What I hope to find is the same gears and the updated syncro's like the latest FD upgrade

What good timing. Looking forward to seeing what you find.

I just realized something, and I probably have some sort of misunderstanding that will clear this up but I figure I should ask before I buy any parts for he swap on T-giving weekend.

My intention is, like many others, to keep The stock gauge cluster working, traction control, power steering, etc. I will probably move to a cable throttle (just preference). From my research it seems like I can simply keep the stock ECU for these functions, use a stand alone system for the 13brew engine utilizing the 13b front cover. Seems good so far.

Can the ECU and EMS need to be wired together to override any CELs or do I just deal with them.

To me, the ECU/PCM is largely a black box. To my understanding, the PCM takes some inputs from the transmission. If I swap out the stock transmission for an FD transmission, will I be unable to keep some of my OEM functions? Say power steering or traction control?

I am hoping to pick up an exedy twin clutch (and some other goodies) during the holiday weekend to save some $ on the overall swap cost. I do understand that the clutch assembly fits both rx7 and rx8, however I believe the counterweights are different, although im not sure if it needs balanced with respect to the flywheel or the transmission. My assumption was the later.

The clutch is a balanced assembly...so you don't have to worry about that. The counterweight is part of the flywheel stock...and if you go to an aftermarket flywheel you need to use a counterweight.....they are different for different applications....best bet would be to get your rotating assembly balanced when you build the engine :-)

FD transmissions use a different clutch than an RX-8...so decide what tranny you are using BEFORE you buy a clutch :-)

Basically, this is where a lot of people get tripped up. The RX-8's ECU is a required input for every other electronic function in the car, and they are keyed with the internal serial numbers so THAT ECU ID looks for THIS ABS module ID, etc... Remove or disable the ECU and the rest of the stuff won't work right.

Your best bet to have all those other features is to have a different ECU that controls the engine itself. And just interrupt the factory signals. This will produce a lot of warning lights (which is how many swaps end up) without some sort of communication box or change to suppress them all. Adaptronic has a 'piggyback' that functions as a standalone for the Renesis, so perhaps they can adapt that to a 3-rotor engine?

Many end up with a Cobb Accessport on the stock ECU to shut off the dash lights...kinda an expensive way to do it...but it works ;-)

I would love to have that option, but I have an S2:banghead:

For my aftermarket ECU, I was planning on using a microtech lt10c with the X4 ignition module. To account for the extra two injectors per the Xcessive LIM, I would tie two injectors signals together (essentially acting like 1 twice the size?).

I guess I should rephase my final question about using an fd transmission. I am not sure what part of the housing the sensor(s) connect to. Will I be able to obtain a proper signal for my stock ECU from the FD transmission?

The ECU doesn't need any signals from the tranny... so you are good. Just the usual reverse and neutral. ..

Fantastic.

Another thing...you would be much better off using some LS? coils instead of the X4box.....they are prone to failure and just another expense that you don't need by using coils with built in ignitors :)

My personal preference is the Yukon coils with the built in heat sink

Little gold nugget comments like that will end up saving me a lot of hassle. Fantastic x2

Well everyone it is an exciting day for me. Today I finished ordering a used 13B-REW block, tranny, and ecu. Low compression, 100 psi and 60 psi. Going to rebuild and port it and then bring it to Slick Motor Sports with a pile of expensive parts to be built. This is a project in the making, I'm guessing 1-2 years.

If one of the mods would like to change the title of this thread to "LiveWire's 13B-REW build thread" and relocate this thread to the appropriate place I would be grateful.

Before I get ahead of myself, where should I think about taking the car to be tuned? I live in NE Ohio.

Carpe diem my friends.

I also have the Rx8Performance subframe on the way, as well as higher flow oil coolers and the canister trio for washer fuild, oil catch can, and meth injection.

Done :)

Great part!
I ran this...very nice piece!

Congrats on going REW.

Find a 5 speed rx8 tranny, put fd tranny gear in the rx8 tranny and you got a tranny that can hold power. Dznutuk made a thread for that

I have one...sitting beside a FD gearbox......I honestly can't see a difference in the gears. They are the same ratio...and it looks identical. Really...doesn't make a lot of sense that Mazda made a weaker set of gears for a tranny they already made.

I will know more end of week when I get them both pulled apart

Ya...read that years ago...not really sure what it means

Will know more soon.

If you were on facebook theres a page for rew swaps and lots more infos. Some did the fd/rx8 tranny and it works good

That definitely seems like the route to go. Seems no cutting as well, how swell!

Thanks again for the add to the FB swap page Maxime.

Not the same ratio, don't know where you got that from. Really, it seems weird that they would make a different transmission for a nutless engine like the renesis? Well they did make a weak one, just like the 6speed is weak. Btw, the starter is the same pattern, I wouldn't use a fx bell, the ppf mounting is not the same on the fd and the rx8, and your shifter won't be in the right place.

The S2 6 speed is weak? I haven't heard of anyone blowing one up.

Don't know anything about the S2

That's the problem I have with this whole topic.....So much conflicting information From what I can tell the Transmission is designated as the R15M-D transmission in the RX-8 Literature that I can find...same as FD??

What are the gear ratios?

The bellhousing is almost identical to the T2 one...it has different starter mounting bolt setup...and casting is slightly different...but other than that it looks the same

The tailshaft is different than the FD tranny...it has the bolts in the correct location to make it bolt on....but other than that...the output shaft etc looks the same

Outwardly the case is identical to the FD tranny...

Going to pull it apart on Friday...and compare....I have both sitting on a bench at the shop

They seem to be stronger than the S1 but I wouldn't trust it anything above 350rwhp.

I know guys here in Florida that are making 500+ and running 10's in the quarter with a stock FD trans.
Another friend has been running his for 3+ years at 600rwhp with lots of track time.

Can a S2 do that? Really dout it :dunno:


.

Yeah my buddy ran the 5 speed RX-8 trans on his single Turbo 20B setup, he never had an issue. He did run an FD trans before that and did break it but he didn't blame the trans because it was a used FD trans he had laying around with an unknown history. He was making a conservative 455WHP.

Back when we were debating this a few years back I asked Ash8 to look into it . He told me all the part numbers for the major components inside the box were the same (Fd trans vs RX8 5speed) . That was good enough for me and so I have run the 5 speed ever since.

That's basically what I thought..... :)