LiveWire

iTrader: (1)

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

LiveWire

iTrader: (1)

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

LiveWire

iTrader: (1)

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

Rotary Engine

Legot

iTrader: (1)

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.

LiveWire

iTrader: (1)

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?

LiveWire

iTrader: (1)

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

Legot

iTrader: (1)

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.

LiveWire

iTrader: (1)

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.

LiveWire

iTrader: (1)

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

dannobre

iTrader: (3)

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 :-)

LiveWire

iTrader: (1)

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

LiveWire

iTrader: (1)

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.

dannobre

iTrader: (3)

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.

RIWWP

iTrader: (2)

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.

dannobre

iTrader: (3)

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 :-)

LiveWire

iTrader: (1)

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?

RIWWP

iTrader: (2)

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.

LiveWire

iTrader: (1)

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/

RedDream

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.

LiveWire

iTrader: (1)

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?

dannobre

iTrader: (3)

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

LiveWire

iTrader: (1)

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

LiveWire

iTrader: (1)

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?

LiveWire

iTrader: (1)

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.

dannobre

iTrader: (3)

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 :-)