GySgtFrank

iTrader: (4)

This is an ongoing verry long term project that has given me endless hours of entertainment and enjoyment even if I can never seem to leave it together after I have it running. I decided that starting a new thread was more appropriate than a continuation of my old thread. The original title no longer really applies. For any that are curious about my many years of less than ideal decision making, the original build thread is titled: 79SA to 87EFI. Not nearly as simple as it looked.

Most of what I did before worked out in the end, but I was less than satisfied with my front suspension (It seemed like a good idea at the time and it kept me entertained). Now that I can get back to it, I'll try a different route. I see that others have done variations of this and their projects look intriguing. So at least I've got a little heads up before I do more stupid stuff (disclaimer: All stupid stuff is solely the fault of the author and in no way should reflect upon others ).

Still trying to get the wiring for the overhead lights, Air Compressor, and 220/110 outlets done in the garage (once again). I'm getting real tired of having to put wiring in garages before I can use them. Especially after having to re-wire the whole house.

I moved the car into the garage. Picked up some parts from Las Vegas and had stock front and rear struts plus a new engine/transmission delivered for round 2.

She looks comfy in her new home.


JDM 09 - 11 Renesis with the six speed transmission.


Front and rear suspension from a 2004 automatic car that is in excellent shape. I'll need to source or build the torque tube connector between the trans and the rear differential.


I don't know if I'll still be able to fit the tires under the stock sheetmetal as I originally envisioned. I still like the idea, but we'll see if it's practical. A wider track width would have benefits. There's always the Mariah Mode 1 widebody kit if I need to go that route.

New adventures await.

Frankenrex

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Subscribed!

GySgtFrank

iTrader: (4)

Thanks. I've followed your project also. A fellow inmate from the asylum.

Frankenrex

iTrader: (1)

LOL. I really need to get back on that now that it's not cold. Of course, right now we're getting out year's worth of rain in Texas, after which it won't rain for 4 months.
Biggest distraction is that I inherited my Dad's '55 Chevy that's been parked in a field since 1985. Plus side of that is parts availability for a '55 Chevy is WAY better than our RX-7s.

BrettLinton7

iTrader: (33)

Subscribed, I'm excited to see this one progress!

GySgtFrank

iTrader: (4)

Well, I did just buy a used M800 MoTeC to run the darned thing. I'll have more money into the electronics than the engine probably. The S2 OMP is going to be a problem from the sound of it. None of the ECUs on the market will run the S2 Renesis because of the OMP. It must be alien technology from the mothership.

82transam

iTrader: (18)

That's interesting, I had not heard about issues with the S2 OMP. Granted my S2 Rx8 knowledge is lacking. I know that transmission is THE one to have though so you're off to a good start. I seem to recall that some of the standalones will have issues running the electrically operated 6 port system on the Renesis, but I have no first hand experience (my rene is the simple 4 port, 5 speed verson - the 5 speed is based on the turbo FC and FD box which actually why I wanted this combo lol).

Track width on the Rx8 is 3-4 inches wider depending on which source you find using google. You might be able to keep it looking fairly stock (stock ish). I went with NB miata because I did not want to go with flares/widebody for mine...

A few additional ramblings for you to consider - the Rx8 electric power steering doesn't seem to have much aftermarket support as far as standalone controllers, but I believe the NC miata (which is still hydraulic) rack can be swapped in. As far as powering it goes you can look at epowersteering.com - they make electric columns using GM parts - this is the route I am going to add power steering to my NB subframe setup.

Also, can relate with the electronics costing more than the engine sentiment. The 4 port rene with transmission was under $1500 - the haltech elite 2500 running it is almost a grand more than that lol - not counting all the other stuff needed.

Will definitely keep an eye on this thread - Rx8 suspension is a great design.

GySgtFrank

iTrader: (4)

I found the problem while researching ECUs. HalTech and the others (including the 1 series MoTeC) do not support the S2. I assume it is because of the S2 OMP as stated by MoTeC on their website. MoTeC states their ECU will run everything but the OMP fine. Hopefully I'll be able to figure out what the issue is. I'm sure somebody on here or the RX8 Club knows. All of the numerous updates, including the transmission, are the reason I wanted to go with the S2. Despite that one drawback. I'll have to premix unless I can figure it out. It's not the end of the world, but I really want that improved OMP system working.

Originally, I planned to try to use the complete stock system and wiring harness. Similar to what I did with the S4 6 port in the original build on this car. However, the Renesis is far more complicated and would require many things I didn't really want to incorporate. (such as catalytic converters, etc.) The MoTeC M800 is massive overkill for this application. I have a friend that has a rotary shop that does installs and chassis dyno tuning who is a MASSIVE MoTeC wienie. (He gets pissed when I misspell that.) We plan to base the setup on the Formula Mazda engines. They used the MoTeC M400 box and from what I've heard they worked extremely well.

Agree. A major goal with this build has always been to fit massive rubber under the stock sheet metal. I hope to be able to actually accomplish this.
The custom front subframe and suspension I built was set at the stock 56" front track width. The outside of the tires and wheels I plan to use (17x8.5 et42 and 17x9.5 et42 SSR Competitions) are a little more than 1.5" from the inside of the unrolled front fender. (3+ inches of track width). Of course, I had to do some not so slight modifications to the inner fender wells to get these wheels to actually turn while staying under the stock fender. So IF things work out according to plan, the front suspension should work out. The rear suspension though is another can of worms. From what I can see, the extra track width is definitely going to be a problem.

The RX8 uses a separate controller for the power steering. I've been told it has a mind of its own though.
As I understand it, the NC Miata front subframe takes all the same parts as the RX8. So, theoretically it should be possible to use the NC Miata front subframe to get the hydraulic rack. However, it looks to me that the shape of the subframe would not allow for the genuinely huge oil pan on the Renesis. A possible solution would be the tubular aftermarket front subframe from V8 Roadsters.
Your electric column idea sounds interesting, I'll look into that as well. I'm going to look at several options, but in comparison to what I have already done, modifying the front subframe to use my Flaming River rack should be relatively simple. Should that prove necessary.

The used M800 was 2200.00. All the other stuff such as harness(es) etc. are going to substantially add to this. Not to mention having to rebuild the S2 engine before trying to use it. This is not the cheap way to go about this that's for sure. I absolutely love the RX8s handling and ability to rev. I also love my lightweight SA, but I only really need one car.

So here I am taking on another evolution of maybe not the brightest project. As someone wiser than I once said, "If you try to make a car something that it is not, it is going to get very involved and very expensive."

GySgtFrank

iTrader: (4)

I got mail.

GySgtFrank

iTrader: (4)

Ok, not a lot done on the car. Finished wiring the garage and the basement. Cleaned up all the clutter in the way and started tearing down my front suspension today. A few things ordered and received. The instruction book for the above ECU ('cuz I'm not so smart), The ignition coils/plugs/wires for the RX8 Renesis engine from Black Halo Racing, and the item I wanted to share in case others are looking for a solution to their EFI conversion fuel tank woes. A 16-gallon stainless steel tank with center baffle and the fuel tray built in for EFI from Tanks Inc. They also carry the pumps and senders (along with a cool signal adjuster box). Pretty much everything you need to get the tank and pump portion of a build going. The tank measures 27.5" L x 17.5" W x 8.5" Deep. If you remove the spare tire well, it is as if it was made for fitting under the rear floor/deck of the first gens. The FC came stock with a 16-gallon tank so this should be plenty of fuel.

82transam

iTrader: (18)

Good tip on the tank^ Do you have the specific model? I see a bunch listed on their site. Getting a tank to fit behind the NB Miata subframe was something I still have to figure out on mine since the stock tank is way too big front to back. Wonder how hard it would be to make the fuel filler still come out in the stock location...

Edit, I think I found it: https://www.tanksinc.com/index.cfm/p...rod/prd173.htm

GySgtFrank

iTrader: (4)

Yep that's the one I purchased. They have a lot of different kinds of filler necks that bolt on. My application is easier as I already relocated the filler behind the license plate for the SA. (I used an old, hinged license plate holder from a 1960s car that I had laying around). If you don't want to route it over the floor in the back (which would be awkward) you could always have someone with a TIG modify it for a side fill close to the stock filler.

GySgtFrank

iTrader: (4)

I managed a test fit on the front subframe this weekend. Hopefully this will help satisfy some people's curiosity about what would be involved with this kind of a swap.

So, for inquiring minds that want to know. The folks that said the tires were going to stick well outside the fenders ... you were absolutely right. I figured as much (which is why I was mentioning widebody kits) but it's good to have confirmation. The stock RX8 subframe with 8.5" +42 wheels mounting 235/45R17s (9.3" section width) sticks out approximately 2.5" outside the fender opening on both sides for a combined 5" more vehicle width. The measurement was right at 69.75" across the front. If you use more offset/narrower wheels and tires (such as the stock RX8 wheel) you could reduce this width slightly but not a lot. You could increase it quite a bit with less offset though.

I fitted the rear tires 9.5" +42s mounting 275/40R17s (10.9" section width) on the rear subframe. Once I leveled the tires, I measured them at just slightly over 70" across. No test fit on this yet, I have my hands full with the front at the moment.

The measurements that I obtained line up rather well with the Mariah GTU body kit. Unfortunately, just a touch wide for the Mode 1 kit.

Getting the subframe holes to line up with the stock frame rails does not actually look that bad. I did need to cut out the center section of the rails to slide the upper control arms/mount high enough to approximate where it will need to sit height wise. I'll attach pictures, but I'm going to try to keep them small. *This is the smallest size I could use that you could still see anything.

GySgtFrank

iTrader: (4)

A little more for those wanting to see the RX8 subframe swap. The following pictures are where the stock RX8 struts sit in the SA/FB architecture. The subframe is placed so I have one inch clearance on my 25.4" diameter tires with the tie rods set to level side to side and the bottom of the subframe main body levelled front to back (Tires centered in the stock fender arch of course). For those contemplating something like this you won't need to do the ridiculous inner fender mods that I did but you likely will need to cut and mod the strut towers. Moving the tires outward will likely give you plenty of clearance for your tires turning lock to lock. The good news is that the RX8 struts fit under the hood perfectly fine. They leave a little over an inch to the bottom of the hood while sitting at projected loaded height.

The reason I left that much room above the tire is so that I can run modern high-performance tires. The springs will settle somewhat as well. The selection in 13" tires is rather disappointing and finding tires 23.2" tall is somewhat challenging. I do plan to change up the front tire size to either 245/35ZR17s at 23.8" diameter or 245/40ZR17s at 24.7" diameter. I'm leaning toward the taller size as it is the Continental Extreme Contact Sport 02 Max performance summer tire as opposed to the shorter Toyo Proxes R1R extreme performance summer tires. The Continentals will likely wear better with comparable or better wet traction and probably only slightly inferior dry grip. I believe that I will have enough tire on the road that it will not make a lot of difference. Coil overs are always an option if I need height adjustment, but the stock strut setup is preferable in my opinion.

BrettLinton7

iTrader: (33)

I love seeing the progress! It's like another chapter of a favorite book :-)

If you have no other option than to go widebody, and you can't find a complete kit, I have some remnants of a black dragon kit from this car: https://www.rx7club.com/se-rx-7-foru...roject-961594/. It caught fire, I bought the carcass for the drivetrain, and have the rear fenders and one partially burnt front fender hanging in my shop: https://www.rx7club.com/se-sale-want...w-rew-1148408/

GySgtFrank

iTrader: (4)

My hopes go up and ... dashed again. That is the exact style kit I've been searching for. More so for the front than the rear unfortunately. I wish rotary engineering would make an alternate kit with that style front end. I'm pretty sure there was another company that made a similar kit at one time as well. Possibly in NZ or Australia? This is a picture off the internet of a car in NZ that has the body kit I'd love to be able to find.

If I decide to build my own molds that fender may come in handy. Black Dragon (aka Victoria British, aka LMC truck) is only a couple hundred miles from me. What are the odds they would still have the molds for that kit?