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-   -   What the Mazda RX-8 should have been (new autocross car build) (http://forums.carmudgeons.com/showthread.php?t=143692)

John V 01-07-2018 12:20 PM

What the Mazda RX-8 should have been (new autocross car build)
 
I'm not 100% sure where this is going to go yet, but for the two or three of you that are interested I'll take a crack at documenting the work to get this thing together.

First of all, I have an irrational love of the rotary engine. I blame Car and Driver. In 1992, they broke the story of the upcoming FD-chassis 3rd gen RX-7, and by all appearances that was going to be a landmark car both for Mazda and for sports car enthusiasts. Given that I was 14 when that magazine landed in my mailbox, I had nary a hope of getting into a third gen anytime soon. But that article also had a little blurb on the second-gen RX-7 and while I had seen these cars on the road I knew next to nothing about them (okay, I knew next to nothing about cars beyond 0-60 times, skidpad g's and braking distances). When I landed a second gen turbo as my first car two years later, I was immediately a member of the Wankel-engine fanclub. That car taught me more than I ever expected about the love and frustration of working on cars.

Fast forward to 2004 and our very own Clyde offered me a ride in his first-year RX-8 at a local autocross. I had actually intended on buying the RX-8 when I got my first real job out of school in 2002, but delay after delay meant I had to postpone that goal, and I took the opportunity to buy one of my other high school dream cars, an E36 M3. I loved the M3, and to be honest my interest in the RX-8 had long-since waned, after the "scandal" of Mazda over-rating the RX-8's naturally aspirated rotary hit the press.

But hopping into that car was a revelation. It turns! It stops! It'll even do both at the same time! The wonders of a low center of gravity, the stiffest chassis on the market, double wishbones with great geometry. I was pretty torn. Clyde and I drove that car together for a few years and I've never forgotten the fun we had. I also never forgot just how phenomenal the chassis was and just how underwhelming the engine was.

I couldn't quite shake the thought of getting one as a street car and putting a real engine in it. LS V8? Seems like a great idea on paper, but it's been done and I'm not sure the character of the engine fits the car. Maybe something that revs a bit faster and puts a little less weight on the nose (mostly it's the weight of the beefy transmission that needs to go behind an LS, but either way it's weight). I had also thought for years about doing an autocross car using an RX-8 as a starting platform. There is one class that seemed to make perfect sense: Street Modified.

For those not familiar with SCCA Solo classing (basically everyone on the planet?) Street Modified is a class for four seat cars where the drivetrain is essentially free. The class was based around one rule: Make as much power as you want, using an engine made by the manufacturer of the chassis. i.e., Mazda power in a Mazda. The rule set obviously consists of more than that, but that's the basic premise. So my first thought two or three years ago was why not drop in a 3rd-gen RX-7 13B? The formula for making (relatively) reliable power (in the 450hp range is generally understood to be required for competitiveness) is known using the 13B-REW. There are kits to get the engine to bolt up to the RX-8 and it would be relatively straightforward to build.

But I got to reading the rulebook and was reminded that in SM, there is a minimum competition weight that is based on drive configuration, induction type and engine type. Long story short, a 13B turbo rotary has to weigh at least 2,700lbs. The same car with a 2.5L four cylinder turbo piston engine can weigh 120lbs less. On top of that, 13B-REW parts are pretty expensive and reliable tuning on a rotary is challenging. My mind was made up. I went hunting for an RX-8.

John V 01-07-2018 12:26 PM

I found this gem on Craigslist on a trip down to North Carolina back in the early fall. I was heading down for a wedding and decided to browse CL to see if anything interesting popped up. It was listed for $2,100 and looked to be in nice shape. Talking to the owner, he bought it thinking it would be a good project car for him but he got in over his head swapping the (dead) engine out of it.

https://lh3.googleusercontent.com/lW...=w1389-h781-no

https://lh3.googleusercontent.com/cj...=w1389-h781-no

I got him down to $2k even and towed it home. It's actually a really nice car. It's got 140k on the clock and has absolutely zero rust anywhere. Perfect project car. It came with a bunch of speed parts, which I promptly sold and recouped the purchase price of the car.

John V 01-07-2018 12:39 PM

The car came with the dead motor, but it wasn't installed in the car. I sold that for parts pretty quickly and got started on removing all of the rotary-related stuff. The stock 6-speed transmission is not compatible with the Mazda piston engine so I removed that. The engine bay was impressively clean already. The ABS unit is on the opposite side from an MX-5 (the MX-5's relevance to this project will become clear shortly) and I can tell already it's going to interfere with the intake manifold on the four cylinder.

https://lh3.googleusercontent.com/2T...=w1389-h781-no

The front subframe and steering rack won't work for me. The RX-8 uses an electrically-assisted rack and it's enormous. The mounts are also set up for a rotary and would take a lot of work to adapt to a piston engine, so I don't think I'll be using it.

https://lh3.googleusercontent.com/mZ...=w1389-h781-no

John V 01-07-2018 12:44 PM

The rear subframe I'll use, but it had to come out to get solid bushings (the stock bushings are very soft rubber) and all the rear links will be converted to spherical bearings (again, very soft rubber bushings).

https://lh3.googleusercontent.com/pE...=w1389-h781-no

This is a view from the rear looking forward, just showing how clean the underside of the car is. I love working on this car - the engineering is so well done compared to the E46 where everything is kind of a pain.

https://lh3.googleusercontent.com/vd...=w1389-h781-no

All of the emissions-related stuff is coming out to save weight and reduce complexity, including this surprisingly heavy charcoal canister / gasoline vapor recovery box.

https://lh3.googleusercontent.com/0f...C=w440-h781-no

John V 01-07-2018 12:49 PM

I started on the rear subframe first, because I didn't have anything I needed to start working on the engine swap. A fellow competitor sent me a complete set of solid aluminum rear subframe bushings in exchange for me making him some delrin bushings for his car, so I got those installed. Removing the stock bushings was an absolute bear, but pressing in the aluminum ones just required some Acme-screw all-thread and some wheel bearing anvils.

https://lh3.googleusercontent.com/K-...=w1389-h781-no

https://lh3.googleusercontent.com/Gx...A=w440-h781-no

The rear subframe with all the mounting bushings installed. You'll notice that the diff and axles are gone. The stock diff is certainly strong enough to handle the desired power level, but the available ratios are all tailored to the NA rotary and are far too short for a lower-revving piston engine. It's also a really heavy unit, and the axles aren't the strongest, so I will be going a different direction here.

https://lh3.googleusercontent.com/Og...-=w440-h781-no

John V 01-07-2018 12:52 PM

So, the rear diff. The stock diff is something like a 4.44:1. For a rotary with a 9,000 RPM redline or whatever that's fine, but the 2.5L MZR (aka Ford Duratec) that I'll be using won't want to rev past 7,000 regularly, so this is way too tall. I was searching for something with around a 3.73:1 ratio to give me 75MPH at 7,000 RPM in second gear. Also, this thing is a pig.

https://lh3.googleusercontent.com/Qg...=w1389-h781-no

82 lbs!

https://lh3.googleusercontent.com/wD...=w1389-h781-no

John V 01-07-2018 12:56 PM

Someone has already figured this out, because LS V8 swaps into RX-8s and RX-7s are becoming more common. The Ford 8.8 IRS is an aluminum-cased differential that has 10+ ratios available from 3.07 up to 4.11:1, and they're cheap and plentiful as they were installed in thousands of Explorers between 2007 and 2010. They also have a ton of different off the shelf options for LSD units, and if I happen to grenade one somewhere in the middle of nowhere (doubtful, but I've broken a lot of stuff I shouldn't have been able to over the years) it won't be hard to find one. I picked one up for $75 from a salvage yard and they even loaded it into my truck for me :)

https://lh3.googleusercontent.com/8L...=w1389-h781-no

68lbs. Not a huge difference, but for a much stronger differential it's a nice side benefit. I fully expected it to be heavier than the RX-8 unit.

https://lh3.googleusercontent.com/Yr...=w1389-h781-no

John V 01-07-2018 01:07 PM

So... I mentioned an MX-5. Interestingly, the third-generation MX-5, the NC chassis, is almost identical to the RX-8 from the firewall forward and from the rear glass backwards. The NC's front and rear subrames will bolt directly into the RX-8, and vice versa. The inboard suspension mounting locations are in exactly the same location between the two cars - the only differences are the engine mounts and the steering rack mounts. The two cars use different uprights, hubs, brakes, and control arms, as the Miata has a narrower wheelbase and less weight.

I figured I'd use this to my advantage. I know that the RX-8's firewall is a different shape than the MX-5 as it's designed for a rotary and not the taller piston engine. The MX-5's 2.0L engine is very similar to the 2.3L and 2.5L versions that were offered in various other Ford and Mazda products, but with far less robust internals. I don't want to use the 2.0L as it's not remotely strong enough to handle the power I'll be throwing at it, but given that it's the only engine in the MZR family that's installed in a rear-wheel drive chassis (excluding the Ford Ranger which used a 2.5L version of the MZR, but with truck-oriented manifolds and tuning) I thought it'd be very handy to have an NC around for parts scavenging.

So I bought one.

https://lh3.googleusercontent.com/ql...=w1389-h781-no

And that's where we are now. Today, the goal is to lower the engine, transmission and subframe out of the NC as one unit and start taking measurements. I can already tell that it won't directly bolt into the RX-8 because the engine setback is so extreme on the MX-5. The top of the 2.0L will hit the top of the RX-8's firewall. The even-taller 2.5L that I'll eventually pick up will be even worse. But as a starting point, it'll be helpful to have everything out of a running NC to get going on converting wiring, which will be far from plug 'n play.

To convert a 2.5L engine (out of one of a million Fusion, Mazda 6, Mazda 3 or similar cars) to a rear wheel drive configuration requires many parts off of an NC Miata, so this 2.0L will donate a lot of good stuff. Looking at how it's installed in the MX-5, I think I can easily lower it 2-3 inches and move it 4-5 inches forward to make it fit in the RX-8. Obviously moving the engine forward isn't ideal for handling, and perhaps a rotary would have upset the balance of the chassis less. But I'm not allowed to hack up the firewall, and I really do think this will be the best long-term solution to making this car fast and reliable. So I'm committed to blasphemy... and ending my long love affair with the rotary.

JST 01-07-2018 01:29 PM

Thanks for the write up! Interesting stuff.

Plus there’s a part of me that really likes the idea of you being forced to use Ford parts. ;)

Josh (PA) 01-07-2018 02:14 PM

very interesting. Maybe I didn't comprehend, but what motor are you using and where is it coming from?

Alan 01-07-2018 02:15 PM

Very cool ... loving this thread and wow I give you a ton of credit, your knowledge is really admirable.

Btw I just drove the yellow RX8 the other day, not side tracking the thread but I continue to be amazed by how good this car is ... even with the slow unreliable rotary which btw really is my biggest disappointment with this car ...

equ 01-07-2018 02:17 PM

Awesome. Great write-up too.

clyde 01-07-2018 02:18 PM

Nice.

Are you going to duplicate the build thread elsewhere?

John V 01-07-2018 04:01 PM

Clyde, I don't know. I'm not interested in hearing about how I'm doing it wrong at every stage :lol:

Sorry I wasn't clear but I'm using a Mazda "L" engine, aka Mzr, aka Ford Duratec (designed by Mazda) in the 2.5L displacement. It's a very light aluminum four cylinder with 9.5:1 compression, factory forged crank and pistons, designed from the start for boost. Obviously I'll build it to handle the power I plan to make (around 520 at the crank).

Same basic engine as the Ford ecoboost inlne 4.
Jv

John V 01-07-2018 06:18 PM

Everything disconnected and the engine crane (thanks Bren!) hooked up to the one engine lifting point. My floor jack is under the tailshaft of the transmission.

https://lh3.googleusercontent.com/lS...=w1111-h625-no

Gradually lowering...

https://lh3.googleusercontent.com/lQ...=w1389-h781-no

Lowered onto furniture dolleys

https://lh3.googleusercontent.com/Tk...=w1389-h781-no

And, out! Installation is not quite the reverse of removal at this point. But now I can at least start to take measurements.

https://lh3.googleusercontent.com/Eg...=w1389-h781-no

It looks like what's been said by the few people who have tried this is true... the back of the cylinder head wants to occupy the same space as the firewall. But it's only about an inch. The taller 2.5 that will replace this 2.0L is another inch taller as well. But honestly, that's not bad news. The factory subframe has enough room to easily move the engine three inches forward, and if I ran a dry-sump oil pan I can lower the engine easily three inches as well. I'm probably speaking too soon, but this doesn't seem like it is the disaster everyone says it is.

I guess part of that is because I'm not going to use the power plant frame, a big heavy steel beam that ties the back of the transmission to the nose of the differential. So I'll need to make a custom transmission mount and have a custom driveshaft made, but... no biggie?

clyde 01-07-2018 06:44 PM

Quote:

Originally Posted by John V (Post 520244)
The factory subframe has enough room to easily move the engine three inches forward, and if I ran a dry-sump oil pan I can lower the engine easily three inches as well. I'm probably speaking too soon, but this doesn't seem like it is the disaster everyone says it is.

If it's a choice, three inches lower seems a lot more preferable than three inches forward. But, 1) dunno what I'm missing and 2) not sure three inches forward is bad enough that it's that bad.

Sandbox or elsewhere thread would probably get a lot more activity than it will get here. And probably more helpful questions/suggestions, too, but I'm sure you'll have it covered anyway.

Gonna be fun to watch either way.

Biggins 01-08-2018 07:26 AM

I'm excited to see the final product! I'm sure you'll run into some snags, but I know you can work around them to make it a cool car that is hopefully really fast too.

John V 01-08-2018 07:38 AM

1 Attachment(s)
Attached is a picture of a stripped MZR on an engine stand. It's not my engine.

On the rear of the block /cylinder head there are two accessory items that stick out. One is the EGR valve (rear of cylinder with black "top hat") and the other is the cylinder water outlet (the black pipe on the rear of the block, above the Miata headlight in the pic). Both of those foul on the firewall when you put an MZR in an RX-8.

The EGR I'm not worried about - I'll delete it and put a blockoff plate in its place. The water outlet is a bigger problem, because obviously I can't delete it. One good thing about choosing the MZR is the engine is cheap, light, and as a result popular for swapping into stuff like Caterhams and old British cars. There are a few companies that have designed unique water rails which remove that factory water outlet and replace it with something much lower-profile. this piece takes the water and routes it above the exhaust ports on the passenger's side of the engine towards the front. I think if I use something like this the engine might come close to bolting in without anything other than lowering it a couple of inches.

http://www.burtonpower.com/media/cat...Rail_large.jpg

anyway... options.

Alan 01-08-2018 09:52 AM

Totally off topic question ... it is cold as Sh*t ..your garage is heated ?

John V 01-08-2018 10:11 AM

Quote:

Originally Posted by AF (Post 520277)
Totally off topic question ... it is cold as Sh*t ..your garage is heated ?

Kinda. I've got a huge propane heater in there (hanging from the ceiling above the workbenches), but I keep it set to a really low temperature and still manually cycle the thermostat when I'm working in there to keep costs low. The detached garage where I'm doing the work is a cinder block building with no insulation and with very drafty old garage doors.

If the air temp is in the 45 degree range I'm perfectly comfortable working in there... the annoying part is the garage is built on a very thick concrete slab and it stays cold basically all year long. Great in the summer (except water condenses on it in the summer) but not great in the winter. Even with ski socks on and work boots my feet get really cold out there.

In the next few years I plan to frame out the walls just enough to put some rigid foam insulation on the walls, replace the old wooden doors with roll-up doors, insulate the attic and epoxy the floors, but I don't know when I'll get to that.

wdc330i 01-08-2018 11:30 AM

Quote:

Originally Posted by John V (Post 520281)
Kinda. I've got a huge propane heater in there (hanging from the ceiling above the workbenches), but I keep it set to a really low temperature and still manually cycle the thermostat when I'm working in there to keep costs low. The detached garage where I'm doing the work is a cinder block building with no insulation and with very drafty old garage doors.

If the air temp is in the 45 degree range I'm perfectly comfortable working in there... the annoying part is the garage is built on a very thick concrete slab and it stays cold basically all year long. Great in the summer (except water condenses on it in the summer) but not great in the winter. Even with ski socks on and work boots my feet get really cold out there.

In the next few years I plan to frame out the walls just enough to put some rigid foam insulation on the walls, replace the old wooden doors with roll-up doors, insulate the attic and epoxy the floors, but I don't know when I'll get to that.

Might consider electric radiant heat for the floors.

JST 01-08-2018 11:42 AM

Quote:

Originally Posted by wdc330i (Post 520290)
Might consider electric radiant heat for the floors.

goddamn i love the heated floors in my kitchen. Seems like a system like that would be prohibitive without busting up the floors though--are there overlay options?

Short term, maybe radiant mats that you could use to at least have a place to stand/lie on when you're working in one area?

John V 01-08-2018 12:05 PM

It doesn't bother me enough to do something about it

bren 01-08-2018 12:30 PM

Quote:

Originally Posted by John V (Post 520293)
It doesn't bother me enough to do something about it

I try to use a couple layers of cardboard underfoot.

BahnBaum 01-08-2018 02:01 PM

Very cool. (thread, not temps)

Alex

Plaz 01-09-2018 11:12 AM

Wow. Impressive.

I’ve got to think that car with >500hp will be formidable. And probably still get better fuel economy than the stock motor. :lol:

John V 01-09-2018 07:05 PM

I think it will compete very favorably with the current class leaders which include a very well prepared and driven turbocharged 240SX, several Evos and STis (which have to run much heavier than rear wheel drive cars) and various E36 BMWs. Even with the piston engine it should have a very low center of gravity, much better suspension geometry than any of them and a much stiffer chassis. Even if I'm off by 200lbs on my weight estimate (I don't think I am) then I'll at worst be on even ground with the BMWs and the 240.

A local salvage yard has a complete 2.5L engine for $300, so I'm planning to head there on Friday (my day off every two weeks) and snag it.

bren 01-09-2018 09:59 PM

I'm just glad that engine hoist had at least one more pull in it. Something about using a HF tool to hold up hundreds of pounds chest high just gives me the hebejebes.

JST 01-09-2018 10:10 PM

Quote:

Originally Posted by John V (Post 520420)
I think it will compete very favorably with the current class leaders which include a very well prepared and driven turbocharged 240SX, several Evos and STis (which have to run much heavier than rear wheel drive cars) and various E36 BMWs. Even with the piston engine it should have a very low center of gravity, much better suspension geometry than any of them and a much stiffer chassis. Even if I'm off by 200lbs on my weight estimate (I don't think I am) then I'll at worst be on even ground with the BMWs and the 240.

A local salvage yard has a complete 2.5L engine for $300, so I'm planning to head there on Friday (my day off every two weeks) and snag it.

What kind of boost setup do you need to make that kind of power?

John V 01-10-2018 05:32 AM

I'm planning to use a Borg Warner EFR7163 turbo running about 21lbs of boost peak.

https://cdn.shopify.com/s/files/1/12...3F-3_large.jpg

lemming 01-10-2018 11:27 AM

holy cow.

simply for educational purposes this is an amazing thread. (didn't know the commonality between MX5 and the RX8 --makes sense, but just never thought about it)

but what you're aiming to do is also super interesting.

John V 01-10-2018 01:38 PM

Don't be too amazed. I haven't actually done anything yet.

This whole endeavor will assuredly test my extremely limited fabrication skills, but the idea is to learn new things...

Josh (PA) 01-10-2018 01:42 PM

Quote:

Originally Posted by John V (Post 520439)
I'm planning to use a Borg Warner EFR7163 turbo running about 21lbs of boost peak.

https://cdn.shopify.com/s/files/1/12...3F-3_large.jpg

Do you have any thoughts on how long the engine will last making that type of power with that level of boost? I always wondered that when I see the N54 guys cranking up the boost on the 135s and 335s and to make 500+whp. I assumed these were all ticking time bombs.

John V 01-10-2018 06:55 PM

With good tuning and strong internals it'll last much longer than an engine that sees stratospheric RPM.

John V 02-01-2018 08:08 AM

Hm. I've done a lot of work lately but haven't posted anything. Maybe I can fix that this weekend.

John V 02-03-2018 04:26 PM

Alright alright. I haven't posted in a while.

Wiring! That's what's on the menu lately. I bought this 2006 Miata to scavenge parts of the "front" wiring harness. The RX-8 and the MX-5 are pretty similar, but the wiring is quite different. Both cars have dedicated engine harnesses, and since I'm using the MX-5 engine (sorta), that doesn't have to be modified. On the MX-5, the engine harness plugs directly into the ECU, located in the engine bay. But both cars also interface the engine harness to what Mazda calls the "front" harness, which handles the lights, ABS, fans, air conditioning, CAN bus, and a bunch of other things. The front harness is also what connects to the engine fuse box. I wanted to make it so the MX-5 engine could plug into the RX-8 front harness and behave exactly like an MX-5, for future troubleshooting.

The first step was to thoroughly understand each car's wiring, and develop a cross-reference sheet. I figured this would be challenging, and it did not disappoint. Even though there are only about fifty unique signals that needed to be spliced in, Mazda locates them in different places on each car, they use different wiring codes, and... it's complicated.

https://lh3.googleusercontent.com/Xz...l=w655-h711-no

https://lh3.googleusercontent.com/5Z...=w1022-h713-no

Once I had all of that sorted out, I bit the bullet... I had to go cut the MX-5's wiring harness. Mostly I needed two connectors, each of which plugged into the engine harness and routed signals like the CAN bus, the taillight and reverse lights, the starter interlock, etc into the interior harnesses.

https://lh3.googleusercontent.com/HG...=w1389-h781-no

The white and gray connectors in this picture attached to the MX-5's engine fuse block. I figured I'd find a place to attach them to the RX-8 chassis, near its fuse block, which is in roughly the same location as the MX-5. I cut them with enough wire attached to allow me to easily splice them into the RX-8's wiring harness. The big gray connector with the lever lock is the second connection to the MX-5's engine computer. I had to cut that off as well.

https://lh3.googleusercontent.com/Xv...y=w440-h781-no

Here they are all cut out and ready to start working into the RX-8.

https://lh3.googleusercontent.com/Xv...y=w440-h781-no

Moving to the RX-8, I had to cut out the sheathing and tape wrapping its harness. I'm converting the RX-8 from electric power steering to hydraulic, so I figured I'd lighten the front harness load and simplify the wiring by removing all of that wiring, plus all of the emission control wiring (which is substantial in the RX-8 as compared to the MX-5).

https://lh3.googleusercontent.com/iu...=w1389-h781-no

To the right of that pic is the fuse box, which is where all of these wires come and go.

https://photos.google.com/share/AF1Q...cxMDlTRGlqbWVn

And on the passenger's fender, a bunch of wires that need to get eliminated from the RX-8 wiring. The fuel pump resistor, the air pump, the EPS computer wiring... most of this is going away.

https://lh3.googleusercontent.com/sJ...=w1389-h781-no

The first splice I made was a bypass for the two-speed fuel pump relay that Mazda runs. The rotary requires so much fuel at high RPM that they run the fuel pump at low speed during idle and at a faster speed when necessary, to avoid heating of the fuel. I don't need this for my setup as I'm converting the fuel system to a true return-style system, so this will simplify things down the road. Basically I'm bypassing the low-speed relay and always running the pump wide open.

https://lh3.googleusercontent.com/tk...=w1389-h781-no

John V 02-03-2018 04:42 PM

Scary pic #1. One wire at a time, and double checking my reference documentation, I spliced in the MX-5 ECU connectors to the RX-8 chassis wiring. I generally like to use non-insulated crimp terminals with shrink wrap, so you see a bunch of little sections of black shrink tubing. I did use a couple insulated crimp connectors for the larger wires. I'll probably re-do these in the future, but I didn't have any non-insulated terminals that were large enough.

https://lh3.googleusercontent.com/-j...=w1389-h781-no

Scary pic #2. Continuing, one wire at a time. This is fairly challenging, as you want all the wires to be roughly the correct length, so the harness has enough length but not a bunch of long wires that you have to bundle up later.

https://lh3.googleusercontent.com/Dk...=w1389-h781-no

Believe it or not, this is pretty close to "done."

https://lh3.googleusercontent.com/rW...=w1389-h781-no

And, with most of the wires bundled up enough so they're not loosely hanging out. I won't fully wrap the harness until I've got the engine in and have verified everything works, but I've checked every wire a bunch and I believe I've gotten everything correct.

https://lh3.googleusercontent.com/Mv...=w1389-h781-no

John V 02-03-2018 04:49 PM

So, back to the engine fitment issue. I've come to a couple realizations. Let's tackle the first one: the water pipe on the back of the cylinder head is the limiter for how far back in the chassis the engine can go. It sticks out about three inches, and that just isn't going to work.

I discovered that the Ford Ranger with the 2.3L Duratec has a much slimmer rear water pipe. But still, it sticks out almost two inches. Better. Not great.

http://uploads.turbosport.co.uk/getr...om/ui83vIi.jpg

Then I came across a guy who custom makes a bunch of parts to put the Duratec/MZR into old RWD cars, like Aussie Escorts. He makes a water pipe that only sticks out 25mm (about an inch). Score! Also, check out that sweet bellhousing... that will become important shortly.

http://www.turbosport.co.uk/attachme...382745&thumb=1

John V 02-03-2018 04:57 PM

Problem number two is when the engine is in the right location fore-aft, the MX-5 transmission's shifter is about four inches forward of the RX-8's shifter hole. The MX-5's transmission is also almost 110lbs, which is pretty hefty.

Well, that bellhousing above is made by the same guy that makes the slim water rail. It is designed to mate to a second or third-gen RX-7 turbo transmission, which has a removable bellhousing. Those transmissions are also very strong, and about 30lbs lighter than the MX-5 transmission. The kicker is they measure four inches longer from the bellhousing to the shifter. Meaning they should line up perfectly with the RX-8 shifter hole. Score!

Josh (PA) 02-03-2018 06:41 PM

I love it when a plan comes together...

nice work, as usual.


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