Jan 16, 2020 update to the Mazda Miata project car

Project Endurance Miata: Trading a Turbo for a V6, but Do We Install a Honda J35 or a GM LFX?

Endurance racing is hard. Doing it on a budget is even harder. Doing both while shooting for a podium finish? That’s nearly impossible, as we proved with our Miata. 

After years of development, three turbos, four engines, and roughly a dozen depressing drives home from the track with a broken car on the trailer, we found success with our junkyard turbo setup: We finished second in class at ChampCar Daytona! 

Then, well, we moved on. After all, we’re looking for good stories, not necessarily a good race car. 

Once we’d sorted the car, reformed our team and earned a podium finish, we couldn’t just write boring stories about by-the-book races. We had two choices: Continue developing the car or get rid of it, and we didn’t want to do either. So we parked it. 

After diverting our attention to our extremely budget-oriented Volkswagen Fox endurance racing car for a year or so, we turned our attention back to the Miata. Did we still like it? Absolutely. Did we think it could be faster, and produce a good story along the way? Definitely. 

We pulled the Miata out of storage with new goals: Kick it up a notch, move away from low-buck racing, and go really fast. We’d trade 500-point ChampCar and 24 Hours of Lemons legality for a fighting chance at competitive AER or WRL showings, and use our VW Fox for the low-buck racing we still loved.

With our biggest limitation, the budget, removed, we grabbed a blank sheet of paper and started planning. What would our Miata look like in a perfect world? What were our pain points before? What would it need to beat on track?

After much deliberation, we came up with these goals: 

  1. A less-stressed drivetrain. Sure, our Miata was fairly quick with a turbo, making nearly 200 horsepower, but it wasn’t repeatable. Every single race, even our podium finish, surfaced new problems, with everything pointing back to one issue: the turbo. We managed to keep things together for an entire race, but the car fought us the entire time and required parts that weren’t in stock at every AutoZone. And we never did solve our car’s cooling issues, which consistently pushed water temperatures near 230 degrees. Yes, it worked. But it clearly couldn’t work forever. We wanted Miata 3.0 to be naturally aspirated, and built with easily sourced, under-stressed parts.
  2. 100 more horsepower. Ok, fine–we’re racers, and we always want more power. But at both Road Atlanta and Daytona, every driver reached a unanimous agreement: If we could just make 100 more horsepower, pushing the total near 300, this car would be unbeatable. 
  3. Better fuel mileage. We’d managed to push our Miata’s stints to nearly 1.5 hours long, but we were still stopping too often to refuel thanks to that turbo. We needed to squeeze as much fuel mileage as possible out of the car in order to stay competitive. 
  4. Proper suspension. Yes: Our low-buck, ChampCar-legal setup worked well, but it wasn’t adjustable, and we never did get the cut springs stiff enough for our liking. Add in wider tires–which we’d need if we were going to add 100 horsepower–and it was obvious that we needed to buy some real parts in this department. 

Goals in hand, we started making calls and putting feelers out to our fellow friends and racers in the industry. Gradually a path emerged, with more and more arrows pointing to one answer: It was time for a V6 swap. The promise was simple: Two more cylinders, roughly the same weight (the Miata’s iron-block four-cylinder is traded for an all-aluminum V6) and nearly 300 horsepower. It would split the difference between our turbo four and a heavy, overpowered LS swap, and meet our goals perfectly.

There was one last question: Which all-aluminum, 300-horsepower V6? That’s right: There’re are two popular V6 swap kits on the market for early Miatas, and both use a commonly available all-aluminum V6. 
The first, from Minitec, uses the Honda J series V6, which is the engine platform found in most of Honda and Acura’s sedan and SUV lineup. Minitec’s kit is designed around the 3.5-liter 2001-’03 Acura CL Type S or 2002-’04 Honda Odyssey engine, and includes the following parts. Retail price is $3950.

  • Front Subframe to adapt Honda J engine into Miata (retains Miata front anti-roll bar)
  • Transmission adaptor from Honda J to Miata transmission
  • Custom aluminum oil pan with pickup
  • Poly engine mounts
  • Flywheel adaptor
  • Aluminum thermostat housing
  • Starter
  • Exhaust manifold and downpipe
  • Clutch kit with flywheel
  • *Available for an additional $715: ECU and wiring harness.

The second kit, from V8 Roadsters, uses the GM LFX engine, a direct-injected 3.6-liter V6 found in most modern GM products fitted with a V6, including the Camaro and Cadillac CTS. V8 Roadsters recommends using a 2012-’15 Camaro engine for their swaps. Retail price is $7995, and their kit includes the following:

  • Front subframe
  • LFX mounting kit for NB steering rack
  • Stage 1 Getrag drive line kit for MV5 or MV7
  • LFX stand-alone wiring harness
  • LFX down pipes
  • LFX fuel kit
  • LFX shifter assembly
  • LFX cooling system–radiator for stock fans and pressure bottle with cap
  • LFX clutch kit
  • LFX power steering kit for NB rack
  • LFX reroute for heater core lines
  • Frame rail reinforcements
  • *Available at additional cost: Power steering, A/C, ABS pump bracket, etc. 

Facts in hand, we decided to use the V8 Roadsters kit. Why? First and foremost, it used the entire Camaro driveline, replacing the relatively fragile Miata transmission and differential with parts from the V6 donor and significantly increasing the durability of the driveline.

The Minitec kit, in contrast, keeps the Miata transmission and differential. Put simply, we just didn’t see those Miata parts lasting behind 300 horsepower in an endurance racing setting. 

There were other reasons, too: The V8 Roadsters kit was far more complete, basically including 90% of what we’d need to get the car running. The Minitec kit, in contrast, would require us to figure out our own cooling system, power steering and fuel system. 

And we were curious about the LFX, as it seems like an engine with great potential that just hasn’t gotten much love in the enthusiast world. Shoutout to Ryan at Good-Win Racing here, too, since his stupid-fast LFX-powered HyperMiata inspired us greatly.

Decision made, we ordered the V8 Roadsters swap kit, then called a local salvage yard and ordered a Camaro engine and transmission, as well as a limited-slip differential from a Cadillac CTS. The salvage yard parts totaled just less than $1500, while the V8 Roadsters kit we ordered retails for $7995.

No longer a $500 race car, we found ourselves sitting in the shop with our trusty Miata on the lift and nearly $10,000 worth of parts next to it. After some serious ups and downs in its career, it was time for our Miata to receive engine number five. We’ll cover that in the next update.

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Comments
View comments on the GRM forums
mazdeuce - Seth
mazdeuce - Seth Mod Squad
1/14/20 3:33 p.m.

My ears just perked up. Listening intently. 

Keith Tanner
Keith Tanner MegaDork
1/14/20 3:35 p.m.

There's also the Rocketeer kit with the Jaguar V6, FYI. I'm not sure if it's available in the US at the moment but it's pretty nicely done.

Ransom
Ransom UltimaDork
1/14/20 3:41 p.m.

Awesome! Very much interested in anything about rehoming LFXen...

Tom Suddard
Tom Suddard Director of Marketing & Digital Assets
1/14/20 4:15 p.m.

In reply to Keith Tanner :

You're not wrong, but it's not really possible to buy it yet. 

https://www.rocketeerltd.com/how-to-buy

Rodan
Rodan Dork
1/14/20 4:19 p.m.
Keith Tanner said:

There's also the Rocketeer kit with the Jaguar V6, FYI. I'm not sure if it's available in the US at the moment but it's pretty nicely done.

There was just some traffic on Miata.net that Rocketeer has discontinued kits as of 1/2020, and will only be building turnkey cars.  As far as I know, there is no US turnkey builder.

Rodan
Rodan Dork
1/14/20 4:22 p.m.

LFX is probably the best choice for racing.

It would be worth your while to spend lots of time picking Ryan's brain... wink

Having followed the Hypermiata closely for several years, his results have been amazing, and he probably has more knowledge than anyone about making an LFX/Miata work on the track.

I'll be watching your progress with just as much interest!

NickD
NickD PowerDork
1/14/20 5:14 p.m.

Too many years as a GM tech makes me nervous around LFXs.

mrhappy
mrhappy Dork
1/14/20 5:16 p.m.

I really like this but I with it fit under the stock hood.

Dusterbd13-michael
Dusterbd13-michael MegaDork
1/14/20 5:22 p.m.

You coulda done a 3400 for challenge money....

The lfx has a good 120 horse on it though. And swapping the differential makes a huge improvement. 

Keith Tanner
Keith Tanner MegaDork
1/14/20 5:29 p.m.
Tom Suddard said:

In reply to Keith Tanner :

You're not wrong, but it's not really possible to buy it yet. 

https://www.rocketeerltd.com/how-to-buy

It was available, but the US distributor shut down. There is not currently a US one. 

Rocketeer would bring the DIY kits back online with the right partner, I believe.

Streetwiseguy
Streetwiseguy MegaDork
1/14/20 6:21 p.m.
NickD said:

Too many years as a GM tech makes me nervous around LFXs.

Maybe Tom will change the oil often enough to keep the timing chain in it.  

That's one problem delayed, anyway.

Number1Gaza
Number1Gaza New Reader
1/14/20 7:58 p.m.

The Honda lover in me wishes you went with the J series, but admittedly it seems that the LFX is a far more complete option, for not only the reasons you list but because making 300hp from an early gen 3.5 liter J series involves a fair amount of J family parts swapping and aftermarket upgrades.  
 

Looking forward to future updates!

Raze
Raze UltraDork
1/14/20 8:20 p.m.

Looking forward to updates.

LFX is fun in a big first gen Camaro, can't imagine it in a Miata.  One request, please open up the exhaust if it doesn't violate noise levels, it sings...

 

Kreb
Kreb UberDork
1/14/20 8:21 p.m.

Love it! Will be watching this one very closely.

759NRNG
759NRNG UltraDork
1/14/20 8:32 p.m.

Hmmm.................LFX in a MGB/GT what could possibly be wrong with that?

miatafan
miatafan New Reader
1/14/20 8:39 p.m.
 
 
Keith Tanner said:
Tom Suddard said:

In reply to Keith Tanner :

You're not wrong, but it's not really possible to buy it yet. 

https://www.rocketeerltd.com/how-to-buy

It was available, but the US distributor shut down. There is not currently a US one. 

Rocketeer would bring the DIY kits back online with the right partner, I believe.

Sounds like an opportunity for FM...

Kreb
Kreb UberDork
1/14/20 9:13 p.m.

The LFX looks very compact. Does anyone have dimensions and weight? Also, you don't mention engine management for the LFX. What's up with that?

Keith Tanner
Keith Tanner MegaDork
1/14/20 9:41 p.m.
miatafan said:
 
 
Keith Tanner said:
Tom Suddard said:

In reply to Keith Tanner :

You're not wrong, but it's not really possible to buy it yet. 

https://www.rocketeerltd.com/how-to-buy

It was available, but the US distributor shut down. There is not currently a US one. 

Rocketeer would bring the DIY kits back online with the right partner, I believe.

Sounds like an opportunity for FM...

I'd like to see it happen. US emissions laws are a problem. Not for everyone, but for us. 

Floating Doc
Floating Doc SuperDork
1/14/20 11:00 p.m.
Keith Tanner said:
miatafan said:
 
 
Keith Tanner said:
Tom Suddard said:

In reply to Keith Tanner :

You're not wrong, but it's not really possible to buy it yet. 

https://www.rocketeerltd.com/how-to-buy

It was available, but the US distributor shut down. There is not currently a US one. 

Rocketeer would bring the DIY kits back online with the right partner, I believe.

Sounds like an opportunity for FM...

I'd like to see it happen. US emissions laws are a problem. Not for everyone, but for us. 

Understandable. Flyin Miata certainly isn't "everyone." And that's a good thing.

alfadriver
alfadriver MegaDork
1/15/20 6:22 a.m.

It's interesting that there isn't a Cyclone v6 swap out there being sold, too.  Last I saw, it was getting 300hp w/o DI.  Must be a much bigger engine....

For a different, and perhaps cheaper (but harder) option would be the Lincoln LS V6 with manual swap.  It's been done before, and drives really nicely- but not 300hp...

SVreX
SVreX MegaDork
1/15/20 7:06 a.m.

This I like. 

Knurled.
Knurled. MegaDork
1/15/20 8:39 a.m.
NickD said:

Too many years as a GM tech makes me nervous around LFXs.

Working on Hondas makes me interested in the J-series kit.

 

But the LFX kit should make for a much faster car.  The Hondas are not very acceleration prone, even in Accords.

 

Keith Tanner
Keith Tanner MegaDork
1/15/20 9:16 a.m.
alfadriver said:

It's interesting that there isn't a Cyclone v6 swap out there being sold, too.  Last I saw, it was getting 300hp w/o DI.  Must be a much bigger engine....

For a different, and perhaps cheaper (but harder) option would be the Lincoln LS V6 with manual swap.  It's been done before, and drives really nicely- but not 300hp...

That’s the Jaguar V6 used in the Rocketeer kit, isn’t it? 

It’s a shame that GRM is doing a swap into a race car, because all the hard parts of a swap involve making it into a real street car. It’s the real way to test the R&D. 

I would recommend reinforcing the steering rack mounts in the V8R subframe and putting a cross brace between the rear control arm mounting points to avoid failures - especially on a track car. 

alfadriver
alfadriver MegaDork
1/15/20 10:00 a.m.
Keith Tanner said:
alfadriver said:

It's interesting that there isn't a Cyclone v6 swap out there being sold, too.  Last I saw, it was getting 300hp w/o DI.  Must be a much bigger engine....

For a different, and perhaps cheaper (but harder) option would be the Lincoln LS V6 with manual swap.  It's been done before, and drives really nicely- but not 300hp...

That’s the Jaguar V6 used in the Rocketeer kit, isn’t it? 

It’s a shame that GRM is doing a swap into a race car, because all the hard parts of a swap involve making it into a real street car. It’s the real way to test the R&D. 

I would recommend reinforcing the steering rack mounts in the V8R subframe and putting a cross brace between the rear control arm mounting points to avoid failures - especially on a track car. 

Dunno- I don't know what year of "Jag" engine they are using- if it's one from the early '00's, then it's really a Taurus engine- not an actual jaguar engine.  

And for anyone considering this swap in the US- the Lincoln V6 with a manual is a better choice, since it has a 5 speed transmission attached- just like the Camaro choice that GRM made.

Vigo
Vigo MegaDork
1/15/20 10:10 a.m.

The S-type and X-type 3.0s were both Duratecs. The S-Type and Lincoln LS were the 'same car'.  The big reason I know of why people tend to avoid the LS 5spd is because it's non-overdrive with 5th being 1:1.  Not that that matters on race car once you're swapping the rear end out for something in the low 3s:1 and you rev to 7000. For a street car it's more of an annoyance although realistically there aren't many engines you can swap into a Miata that will be any MORE pleasant buzzing 4000rpm going 70mph, so a gear swap is almost implied with any larger engine intended to make the miata a better street experience. 

Anwyay, I'm interested to see how this goes even though I personally (partially from my experience as a tech) am more interested in the Honda J series.  The LFX will still be fast as long as it's working, although you could say that about the turbo engine too. angel  All my fascination with the LFX sort of ended after driving Camaros and CTS's with the 6spd and still finding it meh. Taking off 1000+ lbs would help, but it was also about feel and nvh. Plus side is, for a racecar that practically doesn't matter at all! The LFX will be more powerful for a smaller amount of money (engine itself) than the J since only certain J parts are easy to make 300hp with and there is a market for them, versus the LFX in which 300hp versions are plentiful and enthusiasts more or less ignore them once they hit the junkyards. 

 

Knurled.
Knurled. MegaDork
1/15/20 10:26 a.m.

In reply to Vigo :

Non overdrive transmissions are great because they cut down on driveshaft RPM.  Which is not so much a "performance" benefit as it is  a benefit to not have to deal with a driveshaft spinning at 6000-7000 and your U joint angles are less than perfect and the oscillations wreck everything else in the drivetrain.

 

Ahem.

NickD
NickD PowerDork
1/15/20 10:33 a.m.
Knurled. said:
NickD said:

Too many years as a GM tech makes me nervous around LFXs.

Working on Hondas makes me interested in the J-series kit.

 

But the LFX kit should make for a much faster car.  The Hondas are not very acceleration prone, even in Accords.

 

I've heard that gripe too, that they are a little slow to rev. I wonder if a really light flywheel would make the J-series feel much sportier.

Rodan
Rodan Dork
1/15/20 10:41 a.m.

The main problems with the J swap that I've seen documented are the engine being cantilevered off a rear (bellhousing) mount, lack of ground clearance for the oil pan, and re-locating the steering rack.

If anyone out there is seriously tracking a Miata with the J swap, I haven't seen it on any of the various forums.

aw614
aw614 Reader
1/15/20 11:05 a.m.

There was a guy up in brooksville florida that did the J swap, sounded like he was tracking it for a while and he showed up to one corvette autocross, but it seems he went to tracking bmws. Wish I took a good look at it when he did come, I saw it as "just another" miata at an autox with a different sounding motor

alfadriver
alfadriver MegaDork
1/15/20 11:12 a.m.

On a side note- questioning the V6 choice, seems like a good one to choose would be the one that has shown tons of success in cheap car endurance racing.

The Alfa v6.  laugh

Keith Tanner
Keith Tanner MegaDork
1/15/20 11:18 a.m.
alfadriver said:
Keith Tanner said:
alfadriver said:

It's interesting that there isn't a Cyclone v6 swap out there being sold, too.  Last I saw, it was getting 300hp w/o DI.  Must be a much bigger engine....

For a different, and perhaps cheaper (but harder) option would be the Lincoln LS V6 with manual swap.  It's been done before, and drives really nicely- but not 300hp...

That’s the Jaguar V6 used in the Rocketeer kit, isn’t it? 

It’s a shame that GRM is doing a swap into a race car, because all the hard parts of a swap involve making it into a real street car. It’s the real way to test the R&D. 

I would recommend reinforcing the steering rack mounts in the V8R subframe and putting a cross brace between the rear control arm mounting points to avoid failures - especially on a track car. 

Dunno- I don't know what year of "Jag" engine they are using- if it's one from the early '00's, then it's really a Taurus engine- not an actual jaguar engine.  

And for anyone considering this swap in the US- the Lincoln V6 with a manual is a better choice, since it has a 5 speed transmission attached- just like the Camaro choice that GRM made.

Jaguar AJ30, which is the LS engine. Rocketeer mates it to the Miata trans, which means everything from the bellhousing back is Mazda engineered. Even the clutch is a Miata unit sourced from FM. It’s got a custom intake manifold with dual throttle bodies to fit under an unmodified hood, which I know was a problem with the one-off Lincoln car. Runs bespoke engine management.

RossD
RossD MegaDork
1/15/20 11:36 a.m.

In reply to Keith Tanner :

Dont forget, the Mazda 6 had the same family of V6 in it.

Keith Tanner
Keith Tanner MegaDork
1/15/20 11:46 a.m.

It's a more distant relative. That's the "Taurus" engine that Alfa referred to, I believe.

alfadriver
alfadriver MegaDork
1/15/20 12:02 p.m.

In reply to Keith Tanner :

To me, being able to to take most of the powertrain and swap the intake manifold is easier and more properly engineered than an adaptor plate set up.  but that's just me.

And that's why if you are in the US, find the LS V6 manual- they are still out there.

alfadriver
alfadriver MegaDork
1/15/20 12:04 p.m.
Keith Tanner said:

It's a more distant relative. That's the "Taurus" engine that Alfa referred to, I believe.

Uh, the Jag and Lincoln motors are both basically the Taurus engine.  The may have added a slightly different valvetrain, and did add electronic throttle.  But the engine is the basic Ford unit.

Jag people will cringe and argue that all day long, but it's the same engine.

Alas, this is too much of a tangent to the GM V6 being put into a cheap endurance car by GRM...  

Keith Tanner
Keith Tanner MegaDork
1/15/20 12:15 p.m.
alfadriver said:

In reply to Keith Tanner :

To me, being able to to take most of the powertrain and swap the intake manifold is easier and more properly engineered than an adaptor plate set up.  but that's just me.

And that's why if you are in the US, find the LS V6 manual- they are still out there.

Depends on where you think the difficult points are. If you use an LS transmission, you need to re-engineer either the Power Plant Frame or come up with a way to secure the differential and transmission. CMC had real trouble with the diff mount in their Locost design, the one that GRM built at the Mitty failed in about 20 miles. You also have to deal with where the shifter ends up. 

Meanwhile, a transmission adapter plate just has to be square and accurate. It's a flat piece of metal with two sets of holes. You'll also need a custom flywheel or a custom clutch, both of which are pretty straightforward.

I was led to believe that there was a bigger difference between the Taurus and the Jaguar/Lincoln engine from your previous comment, Alfa. Rocketeer used Jaguar because there are a lot of Jaguars in the UK, and an MOT-failed S-type is basically free. I'm not sure if they got the Taurus or the Lincoln. Mondeo would seem to be a common donor as well but the transverse mounting may bring some differences to it and there's a 15% horsepower difference if I'm reading Wikipedia correctly.

This is a long-running GRM project car, there will be lots of opportunities to talk about the LFX :)

Vigo
Vigo MegaDork
1/15/20 12:24 p.m.

Which is not so much a "performance" benefit as it is  a benefit to not have to deal with a driveshaft spinning at 6000-7000 and your U joint angles are less than perfect and the oscillations wreck everything else in the drivetrain.

Sounds like something you'd have to worry about if your differential and transmission weren't held in perfect alignment by a large C-channel. cheeky  In other news, i authored a whole thread about why i thought 3.63s in the stock housing was the best Miata mod for me as a 70-100 mph Texas street driver.  But again,  making a miata a better racecar is easier than making it a better streetcar. This LFX swap will still be a thrill ride in its intended environment.

Knurled.
Knurled. MegaDork
1/15/20 4:38 p.m.
Vigo said:

Which is not so much a "performance" benefit as it is  a benefit to not have to deal with a driveshaft spinning at 6000-7000 and your U joint angles are less than perfect and the oscillations wreck everything else in the drivetrain.

Sounds like something you'd have to worry about if your differential and transmission weren't held in perfect alignment by a large C-channel. cheeky  

Assuming you can get perfect alignment in the first place.  If there is a floor in the way, you might not.

This is, of course, a major advantage to keeping the Miata transmission.

 

Really makes me appreciate Guibos.  Or CV joints in the driveshaft.  

 

NOHOME
NOHOME MegaDork
1/15/20 4:53 p.m.

In reply to 759NRNG :

You are reading my mind.

The Honda option died when it reuired custome drivetrain bits to mate the engine to the gearbox. That never ends well and is a royal PITFA when servicing what broke. Refer to the OP where parts availbility at the nearest NAPA is a good thing.

Knurled.
Knurled. MegaDork
1/15/20 5:39 p.m.

In reply to NOHOME :

Oddly that is a point in the Honda setup's favor to me.  It uses junkyardable/FLAPSable everything except flywheel, and flywheels are generally not wear or failure items.  Meanwhile, when you swap transmissons, now you have a bunch of liability happening in the drivetrain if anything ever happens that damages the driveshaft.  And driveshafts are wear items, besides. And if the PPF gets eliminated, you're introducing chassis stress and NVH. Maybe not a big deal on a race car, but real important otherwise.

 

 

wheelsmithy
wheelsmithy UltraDork
1/15/20 6:49 p.m.
Rodan said:

The main problems with the J swap that I've seen documented are the engine being cantilevered off a rear (bellhousing) mount, lack of ground clearance for the oil pan, and re-locating the steering rack.

If anyone out there is seriously tracking a Miata with the J swap, I haven't seen it on any of the various forums.

Yeah, and the starter bottom center blows in my book. (Please correct me if this is no longer the case.)

 

Knurled.
Knurled. MegaDork
1/15/20 7:04 p.m.
wheelsmithy said:
Rodan said:

The main problems with the J swap that I've seen documented are the engine being cantilevered off a rear (bellhousing) mount, lack of ground clearance for the oil pan, and re-locating the steering rack.

If anyone out there is seriously tracking a Miata with the J swap, I haven't seen it on any of the various forums.

Yeah, and the starter bottom center blows in my book. (Please correct me if this is no longer the case.)

 

I wonder if adapting a rotary transmission would be easier.  The starter is on the trans side of the bellhousing like a Honda J application, and if you are bolting into a Miata, you use an '81-92 nonturbo transmission and stick the Miata tailhousing on it.

steronz
steronz Reader
1/15/20 7:49 p.m.

There are a lot of compromises with the J swap that you don't have with the LFX, but the LFX is basically an entire V6 Camaro with a Miata dropped on top. Which means it's in a different league as far as price goes. The article makes it seem like it's only a few thousand dollars difference, I think it's closer to $10k.

 

Thing 3 Racing out of Indianapolis has had success with their J swap in AER but I think you'd definitely need to go into it understanding the limitations. 

sleepyhead the buffalo
sleepyhead the buffalo Mod Squad
1/16/20 10:42 a.m.

I wonder who the first person to Genesis coupe swap a Miata will be?

wvumtnbkr
wvumtnbkr UberDork
1/16/20 11:20 a.m.
Knurled. said:
wheelsmithy said:
Rodan said:

The main problems with the J swap that I've seen documented are the engine being cantilevered off a rear (bellhousing) mount, lack of ground clearance for the oil pan, and re-locating the steering rack.

If anyone out there is seriously tracking a Miata with the J swap, I haven't seen it on any of the various forums.

Yeah, and the starter bottom center blows in my book. (Please correct me if this is no longer the case.)

 

I wonder if adapting a rotary transmission would be easier.  The starter is on the trans side of the bellhousing like a Honda J application, and if you are bolting into a Miata, you use an '81-92 nonturbo transmission and stick the Miata tailhousing on it.

The rx7 trans does not have a replaceable bell housing and the bolt pattern is different.  

Edit:  I realize you said adapting the rotary trans.  So adapter plate to rotary trans and then miata tailshaft so it still has ppf.

 

This solves the starter issue!

 

I still think finding a more suitable trans would make more sense.

NickD
NickD PowerDork
1/16/20 11:26 a.m.
sleepyhead the buffalo said:

I wonder who the first person to Genesis coupe swap a Miata will be?

I wonder who the first person to LFX swap a Genesis will be? They've already been LS-swapped for Formula Drift use, but the chassis proved to be pretty unsatisfactory, as every driver who tried one dumped it in pretty short order.

Keith Tanner
Keith Tanner MegaDork
1/16/20 11:52 a.m.
wvumtnbkr said:
Knurled. said:
wheelsmithy said:
Rodan said:

The main problems with the J swap that I've seen documented are the engine being cantilevered off a rear (bellhousing) mount, lack of ground clearance for the oil pan, and re-locating the steering rack.

If anyone out there is seriously tracking a Miata with the J swap, I haven't seen it on any of the various forums.

Yeah, and the starter bottom center blows in my book. (Please correct me if this is no longer the case.)

 

I wonder if adapting a rotary transmission would be easier.  The starter is on the trans side of the bellhousing like a Honda J application, and if you are bolting into a Miata, you use an '81-92 nonturbo transmission and stick the Miata tailhousing on it.

The rx7 trans does not have a replaceable bell housing and the bolt pattern is different.  

Edit:  I realize you said adapting the rotary trans.  So adapter plate to rotary trans and then miata tailshaft so it still has ppf.

 

This solves the starter issue!

 

I still think finding a more suitable trans would make more sense.

Especially since you're specifying a transmission that is between 39 and 28 years old.

Knurled.
Knurled. MegaDork
1/16/20 12:38 p.m.

In reply to Keith Tanner :

NC 5 speeds are the same trans, too.

gtpvette
gtpvette New Reader
1/16/20 2:52 p.m.

Excellent choice,, doing one myself!!

 

DirtyBird222
DirtyBird222 UberDork
1/16/20 9:43 p.m.

RIP to that BMW in the cover photo. 

Also came here to say you should've gone with a Marine Outboard J series. 

sleepyhead the buffalo
sleepyhead the buffalo Mod Squad
1/17/20 1:29 a.m.
NickD said:
sleepyhead the buffalo said:

I wonder who the first person to Genesis coupe swap a Miata will be?

I wonder who the first person to LFX swap a Genesis will be? They've already been LS-swapped for Formula Drift use, but the chassis proved to be pretty unsatisfactory, as every driver who tried one dumped it in pretty short order.

Hmm, interesting.  I'll have to go do some digging, find out if there's more specific feedback about issues with the chassis.

NickD
NickD PowerDork
1/17/20 5:37 a.m.
sleepyhead the buffalo said:
NickD said:
sleepyhead the buffalo said:

I wonder who the first person to Genesis coupe swap a Miata will be?

I wonder who the first person to LFX swap a Genesis will be? They've already been LS-swapped for Formula Drift use, but the chassis proved to be pretty unsatisfactory, as every driver who tried one dumped it in pretty short order.

Hmm, interesting.  I'll have to go do some digging, find out if there's more specific feedback about issues with the chassis.

Dennis Mertzanis had one that was supercharged LSX-wapped. It never seemed to work well, and he did so poorly that he lost his competition license and hasn't been seen again.

Pat Mordaunt was supposed to drive one with the the V6 with a blower. The first event it barfed the rods out on all 3 engines they had, and he rented an S-chassis the rest of the season. I don't know what happened to that car, its never resurfaced.

Odi Bakchis bought the old Mertzanis LSX car. He ran at it a limited series of events, with the plan of developing the car and then phasing out his S14 and replacing it with the Genesis. He ran it for a handful of events 1 season, never seemed to do as well, and then it vanished and he stuck with his S14. Odi is heavily involved with Feal's Suspension, so he knows suspension well.

Rhys Millen was the only one who had some semblance of success with one. Not sure if that was just because it was Rhys behind the wheel though. After all, he won a championship with an '04 GTO. He finished 3rd overall one season, then retired from drifting to go do rallycross.

Its funny, everyone expected the Genesis to be the next big platform in Formula D, and then it wasn't. Then again, for all the people driving FRS/BRZ/GT86, that car has yet to win an FD title either. The Dodge Viper, Scion Tc, Dodge Charger and Pontiac GTO all have more FD championship wins than the FRS/BRZ

KyAllroad (Jeremy)
KyAllroad (Jeremy) UltimaDork
1/17/20 9:49 a.m.

FYI, a fellow named Justin Lee in Indianapolis campaigns a J swapped Miata in chumpcar endurance racing.  The team name is Thing 3

AFAIK it's a pretty solid setup and quite fast.

LFXMX5
LFXMX5 New Reader
1/17/20 6:06 p.m.

I built this one last year and it’s really an easy swap with the V8R stuff.  And with mods (cams, porting, throttlebody, E85 etc.) to the engine it really is a perfect little missile. You can see more about build on FB at Miata LFX-MX5. 

I will be happy to answer any questions about build. 

LFXMX5
LFXMX5 New Reader
1/17/20 6:07 p.m.

LFXMX5
LFXMX5 New Reader
1/17/20 6:18 p.m.

Knurled.
Knurled. MegaDork
1/17/20 6:23 p.m.
LFXMX5 said:

 

Aside from the air ducting and the carbon fiber, that looks really OE-like.  Very nice.  I like the little touches, like the use of the GM coolant tank and power steering reservoir.  That engine scoots in a CTS, I could only imagine what it could do with about 1200lb less fat surrounding it.

LFXMX5
LFXMX5 New Reader
1/17/20 6:38 p.m.

In reply to Knurled. :

Thanks. I get that comment a lot. It gets a lot of attention at car shows and I didn’t even build it with intentions of showing it. I am humbled that people respond to the car the way they do. 

Knurled.
Knurled. MegaDork
1/17/20 7:03 p.m.

In reply to LFXMX5 :

You're welcome!  Seeing "sano" swaps like that is inspiring for all of us to do just a little bit better.

 

The black-painted engine bay helps a lot, too, as it mutes the Mazda portion of the car.  To be frank, I had to squint and think to see just what car it was I was looking at, even though the headlight covers should have been a dead giveaway.

 

I don't remember now if GM was doing it on other cars, but I remember for certain that Saturn painted their engine bays black no matter what color the car was.  It works.

LFXMX5
LFXMX5 New Reader
1/17/20 8:13 p.m.
mrhappy said:

I really like this but I with it fit under the stock hood.

NA no, NB yes. 

LFXMX5
LFXMX5 New Reader
1/17/20 8:21 p.m.
Keith Tanner said:
alfadriver said:

It's interesting that there isn't a Cyclone v6 swap out there being sold, too.  Last I saw, it was getting 300hp w/o DI.  Must be a much bigger engine....

For a different, and perhaps cheaper (but harder) option would be the Lincoln LS V6 with manual swap.  It's been done before, and drives really nicely- but not 300hp...

That’s the Jaguar V6 used in the Rocketeer kit, isn’t it? 

It’s a shame that GRM is doing a swap into a race car, because all the hard parts of a swap involve making it into a real street car. It’s the real way to test the R&D. 

I would recommend reinforcing the steering rack mounts in the V8R subframe and putting a cross brace between the rear control arm mounting points to avoid failures - especially on a track car. 

Keith making a real street car with this swap is not any kind of a problem. Not sure what your reservation is?

apex_attack
apex_attack New Reader
1/26/20 10:13 p.m.

As someone who also recently traded in a problematic 3sgte for a 2gr in my MR2, I wholeheartedly know you'll be insanely happy with the V6 powerband.  More power helps, a better powerband is amazing.  Less shifting, more fun.

Mr_Asa
Mr_Asa Reader
1/26/20 10:49 p.m.
NickD said:

Too many years as a GM tech makes me nervous around LFXs.

Knowing the guy that makes V8R stuff makes me nervous about the swap.

Keith Tanner
Keith Tanner MegaDork
1/27/20 8:09 a.m.
LFXMX5 said:
Keith Tanner said:
alfadriver said:

It's interesting that there isn't a Cyclone v6 swap out there being sold, too.  Last I saw, it was getting 300hp w/o DI.  Must be a much bigger engine....

For a different, and perhaps cheaper (but harder) option would be the Lincoln LS V6 with manual swap.  It's been done before, and drives really nicely- but not 300hp...

That’s the Jaguar V6 used in the Rocketeer kit, isn’t it? 

It’s a shame that GRM is doing a swap into a race car, because all the hard parts of a swap involve making it into a real street car. It’s the real way to test the R&D. 

I would recommend reinforcing the steering rack mounts in the V8R subframe and putting a cross brace between the rear control arm mounting points to avoid failures - especially on a track car. 

Keith making a real street car with this swap is not any kind of a problem. Not sure what your reservation is?

My "reservation" is that we won't get to see it. A race car build skips over the hard parts. It may be possible to build an LFX Miata that feels like it came out of the factory with all systems fully integrated, but you don't bother with the full level of finish on a track car. Like AC, or ground clearance, or PS, or NVH and interior heat control, etc. Again, it may be possible. But you don't find out on a race car.

Again I reiterate the suggestion to reinforce the V8R subframe. I've seen a number of failures of those. My own car has broken two of them, and having the steering rack come off the subframe is not good for car control. The same basic subframe is used for the Honda K, the GM LFX and the GM LSx swaps so it applies to all of those.

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