Honda V6 ?
 

I stumbled across this site the other day:

Welcome to SuperFastMiatas.com

Had this kit existed when I built my first Ford V8 almost 10 years ago I probably would have used it. I'd love to see some Honda JV6 conversions on this board (we can always just forgive them the missing two cylinders).

The only down side I see is having a minivan engine in your Miata. An MS3 of course would be the logical answer to tuning out its "minivanness".

-Jason

https://www.v8miata.net/attachment.p...ine=1450790847

it bolts a honda v6 to the stock miata trans... wayyy to much TQ for that trans to handle.

A local guy is doing the swap currently...

Titus's V6 Swap build thread

There is a guy at work that wants to do it too and has been looking for an engine for a while. They are not easy to find as it's a pretty narrow span of years that will work.

I like it a lot and would consider it for my cruiser if it had the 5.0 exhaust note...

This one is for sale in Georgia

1999 MAZDA MIATA WITH HONDA V6 280HP

Thats a cute little swap....

No really I wouldn't mind having one either, bet it gets pretty decent MPG's.

13 grand for a 99?

HEY HEY, easy with that 99 business

our 99's are a little more invested. hahahah

99's are like a fine wine really....and I hear they are the fastest year

I'm really liking what I see, expecially that build thread from Gator. My wife and I are planning on selling our city house for some suburban place which WILL have a garage. Once I have a place I actually own to stash another Miata I may try to take one of these on and turn it.

Is that an AWR body kit with a type 2 nose on the yellow car? I've never seen that combo look that good.

-Jason

I've been following the V6 Miata conversion with great interest. A couple of issues that I see is the crankcase pan sits below the subframe, which as you know is problematic. One hard hit from something on the road and you'll have serious issues. Additionally, the starter is another low point worthy of concern.

All in all, I think it is a worthy conversion for the budget minded as you are preserving the current Miata drivetrain. The consensus is that the transmission can handle up to 300hp without issue. Since the V6 is 260-280hp, it shouldn't be a concern using the stock Miata parts.

We would all love to engage in a V8 Miata swap as it is a worthy endeavor, but the V6 conversion is interesting - and should be considered.

For someone who was considering dropping a bone stock Ford 5.0 in this would be an excellent alternative. Although its relatively easy to bolt-on enough upgrades to get a Ford to 400 hp (and I believe still come in cheaper than a base LS conversion with the same power) stock they only have 225. If 250 to 300 was my goal this would be where I would look. 300 - 400 I'd still build a Ford and over 400 I'd go with a GM (and just never tell my father).
Its good to see another relatively sorted option out there. I hope we can get some builders on here as I'd love to see a build documented.
-Jason

I took a close look at this when planning my exocet build. The smaller package and light weight made it look real appealing. There were a few issues that made me decide against it.

As said above, the oil pan hangs pretty low - but so does the V8R pan. And there's no aftermarket or road racing pan available. Would have to fabricate a dry sump. Not sure what to do about the starter, though.

The V6 is more expansive than an LS1, and harder to come by. In racing, you sometimes blow stuff up. Cheap and readily available replacements are important.

I know of one guy in CO that's building an exocet with honda V6, but I haven't been able to get with him to discuss it.

K Miata Home

if you really wanted a honda in your mazda then go with the K miata. the sub frame is a much nicer unit. the K motor can easily make the same power as the V6-j moor. but the Tq is less, so the trans won't eat itself. You won't lose all your oil when you find speed bumps.

HMMM, I do like that....

My wife is going to kill me but I am seriously thinking about a DD miata with one of these swaps when I am done with the LS car.

Travis my hunch is first time you drive your LS to work will be the last time you think of another car for a DD. :)

I wish....I drive almost 100 miles round trip to work each day, the miata will go to work some days but not much.

LOL you won't get any sympathy from me! 34 miles one way and 2 things I have learned DD commuting a V8 Miata. 1, the V8 car gets better mileage than the 4 cyl auto car and 2, home may be where the heart is but the joy is getting there!

I know it's not for everyone and a lot of people don't want to put miles on the car and wear it out but I've never understood that. I'd much rather run the wheels off it and enjoy it than save it for the next owner to do that. And besides there is nothing that gets me out of bed on a Monday morning like a top down trip to work and nothing caps off the week on a payday Friday like a 34 mile commute in a V8 Miata with exhaust cut outs!

Actually now that I think about it I didn't have 10 miles of road testing on it the first day I took it to work. Didn't have an exhaust system and a few other pieces either!
https://www.v8miata.net/attachment.p...ine=1450939051

I totally agree. I don't get the under 1000 miles a year thing. I put 10,000 miles on my white 1990 in the year I owned it and 20,000 in the four years I had the Laguna on the road. Circumstances have kept it off the road for the last 13 months and not driving it has been killing me!

-Jason

Honda V6 is killer!
 

Everyone seems to be bashing on the J-Series honda v6 swap! My opinion is don't knock it until you try it! Cuz its a really sweet kit and the v6 has tons of torque! I Absolutely love my honda V6 swapped 93 miata its a mean tire smoking drifting machine! It will put you back in your seat very nicely! As of now the trans an 7in welded rear end are holding up flawlessly! And ive beat the heck out of it both trans and rear have over 150k before the swap was done! So just keep an open mind! LOL

ANYONE bashing the little V6s obviously doesn't know the history of the larger engined cobras lack of success over the little 289. The 289 cars frequently were over a lap faster in road races over the 427 ...same will be true in the near future with all of the very powerful V6s available...They are just easier to drive, more reliable, and get better mileage.......Yes V8s are fun, but mostly in a straight line or parking lot cones.

Just my two cents worth from an old Road Racer

I am still considering this as a slightly remote possibility for my next build. I want my next one to be more track centered than my current one and yet a bit more refined. Where the last one's track day inspiration was a C5 Corvette this time I'm thinking more along the lines of a Lotus Exige. With that in mind I'm still thinking a snappy V6 may be more what I'm looking for than the zero-balance 331 and TKO500 I'm planning.

There are really only two areas that worry me with going this route: engine cost and available Miata gear ratios. I looked into the cost of a rebuild kit for the Honda V6 and was amazed that for just a ring and bearing kit the cost is close to a grand. Granted, I really didn't search in depth but still that seems pretty high. My rational behind the TKO500 is that it comes with a nice .81 fifth gear. I looked at getting a T5z retro fitted with the same fifth and the cost of the two trans came with in $200. TKO trumps T5 so no brainer, right? If I went with this option I'd be using the Miata trans which I'm pretty sure does not have any other 5th gear options. I guess I could source a Miata 6 speed...

I guess it really comes down to donor car. If I end up with an MSM as a donor where everything from the bell back is the best than I may seriously look into this, expecially if I can find a donor engine that does not need rebuilding. If I end up with a 1990 I'd be looking at upgrading the trans and rear anyhow...oh well, first to sell the Laguna :)

-Jason

I don't see anyone here bashing it. I've looked at it very closely and think it is a great swap. The plusses are obvious the kit is cheap and it uses the existing trans and rear set up. The down sides is the very narrow years for donors and the tuning. That is not a bash it's a fact.

For me I feel the LFX v6 makes more sense than the Honda set up but that is for me. That being said if I had to pick a next build today for my cruiser no question it would be a SBF all DIY build. :)

^^^what Jim said, no bashing here.

I see you only have one post on this board mopar, which is fine, but what I think you will find here is that there is no negative commentary that is heavily opinion based. What you will see on the other hand is good technical discussion of why some things don't work as well as others.

:jerkit: Honda V-6 swap? Honda sux! This is a V-8 forum. Well, there goes the neighborhood. LMAO!!:yippee::yippee::yippee:

LOL.

That's how I felt when we first started letting these GM people move in on the V8 scene 7 or 8 years ago. All in all they seem to have turned out to be pretty decent people though, right? :biggthumpup:

So I started pricing this out yesterday:

Swap kit: $4000
AEM/MS3 ecu and wideband O2 sensor: $1500
J32a2 engine and harness: $600 - $900, we'll say $750

Since the kit uses the Miata radiator, trans, rear and even exhaust that's about it. I could be rolling with this for $6300 over the cost of the car itself.

That said, since this does use stock Miata drive line components upgrading to the best available would be awesome. To that end I'd likely add from Planet Miata:

Used Miata 6-speed: $700
Used Miata 7" 3.9 limited slip rear upgrade package: $1300

I think that could make a pretty potent package for $8300.

After passing the Laguna on to a new owner I plan to pick up a well cared for white 1991 I know of, upgrade the suspention, bolt on my track equipment (seats/tires/wheels/brake pads) and track it for a summer with its 1.6 while collecting parts for its power train upgrades. I figure a year with only 90 or so hp can only help me develop my line and braking better. The car already has upgraded brakes, sway bars, radiator and a roll bar so suspention and a hardtop and I'll be ready to go.

If I go this route I can get it into Lotus territory for under $9k and have a fun little package to flog at the track for a few years until I feel the need to again "have another". Since this swap seems to able to be done without any modifications to the body of the car I'd be able to at that point sell it as is, pull out the j engine and drivetrain and re 1.6 it to sell it or even pull the j drivetrain to sell and use the '91 as the donor for the next build...

The only concern I still have is the ability of this engine to be flogged at a road course. It seems pretty stout from what I have been reading but I also have not found any one who is actually beating on one like I will be. That said, the replacement cost of the engine is not as bad as I thought it would be. I'm seeing good donor packages (engine/harness/ecu/trans-sell ecu and fwd transaxle) for $600 to $1000. This even makes the rebuild kit not that bad at $600. A good used donor with a fresh rebuild would only run me around $1400 or so which is less than I have in just the rotating assembly of the Laguna.

The coolest part: "Mazda" + "Honda" = "Monza"

How cool is that?

-Jason

Jason,
you don't have to buy the AEM $1400 box, just look at RPM systems (Don) up in NYweb site or video. They can convert your ECU and harness for under 750. It will have to be a matching set, preferably a 99-01 J32a from Acura TL/CL etc. also the SuperfastMiata guys will sell a partial kit as you can make your own sub-frame. Also the flywheel is from an Acura Integra and the disc is a Miata ...This should help you out...I've been looking over and talking to a lot of the guys doing the conversions.

So they do what I do...interesting.

Honestly I think I'll probably look into making up my own MS3 harness for this. I've been doing some reading up on the MegaSquirt boards and I think its very doable. This would also give me then another area I can start churning out parts for on my site.

Does anyone know is VVT an on/off type of thing or is it progressive? If it just actuates at a certain rpm/load point running it via a MS will be a breeze. If it's progressive it could be a deal breaker. Beyond that little issue all I need to figure out is how many teeth the crank and cam sensor have on the particular J engine I'll use and the coil type.

I'm getting excited about this. Someone buy my Laguna!

-Jason

forums like j32a.com all have a wealth of information on things like VVT and which years have them, and how to get them to work..when I get home, i'll provide them to you...doing your own wiring would benefit many and will my prediction be the future for these swaps...The V6 in all of its forms (i.e ne Ford GT) will be eqaul to the number of v8s same as the LFX chevy. The Honda just are very sweet little reliable engines with thousands of racing hours in their veins...You will find that you may still not need a MS system if you can do the cracking of the ECU.

Thanks Fred,
I just checked out j32a.com and a few video links there of a civic with this engine passing some serious competition at a track day:


Apparently the engine can handle track day flogging just fine. I'm really leaning this direction now as my next project.

Funny, if you watch the video above the guy has the same problem I run into at the track: people in high end cars unwilling to just swallow their pride and move over to let the "unworthy" car that has been filling up their mirrors for the last three laps to pass.

-Jason

Yes, there are some very fast V6 miatas cars racing that do not bother to post on Miata sites. To my point about the 427 cobras, if a car can be raced with higher confidence from the driver, that driver will naturally go faster. If you are only going to drive them in a strait line ok, but not a real road course. Both the newer Ford 2011++ and the chevy are great alternatives. anyone who can build of the the V8s will enjoy them possibly more so, and there will be many of those engines at near give away prices for a long time.

Someone please do this swap and document it. I have read of maybe one other swap on Miata.net. Very interested in this as I am sure others are as well.

Well according to a previous above post. SupererfastMiata has sold some 30 kits, but they just don't have out on this forum, or none at all. do some searching and you will find them as I have, some newer Ford and Chevy builds are underway. We will see them, and I remember back many years reading about the "monster Miata" and there was long period before it really caught on as well. I am stopped right now until I relocate back to Colorado

The more I look into this the cooler it looks. I'm 99% sure I'm going this route for my next one at this point. The buzz around this engine reminds me of the way it was with the Ford V8's 15 years ago.

Here's where my thoughts are at this point:
Engine:
It looks like the best pull out engine for this that could be just "dropped in" would be a 2001-2003 Acura CL or TL J32a2. The engine in stock trim makes 260hp/232 foot pounds of torque, which is not too shabby compared to a stock 5.0's 225 hp. Using the engine with the stock intake requires ether turning the intake around and modifying the throttle body mount point to nose it down or having the kit company modify it so it sucks it's air in the side as opposed to the front. The side option looks cool but really started to concern me when I looked at the internal construction of the intake. The intake will work reversed on an NB with just a slight amount of help (not cutting and welding). I did a little poking around and found that the intake off an AWD 2009 Acura TL with a J37 is significantly shorter and lower than all other J intakes and can be purchased new from Honda for under $300. As a bonus it also just happens to be the best flowing and lightest of all J intake manifolds. I'm thinking that the combination of that intake and spacing down the front subframe like we do with Ford builds may just get me the ability to use an unmodified J37 intake and a Corvette aftermarket snorkel (like FM uses on their builds).
In addition to using the J37 intake I can also use the crank, rods and pistons from a J37a1 from a 2007-2013 Acura MDX to make myself a forged OEM "stoker Kit" that would up the displacement from 3.2 liters to 3.7. In the MDX the J37a1 made 300 hp/275 torque which I should be able to duplicate by fitting my J32a2 block with above parts (The J37 block has a different bolt pattern). The MDX parts I would need will run me about $1400 which is typical for a forged rotating assembly. I also found that an additional bump in power could be had by taking the J32a2 cams and installing them in a set of J35a3 heads from a 2001-02 MDX or 2004-2007 Saturn Vue. All told $3000 or so can build a very nice hybrid J engine that can make 300+ hp and get 30+ mpg.

Transmission/differential:
I made up a spreadsheet a year ago when I was looking at different ratios and trans options for the Ford 7.5 in my Laguna. I used it again for this and found that, much to my surprise, the last transmission I'd want is the Miata 6 speed. Where the 6 speeds we see in the V8 world have their "extra" gear inserted between a 1:1 4th gear and a normal overdrive 6th gear Mazda put thiers between 3rd and 4th. Fifth gear is 1:1 which is very odd IMHO. The sixth gear is actually lower than the fifth in a standard five speed. I'd actually do fine with a "normal" Miata five speed if it can hold up. Being that it actually started life in a truck I think I should be fine. If not they are cheap.
The best rear for all this would be the uber-rare 3.6 ring and pinion with limited slip. I have two options here: buy a new 3.6 ring and pinion set from Mazda for about $700 and have it installed in a 7" with existing limited slip or try to find an entire used 7" with the 3.6 in it Australia and have it shipped here. I still need to see which is cheaper. The first option will almost cost as much as the engine after having it set up properly, especially if I start with a 1.6 car.

ECU:
I really think if I had to do it today I'd go with the AEM standalone and a stock customized harness. I have three options here:

1. The above
2. The above with a "cracked" stock ECU
3. MS3 with a custom harness

Most take out engines come with a harness, ECU and transaxle for $1400 or so. The transaxles alone can be resold for $500 - $700 so I'm looking at $1000 here to be safe. Since I have the harness and stock ECU option 2 would be the cheapest depending on how much it costs to have them reprogrammed. If it's less than the $1300 for the AEM it may be worth it. The only downside is that options for tuning and datalogging are less with this option. The MS3 would offer the most opportunity to tune, datalog and such but unless few others are on the road before I do this myself I don't think I'll go this route at this point.

All in all this is really looking good.

-Jason

Jason, you have found the same information that I saw plus, you want the "type-S" engine as most of the Japanese tuners say it has better insides (not confirmed by inspection) The intake is best left to the front, or you will get uneven flow and turbulence , flowing all intakes if possible will gain quite a lot (as with most stock engines). A couple of builders are trying dual TBs by opening up both runners. I would think one large unit would be just as beneficial. Also a guy in NY will convert your Miata harness, and do the ECU for less then $800 @ RPM SYSTEMS - ?? as for Don, he knows a great deal about these engines and various conversions

The guy that is doing one locally just posted yesterday first start up. His will be one to replicate as everything he does is done with levels of OCD I can't even contemplate. (meant to be a compliment)

Great, see if he is willing to post his contact..That would be helpful for others..personally, should I go this route, I may still use RPS as they have a lot of information and are the guys helping the superfast Miata folks. He also has the scoop on what flywheel/disc/clutch to use too..Also I would highly recommend adding a front brace across the engine to the original mount and not just using the adapter for complete support

I thought I had...hmmm...anyway...it's here:

Titus's V6 Swap build thread

Here is the picture that bothers me. Both the starter and crankcase pan are below the subframe…

https://www.v8miata.net/attachment.p...ine=1455760653

Concur,,,but this guy has done some fabulous work ....it is his (Titus) own build site


V6 Miata | V6 Miata

I've done a bit more research on the Engine management end of this project. By far the cheapest route is to just have a stock ecu modified to eliminate the anti-theft programming or get an ecu from an earlier car that did not have the lockout programming. Both of these options are tempting as stock computers are under $50 on eBay and most pullout engines come with a harness and an ecu. To have a stock ecu modified and then harness modified runs about $600. I don't want someone else modifying my harness for me. Maybe it's because I do this professionally myself but my standards when it comes to what a custom harness service gives you are pretty high. Even if I just had the ecu "cracked" I still would not have the ability to tune or modify the tune on the fly which is something I've really come to like to do. Data logging at the track would also be an issue.
The AEM option would give me a plug and play option that would be tunable. It's price is very high and to have the ability to add GPS data to its data logs I'd need to purchase another $300 unit. I'm also not so thrilled about how sort of sketchy the AEM site is about what you can and can not do with the series two ecu. I would also need to make sure the engine's sensors match the ones needed by this specific ecu which does not seem to made for manual transmission donor engines.
My original concern with using an MS3 was control of the VTEC feature of the engine. After looking into it this is not a concern at all. With an MS2 you just pick a rpm/load point to have it switch on using a spare output. The MS3x actually has a whole separate table I can use to iniate the feature and have it switch to a different ignition map when it does. Hooking it up is as simple as running two extra wires to a relay.
With that no longer a concern the MS3x is the best logical option for me that will allow me the level of tunability and datalogging that I need while still coming in under $700. I'd be running a wideband with any of the above so the $300 or so that will run is not really a deciding factor. Another advantage of running the MS3x is that it will give me the chance to build a standalone harness for it that I can market. I thought that adapting a stock CL harness would give me this but as that's already being done I think a stand alone MS3x harness could have more marketing potential, especially since such a harness could theoretically be used by anyone looking to mount a MS controlled J engine in anything.

One interesting thing that I ran into that I totally didn't expect was finding that the go-to large diameter throttle body for these engines is not a Honda one at all but aftermarket FORD MUSTANG THROTTLE BODIES! That's like circle of life, kuma matata Lion King stuff...

-Jason

Jason, Great! with the MS you can also address the other J series engines which no one is offering (yet), but someone will have to address the starter and oil pan clearance issue, or run 32 inch tires.

I'm thinking some type of skid plate would be in order. As far as the mounting system goes I'm not overly worried. The engine is very short compaired to even a Miata engine and fairly light. I think its only attached to the transaxle its usually fitted to using the bell housing bolts.

I'm actually more concerned about hood clearance. It seems like the thing to do in the Honda community is to just leave the hood off and run one of those funky no filter things that look like one big velocity stack. I'm not doing that. It's all going to fit under a stock or lightly modified hood. The main issue seems to be the throttle when the intake is turned around. I think I can bring three ideas from the Ford V8 Miata world to help with this. The first is the idea of having some material shaved from the mating surfaces of the upper and lower intake halves. Its possible there is no room to do this but I'll make sure of that before I give up on the idea. The other is spacing down the k frame. I currently have mine spaced down 3/8" which is about the limit for the factory studs. Since the mounting points are so far back compaired to other engines this may actually become closer to half inch at the front of the intake. Another idea I came up with is to use a throttle body elbow from a SN95 Mustang 5.0 in between the intake and the throttle body to angle it downward away from the hood. Since I'm planning on using a Mustang throttle anyhow this should be pretty easy to implement.

I really don't think the oil pan hangs down any lower than the modified Monster Miata one does.

-Jason

That Mustang front intake should work well, or slightly trim and angle the inlet to where it look like the corvette sneaking air under the front hood edge. BTW, I spoke with the guy at SFMiata,and he told me they have been able to slightly relocate the starter and got it up almost an inch. Combine that with a better oil pan design (flattened out with baffles and all should be good to go. Also, there are a few guys out there using MS3 with motorcycle carbs like ITBs.....wild sounding

I forgot about that titus thread but remember it from when I was doing fender research. Great car!

If they can raise the starter up and raise the bottom of the oil pan that would be awesome. Other than those two spots the only thing I've seen that really concerns me is the picture Titus had of the Miata slave spaced out to clear the adapter plate and J block. It looks like the kit has two 1/2 inch spacers to do this which leaves the slave's pushrod coming out at a pretty bad angle. Originally Monster Miatas were set up this way as well which resulted in slave cylinders wearing out yearly (non-straight pushrod throws the aluminum piston off center in the iron bore and causes metal-on-metal contact which then makes the seals fail and leak). Looking at the picture there really seems to be no solution using the stock slave that would not involve extending the length of the clutch fork about an inch whch would then throw off the pedal to slave movement ratio. It's possible that the adapter and block could be modified to allow the slave to fit without the spacer. If that can't happen maybe it would be possible to replace the Miata slave with one that pulls instead of pushes. I know I've seen ones like that in the past. A puller slave could just be attached to the trans with a few brackets.

-Jason

This picture:

https://www.v8miata.net/attachment.p...ine=1455992242

This picture:

https://www.v8miata.net/attachment.p...ine=1455992245

Puller would be a more simplistic approach, if there is room, or another look at a hydraulic throw-out bearing. I have seen several post which this has been done, but none conclusive with their posted results. I have had success with one on another build of mine


Speedway has this unit which may work well if there is room..price is right
http://www.speedwaymotors.com/Speedw...uery=910-25604