Honda V6 Miata in the Aug 2014 issue

In reply to jsquared: I think the 200whp was with the ecotec 4 cylinder swap

d'oh! You are correct, sir, I fail at teh reeding

now available per Mini Tec FB page... details this afternoon or tomorrow on superfastmiatas.com

Access Denied on gubmint network :(

Side note: it may have been previously mentioned, but this would be intriguing for an Exocet...

The JV6 Miata Kit -- $3,500
Cost Effective kit for all Mazda Miatas 1990-2005

We believe that the Miatas were always great handling sports cars that lacked horsepower. This kit allows the DIY Miata enthusiast to install the powerful Honda J V6 engine into your Miata with the least amount of effort possible converting your mild Miata into a Beast without breaking the bank! Honda J Series V6 VTEC engines are readily available and offer up to 305hp+ with 275 ft/lbs of torque naturally aspirated creating the perfect platform for your Miata. This conversion utilizes the stock Miata transmission and rear differential without any modifications required. Our kit provides the builder with all of the necessary components and hardware to do this swap along with full support from all of our team members. We also offer in house conversions for those that don’t have the time or resources to do it themselves.

Our JV6 Miata Kit includes all of the following to make your swap as easy as possible:
- Front Subframe to adapt Honda J engine into Miata
- Transmission Adaptor from Honda J to Miata tranny
- Stainless Steel exhaust header and downpipe
- Aluminum Oil Pan
- Poly engine mounts
- Flywheel, Clutch, and pressure plate
- Starter
- Flywheel Adaptor
- Oil pickup and Water jacket

Required extras:
- Honda J Series engine, complete
- Honda J engine wiring harness (should be included with your engine)
- Aftermarket programmable ecu such as AEM Series 2 Plug & Play Engine Management System. Note: A stock ECU from the engines listed above will work with this setup, but will have performance limitations.
- An intake modification is required to gain hood clearance. Instructions and pictures are supplied with Kit.

One thing I was attracted to was the hope of running a stock'ish harness and stock ecu.I totally suck with electrical anything and having my 3 or 4th car with a standalone frightens me as I still know nothing about them.

Stupid question on this. As awesome as it sounds, Isn't the transmission an issue at that level of torque? I seem to remember that being an issue especially with the 5 speed.

It would be one of my concerns. There's a lot to like about this concept, but you will retain that weak point.

Keith since there seems to be some differing information(hard to believe I know) on the net about the best of the Miata transmissions can I ask you if there's one that's better than another for sure.The original in my '90 sucks at smooth/speedy(not speed shifting) shifting and needs to be replaced anyways.

The NB 5-speed probably has the best shift feel, followed closely by the NA 5-speed. The 6-speed is strongest but has worse shift feel. The best 6-speeds feel like an average 5-speed IMO. They all interchange as long as you have the matching shifter. These statements, of course, assume the parts are in good condition.

The top gear on the Miata 6-speed (.832) is shorter than the top gear on the 5-speed (.814). In the case of this swap, where they're recommending a 3.9 behind the 5-speed, you'd want to hunt down a 3.6 or 3.3 for the 6. Those weren't found in the wild in Miatas in North America.

I'd like to stay with a 5sp and avoid looking for a taller rear gear,I currently use a 4:10 torsen and since the car is road course only after this yr I could care less about hwy speed rpm as long as I don't top out in 5th.The longest straight I'd most likely hit is Mosport and its all uphill so I think it'd be fine. With all the boosted engines you guys have done in the mid 200's for tq is it really that big of a problem??.

We all prefer the 5-speeds on track because otherwise you're shifting too much. I know the 949Racing guys run the 6, but they're also not running the same powerplants we are.

The 5-speed is going to be a consumable with 275 torque. It's not going to grenade immediately, but I wouldn't expect to get a lot of life out of it.

A 6-speed with a 3.6 and you're not shifting any more often than a 5-speed with a 4.3, except that you now have an extra tall top gear to put it in if you want to. After stripping 3rd on my original 5-speed at Laguna a few years ago (at around 270 rw torque), I put an MSM 6-speed (the best shifting of the lot) with a 3.6 in my car, and I like it a lot. The 3.6 ring & pinion isn't hard to get (Mazdaspeed sells it), it's just expensive. J-series V6s have their redline around the same 7000 point as Miatas, right?

As for the question about running a stock Miata ECU, it seems unlikely to me that you're going to get a 4-cylinder ECU to do anything useful with a V6 engine. :) I have no idea how a stock Honda ECU is going to cope with the fact that there's no Honda automatic transmission in the car, so that may be out too.

No mention of whether or not the Honda AC compressor & PS pump will fit in the Miata, or what fittings you'd need to hook it up.

Haha,no I wasn't intending to try and run a V6 Honda with a 4 cyl mazda ecu....I'm not quite that stupid.

My car has a link so not cutting edge but I still don't even think about touching that keypad.

The swap starts to lose its bucks down if I have a $3500 buy in to start and than need to hunt down a 6 sp and taller gears to go along with the engine.

I was wondering if they'd come up with an AC and PS solution as well. I wonder if the front sway bar is affected? Probably not, a V6 should be short.

You could try to run the car on the Honda ECU, but you'd probably have a constant CEL and the lack of the automatic might indeed give it fits. Unless the Honda boxes can be reprogrammed as thoroughly as the GM V8 ones - on those, you can turn off monitors for things like cats and charcoal canisters.

I guess using a 3.2 tl engine and manual trans ecu would limit tq a bit while allowing the engine to at least run as honda intended.

There website says ac can be hooked up using the honda compressor. No mention of fittings to make it work.

The two engines they list as having used don't have 275 ft lbs. they are 232 and 240. I've seen these torque numbers on flyin miatas dyno runs for the fmii kit. Are all if those running the six speed?

Most Honda ECUs can be opensource tuned or use HonDATA, I don't know about the J-series though.

Hondata doesn't do j series

icaneat50eggs wrote: The two engines they list as having used don't have 275 ft lbs. they are 232 and 240. I've seen these torque numbers on flyin miatas dyno runs for the fmii kit. Are all if those running the six speed?

Not all of them, but a fair number and almost all the ones that are on track. And still, people rip the teeth off the gears. It's a weak point in the platform - you run three times the original torque through the trans, stuff breaks.

codrus wrote: The 5-speed is going to be a consumable with 275 torque. It's not going to grenade immediately, but I wouldn't expect to get a lot of life out of it. A 6-speed with a 3.6 and you're not shifting any more often than a 5-speed with a 4.3, except that you now have an extra tall top gear to put it in if you want to. After stripping 3rd on my original 5-speed at Laguna a few years ago (at around 270 rw torque), I put an MSM 6-speed (the best shifting of the lot) with a 3.6 in my car, and I like it a lot. The 3.6 ring & pinion isn't hard to get (Mazdaspeed sells it), it's just expensive. J-series V6s have their redline around the same 7000 point as Miatas, right? As for the question about running a stock Miata ECU, it seems unlikely to me that you're going to get a 4-cylinder ECU to do anything useful with a V6 engine. :) I have no idea how a stock Honda ECU is going to cope with the fact that there's no Honda automatic transmission in the car, so that may be out too. No mention of whether or not the Honda AC compressor & PS pump will fit in the Miata, or what fittings you'd need to hook it up.

6spd has better spacing for track use as well. There's no downside to a 6spd setup other than cost.

That said... i'd be somewhat surprised if these things ate 5spds left and right, but i think we had that conversation earlier in the thread.

icaneat50eggs wrote: There website says ac can be hooked up using the honda compressor. No mention of fittings to make it work.

I can tell you that on the V8 conversions, the biggest PITA has been building off-the-shelf AC parts.

We do have custom AN adapters for the Miata steering racks. So for anyone who's taking one of these conversions on, that may be useful.

Keith Tanner wrote: You could try to run the car on the Honda ECU, but you'd probably have a constant CEL and the lack of the automatic might indeed give it fits. Unless the Honda boxes can be reprogrammed as thoroughly as the GM V8 ones - on those, you can turn off monitors for things like cats and charcoal canisters.

That's one of the benefits of the Eco swap. A good 2.4 with ECU and harness can be bought very inexpensively pretty much anywhere in N.America, and the ECU is very easily tuned. You might be able to do the complete 2.4 swap for about the cost of just the V6 kit.

Swank Force One wrote: 6spd has better spacing for track use as well. There's no downside to a 6spd setup other than cost.

Not on our track with torques. And there's always the shift quality. Around here, we all drive 5-speeds unless it's a T56. Even our MSM got a 5-speed conversion and was better for it.

You know what they say about opinions