Help me guys with 6 speed swap!!!
 

HI guys:

Recently I pickep up a 6 speed Mazdaspeed tranny from Ebay. Im ready to do the swap(mentally that is) but there is something that I dont know what it is or how it looks:

Solomiata says:

Will the 6-speed bolt in a 5-speed Miata? Yes, make sure to get the trans plate and shifter from the 6-speed donor since they are unique to it. You will have to use only two of the three 5-speed starter bolts but that shouldn't be an issue, otherwise it bolts in .

This tranny came with shifter. But what the hell is a trans plate? I have searched here, googled, everything. Please help!!

Any tips for the swap?

Thanks, Roger

you will be fine i have never heard of a transplate all the bellhousings are the same to my knowledge.

Sounds like the thin metal plate that goes between the bellhousing and the engine.

This is exactly what it is.

Thanks guys for replying.What can I do If I dont have this?

Probably need to find one or modify your 5-speed plate.
I just took my engine back out, let me compare the 5-speed and 6-speed plates and I'll snap some shots. I know the slits for the starter bolts are different on the 6-speed plate, but I didn't notice anything else immediately.

Appreciate that Rotor Nut!

From you sig it looks like you have an 04 and I can assume that this transmission is going in that car. If that's the case, then you can use the plate that is already in your car and the starter will bolt up using all 3 bolts. My 01 was the same way and it bolted up along with all the starter bolts. It appears that it's the NA cars that need to use a different plate and can only use a couple of starter bolts. Can't guarantee that this is the case on all NB cars, but from what I have seen it appears to be true.

If you do end up needing one, let me know because I probably have an extra laying around.

You're totally right Jay. If you could, please look for that plate. There is very little information on miata tranny swaps. Thanks, Roger

The plate is thin and easy to remove. I would think as a worst case senario after pulling the 5 speed out you could pull off the plate, see where it doesn't line up, and drill/cut it to fit without too much hassle.

On the left is the plate from my 2001 base model 5 speed transmission. On the right is the plate from a 2000 SE 6 speed transmission. They are identical. You'll notice that your 5 speed is also different than the NA 5 speed once you get it out, at least mine was.

Thanks guys for the answer. Jay u are the man!! They're exactly the same. U see, this is literature that is nowhere to be found but here!!! JUJU tomorrow I will be installing the 6 speed!!!

Thanks again, Roger

Why doesnt somebody that know their stuff make a writeup which will be later on sticky-ed on tranny swaps for the miata? And differential swaps!!!

The plates are only minimally different NA to NB. If memory serves all NB plates are the same regardless of which manual transmission was in the car.

You'll have to hardwire the the reverse and neutral sensors. That's it, easy swap.

good thread. Thanks for answering questions I didn't know I had.

Now we know!

And knowing is half the battle.

Sorry I returned to the thread kinda late. Got called away to a homecooked steak dinner, it took immediate preference. lol
Anyway, glad your issue was resolved, didn't even notice you had an '04. Sorry.

For later reference, here's an NA plate, the difference is the location and size of the upper and lower right starter bolt holes. That's it.

Attachment 206396

Remember to swap the wiring for the reverse and neutral switches.

Could you guys explain this one a bit more? When I did my swap, the plugs on the 5 and 6 speed were identical and all I had to do was just plug them in and everything worked.

On your '01? That's because you already had NB switches. Everything electrical should be the same between them.

This information is based on putting an early '01 6-speed into my '95, but all I had to do was plug the harness for the neutral switch straight in. For the reverse switch, I just cut off the NB harness end, added the bullet connectors from my NA switch, and I was good to go. Everything operates properly.

FWIW, the NA and NB switch assemblies themselves have completely different thread sizes.

The connectors are reversed on the NB trannies, then. When installing the 6-speed in an NA, you cut the two connectors off both switches and install them on the opposite switch, then plug it in as normal once it's in the car.

I take it the clutch assemblies are indentical for NB 5sp and 6sp trannies ??

Yep.

No need to cut connectors off just unscrew the switches and put them in the other holes If they are in fact reversed. The two switches would be identical if it wasn’t for the connectors.

Bob

I used the stock plate from my 1991 with my 6-speed.

Quick question, is there a different driveshaft needed when dropping in a 6 spd into a NA?

Nope.

^Wonderful, thankyou!

Looks like I'm going down the 6-speed (probably a 2002 NB tranny) into my 1997 NA car.

So, from what I gather, I'll need to do (or not):

1) get the NB trans plate (thin metal)
2) swap the connectors/switches for the wires to reverse and neutral? bbundy or anyone that's done this, can you confirm....or was this speculation?

3) No need to change anything w/ the driveshaft, u-joint, etc.

4) Does the PPF bar for the 5-speed mate up, or does the 6-speed take up more real estate? Do I need to get the 6-speed one from an NB (if so, does it match up w/ the NA bolt holes)?

I'm about to put my six speed in. Quick question. I have two six speed speedo gear assemblies, (gear color yellow and red) , and a five speed speedo gear assembly (white gear, looks to be stained purple)

Which one should I use with the 4.10 gears?

Good call!

whats the point of the transmission plate?

keeps shit out of the area where you fly wheel and clutch spins! i get a pic up in a sec!

BTW, is there anything else we may have missed if we've got an NA (in my case a 1997 1.8) motor/body and are installing the NB 6-speed?

Do I need to do anything w/ the speedo (keep the 6-speed's, use my existing?)? Will my speedo be off? Also, will I see higher cruising rpms at 70mph w/ my existing LSD?

here is the pic!

i used the speed gear out of my 5 speed! you just take out one bolt and it pops right into the 6 speed!

i also used the 6 speed starter!

Nice cut EGR :giggle:

I just put in a 6 speed last weekend into my 94. I reused my speed sensor from my 5speed. I simply unbolted the 10mm and left it hanging when I swap trannys and then bolted it into the 6 speed. You will also have to splice some cables for lights. Cutler had already done that so I did not have to worry about it. You will leave out one of the starter bolts if you use the 5 speed plate. It was the top one on the right that I left out. So far my speedo has seemed to read correct. The cruising rpms are about the same as the 5 speed I had in before. If you come up to the Dyno day next weekend you can drive my car and see how it is.

Ed today I was out driving and was tuning also. Cruising at 70mph in 6th gear put me at ~3500rpms in Tunerstudio. My teach showed one like below 4000rpms. At 85mph TS showed ~3800rpms and the tach showed about 4k.

So confused!

Okay, so if I swap the speedo (keep the 5-speed speedo gear) back into the 6-speed tranny, my speed will be correct (mph)?

But my rpms will be off? Which is correct...TunerStudio or gauge?

Can't teach an old pitbull new word problems.

it is very common for factory standard tachometers (and speedo's) to read a bit high at the top of the scale. Porsche 911 speedo's are off by 20 mph up top (says you are doing 200 and you are really at 180-185). I doubt the tranny swap has anything to do with an inaccurate tach,can't think of any way they are related anyway.

the tack and speedo gear have nothing to do with each other, tach sould be electronic......

FWIW my tack reads high ex: my tach would say 4000 but on both my turbo timer and in MS it would read 3750....even before my 6 speed swap.

I did this swap the other week and this thread was very helpful.

- late model NB 6spd into '89 NA6CE Eunos Roadster.

I thought it was pretty easy although I took my time and spent around 5 hours, didn't change the clutch.

Everything on this page checked out, I used the NA trans plate with only two bolts. The switches on my 6spd didn't need changing but the reverse switch on my 5spd used bullet type plugs, not the spade type so I changed the ones on the 6spd trans for the bullet type.

Used the existing 6" 4.3 diff, the rpm's are a bit higher but not unbearable, I don't drive the mazda to work every day though. I think the 8/6 coilovers are less bearable than the revs.

Speedo drive taken from the 5spd, seems to read the same as before but I haven't driven with the GPS yet so it's difficult to tell if it's changed slightly.

Thanks for the help, it wouldn't have gone as smoothly without it.

sorry to hijak this thread but I'am looking for a 6 speed and was wondering what years of miata to get it from and what engine size is it only 2 litre on nb models that had the 6 speed or did the 1.8 have them as well reason being i phoned a junkyard and he asked me what engine is it off and what year?

it is only of the 1.8's in the US and it is 99-05 anything after 05 is an NC and a totally diferent drivetrain.

There has never been a 2l NB Model.

You're from the Uk, so you have 1.6l and 1.9l engines.

the 6Speed came in the 10th Anniversary and in the first NB with tan leather.

Otherwise, you'll find it in the NBFL Sportive Versions (1.9l)

No factory 1.6l with a 5speed

um there was nvr a 1.9 liter miata to my knowledge man. i am pretty sure it is a 1.8

we mean the same engine.

In Euro, we got two engines for theNB, a smaller 1.6l and a bigger 1.8l.

this engine however has more than 1800ccm and is therefore officially called 1.9l.

Nope, sorry. Unless you guys have something we haven't heard of, all of the 1.8 liter BPs put in Miatas from '94 to '05 are 1839cc, which is still considered a 1.8 liter motor. a 0.5mm overbore bumps it to 1862cc, which is then considered a 1.9 liter.