What's the Difference? | Miata Differentials Explained

[@1.8shawn]

These are the types of videos the miata community needed, before you would have to scroll through forums from years and years ago 🤣. Also I just wanted to throw in, I had a turbo 1.6 making 260 (stock engine, vlsd, and 5speed) and I had no problems ever with the vlsd. I would clutch kick it every chance I got and I had grippy 225 sized tires on, I guess I got lucky.

[@NappMotorsports]

Yeah it’s hit or miss.

[@Orchyarly]

The best information I’ve seen on the internet that explains it clearly.. top work

[@NappMotorsports]

Glad it was helpful!

[@reeceriley5925]

First off I want to say I love these educational videos. I love your channel. Second, I would love to see a similar video on what transmission swap options are and the differences between the 5 and 6 speed Miata transmissions. Nice work.

[@NappMotorsports]

I could do that! There aren’t too many options really but I could make something work

[@reeceriley5925]

@@NappMotorsports that would be awesome!

[@EricJergs]

My favorite part about the VLSDs , is the companies making catbacks advertised as fitting 90-97 and then the ears on the stub shaft smash your exhaust over and over 🤣

[@NappMotorsports]

Self clearancing!

[@babanedelja]

World class explanation ! Thank you and keep up the great work !

[@NappMotorsports]

Thanks!

[@LocoRocoNL]

great informative episode, just finished a TorSen2 conversion myself. I want to say +1 to the subframe comparison idea somebody else brought up.

[@NappMotorsports]

Thanks for the idea!

[@frosty98412]

Id like to know what are the transmission differences, swap options, good trans/diff combos for short gearing, trans adapters, bmw trans options etc. Also I appreciate so much that you point out the differences for the EU market, please please keep those in.

[@NappMotorsports]

I’ll be doing transmission options next month probably!

[@bvward]

Looking good! Perhaps some sort of rundown on how to spec what you need to add to the vehicle when increasing power (necessary, nice to have, if you've got excess cash)...

[@NappMotorsports]

This is a good idea! I’ll get to making notes.

[@philjones5728]

Really appreciate all the work you put in to these videos - thanks (much better than IG!!). I run a stock block 1.6 (yes I know, people always ask WHY?! THe rods are the same in the 1.8!!) with 250hp and as an alternative I bought a 1.8 open diff and put in an aftermarket LSD (torsen) and had the lash balanced etc. Why? The Mazda torsens here in the UK are getting difficult to find and in the end it was hardly anymore expensive to buy the LSD and an open diff plus having the gear lash done professionally. Great content - would be interesting to see an 5-speed vs 6-speed NA vs NB comparison.

[@NappMotorsports]

Good idea on the 5 vs 6 speed! I'll see if I can find a 5 speed.

[@mikesmith8755]

Outstanding tutorial! Thank you Sir!

[@NappMotorsports]

Glad it helped!

[@moltenruby]

FIRST COMMENT! , you fricking rock dude. from the middle east

[@NappMotorsports]

Thanks!

[@perry9492]

Thanks, That takes some mystery. My daughter's Miata has a loud roar and clunk when decelerating. Turns out she has the viscous limited slip rear in her 93. We have a donor open diff to put in it for now.

[@NappMotorsports]

That’ll do it

[@ItsDaJax]

Never knew Miata's came with 4:10 gears. TorSen are gear type diffs and unlike clutch diffs, don't always stay locked under load. Usually you'll see them as 1.5, 2, 2.5, 3 way designations, which if I remember; has to do with lock and slip- the torque to yield. They do have a tendency to go open, which makes them the best option for a fwd or the front diff of an awd vehicle. Unlike an open diff, they'll send all power to the wheel with the most grip in a no traction situation, or can send it to the wheel with the least, which is why you can see something like an F body spinning the inside tire, racing. When you exceed it's torque to yield, it'll go open. Many Eaton diffs, like the TruTrack are TorSen. Personally I think v8s are too big for Miatas and screw up the balance. The only exception would probably be the hyabusa v8. I'd not put anything bigger than a v6 in one.

[@NappMotorsports]

Correct

[@boiled4safety]

Nice video i just got a 4.1 diff for my na6 time to source axles and a driveshaft

[@NappMotorsports]

Rockauto axles honestly

[@boiled4safety]

@@NappMotorsports do you have any experience with them? My buddy is saying OEM or bust

[@fam4sta611]

@@boiled4safety maybe too late but they are good. I've ran them for years. just get some paint on them because they are bare metal for the most part

[@nicnoknoo]

Be cool to have a similar video for NA vs NB front subframes.. rack position differences and control arm mounting point differences etc

[@NappMotorsports]

Good idea!

[@aygwm]

All this information can be found on the internet… I’ve done the swap on my NA. Long story short, stiffer rack mounting, smoother rack and better geometry. Not magic in and of itself, and probably not critical to swap for most people unless you are tracking

[@anth2389]

Do you have a video already of what existing miata wiring is not needed when doing the K swap with the RWD K harness, I'm also using the Kpro conversion harness as well. Just curious as to what parts of the wiring harness can be tucked out of sight.

[@NappMotorsports]

I do not. We built our own harness for that car and I had a good friend do most of the work, so I’m actually very unknowledgeable when it comes to the k swap wiring.

[@aquaculture8028]

You are THE MAN!

[@NappMotorsports]

No YOU are the man!

[@geopouros]

I have a 2004 1.6 nb it had the stock fuji and i installed the 1.8 torsen inside my stock diff parts only : )

[@NappMotorsports]

Nice!

[@robd4163]

Great video. I know it’s a horrible idea but it’s about to happen. Show us how you would weld a diff. Both for 1.6 and 1.8 diffs. Thanks.

[@NappMotorsports]

I’ve never done it before! I need to get my mig set up so I can though.

[@robd4163]

We can learn together. lol. New clutch going in this winter and don’t have fund for full lsd swap. Don’t care if it breaks but curious to see how much abuse to can take before it goes.

[@IndagatorAD4]

Thanks for this informative episode. Much appreciated, keep it up and I’ll try and think up some ideas. ✌️🤓

[@NappMotorsports]

Awesome!

[@ChetJang]

Could one reinforce the notched Torsen with carbon fiber? How hard to change the ring and pinion on my 99 Torsen to be able to put in a 6 speed trans?

[@NappMotorsports]

Doubt it on the carbon fiber. And you can have shops change out your ring/pinion.

[@jeffk5386]

What are your feelings on just filling in the notch with weld ? Would that not do away with the sacrificial fail point?

[@NappMotorsports]

Probably works, but while you're there you might as well just plate it up.

[@BoyStot]

Hey great video, answers a lot. I have a 1.6 diff with 2 piece driveshafts in my car right now so has the stubs in the diff. I have a 1.8 ATB Diff with stubs for 2 piece driveshafts but do you know if it can it bolt up to the existing 1.6 2 piece driveshafts in the car?

[@NappMotorsports]

No they’re different.

[@alexandrubalas1822]

Thanks a lot for the vrey useful info. Can a fuji diff be fited to a 2002 nb fl 1.6, 5 speed. The car has on open diff. Do the fuji diff internals fit in the open diff housing?

[@NappMotorsports]

Internals won’t fit, you need to use a 1.8 diff for the internals to work. But otherwise yes, just use the 1.8 axles and drive shaft as well.

[@Gottayatta]

I bought a diff from a guy for my 1.6 and he told me it’s a Mazda competition limited slip? Is that not a thing?

[@NappMotorsports]

Possibly (they're super rare if it is) and would've had to have been imported from Japan, but it might just be a VLSD.

[@Gottayatta]

How can i find out?@@NappMotorsports

[@malkionx]

Great video as always, more things for me to buy ahha

[@NappMotorsports]

Hahaha sort of sorry but not really

[@histandard31]

Any info on where to source these diffs? I'm out here in California and can't find any used torsens

[@NappMotorsports]

Facebook marketplace is your best bet.

[@Rynowhite14]

Great video. I have a 94 m edition. I'm looking to do some drifting. Would you recommend welding the diff or just stick with the stock torson? Thanks!

[@NappMotorsports]

Welding the arms is always recommended.

[@longbow1997]

Have you ever tried the Mfactory 3.33 ring and pinion for these diffs or heard of people who used them? I know bofi racing sells them and have a video on it but it's good if more people share their opinion on them.

[@NappMotorsports]

I have not, I didn’t know they were a thing to be honest.

[@longbow1997]

@@NappMotorsports they are a pretty interesting upgrade if the strength is at least equel to factory gearing. From bofi's website the gearing with a 6 speed would be the same as a 5 speed with a 4.1 diff i think, but you get 6 gear as extra overdrive or speed gear.

[@thebox5986]

I am currently doing that r&p swap, very excited to see how it will pair with my 6 speed(coming from a 4.1 & 5 speed). 3.9 & 6 speed is too short

[@hoffmods]

I have a 2001 NB 1.6 with the same housing as the 1.8. It´s the diff that came with the car, eu spec open diff. But i can´t seem to find any information supporting that later eu 1.6 was delivered with 7 inch diff.

[@NappMotorsports]

Yeah it's more of a year range that affects it, but in the US that aligns with 1.6 vs 1.8

[@Big_Gima]

Isnt there a way to tell if you have a torsen at least in like a 99(thats what i have so thats what i was researching). if it comes with certain features. Power door locks. Factory leather seats. Think there is a couple other things too. I read a write up on it a while ago. I had all that stuff and turns out i have the torsen. Plus i could just tell by pulling out. They lock up pretty easy considering they lock up mechanically. The fact mine is a 4.30 has its pros and cons. Kills your 0-60 because u have to shift to 3rd for like 3 mph to get 60 also having to rev to like 4k+ to go 70 on the highway. But they give you a good feeling of acceleration esp with mine being turbo but 1st is useless. I just start in 2nd i have the power. And 6sp it’s a 3.9

[@NappMotorsports]

Yes, or you could call Mazda with your vin.

[@wherehumanscycle9859]

Quick question. I have an 03 MX5 with an open diff and a 5 speed. For motorway/highway driving it sits at over 3k for 70 mph so I want a longer ratio, what would you recommend?

[@NappMotorsports]

Either a 3.9 or a 3.63 Torsen differential

[@RicSupra]

NB 1.6 have the bigger diffs as well, in europe with 4.1 ratio that makes them even more slow af. Every Euro 6speed car has the 3.6 diff, we never got the 3.9 sadly (Have stripped several 10AE and Miracle Edition NB's to confirm this).

[@NappMotorsports]

Interesting!

[@xuv5607]

Great Info!

[@NappMotorsports]

Thanks!

[@unified95]

Mine is EUDM and is a 1.6 94, so what diff could I have? doesn't feel like any LSD tbh

[@NappMotorsports]

Not sure on the European options man

[@liltoucan4223]

i have a stock 97 miata that i daily drive and drift all the time, do u think a nb2 torsen lsd would bolt in fine and be good for my application, or is there a better lsd for my needs?

[@NappMotorsports]

That would be fine

[@adamgaber4711]

Is there any difference between a regular torsen and a msm torsen?

[@NappMotorsports]

Yes, splines are different, axles are beefier.

[@jptperformance]

Yes the axles are a different spline

[@boa3062]

Hey man I'm doing a nb torson swap rn on my na Miata. Do you recommend a driveshaft and Axel's?

[@NappMotorsports]

Stock

[@MrHeisenb3rg]

Minor detail, but I always thought that the auto driveshaft is different because the trans is different, and the diffs are the same. Can anyone confirm or deny?

[@NappMotorsports]

I believe it’s manual driveshaft only, but the auto trans’ are so rare that finding an auto driveshaft is a big outlier and arguably not worth worrying about when you look for swaps. If someone is selling a seal package, just look for the rubber guibo on the diff input flange and everything else *should* line up.

[@MrHeisenb3rg]

@@NappMotorsports sweet, good to know. It looks like an auto 1.8 diff is the cheapest way to get into a 1.8 swap for me now. Junkyards have the auto diff listed for easily half the price of another open diff

[@RSG56]

Thank you a lot

[@NappMotorsports]

No worries!

[@thewolfpackgarage5046]

Youre the man

[@NappMotorsports]

Thanks!

[@galosengen856]

Time for the MFactory 3.3 swap. I'm really liking your educational series stuff lately. Didn't Big Greg snap his diff after doing the drilled """reinforcement""" some years ago, lol.

[@NappMotorsports]

I’m not sure if it was Greg, but I definitely saw it happen.

[@daylindrake768]

Can we get a video on the pinion seal my front pinion is leaking and I can’t understand the simple way of doing it not one video

[@NappMotorsports]

I outsource that stuff so I can’t help ya there

[@daylindrake768]

@@NappMotorsports yeah seems to be a big secret haha

[@Birb_of_Judge]

The only thing stopping me from doing this is (aside from money) is finding the gearbox takeoff for the speedo cable. Because I want to get a 4.1 and I have a 4.3 at the moment

[@NappMotorsports]

You can get the right gear combo from Maruha

[@38tech]

Love the vids. Keep up the good work. Interesting that they were made in Rochester. ...wonder if that is a Ford thing?

[@NappMotorsports]

Torsen is based out of Rochester overall. They still make diffs just not the Miata one.

[@ItsDaJax]

Ford thing? I suppose the fwd cars might have a torsen, maybe, but doubt it, but the rwd cars don't.

[@jptperformance]

Fun fact for everyone If you are curious about the gear radio there is a 4 digit code in the ring gear and will give you the ratio

[@NappMotorsports]

Cool! Didn’t know that.

[@choco107]

Fuji LSD is not a clutch type LSD. Its uses fiction cones . It acts very like a Torsen LSD due to the low TBR. McNeill engineering in Northern Ireland strengthens these LSD's . The OEM diff will eventually break off the tabs.

[@NappMotorsports]

That’s the company. Thanks

[@choco107]

You could argue that the cones are clutches but they don't act anywhere near as good as "normal" clutch pack lsds.

[@conorliddy11]

McNeil Engineering in Ireland rebuild the Fujis.

[@NappMotorsports]

Excellent. Thanks! I couldn’t remember the name. I’d love to get my hands on a unit.

[@egilsaerman8769]

Uh oh, seems like my VLSD is on borrowed time then. Stock power, yes. But i've driven it like i stole it, and 150k on the clock 😁

[@NappMotorsports]

They do last if you take care of them on stock power.

[@tylersmith6979]

When I was a teenager, I blew up 3 1.6 diffs in 6 months

[@NappMotorsports]

RIP

[@ricks_toys]

Brother preaching gospel

[@NappMotorsports]

👏🏼👏🏼👏🏼

[@miatasta8521]

please do a "how to shave the back of your head" tutorial!

[@NappMotorsports]

That’s on my OF

[@trailblazer8380]

I may park on a half wet/ half dry spot and let her rip 😂

[@NappMotorsports]

That works too

[@supradoom]

I have the 1.6 vlsd. Nice surprise considering I bought the car for $1000 (with the hardtop).

[@NappMotorsports]

They’re ok until you add any real power