1.8 torsen into 90 na6.

turbona6 · Postby **turbona6** » Fri May 10, 2013 4:05 pm

Hey guys!

I'm currently buttining up 1.8 diff conversion in my turbo 1.6 and have run into a bit of a pickle I'm not quite sure about.. I've never really done much like this before but noticed that this can't be correct.. so I picked up a 3.9 torsen out of a 6 speed along with tail shaft and drive shafts that were connected to bottom arms and hub. I also picked up some nb 1.8 sway bar drop links as I fitted the whole bottom arm. The problem I have at the moment is that the driveshafts aren't going all the way into the diff as I'm guessing they should.. I will attach some photos in the next 5-10 mins so you can get a better understanding of what I mean!
Any help is greatly appreciated! Thanks guys

CheyneX5 · Postby **CheyneX5** » Fri May 10, 2013 4:21 pm

You need to also get drive shafts from an NB. The tail shaft is also different.

CheyneX5 · Postby **CheyneX5** » Fri May 10, 2013 4:22 pm

Also, if you are only changing the diff, you will find that running a 3.9 make the cal feel slower and each gear will feel taller.

The correct ratio for an NA6 is 4.3.

turbona6 · Postby **turbona6** » Fri May 10, 2013 4:39 pm

i have the tailshaft and driveshafts to suit the diff as the 1.6 ones are 4bolt type and the 1.8 are actual shaft type that go into the diff..

Jace · Postby **Jace** » Fri May 10, 2013 5:11 pm

you need to push them in far enough for the circlips to pop into the diff center.
try holding each shaft straight and giving it a good hit with a dead blow hammer/mallet.

don't push them in too far though, or you can damage the output seals and rip the outer ends off the driveshafts. ask me how i know. :roll:

turbona6 · Postby **turbona6** » Fri May 10, 2013 5:27 pm

yea i reckon i need to pull em all apart.. i dropped the whole bottom arm/hub/driveshaft into my 5 so i'll just nip the hub bolt off and give it a whack! cheers mate.

Postby **NitroDann** » Fri May 10, 2013 8:58 pm

CheyneX5 wrote:Also, if you are only changing the diff, you will find that running a 3.9 make the cal feel slower and each gear will feel taller.

The {original} ratio for an NA6 is 4.3.

FTFY

Dann

Steampunk · Postby **Steampunk** » Fri May 10, 2013 9:14 pm

Did you also get the appropriate speedo sender from the gearbox?

trader · Postby **trader** » Sat May 11, 2013 3:58 pm

I had the same problem - to get the circlips to remain centred I put a bit of grease on them. I have a speedo sender if you need one.

Jace · Postby **Jace** » Sat May 11, 2013 6:48 pm

speedo in an na6 is closer to accurate with a 4.1:1 than 4.3, if you trust speed sensors signs.

indicated 100km/h is more like 102km/h than 94km/h, with a 4.1 on 185/60 14".

turbona6 · Postby **turbona6** » Sun May 12, 2013 4:05 am

trader wrote:I had the same problem - to get the circlips to remain centred I put a bit of grease on them. I have a speedo sender if you need one.

I might have to take you up on that offer. I took it for it's maiden voyage tonight. (In the pouring rain mind you

) and have come to the conclusion my speedo is out approx 8-9km/h. So 52ish is 60 according to my gps. Is it to suit 3.9:1 ratio ? And will fit in a na6 5 speed gearbox ? Cheers.

trader · Postby **trader** » Sun May 12, 2013 2:14 pm

Apparently there is only two types. The spare I have is purple and has 22 teeth. Should only take a minute to check yours out. Fits both na and nb box but didnt suit me as I have a weird speedo. You may have to do what I did by advancing speedo needle to 10 kms when stationary. let me know how you go.

Postby **tomli123001** » Sun May 19, 2013 10:48 pm

I did this to my car just last week at MX5plus by Jason there.

Two ways you can go about it. 1. buy an adaptor kit, as the attachment mount is different between NA6 and NA8.
2. Buy a used NA8 subframe with brakes hubs and control arms. The the diff will fit in just like at home.

I went with the 2nd option, bought a complete rear sub frame off MX5plus. They had tons of these on the rack. Guess you could do cheaply at a lucky wrecking yard, as not many people took the subframes, ,after the diff is sold off.

gslender · Postby **gslender** » Mon May 20, 2013 9:43 am

Really? You need the entire 1.8 subframe? I've seen/heard plenty of folks install a 1.8 diff into a 1.6 and all they needed was the shafts? What's this about needing the entire subframe or some adapter plate? What specifically for?

G

Sean · Postby **Sean** » Mon May 20, 2013 11:08 pm

gslender wrote:Really? You need the entire 1.8 subframe? I've seen/heard plenty of folks install a 1.8 diff into a 1.6 and all they needed was the shafts? What's this about needing the entire subframe or some adapter plate? What specifically for?

G

Yeah, news to me. You need the aluminium Y frame hanger bit that houses the diff, the side shafts (potrentially hubs delepnding on shaft types) and the main drive shaft....

I've done two like that unbolt old one, bolt in new one. No subframe, no special modded bits.