Nb series diff strength

Engines, Transmissions & Final Drive questions and answers

Moderators: timk, Stu, zombie, Andrew, The American, Lokiel, -alex, miata, StanTheMan, greenMachine, ManiacLachy, Daffy

Pocoed
Learner Driver
Posts: 8
Joined: Wed Aug 03, 2016 9:59 pm
Vehicle: NA6

Nb series diff strength

Postby Pocoed » Mon Aug 08, 2016 11:39 pm

Hi all,

Hoping someone on here has experience with testing the strength of the nb8b 7 inch diffs? Looking for information regarding either the non lsd 3.63 or the 3.9 Torsen limits. Any idea on maximum torque ratings??

Thanks in advance

User avatar
beavis
Forum sponsor
Posts: 1405
Joined: Mon Feb 02, 2009 12:31 pm
Vehicle: NB8B - Turbo
Location: Melbourne

Re: Nb series diff strength

Postby beavis » Tue Aug 09, 2016 12:02 am

Over 350nms I think... don't run slicks and you should be safe.
Usually a gearbox will fail before a diff.
Turbo NB Build Thread | BeavisMotorsport.com | YouTube.com/bbeavis | Cars: NA6, NA8-VVT, NB-Turbo, ND-2L

Pocoed
Learner Driver
Posts: 8
Joined: Wed Aug 03, 2016 9:59 pm
Vehicle: NA6

Re: Nb series diff strength

Postby Pocoed » Thu Aug 11, 2016 11:24 am

Thanks for the reply. Do do you have think a car with 350nm with a different box would be then ok for street use but right on the limit? Would the diff, hubs or driveshafts be the next weakest link?

User avatar
greenMachine
Forum Guru
Posts: 4053
Joined: Thu Apr 24, 2003 11:00 am
Vehicle: NB SE
Location: Sports car paradise - Canberra
Contact:

Re: Nb series diff strength

Postby greenMachine » Thu Aug 11, 2016 3:03 pm

Is this a question based on a real car, or ... ?

Gearboxes are THE weak link. There is no easy/quick/cheap/good fix. Live with it, or go find something else to modify.

:mrgreen:

PS Try google. There is a cubic shedload of information out there on this issue, not so much on this site.
I never met a horsepower I didn't like (thanks bwob)

Build thread

NB SE - gone to the dark side (and loving it 8) )

User avatar
smy0003
Racing Driver
Posts: 1870
Joined: Mon Dec 30, 2013 12:35 pm
Vehicle: NA8
Location: Melbourne

Re: Nb series diff strength

Postby smy0003 » Thu Aug 11, 2016 4:27 pm

Hopefully Pocoed won't mind me speaking for him, but he was talking about an engine and box swap the other day, and was wondering whether the rear subframe and diff needed to be swapped as well.
Maybe Dann will chime in, he has tuned 5's with forged engines and lots of torque.

Sent from my LG-H815 using Tapatalk
[b]Then: Sunlight Silver NB8B
Now: Chaste White NA8

Pocoed
Learner Driver
Posts: 8
Joined: Wed Aug 03, 2016 9:59 pm
Vehicle: NA6

Re: Nb series diff strength

Postby Pocoed » Mon Aug 15, 2016 10:46 pm

Thanks smy0003, am looking at a v6 conversion and am not sure whether I would be pushing my luck keeping the factory diff and driveshafts

speed
Speed Racer
Posts: 3471
Joined: Sun Jan 19, 2014 9:52 am
Vehicle: NA6
Location: Lugarno, Sydney

Re: Nb series diff strength

Postby speed » Tue Aug 16, 2016 6:54 pm

Just curious.. what V6?
I love a good engine conversion :)

Sent from my GT-I9506 using Tapatalk
NA6 turbo - 140kw atw - not the most powerful but so much fun :D

User avatar
NitroDann
Forum sponsor
Posts: 10280
Joined: Thu Nov 05, 2009 12:10 pm
Vehicle: NA6
Location: Newcastle NSW
Contact:

Re: Nb series diff strength

Postby NitroDann » Tue Aug 16, 2016 7:16 pm

LFX V6.

230 Ft Lb,

Less than many stock engine turbo builds, the diff and shafts will be fine no problem at all, however a 5 speed wouldnt. Youd wat to keep the LFX box or a 6 speed.

That simple,
Dann
http://www.NitroDann.com

speed wrote:If I was to do it again, I wouldn't even consider the supercharger.

speed
Speed Racer
Posts: 3471
Joined: Sun Jan 19, 2014 9:52 am
Vehicle: NA6
Location: Lugarno, Sydney

Re: Nb series diff strength

Postby speed » Wed Aug 17, 2016 6:33 pm

Interesting. I'd like to see it happen. Good luck with the build :)

Sent from my GT-I9506 using Tapatalk
NA6 turbo - 140kw atw - not the most powerful but so much fun :D


Return to “MX5 Engines, Transmission & Final Drive”

Who is online

Users browsing this forum: No registered users and 60 guests