Mx5 gearbox/diff choice

T

Tsg

New Member
Dear people of sideways-ness

I have a question to ask regarding MX5 gearbox/diff ratio.

For a while now I’ve been driving an mx5 NB 6 speed with a poxy helical LSD.in the dry I struggle like hell to skid in second gear. The car Boggs down or just grips and fucks-off up the road, my question is could this be down to the diff ratio? I have driving a friends mx5 (NB,6speed) which Had no trouble in the dry.

If anyone has any experience with multiple mx5’s and their different diff/gearbox combinations you input would be awesome. Google and the Americans seem to be too focused on “gas milage” (which I believe translates to fuel economy) and what make the car feel better......Honestly I couldn’t careless how the car feels or if I get an extra 5 miles from £20 of petrol I just want to skid the bloody thing.

Ps, might be worth mentioning my friend no longer his an MX5 and has no idea what diff ratio was. I have tried different brands of tyres and the rears, usually only have 48psi (because 50psi sounds dangerous pmsl)

Tom
 
Only experience I have is with the na 5-speed. Both with a 4.10:1 open diff and a 4.30:1 torsen. I hardly noticed the ratio difference. Obviously the open diff was terrible.

If you're talking stock power, the mx5 does not really have what it takes. Some slow corners may be very difficult. Because first gear is always shit.

Your mx5 may also just have less power than your friend's. That 20 year old engine may even do under 100 whp.

You ever have that feeling like you should actually lift off the throttle a little, but knowing if you do that it's gonna bog down so you keep your foot to the floor and get a messy line? :p

More power will work, less grip will work too. Another gear ratio could work for you, or the track you drift. But it will also make 2nd gear shorter. You will have to use 3rd more often, next problem?
 
Hi Ramon,

I’m glad to hear you found very little difference between the 4.30:1 and the 4.10:1 diff ratios. Most of the 1.8 open diffs on eBay seem to be one or the other.

Other then the obligatory K/N typhoon air intake and cat back both cars where relatively the same other then the RPM in 6 at 70mph. He always complained he was at nearly 4000rpm in 6th whereas mine is 3100rpm using gear-calulators on flyin’miata ect etc would put his diff at 4.30 and mine at 3.60. Though google is a little bit sketchy with regards to if the 3.60 came on uk cars or not. Mine may actually be 3.90 and maths is just wrong on this occasion. Hence my question really. I’m going to have a go with different combination because I’ve seen some people skid the mk2.5 effortlessly where as I am trashing the car with little effect.

....more power would be nice but “head office” has banned that due to me already having a car in the garage and a bike in the back garden that doesn’t get used unless it’s at least 39*c outside....plus it seems she is set on adding 2 fire places to the house now.

Tom
 
Wow, but that is a big difference. For reference, my 5 speed would do a lil over 4000 rpm when 120 km/h on the clock, I believe that's in the range of your friend's. That is in 5th gear obviously. I don't know if 5th and 6th are much different on these transmissions.

I suppose wider corners are better for your setup right now... Do you ever hit rev limiter in 2nd and feel like you need 3rd? Or do you use 3rd? For me, power starts at 4k rpm, so dropping below that pretty much only does it on wet.
 
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