Just wondering what the usual ratio was. My standard Ek has very low gearing..stock grey only really does 55mph on freeway, but takes off from the lights nice and quick. I've heard that I'm running lower gears than a stock Ek special etc. Is this true and if so, will a stock EK diff centre fix my problem and let me hit the big 60 on the freeway??
It sounds like you are already running a stock diff. They were 3.89 : 1 ratio. I own a FB sedan and an EK wagon, both stock and 55mph sounds about right if you dont want the mighty grey to work too hard.
A 3.55 : 1 ratio diff would help you but I believe if you go any firther than that (3.36 or 3.08) you greatly increase your chances of destroying first gear.
Hi Mai,
I have had three diff ratios in my vehicle so far.
The original 3.89 : 1 was the standard issue which served my car well whilst it was unmodified.
It performed very reliably, economically and was I believe most appropriate for both grey engines I had powering it.
On the down side was the engine revs - just a legacy of having to make the most of those quoted 75 horses. It did however pull trailers, caravans and rescue the odd vehicle from time to time.
It had a maximum of about 52 mph in second (just before valve bounce) and although I doubt it now, showed 90 mph on a couple of occasions when I was a kid. It seems a little busy at 70 mph but still quite unstressed.
When I put the 179 motor into the vehicle I opted for a 3:55 diff.
With that motor and 4 speed box the car would metaphorically climb a cliff in first and second. Top speed was beyond the gauges limit but the tacho suggested about 106 mph. Third had a limit of about 60 mph.
With that diff it behaved marvellously but economy wise it actually improved from the grey a fraction - perhaps it was just my eager method to use those 30 new horses I longed for beforehand.
I tried to make more use of the 4 gears by fitting a 3:08 centre (which is still in the vehicle). It dropped the revs off dramatically and certainly made it crucial to use second gear when making turns. The downside is that it doesn't like these new confounded 50 km/h limits around town and I find myself using 3rd much more than I would like.
At 35 mph (60 km/h) - 1600 rpm, it is just above grumbling when trying to draw away in 4th. At 50, 60 and 70 mph it suits the engine well.
Torque is reduced dramatically when towing and instead of climbing cliffs - it probably equates to negotiating a fairly stiff ski ramp.
Hope these ramblings have given you some insight to my experiences.
P.S. - economy is marginally better with the 3:08 and engine wear probably reduced somewhat (definately the risk element of overstressing through acceleration to valve bounce is almost gone).
Would like to play with a 2:78 but don't think the engine would pull it in 4th without the assistance of the starter motor in certain situations.
frats,
Rosco
Seem to have seen that name before , as you know Im doing up an EK, I have a diff sitting there not being used I will see what ratio it is. Also picked up another complete car so I will see whats in that and get back to ya.
Speed and Style........... One day I'll get the speed bit.
maiki,
If you are running radials on your car, switching to crossplies may be the go as the larger diameter wheels should give higher gearing, hence higher top speed
G'day Maiki, i am running a 3.36 diff in my stock grey motor FB (changed the old 3.89 because highway cruising was a bit noisy) , if your motor has a few miles on it a 3.55 would be a good swap but if the old grey is still pretty good a 3.36 would still do the trick. I recently did the Nowra trip and the hills didn't frighten the old girl one bit. Round town driving is also not a problem. Regards Reidy
, as you know Im doing up an EK, I have a diff sitting there not being used I will see what ratio it is. Also picked up another complete car so I will see whats in that and get back to ya.