Differential gear ratios

[Mazzini]

Ive had S4SE an S3 Se both with close ratio and 3.55 diff fitted and loved them both, the S3 was however a Mike Spence car and made about 135bhp, the S4SE was UK delivered Strombergs with the D type cams and larger inlet valves standard and it had and Ed Winter head job, it made a solid 125bhp on QED's dyno, when Ken Snailham owned it. I assembled the engine, QED supplied parts and Ken ran the engine in and then set it up on the dyno, we adjusted ignition curve, springs and replaced the needles in the Strombergs. The S4 was nicer less fussy down low than the S3 but both terrific to drive and fast.

What happened to your S3? Did you take it back to Australia?

[vstibbard]

I bought the S3 off an Englishman here in Sydney who bought the car over to Australia when he emigrated.

V

[TBG]

3:1 being fitted over the next two days. Please cross all your fingers for me...........

[TBG]

Well it is fitted and I have had a shortish blast. It is fantastic. Very very close to the chart above so kindly provided by 1owner69elan. Absolutely no problems pulling away and second and third are amazing. In top I cruise on the French auto routes at about 82mph at about 4650rpm. Those rpm now give me 94!! Checked with a gps speedo. So cruising is MUCH more relaxed and there is still plenty of pull in top. Cost of CWP £430 and what does a five speed cost? Happy bunny!

[1owner69Elan]

Glad your "experiment" worked out. Congrats on your thinking outside the box.

[Quart Meg Miles]

+1 A brave decision and I'm glad our data worked out OK and gave you the confidence to do it! Now enjoy!

[vstibbard]

Great to hear that, also interesting as it gives the 2.97 ratio boxes a longer first which I always felt it needed, and would be a valid alternative to a change to 2.5 close ratio set.

[TBG]

Just been for a much longer drive and all is brilliant. Yes following a slow car up a long hill now needs third but that is not a problem. No lack of performance around the windy bits of our Somerset roads - great torque in all the gears and on the 303 dual carriageway - so comparatively restful . Absolutely no problem pulling away on very steep slopes. Getting about 21 mph per 100 rpm in top. Oh joy! Now need to get the speedo re calibrated..........off to Speedy Cables in Swansea over the winter. Too much fun at the moment to stop driving.....

[trw99]

Another Euro trip planned, then?

Well done, showed us all the way.

Tim

[TBG]

June 2021 - Alps and Italian Lakes - Yee Haaa!!

[vstibbard]

It maybe an option for a group order if enough interest.

Cheers

Vaughan

[alanr]

TBG (Sorry don't know your name.)
Where did you obtain or who did you get to manufacture your 3:0:1 Crownwheel and Pinion?

Thanks,

Alan

[Quart Meg Miles]

TBG (Sorry don't know your name.)
Where did you obtain or who did you get to manufacture your 3:0:1 Crownwheel and Pinion?

Thanks,

Alan

https://www.ntgear.co.uk/buy-gears/ was quoted on page 1, Alan, and ntg above!

[Davidb]

The highest ratio on that site is 3.3:1 which retroford also sells for less money...

I am delighted to hear that this works as well as it does-concerned however that I have a close ratio 2.5:1 first gear.

This is a apparently a much cheaper alternative to the fifth gear options which were sounding very expensive/difficult to fit.

Well done LBG

[TBG]

If you speak to Gordon Strachan at NTG company in Arbroath he will do a 3:1 CWP for you. A very helpful chap indeed. https://www.ntgear.co.uk/ Good luck.