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1.4 Supersport 5 speed vs. 6 speed?

Hi all,

Wondered if anyone has driven a 1.4 SS 5 speed and 6 speed back to back and can comment on the difference in driving experience?

As an owner of the former, I would love to know what difference a 6 speed really makes?




My 1.6 supersport originally came with a 5 speed which I changed for a 6 speed 3 or 4 years ago. Out of all the upgrades I've made to the car this has made the biggest improvement to how the car drives. Whilst you obviously have to change gear more often, the ratios keep the engine in the powerband so as you change up each gear, the engine is eager and the acceleration is addictive. I also fitted a lightened flywheel at the same time as the 6 speed box.

That said its been an expensive journey - the box I bought 2nd hand at the market price, however, it needed an £800 rebuild. The diff needed changing to 3.62 also. Then last autumn the box developed a fault needing the engine to come out. I managed to fix it myself and posted a thread on the topic.

My recommendation would be to buy one that has just been refreshed (zero miles) at one of the known specialists - McMillan can also rebuild them. You could try it with the 3.9 diff - great for acceleration but poor for motorway.

If you mainly do trackdays and local outings, say 200 mile round trip, then the 6 speed would be worthwhile. If you do lots of touring / car holidays I'd stick with the 5 speed.



I owned 1400 Supersports with both gearboxes and found very much as Ian describes above for every day use the 5 speed was the best.

What I found was that as the 6 speed 6th is a 1:1 ratio I was always looking for the next gear as opposed to the 5 speed in which 5th is an overdriven ratio so when in 4th another gear was available for more relaxed cruising if you found yourself on a dual-carriageway or motorway. At times the 6 felt like there were too many ratios close together so you'd end up missing some out so perhaps going 1-2-4-6 or 5-3 or 6-4 coming back the other way, it did work very well used like that though so that's more of an observation than criticism.

Also I think the first cars 5 speed was a good one (I have experienced many type9 5's of varying quality) but the second cars 6 a not so good box, awkward and klunky at times with temperamental synchro on 2nd when cold.

Personally, all considered and given the massive price of a 6 speed I'd put up with one less gear and have done ever since myself.

The halfway house is to fit a BGH 5 speed with different ratios, retaining the overdrive top but getting rid of the cavernous gap between 1st and 2nd.

  Freestyle Caterham #1

..or fit a 1.8 engine which with the wider torque band works much better with the 5 speed.  Thats what I did with my 1.4k 5 speed.  I wanted a bit more grunt so did the well established 1.4-1.8 conversion, swopping all the 1.4 head and ancillaries onto the 1.8k bottom and tricking the ECU to run it by fitting bigger injectors.  

Thanks all for your feedback.

A friend of mine is letting me drive his R300 tonight, so while not a direct comparison with my little 1400, it will let me experience the 6 speed box in a Caterham which is a first for me.

I've seen a 6 speed box for sale - it was refreshed but then participated in 6 races before removal. To my mind, this would now need another refresh and he is asking £1500 which seems steep to me for a box needing a refresh... that must be another 500 notes?

Anyway after last nights drive, my 7 has now developed the k click... Grumpy




my 2nd hand box was also from a race car - only a few race hours since full rebuild. It had 2 broken gears and 3 of the 4 bearings needed replacing. It was 1/3 of a tooth away from destroying itself.

I wouldn't buy it - just wait for the right one if you're set on having one, unless you can get the price down a bit. Also see if the vendor will remove the top plate so you can check the gears - its only 5th you cannot see.



Thanks Ian - sage advice I'm sure.

I'm thinking of maybe putting mine on the market towards the end of summer and see what bites... it's well specc'd and ripe for being re-engined to 1.8 which was the route I was originally intending, but I think it might be better putting the money into another car...

Looking forward to driving the R300 tonight! Driving

I swapped 5 speed to 6 speed in my 1.6K a couple of months ago.

For track use it's much better and I love it, really helps keep the engine buzzing. On the road it's fine, just have to shift more frequently but to be honest with the closer ratios you can easily just skip a gear. I'm still running a 3.92 diff which means about 4000rpm at 70 but then I don't do much motorway cruising.

I bought a race box that just been serviced by Road&Race, only downside with a race box was it's fitted with the race crossgate detent spring, great for 3-4-5-6 but stiff going into 1-2 and real force to get into reverse.

The upgrade is not insignificant in terms of cost and effort. Finding a decent box, fitting, plus you might as well put in a lightened flywheel and new clutch while you got everything apart then you could put that money towards a car that already has a 6 speed box.



This was the dilemma which prompted my first ever post on blatchat in what feels like 1904 now.Having done the sums , upgrading to 6 speed from 5 on my 1.4 SS was not much less than getting a new engine.I opted for the latter  . I adored the 1.4's noise and response at high revs but it was a liability with 5 speeds  with no real power below 5k revs. The 160bhp VVC transformed the car and 5 speeds was no longer an issue.

But I have 6 speeds now on my R400 and on first use it was bizarre - a long first and what first felt like five second gears. It's pointless on such a torquey car but I am not sure I'd go back to 5 speeds - on the right road it's sensational (as long as warmed up as it is notchy when cold) . On Mways - whatever - I console myself it's a Sixties car with Sixties gearing - about the same as an Elan or Dino in terms of mph/1000rpm in top. 


how was the R300?