5 or 6 ratios 'box... Can someone give me a definite answer
Discussion
thinfourth2 said:
ewenm said:
As you can see from the above two replies, there is NO definitive answer. I do relatively big miles in my 7 and appreciate the longer legs 5th gear in the 5spd box, but occasionally on track find the ratios a bit widely spaced. However, I spend far more time on road than track.
When I bought mine, it wasn't even a minor consideration.
There is no correct answer as to which is best. Its like arguing that yellow is a better colour then green a wholey pointless and fruitless exercise with many many caterham owners screaming that yellow is best while others claim that green is better as it is better for cruisingWhen I bought mine, it wasn't even a minor consideration.
You can get good rebuilt 6 speed bixes from Phil Stewart at Road & Race Transmissions 01959 525105. He has histrically provided gearboxes for all the racers as the factory appointed repairer, so he knows what he's doing. Around £1300 ea IIRC.
You can also calculate your gearing using this little application here http://www.the-webbs.com/k2rum/GearCalc.exe
Aim for a 6mph range 1st gear if you want rapid accleration, or 7.5mph - 8.2mph if you are looking to go touring.
Whats surprising is that the extremes of ratio (6 speed on 3.92 vs. Quaife 5 speed on 3.92) make only for a 750rpm difference at 100mph!
You can also calculate your gearing using this little application here http://www.the-webbs.com/k2rum/GearCalc.exe
Aim for a 6mph range 1st gear if you want rapid accleration, or 7.5mph - 8.2mph if you are looking to go touring.
Whats surprising is that the extremes of ratio (6 speed on 3.92 vs. Quaife 5 speed on 3.92) make only for a 750rpm difference at 100mph!
Fishy Dave said:
I would disagree with the comment about 1400s being a waste of time. It's quick enough, good on fuel, cheap on tax and I can keep up with a good many 1600 and 1800s. I personally find mine excellent, although do wish it had a 6 speed.
I agree with you Fishy Dave - the 1400 SS has a lot going for it, especially in these times of ever increasing costs, particularly motoring related. However, never experienced a 6 speed box in a Caterham so can't comment really. Just don't knock the 1400 SS (or any Caterham for that matter) as they are all a million miles away from 'Euroboxes'...Rant over :~)
Ok I've never driven a 5 speed car but have done plenty of miles in the 6.
The shift quality and close ratio suit the nature of the car perfectly. Mine has the 3.9 ratio diff and I've done loads of cruising / motorway miles without issue. Plug into the ipod on the motorway but even without doing that it's not as tedious as some would suggest.
Ultimately its a personal decision, try both & see what YOU prefer.
The shift quality and close ratio suit the nature of the car perfectly. Mine has the 3.9 ratio diff and I've done loads of cruising / motorway miles without issue. Plug into the ipod on the motorway but even without doing that it's not as tedious as some would suggest.
Ultimately its a personal decision, try both & see what YOU prefer.
I'm really surprised that no one has mentioned that a modified 5 speed box, for the uses outlined, is the best of the lot. If you have a K series engine use a 3.92, if you have a Vx or Duratec install a 3.62 cwp. Go for a longer 1st and 2nd, keep 3rd and 4th as they are, as well as the standard long 5th as an overdrive cruising gear. Have the internals beefed up, including the sycnhro rings and have the change modified slightly to give a slicker feel, and Bobs your uncle. Both Phil Stewart and Brian Hill do these boxes and come with plenty of recomendations from Seveners.
If you go for a 1400 stick with the 6 speed though.
There's your answer from someone who has done it. [Currently running a 260 Duratec with a BGH 5 speed box and a 3.3 diff.]
If you go for a 1400 stick with the 6 speed though.
There's your answer from someone who has done it. [Currently running a 260 Duratec with a BGH 5 speed box and a 3.3 diff.]
Edited by paulejacobs on Monday 28th July 17:39
"260 Duratec with a BGH 5 speed box and a 3.3 diff"
Paul, What 1st ratio do you run? UNless its about 3.5:1 I'm sure this is a sharp as a blunt pencil off the line. These converted 5 spds from Brian Hill provide a low cost solution for someone who does not want to pay for a Quaife gearset for a type 9.
Paul, What 1st ratio do you run? UNless its about 3.5:1 I'm sure this is a sharp as a blunt pencil off the line. These converted 5 spds from Brian Hill provide a low cost solution for someone who does not want to pay for a Quaife gearset for a type 9.
The 3.62 diff was only 'standard' with the 6speed box on the superlights - the roadsport I had came with the 3.92 diff as standard.
The CSR I now have has the 3.62 diff, but the 3.38 is supplied if you ask for the 'touring' option.
It was a no-brainer for me to go for the 6 speed box as it is so nice to use.
If your engine has reasonable torque (1.8 VVC for example) then you can put it in 6th and it will drive like an automatic from about 25mph upwards if you are in cruise mode. If you want a more enthusiastic drive then the 'BlaaAAT - snick - BlaaaAAT - snick - BLAAAAAT' feeling is addictive!
On track, the 6 speed is much better than the 5 as you always have the right gear for the corners. Ignoring the end of long straights you will have 4 gears to choose from (2-5) rather than the 2 unevenly spaced ones (2-3) that you get with the 5 speed. Remember that 6th on the 6spd is the same gearing as 4th on the 5 speed.
On the other hand, if money is tight, go with the 5 speed as it still drives brilliantly - but try and drive both before you decide as you won't have had experience of the advantages of a close ratio box in most normal cars. This was summed up in one of the reviews I read about the 6 speed roadsport - "it has 6 gears, but they are all the same!"
Steve
The CSR I now have has the 3.62 diff, but the 3.38 is supplied if you ask for the 'touring' option.
It was a no-brainer for me to go for the 6 speed box as it is so nice to use.
If your engine has reasonable torque (1.8 VVC for example) then you can put it in 6th and it will drive like an automatic from about 25mph upwards if you are in cruise mode. If you want a more enthusiastic drive then the 'BlaaAAT - snick - BlaaaAAT - snick - BLAAAAAT' feeling is addictive!
On track, the 6 speed is much better than the 5 as you always have the right gear for the corners. Ignoring the end of long straights you will have 4 gears to choose from (2-5) rather than the 2 unevenly spaced ones (2-3) that you get with the 5 speed. Remember that 6th on the 6spd is the same gearing as 4th on the 5 speed.
On the other hand, if money is tight, go with the 5 speed as it still drives brilliantly - but try and drive both before you decide as you won't have had experience of the advantages of a close ratio box in most normal cars. This was summed up in one of the reviews I read about the 6 speed roadsport - "it has 6 gears, but they are all the same!"
Steve
rubystone said:
subirg said:
Easy - 6 speed is the way to go.
....is the wrong answer!!!!!!!5 speed - and also, buy one with torque - VX 2 litre, VVC....
On-track, no contest, but on the road - you'll be hitting the rev limiter if you stray over 6 leptons
Edited to add - please don't waste your money on a 1400 though - they develop bugger all torque and the 6 speed 'box was built for the 1400 Supersport to keep it in that "power" band.
Edited by rubystone on Thursday 17th July 15:25
Fat Arnie said:
"260 Duratec with a BGH 5 speed box and a 3.3 diff"
Paul, What 1st ratio do you run? UNless its about 3.5:1 I'm sure this is a sharp as a blunt pencil off the line. These converted 5 spds from Brian Hill provide a low cost solution for someone who does not want to pay for a Quaife gearset for a type 9.
Afraid I have to agree, I ran a 2.29:1 1st in the Megagrads using a Quaife Clubman's gearset with a 1.6 Supersport and its a pig to launch cleanlyPaul, What 1st ratio do you run? UNless its about 3.5:1 I'm sure this is a sharp as a blunt pencil off the line. These converted 5 spds from Brian Hill provide a low cost solution for someone who does not want to pay for a Quaife gearset for a type 9.
sjmmarsh said:
Remember that 6th on the 6spd is the same gearing as 4th on the 5 speed
If that's the case, and you are going on track, I wouldn't go near the 5 speed. I use my car almost exclusively at the Ring and only hit 6th twice in a lap, and that's after shifting at 8k with a 230hp k series. the 5th in a 5speed box will be way too long geared (depending upon the final drive of course)....Personally, I would like a closer 6 speed box, but that's just a personal preference. The 6 speed Sadev sequential in my Clio cup race car is closer than the caterham 6sp box and is way better spaced for most UK tracks (and Spa).
fergus said:
sjmmarsh said:
Remember that 6th on the 6spd is the same gearing as 4th on the 5 speed
If that's the case, and you are going on track, I wouldn't go near the 5 speed. I use my car almost exclusively at the Ring and only hit 6th twice in a lap, and that's after shifting at 8k with a 230hp k series. the 5th in a 5speed box will be way too long geared (depending upon the final drive of course)....quote]
Really? A 1.6 Supersport Megagrad with a 7600rpm limit and a 3.62 diff will quite happily hit the rev limiter in 4th at Spa with a slipstream, and do a good 7400rpm before it runs out of puff in clear air on its own! And thats with the bigger Yoko A048R's. On the standard smaller CR500's in a roadsport I've hit the 7200rpm rev limiter in 4th before the end of the start finish at Brands before!
As I understand it, the 6 speed box was designed for the 1.4, and when larger engines became available, it was transferred to the whole range, but for road use the ratios are just too close, great for the track however.
Arnie asked what the 1st gear ratio is on my 260 Duratec with a 3.38cwp. It's 2.75, with a 2nd gear ratio of 2.25 which, frankly is perfect for that engine, with 200ft/lbs to haul it along. It gets off the line as quickly as you want, but it is not set up for track work, I built it to use predominantly on the road, and the 5 speed with those ratios is perfect for touring.
Arnie asked what the 1st gear ratio is on my 260 Duratec with a 3.38cwp. It's 2.75, with a 2nd gear ratio of 2.25 which, frankly is perfect for that engine, with 200ft/lbs to haul it along. It gets off the line as quickly as you want, but it is not set up for track work, I built it to use predominantly on the road, and the 5 speed with those ratios is perfect for touring.
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