What's a Sequential Box Like for Road Use ?

What's a Sequential Box Like for Road Use ?

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Discussion

andylaight

Original Poster:

172 posts

125 months

Friday 21st August 2015
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Your comments please. Looking at R500D and use will be 80% road 20% track, so what's it like to use on road?
thanks Andy

DCL

1,215 posts

178 months

Friday 21st August 2015
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IMHO . . .

The Sadev is a nice box - not too noisy and it easily runs up and down the gears. But it is tedious at road speeds compared to the manual Caterham Six and, at minimum, it needs a flatshift. I'm upgrading mine to a Geartronics paddle shift with a blipper, which I hope will change that opinion. But it also has a lot to do with the engine spec, and a lightweight flywheel/clutch is really needed too.

Edited by DCL on Friday 21st August 16:22

GreigM

6,726 posts

248 months

Friday 21st August 2015
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Depends on what kind of driving. They don't like tickling along at low revsand will jerk a bit, so you tend to drive in a lower gear - in the 620R I drive around town in 1st a lot as its smoother at 3krpm than 2k. They can be noisy (clunking and whining) so not exactly inconspicuous. Apart from that its a gearbox, you dip the clutch, change the gear and release the clutch and drive away.

Personally I thought the caterham 6-speed was a horrid gearbox, and much prefer all driving with the sequential, road and track.

nigelpugh7

5,996 posts

189 months

Saturday 22nd August 2015
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Well I Have owned both variants of R500 Duratecs, a 2009 model with the Quaife sequential, then a 2011 with the Caterham Six Speed Box.

The Quaiffe was great on track, but still very noisy, and sounded like it was broken when driven on the road.

The six speed is very nice to drive with, and makes for much happier on road use, and still great on trackdays.

I have not driven one of the newer cars with the Sadev, and or the combination of the new BMW Diff.

As some other already stated it all depends on your intended use, but personally if I was going to spec another car for mostly road use, it would only ever have the Caterham Six Speed Box.

andylaight

Original Poster:

172 posts

125 months

Saturday 22nd August 2015
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Thanks for replies all. As I thought I need a test drive.
Any idea on what year Caterham started using the Sadev?

nigelpugh7

5,996 posts

189 months

Saturday 22nd August 2015
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I am not sure the Sadev was offered as an option on road cars Andy, apart from the current 620R of course!

Still it was available for the race series cars, so I could have been put on a road car as a special request to CC by a customer.

I have not seen one in the flesh at any of the owners events though.

GreigM

6,726 posts

248 months

Saturday 22nd August 2015
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nigelpugh7 said:
I am not sure the Sadev was offered as an option on road cars Andy, apart from the current 620R of course!

Still it was available for the race series cars, so I could have been put on a road car as a special request to CC by a customer.

I have not seen one in the flesh at any of the owners events though.
I think it was on later R500s - there was a R500 with Sadev in the showroom in crawley for a while and I know of at least one other.

nigelpugh7

5,996 posts

189 months

Saturday 22nd August 2015
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GreigM said:
I think it was on later R500s - there was a R500 with Sadev in the showroom in crawley for a while and I know of at least one other.
Good to know Greig, sorry I had not heard they were offering the Sadev in R500's too!

One of the other guys on here has just bought a 2012 R500 which has the later BMW diff, but that is fitted with the Quaiffe box still, which was why I made the assumption the other cars were too!

Have you thought about putting a paddles shift system like the geartronics one on your Sadev unit in your 620R, I wonder what it would be like with such a setup?,

GreigM

6,726 posts

248 months

Saturday 22nd August 2015
quotequote all
nigelpugh7 said:
Have you thought about putting a paddles shift system like the geartronics one on your Sadev unit in your 620R, I wonder what it would be like with such a setup?,
Yes and no. Would be nice to have, but you are looking at over £5K all-in, not money you will get back at resale time.

DCL

1,215 posts

178 months

Saturday 22nd August 2015
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The factory only fits Sadev with Ford diffs. So, as far as I'm aware, there are no cars with Sadev and BMW diffs. My understanding of the reason is that the Ford diff was well proven with a better selection of final drives and LSD's.

GreigM

6,726 posts

248 months

Saturday 22nd August 2015
quotequote all
nigelpugh7 said:
One of the other guys on here has just bought a 2012 R500 which has the later BMW diff, but that is fitted with the Quaiffe box still, which was why I made the assumption the other cars were too!
Interesting, now that I think about it, I did ask the salesman if it was the "same sequential box" as the 620R in the one on display to which he said yes, but the amount of other stuff he was wrong on generally could easily mean it was the quaife box.

Pdelamare

659 posts

127 months

Saturday 22nd August 2015
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I have the Geartronic paddle-shift system on my Sadev and it's actually very good indeed. It makes such a difference being able to flat shift up/down whilst keeping hands on the wheel. It's a bit clunky at low revs or part throttle but gets smoother the faster you go.

short-shift

340 posts

178 months

Saturday 22nd August 2015
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I'm the person that Nigel mentioned, having just bought a 2012 R500 with the Quaife sequential, fitted with straight cut gears. It has the BMW diff (which is well braced, using some struts that come up vertically through the boot floor and located to the same mounting points as the inboard shoulder seat belt straps on the rear bulkhead upper rail) and the diff is fitted with a Titan LSD.

As far as I knew, all sequential R500's were fitted with the Quaife box so it's interesting to hear of some later ones having the Sadev unit. I know that the 620R uses the Sadev unit, in conjunction with the Ford diff which, I think, can handle more torque than the BMW unit (but as we know, the Ford diffs that are used are nowadays effectively reconditioned units and tend to be noisy) and, I think, still fitted with the Titan LSD internals.

It's early days for me, and I came to this car from a particularly well sorted k-series R400 with the Caterham 6 speed manual. So I guess I was looking for a change, and the sequential does provide a different experience - in spades! Sure, it is noisy - and the gear and gearbox noise is transmitted very efficiently through the diff and its uprated mounting braces in my car, but with straight-cut gears, you have to expect noise. It also knocks and clunks as you shift at low speeds, but... get it on an open road (I'm yet to get on track) and the experience is just terrific! Rifle-bolt changes ("flat" - or clutchless on the way up, assisted with the clutch on the way down) - a really different and fun experience and one which, as someone else said either here on or BC, provides a real sense of theatre.

So there are benefits either way; there's no doubt that the sequential makes the car less suited to using in a touring mode (I suspect that my wife woudl tire quickly of the noise and 'drama' if we were to undertake a lengthy road trip) but, let's face it, a R500 is a fairly extreme machine and should be viewed in that light.

I'll be interested to see other views coming in; I suspect there's no right or wrong on this one, irrespective of % use between track and road...

James

short-shift

340 posts

178 months

Saturday 22nd August 2015
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Just to add - for the sake of completeness (or something along those lines), not all R500's were fitted with the BMW diff. I understand that the early cars were fitted with the Ford unit but the noise issues were becoming more problematical across the range, which prompted Caterham to change (around 2010 or 2011? - I'm not sure) to the BMW unit on all vehicles, including the R500. So you will find a mixture of manuals and Quaife sequentials being used with either Ford or BMW diffs fitted, dependant on age. And that's before we get to the question of whether the later R500's were built with the Sadev sequential box and, if so, whether these reverted to the Ford diff or not...

James

jeffw

845 posts

227 months

Saturday 22nd August 2015
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The Quaife 60G which is in the R500 mentioned is also available in a Helical gear version. So dog engagement sequential with helical gears so no straight cut whine....and this is what is fitted to my Phoenix.

short-shift

340 posts

178 months

Saturday 22nd August 2015
quotequote all
You are right, Jeff, but I suspect tha all R500's were fitted with the straight-cut version of the Quaife sequential...

Happy to be proven wrong - in fact, would like to know if there are helical units out there if anyone knows of one.

James

jeffw

845 posts

227 months

Saturday 22nd August 2015
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The R500 I've seen have all got the straight cut box. The helical is a lot quieter on the road and is just as quick to change gear.

short-shift

340 posts

178 months

Saturday 22nd August 2015
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Yes, the gear mesh (helical or straight-cut) in a sequential gearbox (which is a form of 'constant mesh' transmmission) won't have any effect on shifting, which is all about selection, movement and engagement of the dog rings which are controlled by the shift mechanism (normally a fork mechanism controlled by a rotating (or incrementing) selector drum, which is itself rotated by the selector mechanism (moving the gearlever back and forwards!).

I have a feeling that there is not as much choice in helical ratio sets offered by Quaife as they provide on their straight-cut transmissions; it may be that this (choice of ratios) is one of the reasons why Caterham seem to have gone for the straight-cut option; another reason might well be to maximise transmission efficiency in-line with the track-day/ultimate performance positioning of the R500.

Anyway, the OP was asking about driving/ownership experiences - so it would be interesting to hear more views about this aspect.

James

anonymous-user

53 months

Saturday 22nd August 2015
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short-shift said:
Yes, the gear mesh (helical or straight-cut) in a sequential gearbox (which is a form of 'constant mesh' transmmission) won't have any effect on shifting, which is all about selection, movement and engagement of the dog rings which are controlled by the shift mechanism (normally a fork mechanism controlled by a rotating (or incrementing) selector drum, which is itself rotated by the selector mechanism (moving the gearlever back and forwards!).

I have a feeling that there is not as much choice in helical ratio sets offered by Quaife as they provide on their straight-cut transmissions; it may be that this (choice of ratios) is one of the reasons why Caterham seem to have gone for the straight-cut option; another reason might well be to maximise transmission efficiency in-line with the track-day/ultimate performance positioning of the R500.

Anyway, the OP was asking about driving/ownership experiences - so it would be interesting to hear more views about this aspect.

James
Yes, most likely the gears are straight cut because it's a lot less expensive if you're offering a range of ratios.

Straight cut will reduce the power loss a little but I wouldn't have thought that would be the major factor for a road car.

DCL

1,215 posts

178 months

Saturday 22nd August 2015
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Straight cut gears don't produce any sideways thrust and that is the reason they are used. In a purpose designed box, like the Sadev, that means a simpler and stronger design for any given size of box. The Quaife, I believe, owes much of it's design to their helical synchro designs and so can deal better with the side forces of helical gears and is probably why that option is available.