What's a Sequential Box Like for Road Use ?

[GreigM]

nigelpugh7 said:

You will,also notice that from the 1 minute mark on as they sit at the end of the pit straight, there is significant noise from the box as he has the clutch let out as they wait.

Thats not noise from the box, thats just the engine idling (the 620R doesn't idle smoothly when warm it has a distinct put put put thing going on) - that combined with some vibration from the camera mount is what you are hearing. The box itself is silent at idle.

The rest of the noises are present however, it clunks and rocks at low revs (hence my comment earlier about driving in a lower gear than normal to use more revs - the whole thing is smoother). It doesn't like very light throttle, however I attribute some of that to a less than optimal fuel map which makes the car a bit lumpy at very gentle throttle.

I see other people saying the sequential is no noisier than a 6-speed, but I struggle to believe that - the noises the box give are typical sequential noises - whining, backlash, clunking - this isn't unique to the Sadev or Quaife boxes (I help maintain an ex-Carrera Cup car and you wouldn't believe the nosies its box makes, it sounds like someone has thrown nuts and bolts into an industrial meat grinder while idling). I would suspect the 6-speed was noisy rather than the sequential being quiet.

[GreigM]

This video has a better mic than that one from Caterham, if you watch the begining when I'm trundling down to the marshal with my foot on the clutch you can hear the engine vibrating away, there is no noise from the box until engaged. There is always the distinctive whine from the sequential in the background when moving: https://www.youtube.com/watch?v=JnzTylDzdV8

[nigelpugh7]

GreigM said:

Thats not noise from the box, thats just the engine idling (the 620R doesn't idle smoothly when warm it has a distinct put put put thing going on) - that combined with some vibration from the camera mount is what you are hearing. The box itself is silent at idle.

The rest of the noises are present however, it clunks and rocks at low revs (hence my comment earlier about driving in a lower gear than normal to use more revs - the whole thing is smoother). It doesn't like very light throttle, however I attribute some of that to a less than optimal fuel map which makes the car a bit lumpy at very gentle throttle.

I see other people saying the sequential is no noisier than a 6-speed, but I struggle to believe that - the noises the box give are typical sequential noises - whining, backlash, clunking - this isn't unique to the Sadev or Quaife boxes (I help maintain an ex-Carrera Cup car and you wouldn't believe the nosies its box makes, it sounds like someone has thrown nuts and bolts into an industrial meat grinder while idling). I would suspect the 6-speed was noisy rather than the sequential being quiet.

Great feedback, thanks Greig!

I am not surprised that the fuel map is not that smooth on the 620R, CC don't ever seem to deliver a good standard map with their cars as they leave the factory.

I had both my previous R400 K series and the White R500 rolling road mapped, and it transformed the way the engine responded, and dramatically improved the fuel range too.

I am surprised by people saying they don't think the Sadev box is quiet, and don't think you can ever get NVH levels for a sequins is box comparable to a H pattern six speed box.

Yep your comment re the Cup car is similar to my experience in a full race Clio Cup racer we went out in, in literally sounded broken at low speeds, but came into its own at full throttle clutch less changes, great fun!

My previous White R500 was so bad at low to medium road speeds,,that people who came out with me often commented that it sounded like the gearbox was broken!

This constant noise of runs of 100 miles or more, was what made the ownership,proposition so poor for a road car,,and was the reason I decided to sell it, and replace it with the later Green car with the six speed box, which with the new BMW diff was the quietest transmission I ever owned in any of my Caterhams!


I suspect we might be seeing 620R models with Sadev and the BMW diff as production models in the very near future!

Edited by nigelpugh7 on Sunday 30th August 19:30

[GreigM]

nigelpugh7 said:

I suspect we might be seeing 620R models with Sadev and the BMW diff as production models in the very near future!

Indeed, I believe they are preparing the 620S (S=street, R=race). There is no really outstanding nosie from the ford diff though, so not sure what advantage they gain? Perhaps it is more cushioned against the backlash so you don't get so much of a clunk, I've no experience of it. I can say I'm very happy with the current diff, the back end is very controllable and you can hold some comedy drifts.

I'm happy with the car and the noises it produces, I wanted a car I can drive on a good b-road blast and also drive relatively hard (for my competence) on track without it failing. Barring an earlier issue with the ECU and the ongoing thermostat problem in 620Rs the car has delivered - it feels very solid.

Edited by GreigM on Saturday 29th August 10:06

[nigelpugh7]

GreigM said:

Indeed, I believe they are preparing the 620S (S=street, R=race). There is no really outstanding nosie from the ford diff though, so not sure what advantage they gain? Perhaps it is more cushioned against the backlash so you don't get so much of a clunk, I've no experience of it. I can say I'm very happy with the current diff, the back end is very controllable and you can hold some comedy drifts.

I'm happy with the car and the noises it produces, I wanted a car I can drive on a good b-road blast and also drive relatively hard (for my competence) on track without it failing. Barring an earlier issue with the ECU and the ongoing thermostat problem in 620Rs the car has delivered - it feels very solid.

Edited by GreigM on Saturday 29th August 10:06

Great thanks for the feedback Greig!

Oh yes the 620s, they announced that would be an option when the 620 was first announced back in 2013, I wonder what the delay was it finally offering it as a customer variant?

Out of interest what is the issue with the thermostat?

When we were at Throckmorton for the Lotus seven club track day, they're were 3 620r's there, and the fan seemed to be running almost all the time, I see to recall one of them had issues with his battery as a result too?

[GreigM]

nigelpugh7 said:

Out of interest what is the issue with the thermostat?

It's absence! The 620R has no thermostat, so unless the ambient temperature is reasonable the car runs way too cold. Not a problem during the summer, but becomes critical for the other 11 months of the year. I object to having to tape up the front of a £50K car. Caterham are aware of the issue and are apparently working on a fix. Add that to not having an oil temp gauge and I would wager most cars are being used with damagingly low oil temperatures.

[nigelpugh7]

GreigM said:

It's absence! The 620R has no thermostat, so unless the ambient temperature is reasonable the car runs way too cold. Not a problem during the summer, but becomes critical for the other 11 months of the year. I object to having to tape up the front of a £50K car. Caterham are aware of the issue and are apparently working on a fix. Add that to not having an oil temp gauge and I would wager most cars are being used with damagingly low oil temperatures.

Thanks for that Greig,

Sorry to hear about that, but for such an expensive tack day car, that sounds like a pretty basic flaw that should have been solved prior to the car as a production model being released for general public consumption!

I can't help wonder why they released the car with no thermostat, it must be due to a problem with engine heat management that really should have been resolved prior to general release availability .

The more I read on threads like this, and feedback I have had from the few other owners of 620R cars, leads me to believe that the car was premature, and Caterham rushed it to market..

Whilst this is not a problem with a one off race car, it's unacceptable in a road car intended for track use that costs £50k+.

I got some uncorroborated info from one of the race series support companies that I know well, and I am sure that the information is accurate, that CC have had so many issues with the 620R that they are considering withdrawing it from sale, as they have sold less than 50% of the 620R units they had forecast to the business, the year to date sales was forecast at 100 units, but is actually less than 50 units sold and delivered, which is pretty woefully low compared to R500 units sold in the same period.

Now that makes for pretty hard reading when you consider how bad the overall sales of every model of Caterham has been in the last two years, but sadly it's the 620R that is the worst selling model!

Such information is a hard fact to swallow for me as a dedicated supporter and fan of the cars and the rode the business, but combined with a poor management team, disastrous strategy decisions, and withdrawal of several,parts of the main stream business such as CC Mids,,and appointment of less than average routes to market such as Oakmere group really makes me wonder if Cc really has any future at all!

Sorry for the brain dump in this thread, but from the feedback I have had from so many existing, and prospective new owners the future looks pretty bleak for our beloved marque!

[GreigM]

nigelpugh7 said:

I can't help wonder why they released the car with no thermostat, it must be due to a problem with engine heat management that really should have been resolved prior to general release availability .

It is down to packaging - basically the supercharger sits where the thermostat would normally be, so to make it all fit they took it out - wasn't a problem with the C600 race cars that the packaging design comes from, but for road use is more of an issue. To be honest its easily dealt with and I have a nice carbon fibre blanking plate I put on the front in winter and the car runs perfectly with that - it was just a bit irksome to have to do this "DIY" solution regardless how easy it is.

nigelpugh7 said:

I got some uncorroborated info from one of the race series support companies that I know well, and I am sure that the information is accurate, that CC have had so many issues with the 620R that they are considering withdrawing it from sale, as they have sold less than 50% of the 620R units they had forecast to the business, the year to date sales was forecast at 100 units, but is actually less than 50 units sold and delivered, which is pretty woefully low compared to R500 units sold in the same period.

I'm not sure that is correct, I've heard higher numbers than that directly from Caterham. The issue they had was with delivery timescales rather than orders - they are selling so many variations and export-spec models etc that they didn't plan to have the same numbers as the R500 of old. It means they are trickling onto the market, as far as I know there are plenty of orders in.

As for the "many issues" I'm also not sure that is correct. I know several 620R owners and know of no model-specific issues. My car is one of the early cars and having relatively high mileage (i.e. more than 1000 ) compared to some of them has been pretty bullet-proof and feels very solid. Aside from the ECU failing which could happen to any model then there has been no problems which you could point to being model-specific. In fact I believe the contrary is true, that there was more extensive product development on this than most of the prior top-end models.

[nigelpugh7]

GreigM said:

I'm not sure that is correct, I've heard higher numbers than that directly from Caterham. The issue they had was with delivery timescales rather than orders - they are selling so many variations and export-spec models etc that they didn't plan to have the same numbers as the R500 of old. It means they are trickling onto the market, as far as I know there are plenty of orders in.

As for the "many issues" I'm also not sure that is correct. I know several 620R owners and know of no model-specific issues. My car is one of the early cars and having relatively high mileage (i.e. more than 1000 ) compared to some of them has been pretty bullet-proof and feels very solid. Aside from the ECU failing which could happen to any model then there has been no problems which you could point to being model-specific. In fact I believe the contrary is true, that there was more extensive product development on this than most of the prior top-end models.

All good points Greig thanks!

I think I understand the thermostat problem now, I wonder why they did not go with a remote thermostat as a solution though?

The feedback I got on the low amount of sales compared to forecast sales was not from,CC, but from another independent Caterham so they may not be accurate.

However it seems that some of the issues have been with supplies of certain components to complete the 620R cars handle the reason why such a relatively small amount of 620Rs are out there right now!

The next saga in the ongoing Caterham story seems who is going to be the new owner, and what they will do to the current components supply issues, we can all hope that any change can ideally be for the better and things would ideally improve!

I hope you and all the rest of the Caterham owners are managing to get some use out of your cars, the weather has been pretty poor here with torrential rain!

Have fun!

[jeffw]

The spec Caterham chose to produce in the 620R is very conservative. A 2lt Duratec with a Rotrex C30-94 is capable of 450BHP, my 2lt Zetec is 397 BHP with the same supercharger. I've done well over 5K hard sprint/track miles with mine so the 620R should be bullerproof on such a low level of boost.

[jeffw]

double post.

[nigelpugh7]

jeffw said:

The spec Caterham chose to produce in the 620R is very conservative. A 2lt Duratec with a Rotrex C30-94 is capable of 450BHP, my 2lt Zetec is 397 BHP with the same supercharger. I've done well over 5K hard sprint/track miles with mine so the 620R should be bullerproof on such a low level of boost.

Never thought about the potential of the 2.0 with a supercharger, but I did wonder why bolting a supercharger on top of the same engine in my R500 with 263BHP should have got a better result than 310BHP too!

Of course as you say I am sure that it was designed for longevity and reliability.

And wow nearly 400BHP must make your car amazingly quick too!

[GreigM]

jeffw said:

The spec Caterham chose to produce in the 620R is very conservative. A 2lt Duratec with a Rotrex C30-94 is capable of 450BHP, my 2lt Zetec is 397 BHP with the same supercharger. I've done well over 5K hard sprint/track miles with mine so the 620R should be bullerproof on such a low level of boost.

Indeed, I've heard that the first run on the dyno produced over 350bhp with ease and they effectively de-tuned it to make the package ultra-reliable. Expect a 700R soon with the wick turned up.

I can't wait until my warranty runs out then its a new ECU (locking the ECUs really is being a bit of a spoilsport!) and to the dyno for even more mental power

[nigelpugh7]

GreigM said:

Indeed, I've heard that the first run on the dyno produced over 350bhp with ease and they effectively de-tuned it to make the package ultra-reliable. Expect a 700R soon with the wick turned up.

I can't wait until my warranty runs out then its a new ECU (locking the ECUs really is being a bit of a spoilsport!) and to the dyno for even more mental power

Oh yes Greig, it would be great to see what is capable with a bit of tweaking!

I wonder what they did do to the engine though to detune it? Surely it can't be only restrictions in the ECU?

[jeffw]

nigelpugh7 said:

Never thought about the potential of the 2.0 with a supercharger, but I did wonder why bolting a supercharger on top of the same engine in my R500 with 263BHP should have got a better result than 310BHP too!

Of course as you say I am sure that it was designed for longevity and reliability.

And wow nearly 400BHP must make your car amazingly quick too!

Yes, quite quick. This is from the datalogger during a sprint at the Stowe circuit, Silverstone. Note this is on cold tyres with a level of mechanical sensibility hence the slowish 0-60 times.



Castle Combe sprint
https://www.youtube.com/watch?v=24DaZoD1b6c

Dyno run
https://www.youtube.com/watch?v=jXN1vPWLs04

I'm told that Caterham approached TTS Performance to do the kit for them but decided to do their own thing once that had the information from TTS. This is a TTS Duratec running over 450BHP
https://www.youtube.com/watch?v=HMnldIR1FbI

Edited by jeffw on Monday 31st August 13:48

[mic]

No information came from TTS.

[jeffw]

That differs to the information I was told. Anyway, maybe they should done. would have got more than 310BHP...

[mic]

May be :-)

[DCL]

I think in terms of marketing, there's little to be gained from going more than you need to. The level of power required was well understood.

I'd love to know how far they've taken the engine internals but with rotational mass likely to be higher with a supercharger, it must need care about how far you can push things. My concern would be the drive chain, flat shifts with a heavy engine can be a bit of a compromise.

[curley]

GreigM said:

This video has a better mic than that one from Caterham, if you watch the begining when I'm trundling down to the marshal with my foot on the clutch you can hear the engine vibrating away, there is no noise from the box until engaged. There is always the distinctive whine from the sequential in the background when moving: https://www.youtube.com/watch?v=JnzTylDzdV8

Greg
That's a really funny chug chug from your engine . Mines nothing like that , it idles smoothly and will pull away easily if you just release the clutch , yours sounds as if it would stall if you tried that .
I wonder if your idle speed needs raising a tad , mine idles circa 1150 on the dial .