Sadev with flat/paddleshift - still the best option?

[jimmyslr]

I have been out of caterham circulation for over a year and am thinking again about sequential boxes, with flat shift capability. Ideally, full clutchless up/down shift capability which probably means pneumatic paddle shift.

 

A year ago Sadev was seen as the box of choice (6k), with a Geartronics flat shift system (with the option of a Geartronics full paddle system taking it to c4k), plus fitting and Vat. Call it 15k all in for paddle shift option or more like 10k without paddles/downshift capability.

 

I get the impression from some googling that more Caterhams have gone the Sadev route in the last year. Does anyone have any useful feedback on the various options and recommendations today?

 

Also, I know you can source the box and the Geartronics kit, but who's installed a number into Caterhams as I assume some familiarity with the packaging inside a Caterham would be helpful. I'd rather not be someone's guinea pig!

 

Thanks, James

[Mike Biddle]

I have the box, and am happy with it, apart from the fact that it rumbles/clatters on idle in neutral with clutch engaged.

 

The box already has a sender unit in it to connect to ECU for flat shift, so unless you really want paddles they are not required if your ECU can manage the fuel/sparks cut.

 

I have not connected mine yet but will be doing so over winter.

 

Have a chat to Steve at SWR, he will give you some valuable advice on this one.

[jimmyslr]

Mike - that set up will work for flat upshifts, but doesn't do the clutchless downshifts I believe. Is that correct? I really want clutchless up and down with rev matching on down shifts.

 

The idea is a quick flick thru 3 gears on the way into Paddock Hill bend under hard braking! I've raced a paddleshift once or twice, but in the caterham have always been old school with a 6 speed box.

 

James

[Mike Biddle]

You are partialy correct, clutchless downshifts are no problem I can do them with my current set up. As long as you are on the brakes and off the throttle you can shift down without the clutch, but if I want to match the revs then I must dip the clutch.

 

Is rev matching on downshifts possible with a sequential box without disengaging the clutch? I don't think so, but I could be wrong.

 

 

[Gridgway]

Quoting Mike Biddle: 

Is rev matching on downshifts possible with a sequential box without disengaging the clutch? I don't think so, but I could be wrong.

Can't speak for a "proper" seq box, but the Radical paddle system blips on the way down (Hyabusa) and is clutchless.

Graham

[Mike Biddle]

OK, then the ECU must know the following.

Engine speed, which is a given.

What gear the box is in and which way the driver is shifting.

Must be programmed to account for ratio change to know how many RPM to put on the engine.

 

Graham, are you sure the radical system does not quickly, and briefly, disengage the clutch while its doing this?

 

Don't know about the Busa box, but the Sadev for sure does not have a "neutral" between gears to alow for a blip.

 

I suppose a very precisely timed blip could occur just after the lower gear is engaged, but that would also rrequire the ECU to know exactly where the gearlever is during the change in order to get the timing right.

 

I do know from experience that the Sadev will not change down if the clutch is engaged and there is any throttle on.

 

Maybe the geartronics system includes this function?

 

Even if it does, is it worth 4K just to acheive a throttle blip?

 

Again, suggest you talk to Steve at SWR, he will explain all in great detail.

 

James, when are you planning to do this? I would be happy to demonstrate the box in my car, but that would probably not be posssible untill next April due to shipping back to Dubai and back to UK again.

[paul richards]

I have a Geartronics paddle system to incorporate in a build with a Sadev gearbox (it's the RST V6 that Richard Lee started - I'm trying to complete some of the build for his widow). My understanding is that it will complete clutchless up and down shifts. It incorporates a pneumatic throttle blip and a GCU (Gearbox Control Unit). I've yet to start on the fitting, so I'm interested in this thread.

[NoLimits]

Hi I can answer for all the systems above due to my representing MOG in UK (SADEV and Geartronics stockists) and our own SBD/MBE/Radical package.

 

However I can only do this on the understanding it is for technical info only and not seen as advertising.

 

Up to you guys if you would like me to contribute. If not please ring me to do so off line and someone else can post back instead

[jimmyslr]

Quoting NoLimits: 

Hi I can answer for all the systems above due to my representing MOG in UK (SADEV and Geartronics stockists) and our own SBD/MBE/Radical package.

 

However I can only do this on the understanding it is for technical info only and not seen as advertising.

 

Up to you guys if you would like me to contribute. If not please ring me to do so off line and someone else can post back instead

 

Please go for it as I think a few of us are interested and the path to all singing/dancing sequential bozex and flappy paddles is not well worn.

 

Oily often posts very informative explanations and is himself also in the trade and this works fine for all concerned

[Gridgway]

Yep, I agree, go for it!

[NoLimits]

Hi Guys

 

OK to start with both systems are very very good.

Both are tried and tested.

 

The main difference between the two is that the Geartronics is a piggy back system which sits on top of your existing ECU and the Meteor system is fully integrated - it is the ECU and GCU combined.

 

There are 27 Sadev boxes in use in Europe and around the world sold by MOG - some of these have Geartronics also. (Sorry do not have these figures).

 

I am not a tech gut but i try to understand the systems and their differences. My original system on my Rover K and Elite box was not closed loop and so I am told my original feedback to Powertec/Radical is what helped them realise they needed to develop the system.

 

Geartronics

It has a Gear Position Sensor (GPS) - which senses the position of the main shaft to minute accuracy. This is the key to higher end systems. It allows the electronics to measure very accurately where the gear change is currently positioned.

 

So assume 0% = still in current gear 100% = completely engaged in new gear (up or down for this explanation). As the paddle is pulled and the actuator begins the movement on the lever the GPS senses this and starts to do its thing (many things), This can be cutting spark, retarding or bliping on the down shift. (The exact detail here is beyond me and more to do with the programming than the installation and use). These high end systems can then begin to re introduce spark or return to the correct advanced position as they sense the main shaft position change. Some will do it as soon as it reaches say 51% the MBE tries to leave this as late as possible say around 80% so as to ensure the gear is fully changed before returning to full power. This is the point it can all go wrong. Return to full power to soon when the change is not complete and it can get messy and expensive but the faster /sooner you return the faster the change.

 

Both systems can be adapted to do this at various speeds,

 

I'm told there is no "right" way to do all of this cutting and retarding just different ways.

 

SBD and the MBE system prefer to limit the retardation and stick to cutting spark where possible. This limits any unburnt fuel in the system and any pre ignition when returning to the correct timing.

 

To describe the difference in the systems better think of the Geartronics knowing when the ECU is sparking and fueling but not knowing when the next one is coming. (The speed this all happens at is mesmerizing )

 

The MBE system knows exactly where it is and what is about to happen next and so can take the appropriate action - I guess you could see it as preparing itself for the change with obvious advantages.

 

The Geartronics simply tells the ECU it wants to cut a spark or whatever - this could be half way through a charge of a coil which again the MBE one wont - it simply wont begin the process until the coil is empty.

 

The throttle blip recommended by Geartronics is the SBD one. Its the size of your little finger - very clever and works direct from the pneumatic valve block when down changing. Its all timed to work as the gear is disengaging and before it has re engaged.

 

On the system I have installed on the Busa it is very sweet. Again the exact change is controlled by the system. The Geartronics system sometimes has to really be tuned by them to allow the throttle bodies to react in such a short time frame rather than flood the system.

 

The MBE system prevents buzzing the engine by blocking early down changes if the revs are to high.

 

It can run in various modes including fully automatic where it changes gear at pre set revs - took some getting used to but now very good fun.

 

The Geartronics can do this also but here is the main difference as I see it.

 

If off the line you spin the wheels the Geartronics would see x revs and change - you may still be standing still Our system for a small additional cost can run with 4 wheel speed sensors and thus allows the system to prevent a change as the speed recorded does not equal the revs and gear position. It then applies its traction control methods until speed equates to the correct revs and the change can proceed.

 

If someone wants more detail please feel free to contact me.

 

[paul richards]

Seems to tie in with my limited information. Thanks for your input Simon.

[Gridgway]

There's also open loop I understand which is pretty horrible but I think is what Radical used to run. Rather than sense position and react accordingly, going up, you cut throttle for a fixed time and then give it a fixed length shove and hope it goes into the next gear.

 

Now they run a closed loop system built into the Life ECU.

 

Graham

[NoLimits]

Yes that's correct Graham.

 

It was a result of me feeding back in my more mechanical way that when I installed for 2005 their system it could not actually carry out a change on the car gearbox when it was under load (up or down the box) as the cut in the spark was actioned at the same time as the pneumatics. The dogs were still engaged under load and could not disengage.

 

I asked for some electronics to delay things as I could feel this happening. I was then told by Neil of Geartronics that radical then employed him to write the appropriate software. - He then went on to develop his own kit.

 

I simply drove around the issue by using the clutch slightly during the changes - it worked perfectly for 6 years until I moved to the busa and sold it all.

 

 

[James.S]

I have used both Sadev and Quaife boxes, both with and without flatshift - netiher with paddles though. Both are similar in operation, although Sadve lever needs some mods to be in the ideal position. It wins out quite a bit on the weight side though.

 

The Quaife is pretty rock solid in the reliabilty stakes, the Sadev has just been specced over the Quaife for the new R600 - says it all really.

 

Stuart at Fauldsport has decent experience fitting both systems, worth a call.

 

J

[mic]

Gear lever has been sorted James, Stu tried it at Spa and thought

it was lots better.

[James.S]

Cool, sounds like it was an awsome weekend.

 

Bitter not to be there. I hear you all met my mate Brato.....

 

Yours must have been a hoot round there.