Caterham 6 speed Box

[Ross_328i_sport]

Good morning,

How reliable is the Caterham 6 speed manual gearbox for heavy track use i have heard rumors that for heavy race use the R300 races cars were having them rebuilt every 5 rounds? Is this rumor true?

I would assume that with heavy track use and more power you could start running into problems, however i know that this box is used in the R500's. Does anybody have any information or experience?

Thanks

[DCL]

Is it not the Sadev used in the R300? It is a primarily a racing box and is designed to rebuilt easily and more frequently.

The six speed is OK to run for much longer. It does have its weaknesses but this is my 6th year on track with mine and I haven't rebuilt yet - it just needs frequent oil changes if its used on track. A little mechanical sympathy helps too.

[Ross_328i_sport]

They do use the Sadev however this year was the first for that and was thought to be cheaper in the long run as the the teams were rebuilding the manual six speed very frequently.

[framerateuk]

From what I've read, the R300 championship is very competitive and the box problems come from the competitors constantly flat-shifting. The upgrade to the Sadev was made so that they'd have rebuilds less often.

[sfaulds]

R300 racers are a particularly brutal bunch - a combination of very close racing and a slightly dull throttle response means they virtually all flat-shift. The Bookatrack hire R300's are getting well over 100 hours between rebuilds, which is much more relevant to trackdayers.

[Ross_328i_sport]

Thanks for the replies. Out of interest of the Sadev boxes proved to be far more reliable then in the championship?

[framerateuk]

From your other thread you can see that you'd be changing the clutch more often with the Sadev box. I remember reading that you'd need a strengthened prop too.

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[cwin]

Ross_328i_sport said:

Thanks for the replies. Out of interest of the Sadev boxes proved to be far more reliable then in the championship?

Yes, but I wouldn't like to use one on the road with the clutch we run, and ours had a cracked plate after 5 meetings,

[BertBert]

what heavy use are you thinking of? Seemed fine (and very enjoyable) in my k-r500

Bert

[k20erham]

Hi Ross, as per our previous chat the SAdev with geartronics is the very best option,, when set up properly up shifts and down shifts are seamless, I dont suffer clutch issues nor any box wear at all, 3000 miles now and nothing, I do run a g box oil cooler which doubles the oil capacity, I broke a 2nd gear synchro and then over temp and 2 bearings on the dyno on my old 6 speed 500 miles after overhaul with less torque than I have now, like everything they have a limit

[SimonRogers]

There are other perfectly suitable and seamless Paddleshift systems.

[Ross_328i_sport]

The main reason for the initial thread was to understand the limitations of the gearbox in order to make a decision on the new engine rebuild as I had heard that in the R300 championship the boxes were rebuilt every few rounds therefore assumed with heavy track use and more power rebuilds would be frequently required.

Needless to say that I have made the decision on the engine and gearbox and will be going for R400 spec engine and keeping the 6 speed box. I believe that this is more than enough power for track days whilst also keeping the raw driving element manual box, heel toe etc. This is different from the initial plan to race the car as I will now only track day this car and race in the fun cup.

[Murph7355]

I think your spec choice is ideal for track days. Powerful enough not to get frustrated by cars that are fast in a straight line but nowhere else, enough grunt to avoid you thinking the car is the problem and hence trying to finesse your driving, but not so balls out that run costs get silly.

On the 6spd I was once told that the selector forks can be a problem if you're sloppy with gear changes. I was told (by a race team's engineers) to make definite "H" pattern shifts rather than cut the gate. And also to be sensible with the clutch and use it properly. So again, I think if you're tidy with your driving it should last well.

Might be worth speaking with RRT for an opinion/advice?

[sjmmarsh]

I've done 50k miles with a 6speed and had no problems at all.

Steve