How strong is the EG6 transmission ?

My Civic EG6 SIR 2 autocross car has had to have the transmission out for the second time this year. ( I am waiting on a report from my mechanic once it is disassembled) The first time 3rd gear synchro failed and this time it has been jumping out of second gear. The second gear problem happened repeatedly during an event at around 7500 RPM on a rough corrugated surface . (It is an internal problem. The mounts and linkages are all OK).
The notes provided by the previous owner indicate that the gearbox is a "standard type R unit". I suspect a combination of a fairly brutal Kaaz LSD, a brutal clutch, very solid nolathane mounts, grippy rally rubber , a very firm suspension and frequently rough competition tracks etc might be a bit too much of an ask for a standard unit. The fact that the original builder of the car gave me a spare gearbox casing and a box full of transmission components has not given me a lot of confidence either. :(
I would be interested in comments and suggestions.Thanks.
Steve

yeh as far as street driven boxes go,they are a fairly solid unit but for what your asking of it,maybe time to upgrade a few components.

how much of a warmup does the gearbox get before a run?,im lead to believe the honda synchro design lends itself to needing a bit of warming up to operate effectively,as most people do find them a bit notchy from a cold start

It is not really possible to properly warm up before a run. You get into a stop/start queue until you get to the start line and the light goes green. After 1 to 2 minutes of competitive driving it is back to the pits where the car is parked for about three quarters of an hour before the whole cycle starts again.
Steve

There pretty strong. Been racing honda's for years now and havnt had a issue with honda boxes. *touchwood*

less than an hour between runs shouldnt see u have any probs,like i said its mainly from a cold start,especially in the colder months of the year,these boxes will lock u out of the lower gears till they're warmed up sufficiently.maybe just try getting it warmed up a little before the first run,or just take it a bit easier on the shifts on the first run.

u really have to find out what broke this time & also what did fail in the synchro system the first time around?

maybe even try backing down a little on the clutch specs if your not making an overly shitload of power over stock on the motor.

Motor is pretty stock apart from a Motec and exhaust. Puts out 105kw atw.