Johnad replied:

Don, I cant answer your questions, buit you do raise an interesting point. I would like to see this developed before I have to replace my flywheel. The dealer told me not to tow my van in 5th gear as this can reduce clutch life.

Im also interested in your rapid booster. Where did you get this fitted and is it really good for a 30% increase in performance?

Cheers

John

ramp replied:

donald interested to hear more about the rapid turbo boost as i have the 2.8 and am thinking of the unichip or the rapid as well as exhaust upgrade, do you really notice the extra torque in the lower gears cheers ramp

Martyn (WA) replied:

Donald,
I'm in a similar role to yourself and have some reservations about this hardened layer you talk about. I don't know what grade of steel the flywheel is but as far as I'm aware they don't have a hardened layer be it case hardened or a dissimilar metal, I don't think you would want a hardened layer, the co-efficient of friction would be lower so you would just generate more heat, something you don't want. I imagine the metal would be quite "soft", relatively speaking, making the metal more 'grippy' if you know what I mean. This would also apply to brake drums and discs and they definately don't harden them, they skim the discs to brake the hardened glaze so the brakes work better.
I don't know what the hardness of a standard flywheel is, it's a question I've never seen before. I know there is a lot more going into the metallury of brake and clutch componets due to the change from asbestos to other friction materials, some of which vary considerably with their coefficient of friction. This is why I personally buy brake pads and clutch plates from the OEM, I would like to think that they have the customer in mind, sometimes I do wonder.....
If you were considering this hardened layer you would have to go for a HVOF coating rather than the standard powder metal spray coating. Hope some of this helps Keep the shiny side up

Donald replied:

Thanks HUGH,
Greatfull if information & drawings become available.
I still would like to get my hands on an old one. Maybe the scrap bins at the back of the Nissan dealers may have one in it from time to time. It would be interesting to know what they do with them.
I might ask for 1 & tell them I want it to make a truck stand or a letter-box base or something. You never know your luck.
cheers for now.
Donald

Martyn (WA) replied:

Hugh,
Thanks for the input, great to hear from someone else in "the know" so to speak. Being the owner of an old but reliable GQ diesel I haven't got the same concerns about my crutch as people who own the newer more modern GU's, by the sounds of things, I do share the interest it's always handy to know and maybe pass things on in the future, and something to be aware of when buying a different fourby. I opted for the "heavy duty" crutch when I replaced mine which apparently has a 30% higher drive plate crush, seeing as this is very difficult to measure I have to believe what the man in the shop tells me, it looked stronger and certainly weighed a bit more, when I had the rotating bits balanced as part of the rebuild I was surprised as to how far out of balance the crutch pressure plate was, seems good now, this was a part of the rebuild I nearly ignored due to the ever mounting cost, I believe now it's paying off, the engine certainly feels smoother.
I have a servo assisted crutch so if it was 20, 30 or 50% heavier I don't think I would notice by pedal pressure, this to me would seem the more logical way to go rather than looking at a hardened overlay and introducing other elements into the equation, ah well, onward and forward, catch you all around. Keep the shiny side up

Donald replied:

My apologies to Hugh re spelling , I meant Martyn...I think I've had too many beers.
cheers
Donald