Harzut,

I read in a recent british classic magazine the collective noun for a group of datsuns is a "zed of datsuns"........ I have a zed in my zed?

In the past 18 months or so my granny spec. 1000 (B10) sedan has undergone some fairly major upgrades, I pulled the A15t from the dragin` wagan and fitted a T50 dellow 5speed and fitted it into sedan. The clutch setup in the wags NEVER slipped (cortina 4speed, custom 180mm clutch plate, custom pressure plate) it could handle 30+ psi without any problems. so it makes sense that the clutch supplied with the box was always going to fail at any decent boost.

I tried running the custom pressure plate from the wags (twin diaphram springs) it did hold the boost (20psi) but would not fully release when it got warm.
I fitted a RPM pressure plate, it holds about 10psi and is nice and light under the left leg , however it tend to slip in 5th.

So time has come to bite the bullet and spend a bit of time (and money) on the old girl.
I searched the forums on this site and found everything from SR20/Toyota clutch combos to re-tempered pressure plate srings. I also decided to search some AE86 sprinter sites (as all T50 toyota boxes use the same input spline) and there is a wide range of performance clutch kits for the "HAICHIRUKO".

I`v got a AE86 clutch kit on the way and I`v got a flywheel in the machine shop getting machined to suit a 200mm AE86 clutch kit. I`m hoping that the standard clutch kit will cope with reasonable boost levels (20+psi) but I`m unsure of the datsun/toyota release bearaing setup will work?

I`m thinking that it would be nice to be able to get "off the shelf" performance clutch kits instead of having to "bring in a sample" and wait for six weeks (ABS).

If all goes to plan I should have the clutch and fly wheel early next week and be on the road in the new year.

I don`t think the old 165 remmington aquaplanes will be upto the task though, there is not a lot of room in the rear gaurds of a 1000, I want to keep the old girl looking fairly standard, so bolt-on flairs are not an option (although they would look quite cool). If i can find some 13 inch steel rims with the right offset i reckon i could fit 215`s.....just?



The old girl on the Youtube
http://www.youtube.com/watch?v=vAJPG42FXqU


G O T H E D A T !

I have my flywheel remachined to take a 200mm L series plate, which it turns out is the same as some fwd sr20 p/plate. A local clutch guru sold me a 300pound p/plate for it, and it has loads of grip. Only running 10psi though.

Cheers,

I got the flywheel back from the machine shop and it looked pretty good, so I fitted up a standard 200mm toyota clutch kit (4AGE sprinter),
It felt pretty good under the foot and was smooooooth on the road(nice) But as before when it boosted up in 4/5th it started to slip.

I spoke to a number of clutch specialists and decided to upgrade the clutch plate to a 4 puck item i was told this add 30-40 percent less slip.

I pulled the motor and box (getting pretty used to it now), I found that the machine shop had only machined a standard 0.2mm step onto the flywheel as opposed to the 0.5mm I had asked for (They re-machined at no cost).

I fitted it all back up again with the new 4 puck clutch plate, and you guessed it,...... it still slips.


I`m starting to get a bit pissed off about the whole thing, but I won`t let it beat me,
I`m now thinking that I will have to get a new h-duty pressure plate but am not sure , I have been quoted $190.00 for a custom, 100 percent clamping force item. I might have to trawl some 4AGE/sprinter forums and see what they have to say.
[img width=300]http://datsun1200.com/modules/myalbum/photo.php?lid=21562[/img]

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You should have started off with a heavy duty plate on any boosted setup anyway

I personally would have gone with a sprung cushioned ceramic plate myself... but the 4 puck if you can get it off the line and live with the "on/off" way it works will be good too
I used to run the puck clutch in my racecar but switched to the ceramic cushioned

Take some more weight off that flywheel too

the thing I don't quite get is the center spline, are they all matched to the datsun spline profile or is there a step in it for the toyota clutch?

Cheers,

The gearbox and clutch kit are both toyota items, I have had my datsun flywheel machined and drilled to suit the (200mm) toyota setup.

I bought the standard AE86 kit because it was fairly cheap ($140 on my door), and I thought that at 200mm and about 30 percent more clamping area it should have been up to the task.

Your not wrong about the on/off nature of the puck/button setup, and with a slapper bar setup on the back end can be pretty nasty to reverse park, and take off from the lights (shudder, shudder, shudder, slap,slap,slap).

I`m trying to find a good ultra heavy duty pressure plate, I would have thought that the "haichiruko" squad would have plenty of off the self bits, but I can only find them in kits ($450+), ABS said they could get a (heaviest they make: 100 percent extra clamping load) pressure plate made up, but will take a couple of weeks and about ($220 on my door)this might be my only option.

If I get this new pressure plate I`d like to try the standard clutch plate again and use the puck/button plate as a last resort, My old setup in the wagon had a full face style clutch plate (180mm) and never slipped, so maybe a full face (200mm) unit will be upto the task?

It "only" takes a few hours to pull the motor and box, swap clutch kits and get it back in again, But I`m not as young as I once was, and I really know about it the following week.

Could there be a problem with your thrust bearing not allowing the pressure plate to fully engage?

Well, I think I have it all sorted now.
I pulled the motor and box again and fitted a bright pink exeedy brand pressure plate.
I was thinking of using the standard clutch plate but in the end I decided to fit the 4-puck item as I wasn`t keen on pulling the motor and box again if the standard clutch plate was slippy.
I am quite impressed with the reults, the clutch "feel" is really nice, it is a little heavier than before and doesn`t seem to shudder, it still seems to be of a off/on nature (but not as bad as a lot of people would have you belive) when it is on "hold on to your hats" I had forgotten how fast this little rocket really is with "only" 15 psi boost.
I have yet to boost it up in fith gear and i`m not sure if I want to (I have only had my licence back for six months and the old girl didn`t like being locked away in the police impound yard).

I have read various ideas about running/bedding in puck style clutches, some say to "baby" it for 500km or so, others say the the complete oposite and just thrash the hell out of it from day dot?.

Whilst the old girl was off the road I also ditched the slapper/lift bars and fitted the rear springs from the old draggin` wag`n. These springs seem to be somewhat of a custom setup, the springs seem to biased with one being about 1/2-3/4 of an inch lower on one side than the other with different lowering blocks to get it level. Is this some sort of old school drag racing technique to keep the car level off the line?.

Cheers,

G O T H E D A T!!

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Over the years, any solid axle rear will cause the right side left (or coil) to sag more - because every time you accelerate there's some %ag of the force trying to twist the diff, and raise the right rear.

Even with std new springs, this force will lift the right rear and is why you'll see single spinner burnouts almost always only ever being right hand rear. Once you add in some years of use, then that right rear spring has sagged more than the left and so it'll spin up the right rear easier and easier as it progresses ver the years.

As mentioned, even std new springs and level ride height will still experience right rear lifting under acceleration (esp in first, and esp with a setup with probably 3 times the output of any factory engine (maybe more than 3 times).

So - stock springs - spin right rear
more power and stock springs, spin right rear easier.
sagged/used springs spin right rear easier
sagged plus more power, massively right rear spin-up

So the goal, with identical springs, for dragging, would be to run about 0.25-1 inch lowering block on the left hand rear. This would then mean that at a standstill there is a slight bias of downforce - more on the right rear. Then when you launch, it lifts the right rear, but with enough spring bias, you won't raise it to the pint it loses grip, instead, optiamlly, it raises the right to the point that you can get good grip off of both tyres.

Since the springs often have sagged, technically a lowering block wouldn't be needed. What you'd do is simple (some cars it's impossible since springs are mirror images, not identical) - swap over the rear springs left to right and right to left. Automatically has a slight bias of download on the right rear that becomes neutral under launch.

Another thing you can do, possibly combined with this, is to run an air shocker on the right rear, and have dead level springs, for better handling (or more consistent on right and left turns) and just add air to that right rear shock to get the launch perfect. With a bit of trial and error, you could find the pressure that suits.

Very very very generally, you'd not want to use lowering blocks at all, as it raises the axle centreline vs the front spring eye (or pivot point on more complex front spring locators) The lower the axle centreline vs the front spring pivot point, the more it tries to lift the rear/body as it launches, and the body wll attempt to travel rearward/down due to it's own inertia, which basically means that such a rear susp angle leads to the rears being pushed down VERY hard during launch, with maximum loading (remembering there is a difference between where/how the body might roll and where the load/downforce/weight transfer might be targetted.

Even without that, lowering blocks give less support to leaf springs at the axle tube brackets, and move axles away to all conspire to wrapping up the springs/axle tramp.

SO basically the 'go' is to swap rear springs side to side, and generally that does the trick.

Another alternative to an air shocke is a rear sway bar. You can have one adjustment (or disconnect it altogether) on the street, but for the track, you can 'stack' washers and bushes to bias and give more downforce on the right rear.

The point of all this is that even with an LSD or locked diff, there's still some potential to be had from even downforce on the drive wheels under launch, and one of the best ways to sus that out is to test somewhere safely with an open diff, practising launches, and dialling in a touch more preload/added downforce to the right rear, untill it no longer spins the right rear up to buggery (or reduces it to a bare minimum, and then marking/recording this settting and then fitting an LSD or locked centre, you'll get the most out of it.

Cheers jmac,
I`d rather not be using lowering blocks at all, but using the springs from the wag`s made the sedan sit 50+mm higher in the back end due to much more heavy duty springs.
Thanks for the very interesting info, there is a lot of stuff I hadn`t thought about.

G O T H E D A T!!