dat2kman Posted October 23, 2009 Posted October 23, 2009 Any here had experience with this: On my 260/280 race car, I am getting (depends on wheel rim sizes used) a distinct grinding of the inside lip of rim onto the bottom of the tie rod end. At static, there is approx 5mm clearance, bear in mind when looking, from say LHS at wheel, the Tie rod end is at 7 o'clock, this would indicate greater movement at 6 o'clock ( bottom of the rim) than the said 5mm+ ability to grind rim into tie rod. This only occurs when i fit a 15x8 rim with +4 offset ( performance superlights) and I have the AZC bumpsteer/quicksteer knuckles fitted ( yes, no bumpsteer and quicker steering, but it is heavier) I am clearly getting either or both stub axle bending, or, stub/backing to strut tube bottom bending. The struts are about to be "wedged and welded" at the bottoms of the strut to stub backing area. With my Datsun Sports 2000 race car that has factory upper and lower wishbone front, I have had a stub axle snap, caused plenty damage, but the stubs on these are approc a fat thumb in diameter. The Z stibs are much thicker. I now hope much stronger! Question,------- Anyone ever had one snap?? In rally/dirt use I can understand one snapping under severe landing situation, thats expected, it will initiate as a break at the "bottom" of the stub. The Datsun Sports 2000 on, x ray, and x ray of the unbroken other side, showed up that a hairline crack evidence on the TOP of the stub. Ie; due to cornerring forces, the front wheels, due to grip levels of our modern tyres, are being forcibly tucked UNDER the car, thus causing flexing/bending. I have lost approx 1/2 degree of static front Neg camber in two years, using same alignment guy, hence now getting "wedged and welded" Stew Wilkins was a stickler for this on rally Datsuns, not so important on others, maybe we should be looking closer and x-ray testing our 40 year old componentry, only to rplace it with further 40 year old componentry, I turned up steel bushes that fit between the inner bearing races of the outer/inner front wheel bearings for the Dato 2000, maybe a pair for the Z might be in order. Lurch, jump right in here:--- Anyone else??? Quote
NZeder Posted October 23, 2009 Posted October 23, 2009 Not heard of it happening before - however as you state with more modern rubber and track services + I am sure the zeds are going quicker now than they did in the day = more forces etc. I have seen others do the wedge welded in between the strut tube and the stub axle to eliminate this bend/flex as you have found. I did see a pic on the interweb at one point - will see if I can find a sample again. Might be a good idea to do something as I am sure finding replace front struts/stubs will become harder and harder as time goes by. Quote
RB30X Posted October 23, 2009 Posted October 23, 2009 I've only just recently learned of the datsun 2000, they are a serious bit of gear. Have you got some pics of yours?? They must be as rare as hens teeth aye? I want one to stash away in a shed. Quote
PZG302 Posted October 23, 2009 Posted October 23, 2009 Jason, Haven't had any problems with mine running 18x8" rims -2.6 offset with slicks, or the 15x7" rims with toyos, with backspace of about 110mm. Come round and have a look, I haven't had to do anything special yet to the struts other than drop spring seats to lower static ride height and keep the full travel of spring and damper. Neg camber is at about 2 deg without having to worry about bending struts yet, and no problems with bump steer. Quote
C.A.R. Posted October 23, 2009 Posted October 23, 2009 When cornering forces go up, stub axel flex can increase. What your doing/done Jason is about all that you can do. The wedgeing will help as will the stub axel stiffners - the stub stiffners will also help in reduceing pad 'knock-off' Quote
ackent1 Posted November 9, 2009 Posted November 9, 2009 FYI Placing a wedge between the strut tube and the stub axel was standard practice on all of the datsun works rally cars. it consisted of re-enforcing the lower tube and then inserting a plate from the axel across to the re enforced area which ran about 2" up the strut tube In Aussie this work was carried out by Peter Davis, not sure if he's still doing that type of work haven't spoken to him for many years. But this should fix the flexing problem. Quote
dat2kman Posted November 11, 2009 Author Posted November 11, 2009 Am aware of this "fix" in rally cars, it has now been done and tested at Sandown Nov 2009, car has bettr "turn in" and feels more stabe mid corner, lap times were improved to 1.28.2 from 1.29.5 with no other changes. I just wouldnt have belived that we can get as much as 6mm deflection "tuck under" from our stubs The rally mod was to stop the stubs/struts from bending upwards on severe landings. Our old 260Z PRC rally car had that mod, We went on to place 4th O/r in Rally Australia in 1987, and won outright the NSW State Rally Championship in 1988. Very strong car, and it is still surviving!! Quote
PZG302 Posted November 12, 2009 Posted November 12, 2009 Well done on the fix and the improvement in times. Don't s'pose I'll see you at Noosa over the weekend? Heading up tomorrow (Friday) at sparrows to get everything sorted and have a good walk of the track. I should be around most of the day if you want to call in for a cool beverage. Quote
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