Datsun Roadster Forum-311s.org

Rob I am definitely watching and admiring!
I love all of the new cool parts you are installing, when will the cross brace be available to the masses?
Looking forward to more closeup pics of the wheel/tires!

Ok guys about the front cross brace, the cost is $330 AUD and before you all faint let me explain why…..

The brace is made from 1.6mm thick chrome moly tube, it is made in a jig and also pressed so that it is very precise, strong and also light. It is powder coated as well.

As I mentioned earlier the holes need to be elongated slightly depending on the car.

Both Lou Mondello and Hardy Kuhn developed this cross brace, Hardy , who works with Austin Healeys as well as roadsters mentioned to Lou that the big Healeys had a cross brace in the front and that when a brace had broken that the cars felt very sloppy, he felt that the roadsters could benefit from a front brace so they both set to work using Lou’s car as a guinea pig.

They tried maybe 3 versions but like this one the best.

Why it works, so we know that the chassis is the major strength for these cars but the chassis is flat and still flexes corner to corner, the only major strengthening section that stops the chassis flexing is the firewall and some cars will have cracks around the tunnel- firewall junction, so this brace ties the front fenders to the chassis and makes the car feel taut. Because this brace is up the front near the steering it makes the steering feel more precise. I know that this is the case with my car, when I back out of the driveway the car doesn't flex as much, now before I didn't think that my car flexed much but after fitting this I can definitely notice a difference, the steering has half the vagueness that it used to have.

As far as tightening the car goes, you should also tighten up all the chassis – bolts and also all the dash and console bolts as they are structural as well, when they are tight form a more rigid car.

Hardy has made approximately 30 braces, Lou has fitted maybe 18 and sold another 5 or so, when Lou fits one to a car he says to the owner that if after a week they don’t think that it has made any difference he will remove it for them but no-one has removed them.

Rob

Thanks Notoptoy, James, Dave Pa and Ferg02k for your thoughts,

I am glad that you like the photos and what I have been up to.

Alvin, I will post some better pics of the wheels in a few weeks when I have a better pair of wheels on the front.
I got a call today from my wheel guy in Sydney to say that my rims have been polished and he will send them back to me next Monday.

I will have to swap the centers over then have the tyres swapped over and rebalanced.

The front rims are SSR MK2R 15"x6.5" with a +21 offset, they are 25 years old and it has taken a very long time to come up with these from Japan. The ones on the front at the moment are 6.5" with a +34 offset, they are ok just for getting the car around at the moment but the new ones will be 13mm (1/2") further out, meaning the outer lip will be deeper, a better look and only 2mm off what Victor had with his Mk111's.He had +19 offset.
The rears are 15"x7" with a +13 offset.

The tyres are 195, 55, 15 front and back.

Rob

Rob thanks for the brace description, very trick part!
Look forward to the instal pics of the koni's and roll center adjustment

rp975 wrote:The water temp gauge isn't working as well as the fuel gauge so I replaced the water temp sender.

This didn't fix the problem so I will replace the instrument voltage reg with one that Lou modifies with new electronic regulator and see if that helps.

Hi Rob,
The Temp Guage and Fuel Guage are both tied to one of the fuses. When that fuse would go out, the car would not charge either. Be sure that the car is charging as well.

Car looks great.

Ron

I am more interested in the A-arm spacers......

Did you guys ever look at lowering the upper by making an offset pivot or slotting the holes?

Rob, great work on your new car and I'm glad you posted the pics of the rear shoes as mine were mounted wrong. So easy to do cause when one swaps these you think that there's only one way they fit together. I was replacing a broken top spring when I noticed it. They seem to stop better now maybe even better when bedded. They are still rather new.thanks,

Hi Alvin,
I will post some pics of the roll center adjustment when I install them which will be just after I go for registration, they are pretty strict when going for a "blue slip" so I have to have everything just right.

Hi Ron,
Thanks for your comment on how the car looks, and for your help with the instrument problem, we have had the wiring out and replaced the wires that were shorted out, hopefully we have fixed the charging issue, time will tell.
We do have to replace the instrument voltage regulator as it is not working, firstly there was a wire that came from this that was squashed between two metal brackets so we replaced the wire but it needs replacing the unit.Thanks for your help.

fj20spl311,
I will get back to you regarding your question, I will need to look at some things and talk to some people.

nismou20,
You are right, the photos are helpful, I am just passing on information that was given to me, I would have just put them back in the way the old ones came out (an easy mistake) and when I see photos of these rear shoes now I always check to see if they are correct.

Rob

The rear brakes shoes fit either way. What I have been told is that the 'leading' edge should be the 'champhered/angled' one.

Hi Phil,

I put your question to Lou and this is his reply...


Hey Rob/'Guys, the trick here is to move the center of the lower spindle upwards to get a better angle on the lower control arms on a lowered car to lift the roll center above ground. The upper A arm does not influence the roll center a great deal. Hardy made a scale template of the front end and many things were tried to "improve" the geometry on a lowered car. We had a pretty stripped down chassis and did string extensions on the A arms to determine roll centers, instantaneous roll centers etc on lowered cars. We both played around with all of this for a while. A few old race cars here had the top A arm lowered but it went against everything we were trying to achieve. This pushes the roll center slightly more underground on a lowered car. If anything, the top A arm should be moved upwards but as we discovered, the top arm has less bearing on the roll center than the bottom arm. The only thing that i could think of why the upper A arm was moved downwards was to increase negative camber rate/gain on bump. Aside from that, shifting the upper arm has no benefits. The basic design of the entire front end belies its age in terms of location, negative camber gain on bump, lightness vs strength, bump steer , caster, anti dive etc. It certainly can be better in terms of spindle design, moving parts, wearing parts etc but you have to be aware its design is 50 years old.
What all of this measuring and testing proved that at the standard height the roll center was in a pretty good location vs center of gravity. Dropping the car over 1.5" (38mm) threw all of this out the window in terms of roll center being pushed underground, bump steer etc. As soon as the lower control arms are flat or the angle goes the wrong way, the wheels sees a falling spring and shocker rate. It all became apparent when i revisited a race car here in my shop which had 1400lbs front springs. This car had been dropped over 3" (75mm) from the factory ride height many years ago. Even with such huge front spring rates, the car would literally fall over itself when pushed hard into corners. Lifting it almost 2 inches transformed it into a good handling very stable car.
What I'm trying to doing with your car Rob is to get a more correct angle on the lower control arms with your competition springs. Flipping the spindle and spacing them was Hardy's idea and I ran with it making these spacers. This moves the pivot point upwards by 8-9mm. This will lift the ride height slightly but will do wonders to the roll center improving the feel of the turn in, rising shock and spring rate etc.
If you have ever looked at my own car, you will notice its quite high. This is no accident. Best way to lower a car without affecting anything is to use small wheels and tyres but the huge gap over the wheel arch makes people think it does not look "cool" so the dropping of the car inevitably comes next. People tastes are very different as to ride height, wheels, tyres etc but the roll center and bump steer do not care about that......

Knowledge from Lou, cheers Rob

Thanks for the reply.
I knew it was a compromise between lowering the instant center and camber gain on bump.

If I were to have seen your spacers without the description of the installation, I would have made them to raise the lower ball joint to above the A-arm. Of course that would not help because the spacers are on the wrong side on the ball joint.

BTW, My cars are much close to stock ride height for that very reason.

Ok, A few weeks ago I got my rims back from polishing, I then swapped the centers over and had the tyres swapped over as well.

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So these have a +22 offset, so another 12mm or 1/2" deeper rim on the outside, 15"x6.5" with 195 55 15 tyres.



They fit the width of the front flares and do not rub inside when on full lock.



I have also modified the air filter base to fit the Solex ram tubes and also to clear the brake master cylinder, I know I will put quite a few people offside with modifying the air cleaner , but I figure that when the alloy cover is as badly cracked as this one it wouldn't matter so much because no one would have bought it as is or even if repaired no one would want to buy it.





I assembled the two filters with the cover and base off the car and when I held it up to the light there was a slight gap between the two filters, I did not like this idea so I put some household door draft excluder foam between the two filters, this compresses to next to nothing which works great for this application.





I found another issue, the valleys of the inlet manifold were filling up with engine oil, I would clean it out and it would come back. A PO had replaced the top manifold studs for bolts, probably to make it quicker to swap the inlet manifold, so once again Lou had the answer, he sent me some new original studs, nuts and washers. What was happening was that the oil from inside the rocker cover was leaking out through the threads of the bolts and out onto the outside of the manifold. Whereas the original studs have a plain section near the center of the stud with a thicker diameter and a taper on each side, this seals up against the cylinder head.





I removed the bolts one at a time and cleaned out the threads with a solvent ( in this pic it looks like my car is injected!)





I used a thread sealant then installed the studs with two nuts on the ends so you can use a spanner without damaging the studs.



Now it doesn't leak which is great.

I have fitted some led tail lights and a 3rd led tail light strip that tucks under the rear edge of the top boot.





Also some led instrument lights and led strip in the glove-box.





On Friday my car passed a blue slip and then rego so now I can drive it after 6 months of work.

Here is a pic from this morning when my wife and I went out for Sunday breakfast and a drive around the beaches with beautiful weather.



Next up is swap the front Koni's in with the front wishbone spacers, then a front wheel alignment.

I have a little while before the Nationals are on to chase out some of the rattles and squeaks.

Top awesome Rob. I never knew how tight that air cleaner for the sidedraft setup is. That's unreal!
Congrats on your blue slip. Finally you can enjoy your ride. Well done.

Dave

I am so glad I finally got to read this and on such a momentous occasion. I love that pic. It looks as though the car is looking back across the Pacific Ocean to Japan where it originated and saying "Look at me now! I have been around the world and been loved wherever I have been and now I'm about to start a new life in the other hemisphere".
You should be very proud of yourself Rob. You've done some amazing work here. The car looks great and is quite unique, especially here downunder. Good on you.

I love the third brake light and glove box light solution! First class thinking there!!