260DET

Yes, I was talking with a radiator man who is himself a racer and he said he regularly fixed problem overheaters by modifying single pass radiators to double or triple pass. And that modification alone will usually fix the problem, if the radiator is big enough in the first place. But he did say that the baffles so used must be very securely fixed in place.

What size anti-sway bars do you have at present? Unless my speed reading has failed, possible, there has been no mention of this. Facts, we need facts. Anyway, 22mm front, 20mm rear (stock on my 260) are big enough providing they are poly bushed. Anything bigger than that will tend to bounce the car around. Back when you could get Z competition parts from Nissan the biggest front bar they sold was 23mm, which should tell us something.

He, he, and we went to the local sprints on Saturday, lots of SR20's there but mostly in Silvia's. Those little buggers are quick, too quick. Then there was the Skyline GT-R V spec.......... 8)

Have another glass of wine, or two, instead of pictures.

It is not that hard to make up replacement arms using the original inner threaded tube part and rod ends with the eyes fitted over the original outer spindle pin. I made a jig using some heavy particle board with big nails belted into it at the crucial points. Then it's just a matter of cutting and fitting the various pieces of tube in place ready to be tacked together prior to final welding. The threaded part of the rod ends go through holes in a piece of angle iron which forms the outer part of the arm, parallel to the spindle pin, with nuts on both sides of the angle iron. The outer nuts are half nuts, the inner nuts have a shoulder machined on them which fits in the hole so that the thread is protected. Easy peasy to adjust, using OE inner bushes it's quiet. One of my more successful mini projects. So Jon, you are obviously thinking your idea through and taking your time. But I must say a set of pretty fabricated arms will look a lot better than modified originals, which are none too inspiring in the first place. It is what you really want to do, isn't it. 8)

There are seals in the speedo drive, you have to pull the drive assembly out of the gearbox casing to service it. When you do that though your gearbox oil will run out.

My 260 has a four cylinder FJ20DET engine in it, a mate has a RB30ET in his and there is one around with a RB26DET engine. All are good conversions, it depends what you want but I think most people would be happy with either. The FJ engine is a bit heavier than the SR20, IMHO weight is particularly important in a Z unless the body is strengthened. The FJ engine gives much, much more performance than can ever be used around town, the boost gauge hardly ever goes into +, it is very tractable and will pull well at low rpm particularly under load. And it is economical, except when I let her loose around the track. So if you think that you would like a SR in your Z you very likely will.

That sounds like a great idea Mark. The tape should not attract dirt, like grease does, either.

On the efficiency of stock type aluminium crossflow radiators, the ones with the plastic tanks, I'm getting one which is slightly smaller in area than the OE '77 260Z one, thinner at 35mm, yet 20% more effective. And it is a lot lighter.

Don't do autox myself but to get the back of the car to come round I would increase the rear anti-sway bar size. Its a fairly quick and easy thing to do during a test session, there are several stock sizes to chose from so keeping the cost down and it should not be detrimental to your front end grip. The other alternative along similar lines is to reduce the size of the front sway bar. One thing I would not do is to go bigger than stock sway bars.

Its interesting John that our springs and bars are pretty much the same and the differences are likely due to slightly different total weights and front/rear weight distribution. And mine were arrived at independantly after a process of trial and error. So naturally I support your opinion although the view of a couple of experienced racers is that my setup is not bad at all for ordinary road use as well.

Potentially a big topic. On the sway bars, I have replaced both front and rear stock bushes and retaining brackets with heavier/wider items and strengthened the stock rear bar mounts as well. After a lot of experimentation my front bar is now 22mm dia, the rear 14mm dia which may be a bit light. Track test day coming up so we'll see. My firm conclusion is however that the stock bar bushes are too narrow and too thin in section and consequently allow too much (poly) bush flex and distortion under load which does not allow the bars to work properly. As an example of how complicated suspension setup can be, the rear end of the car was breaking away prematurely. What to do? Got the Koni rear shocks revalved to increase bump significantly and with no other changes rear grip improved dramatically. But its a matter of attending to considering and attending to every suspension component because they all effect handling. Get the basics right and work up from there.

An alternative to using the stock tension rods or modifying them to incorporate a free pivoting arrangement like a rod end is to find heavier stock adjustable rods from another car. For example, in Oz the strut suspension model Ford Falcons have such (adjustable) rods whch can be modified to fit. They are quite a bit heavier in section than the stock Z ones. Of course no matter what rods are used, their ability to pivot freely throughout the suspension movement range should always be checked prior to final installation.

On my '77 model, a larger 2+2 booster bolted straight on IIRC. Don't know about the part # but the 2+2 booster measures around 250mm (10") diameter at the widest part.

Its a bit hard to work out what is happening here. But it seems from the explanation that the wheels are not the problem, the problem is that the car is riding too low causing the body (wheel arches) to sit on the tyres. If that is the situation, from the photos it appears that the threaded sleeves on the struts are fixed too low and/or the springs are too short. Remedy: relocate the sleeves and/or get longer springs. On the wheels though, I would have thought that to fit 17x10" wheels the wheel arches would have to be flared out to provide the required clearance. To check this, remove the spring from one side (with the car jacked up on stands) and with the wheel on use a jack to move the suspension through its normal travel range. This way you will see whether or not the wheel/tyre hits the wheel arch. Best of luck.

Douglas, it is your decision of course but except for a track only car I'd retain the insulators. They do a lot to isolate NVH which can greatly affect driving pleasure.

Someone I know used parts from a Nissan Navara 4x4 three inch diameter driveshaft. But the gearbox he had was ex a Nissan Sylvia which is basically a 280ZX box. Don't have any more info than that.

For brake and suspension info, did you search the Brakes, Wheels, Suspension & Chassis section? There has been a lot of discussion on what you are interested in recently.

Quite impressive, particularly liked the well turned out Z's.

Came across some suspension related stuff, scroll down from the 'New Go-fast Parts for the Flamemobile' part and check it out. Nice photos. http://www.nsxfiles.com/otc0.htm

Make it bump steer IIRC. As a rough guide, the suspension arms and steering links should be parallel to avoid the dreaded bump steer.

Plenty of forum discussion at this site. http://www.eng-tips.com/supportus.cfm Search in particular 'Ackerman Geometry'. A very controversial subject apparently. But the statement which made the most sense to me was that in high speed/g corners anti (reverse) Ackerman produced the best result because the heavier loaded outside tyre could operate at a higher slip angle than the lighter loaded inside tyre.

Thanks all for your useful input. Yes, moving the rack/crossmember forwards/back seems to be the most practical way to change Ackermann on a Z. That would not require a full wheel alignment each time a change is made. Only toe? To do it methodically it looks like you would have to know the various turned front wheel angles (in plan, from above) in relation to the point where they intersect with an imaginary line (in plan) running from the center of the rear 'axle' to the center of the front 'axle'. That is if you have decided what Ackermann variation you want. Alternatively one adjustment could be made at a time and the car tested each time until you get the best result. For doing laps on a sealed surface track I'd guess that having the inside wheel turn just a bit sharper (a couple of degrees?) than the outside would give the best result. The site below has some useful info on Ackermann and other suspension adjustables. http://stockcarproducts.com/techindx.htm

My understanding of the Z steering setup is that if you move the outer tie rod end pivot points forward you will get more Ackerman. Or, to illustrate it another way, you would get more Ackerman if you moved the steering rack back. It appears that the Z originally has 'normal' Ackerman ie the rack is in line with the tie rods. Looking at it from above. That so? So, has anyone done any experimenting in changing Ackerman or got any thoughts on it? More or less Ackerman? Is there anything really to be gained here?