260DET

Sorry Mike, someone has borrowed the scanner. But the setup is quite simple. Because the car is also driven on the road, the front air dam is mounted so that its bottom is a bit higher than the front (removable) X member. Which gives the pan a 'down at the rear' slightly convex curved slope when it is attached to those two items and to the radiator support (fixed) X member The splitter, as a horizontal forward extension of the pan, projects in front of the dam by only about 50mm (2") for road safety reasons. The setup is deliberately limited in its design for road clearance purposes eg the pan does not have downward facing lips along the two sides to better contain and channel air flow. One thing not mentioned before is that the adjustable suspension heights are set up to give just a bit of rake, about 20mm (3/4").

My car has a pan from the bottom of the front spoiler to the back of the engine. It is higher from the ground at the front than the rear. The theory for that is the venturi effect, where air is forced into a narrowing space it speeds up and loses some pressure. The front edge of the pan actually projects forward in front of the spoiler to form a horizontal splitter. That, in theory, reduces the amount of air flowing under the car. The less air under the car the lower the air pressure under there. When driving on public roads, the sharp edge of the splitter is covered with a piece of clip on rubber strip for safety reasons. Now I have only reached around 200kph (110mph) or so on the track but the car is rock solid with absolutely no nose lift. There is a bit more detail in what has been done overall, eg spring rates, rear spoiler, but basically thats it for the front. PS Nearly forgot. The bonnet has two air exit vents towards the rear. The reasons for that are to- reduce the amount of air going under the car, to spoil the airflow over the rear of the bonnet and so reduce potential lift there, and, as a engine cooling aid.

My mates car has a RB30ET engine with air con. With him sitting in the car it is just slightly heavier in the front.

Good thinking, Douglas. The donor Xmember could be cut and shut to widen it if required.

If you are fitting a SR20 engine you may like to consider your diff and gearbox 5th gear ratio too, assuming you are using the SR20 5 speed gearbox, as they all affect the speedo. I have the great FJ20DET engine and gearbox in my '77 and run a 3.9 R200 LSD and 15X7" wheels. There is a formula for calculating what you need, tyre suppliers should be able to provide you with your tyre diameter/circumferance to include in the calculation.

Thanks muchly for the links. The Arizona set up looks quite good except that it seems while toe may be adjustable without any disassembly, camber is not. I'd guess that you would have to use a sliding clamp to connect a sway bar, too. But for my purposes the Arizona approach indicates that using rod ends as they have is a sound engineering practice. I hope. The set up shown on your link peej410 would, as you say, not allow any significant toe adjustment.

My '77 model has the heavier strut tubes. It also had thicker top rubber mounts at the rear which were replaced with earlier 240 mounts so as to give more bump travel with a lowered suspension.

In order to have adjustable rear camber, I am in the process of designing replacement wishbones (transverse links). The idea is to use the stock inner threaded tubes and their rubber mounts, together with two rod ends on the outer shaft which locates in the hub. The eyes of the rod ends would locate on the stock outer shaft. So the threaded part of the rod ends would point inwards at 90 degrees to the wheels. From an engineering point of view, is it OK to use rod ends in this way, keeping in mind that the rod ends will not be angled in the direction of travel? From a practical point of view, the proposal seems quite workable, using structural steel pipe to make the basic wishbones.

For autocross with a V8 you will need new, heavier springs so the ride height will almost certainly change. Coilovers therefore are a good investment as are adjustable shocks. Spring rates with a V8? Dunno, but with my probably lighter engined car I'm happy with 250 pound linear springs on the front. With adjustable Koni shocks set at the softest setting it rides quite ok on the road, firm but not rough.

As has already been said, there are the named experts here with their proven products. So I'll keep out of it, except to say that the original type strut suspension can be made to work very, very well at a reasonable cost. I have seen lots of highly competitive track and rally Z cars and they all retain the original type strut suspension.

So what are the figures applicable to? Camber, caster, toe? The latter is a measurement eg inches/mm, the first two are expressed in degrees. Anyway, some negative camber is a good thing, front and back, particularly if you drive it fairly hard and a little inside tyre wear is acceptable.

A large, strongly mounted FRONT sway bar helps a lot. IMHO the stock Z front sway bar mounts are not strong enough. Unless for some reason you want the rear to lose grip when cornering hard fairly readily, I would not use a rear sway bar. Concentrate on improving the front suspension first anyway, good shocks and some negative camber at least.

You may do better by asking specific questions as the queries arise. There are plenty of knowledgable and helpful people around here but I for one am not clear on exactly what it is you want advice on.

With stock front suspension, the only 'alignment' that can be done is toe adjustment. Both camber and caster are not adjustable. But your problem could be caused by shot tension rod bushes ie the rubber pads at the rear end of the tension rod body mountings. Replace them with poly equivalents if in doubt, they should not be expensive, unless you are sure on inspection that they are OK.

Having tried Hawke blacks, I think that they are terrible. After fitting a set of fronts I drove around the block. They squealed like a banshee when cold and were no better when warmed up. And they started to rip hell out of the rotors.

Any suspension work may alter the settings, including the fitting of new ball joints. In Oz a full wheel alignment cost me A$38, around US$20. Money well spent IMHO.

Perhaps a silly question, but have you actually had it checked on a wheel aligner? Visual estimations can be misleading. Anyway, what I would do is to have it checked and make a note of the various settings. Then take it from there. On my understanding, both rear wheels should toe out slightly and camber can be altered by bending the strut tubes in place using a special tool. But obviously get pro advice on that, preferably from someone who sets up car suspensions for competition purposes.

The reason why I specifically mentioned the Toyo RA1 tyres is because the factory say that these tyres work best with around 3 degrees negative camber. Certainly going from 2.2 to 3 made a lot of difference, although there were other changes made as well at the same time. Now I have to work at using more accelerator input during the steering process. Hell this is fun

Having moved the front X member 15mm forward, the max caster that could be obtained was 1.2 degrees with the existing adjustable tension rods. So it was set up with 3 degrees negative camber and 2mm toe in. On a sealed racing circuit and using Toyo RA1 tyres the car handled beautifully. Turn in was good and there was no instability down the straight or otherwise. In fact I got her into a controlled 4 wheel drift at 140kph once. So, rather than get another set of adjustable tension rods for more caster, I'm thinking of leaving it as is. Anyone else had a similar experience? Comments?

A decent brake upgrade will be expensive so an 'off the shelf' conversion may be the way to go. Just make sure that it is big enough for your purposes eg with most 15" wheels you can fit up to a 295mm diameter rotor and with the Nissan 4 spots that will be big enough for most. The R32/Z32 280mm diameter rotors would also be OK but 'biggest is best' IMHO.

'day fellow Aussie. Is the R33 4WD? If so a friend of mine looked at what you are proposing and concluded that new made up hubs would be required. He is still looking at various options, none of which are bolt on. The Nissan 4 spot front calipers are good though. Lots of pads available for them too. Once again, not bolt on. I use U12 Bluebird calipers and Z31 4 stud solid rotors on the rear. The rotors bolt on, the calipers, no. Let us know what works out.

There has been quite a few posts fairly recently on most of the various points you have mnentioned. From what I recall, for Autocross you need a lot of caster on the front and not so much camber. Keeping in mind that when you use a lot of steering input, caster creates more negative camber. But a lot of caster tends to make the steering heavy. The yellow Koni's are a good value for money shock in my experience. Have seen late Toyota MR2 cartridges mentioned as being suitable. I use 250 lb springs all round for race circuit and road use but I have no experience with autocross, so be warned.

All the above, plus if you can't get a helper, use a suitable length piece of wood to apply pressure to the pedal once you have pumped it a few times. Rest the back of the stick against the X member under the front of the seat. Plus, after the initial bleed and if the pedal is not solid, come back next day and bleed again, just a couple of bleeds at each point. This usually gets a few bubbles of air out and can make the difference between a reasonable pedal and a solid one.

After doing a short road test the results so far are excellent. Nice high pedal with just right for me boost from the 2+2 booster. Ended up removing the residual pressure valve from the rear (disc) brake outlet port as well, because the back pads were dragging a bit. The real test will be in a few days. A fair drive to a racing circuit and a few laps there.

Thanks Steve. Now I have obtained a new iron bodied 1" (25.4mm) master cylinder from the local Z car specialist that bolts straight on to the 240/260 booster although I use the larger 2+2 booster. But the box it came in had no ID so I don't know what it was originally made for, sorry. However this mc had residual pressure valves in both outlets which resulted in the replacement front 4 spot Nissan Z32 calipers binding. So the valve for the fronts has been replaced with a non residual pressure valve from a 15/16" 280ZX mc. Which goes to show that if you can buy a proven brake upgrade kit you may save yourself a lot of stuffing around. Should be able to do a road test in a day or so.