johnc

Beautiful work! Seems a shame to hid it all behind a wheel and tire.

Any radiator you install must not be bolted directly to the front core support. The core support flexes and will slowly tear a part a solidly mounted radiator. Happens much sooner with an aluminum radiator and tank separation is the first sign.

The 240Z does not have a frame. There's not such thing as a frame off restoration on this car. Your idea of using a separate tubular chassis and putting the 240Z body on it can be done, but its hundreds of hours of work to do it correctly and will require a lot of fabrication skills, a surface plate, jigs, etc. My suggestion would be to strip the car down to the bare shell removing everything including the glass and the wiring harness. Mount the shell on a rotisserie and have it media blasted. From that point you can start fixing the rust issues and reinforcing the chassis with seam welding, welded in subframe connectors, tower braces, roll bar, etc. That will give you a strong chassis for anything you want to do in the future.

You can put a sending unit from Summit into that cell. I would also buy a fuel gauge from Summit that works with the sending unit you buy. But, far more important: build a metal cover over that fuel cell that seals it from the passenger compartment. One zoned out old lady rear ending you at a stoplight and you'll get sprayed with fuel. You might survive the impact only to burn to death - which takes a couple minutes and really hurts.

Here in CA that's a $500 car.

Take it down to bare metal and see what you actually have. Ideally you would run the panel over a roller to get more definition of that body line but I think you would have to machine a custom pair of rollers to get the break angle right. That would work for the front fenders and door skins. For the rear fenders you would have to dolly the line or cut the fender off and run it through the bead roller.

Yes.

Now for the mods: 1. LSD should be the first thing. It is the single best mod you can make to improve lap times and handling in a S30. 2. Repalce selected suspension bushings with urethane. You don't need adjustable LCAs to get a good handling car. They do make alignment a bit easier. 3. Springs, shocks, camber plates and anti-roll bars should be done all at once. Coil overs should be where you go based on your past experience and goals. You can do the AZC stuff or build your own from kits I or Ground Control sell. 4. Alignment. Next to the LSD, this is critical to get an S30 handling well. These cars are very sensitive to alignment. 5. Roll bar is a good idea for safety. I do not recommend a full cage in a street driven car. A small accident can become a major concussion. Also, you'll need to upgrade the seats to FIA certified seats if you're going to run a harness. The Scroth 4 point with ASM is a good harness setup for a street track car. 6. Brakes are optional. I've raced SCCA ITS with the stock brakes and, with proper maintenance, pads, and cooling, they work with really good balance. Lots of different upgrades available but most make the brakes very front biased. If you know how to brake well, pick your brake upgrade carefully.

From your post it doesn't appear that you want to be competitive at autocross. Open track events are by nature not competitive. Before you starting thinking about mods, you need to make sure the basic car is safe, sound, and reliable. Get under the car and check the chassis for rust. Fix that first. Make sure the seats and seat mounts are good and solid, check the seat belts and pedals. Make sure the doors close properly and the door locks work. Check the ball joints, tie rods, steering rack, steering shaft and coupler, all the nuts and bolts, brakes, brake lines, wheel bearings, hubs, spindles, seals, engine, trans and diff mounts, shocks, anti-roll bars, bushings, e-brake, and everything else to make sure its all in good working order. Make sure the cooling and oiling systems are good and can handle 30 minutes of track time with half of that time at full throttle. Change all the fluids. Replace all the belts and hoses. Fix any fluid leaks. Do a complete engine tune up including valve adjustment. Go through the engine wiring harness and fix any problems. Make sure the alternator charges. Put covers over the battery terminals. Adjust the clutch. Check the driveshaft and halfshaft u-joints. Bleed the brakes and the clutch. Lube the front suspension and driveline. Once you've done the above you'll have a safe and solid car that can run on a race track for 30 minutes.

Not enough droop travel. You'll have to adjust the ride height up enough to get the roll centers correct in front (LCA pointing down) that you'll only have an inch or two of droop travel before picking a wheel up off the ground in a hard corner. Not an issue for the front but, in back it can lead to: As I posted above, shorten the rears about 1.5".

I have experience installing and using center lock wheels on a Viper GTS-R during the 2000 Rolex 24 Hour race (we finished 7th overall). If its a style thing, go for it. If its a performance thing, they offer no performance advantage other then a quick pit stop. And Mike's cost estimate for the related tools, hubs, etc. is very low. And the Forgeline link is for a styling part. You won't find those things on any serious race car. Too heavy and as mentioned above, another serious point of failure.

I cut as much as 1.75" out for the typical Koni 8610 install. You might have an issue if your tires are taller then 24". You can relocate the inner mounting point for the front LCAs and that will help if your tall. Only cut about 1.5" out of the rear strut tubes.

It really doesn't matter much on a street driven car. Today's oils are so much better then what was available in 1970 that anything you put it will be fine.

The spring have the same number of coils and the same height. Measure the OD of the wire. The stiffer spring has the thicker wire.

With TIG fitup is critical. No gaps wider then the thickness of the filler wire. Cleanliness is also very important especially on the back side of the panels. IMHO, I've found no difference in thin panel warp between MIG and TIG. You do have to a a bit more grinding/cleanup with MIG but the time saved in the actual welding process makes up for that.

FYI... my pics above are an extreme example of Mustang suspension mods for essentially an unlimited class road racer (NASA American Iron eXtreme class). You can make a good handling Fox chassis Mustang for a lot less money and work.

A lot depends on where you want to help your power band. I won't post this stuff on forums anymore because other people are making money on the work I did with Sunbelt years ago.

Looks fine to me.

That's quite a project. Looks great.

Just don't lower it more then a inch. If its got adjustable coil overs, put it at the stock ride height. To fix the front roll center/caster issue you need to swap out the K-member. To fix the rear bind issue you need to install a torque arm or a 5 link. Below are some pics of a complete Griggs setup I did ona customer's NASA AIX racer (a 91 LX):

A '96 convertible should be left stock. Its too heavy and too flexible to respond well to performance suspension mods. Keep it shiny and stock. Both the front and rear suspensions on the SN95 are carryovers from the previous Fox chassis. Roll center and caster problems in front and bind in back. On a lowered car (without any other suspension mods) its a zany, wacky mix of understeer and snap oversteer.

I prefer a single exhaust for engines under 4L. In many cases a single exhaust can help engines over 4L if the tubing diameters are increased. Trans Am race cars that had a 180 degree header setup ran a single 5.5" exhaust through the passenger seat area and out the passenger door. I order merge collectors from SPD all the time. I have a couple different variations depending on your horsepower and torque goals and what you're intended use is.

A nice, simple overview. And this is the best paragraph in the whole article: http://jalopnik.com/5932857/how-to-drive-a-bad-handling-car-fast

Its not ideal but most of the performance from from the header comes from the two merge collectors. I don't know the specific thoughts from the designers but it appears they felt equal length primaries were more important then outlets at the same point. They may have also made the outlet difference enough so that the exhaust pulses merge correctly at whatever final point the system is merged into one. Or maybe they designed it for two exhaust pipes all the way out the back. But... even with the different outlet positions this header made more power on my racing 3L with a single 3" exhaust then any other header tested - although we didn't test the Stahl header.

Think of this place as an advanced automotive site. You should already have the factory service manual for your car, know how to tune it up and keep it running well, have all the necessary tools, and know the names of the parts on the car. This isn't auto shop 101.