1973 240z LT1 V8 with 6sp T56
I always wanted a car with classic lines, the sound of a V8 and solid performance. I cant afford a classic GT40, or even an Ultima GTR so I built a car of my own.
I started with the car on the left and ended up with the V8 car on the right. It was in better shape for a short time and in addition to the engine swap had the modified suspension with 240sx rear disks and the 15" wheels.

As you can see it had and incident, I did a lot swearing and then for months I did not touch the car, I felt better than death only because the other party got a fist full of tickets and a day in court. When I had composed myself enough I ended up the car below.

 

It took a few years and lots of encouragement from family and friends, its amazing how the details can drag it out.
I am sure you could build a V8z in a couple of weeks, and some of the guys on the invaluable
HybridZ forum probably have, but for me touching one thing lead to changing something else whilst I was there.

 

SUSPENSION

Lowered, with Tokico 6 way adjustable shocks and 2.5" coil over springs with adjustable perches. The sway bars are 1" front and 3/4 " rear and they had a significant positive impact to the the feel of the car when turning in.

 

The red shock is the original rear shock, as you can see sectioning the strut to take the white 204Z front shock gained me a lot of travel in the rear.
The fronts were also sectioned and use an MR2 shock that gains a slightly smaller amount at the front.

STEERING

My only issues have come from remanurfactured racks, all of which have been uniformly terrible. I think reman means they clean all the oil off and paint them gray. I sent multiple racks back with the same issue, the  on center feeling was of  a big notch in the rack, you could feel it, and this lead to a vague feeling at speed when going straight. A second hand rack from an automatic fixed the problem, its now perfect, and I dont hold the wheel so tight over 120 mph  :-)

BRAKES

The front wheels are 17x8 with 245x17 tires over 13" cobra mustang rotors and calipers.

 

The hubs have been converted to 5 lug from 4 to accommodate 5 spoke wheels patterns.
Rear brakes are converted from drums to good size Nissan 200SX rear rotors with 17x9.5 rear wheels 275x17 Tires.

I am exceptionally happy with the brake feel, although I plan to use the gTech Pro to optimize the bias by measuring the stopping times

TRANSMISSION
A rebuilt T56 6 speed manual gearbox drives a 3.74 R200 with Quaife torsen torque sensing carrier. The drive shaft was custom made and requires selecting the right ends so that it can mate to the R200.
The T56 has the uprated triple syncros and a few other bits. I broke 2nd gear previously and once its apart it just made sense to make it a little stronger.

The LSD is mandatory for this car, the car just doesn't have the weight to stick the HP on the ground.

The Quaife was expensive, but I think its fair to say that as a torque sensing (i.e. no clutches) unit they are considered the best for road racing, and those from Quaife have an enviable reputation.

With the tires finaly managing to hang on the stock diff mount from Datun was way out of its legue, for some reason the Datsun mount sits uonder the diff and when torque is applied it tears the rubber mount apart. What is needed is a mount that puts the rubber mount in compression under load. Ron Tyler it turns out, had already worked out the dimentions for a superb mount that was exactly what I wanted fabricate, so I used 95% of his design, just rounding things and creating a pretter shape on a milling machine for the plates.

Once I had the diff mounted from above, I wanted to retain the now somwhat unessisary lower mount for body stiffness, however as you can see I needed to weld in a plate a little lower in the center to gain clearance for the new top mounting. Not everyone may need to do this, it depends on the pinion angles that are chosen when aligning the drive shaft. For a shaft as short as you end up with using a T56 you need to pay a lot of attention the angles to avoid vibrations.

ENGINE
Is a 1995 LT1, amazingly this fits nicely in the engine bay with minimal trouble, the plumbing, electrical and PCM were much more trouble.

I gutted the un-needed power steering pump to act as an idler and removed the stock air condition pump to clear the frame rail. A Mazda air conditioning pump looks like it fits above the engine and will be used some time. A new shorter belt was all that was needed then.

Home brew intake and radiator shroud, it took a while to make the circular section of the fan shroud with a sheet steel shrinker tool. Fan is a Taurus 2 speed fan, it is incredible how much air this thing can move.

 

Ok, I know K&N filters are not great at filtering (good at flow like they claim though), so I made the intake out of 3.5" pipe and it appears to flow well, matched with the 3" exhaust.

The intake splash guard also took a while with the metal shriker to form the curves out of a single sheet of steel, I used crinkle paint as I think it has a more factory feel, it also has the benefit that the creases from the forming are completely covered.

 

It has a straight though muffler in the center of the car to cut the high frequencies, and a large Dynomax box at the back.
I hope to make a real air box that can take an off the shelf OEM filter from a high horsepower car.

 

The LT1 is close to stock right now, it is supposed to be good for 310hp, it sure feels good! Acceleration is instant except in 6th which pulls 1500-1600ish rpm at about 65-70 mph.

The LT1s computer is OBD1 and my engine came with an OBD1 type connector although some OBD1s came with a OBD2 connector. Since I modified the engine, changing the gear ratios, EGR valve, removed the VATS etc I needed to edit the program in the PCM. I used LT1-Edit .

ELECTRICAL
I rewired the engine in to the Z harness using stock GM style metripac connectors, so all the connections to the engine look factory.

 

I also added Hi amp relays to drive Hella upgraded headlights which give fantastic hi beam visibility without out been stupidly bright, low beam is a little weak though, so I may aim the light up a little.
The Fan also required relays to convert from stock GM wiring which expected two fans to allow it to drive one two speed fan.
Apparently the lo speed pulls 9 amps and the high pulls nearly 40 Amps! again I used com

mercial connectors to assure reliability.

I was having a problem with the new starter clicking and not engaging, I checked all the cables and connections and it was solid. Being that kind of guy I took the starter apart, nothing wrong with it. Then I checked the wiring diagram for the 240, the solonid is driven right off the key! I expect the new solonoid takes more current and the 30+ year old key switch was feeling its age so I added a relay - probelm solved - instant engagement.

BODY WORK
Welding, grinding, welding, phew, this took ages.
The arches are cut from 69 Volkswagen Beetle rear arches, they were an absolute pain, but I wanted an all steel car. In hind sight it may have been better to give up my ideals and use one of the kits such as the subtle Z or other wide body set up.

Note the reinforcing bar used to tie the shell back together after cutting out the existing arches to clear the rear wheels.

The front spoiler started out as an MSA fiberglass item, but to match the much wider arches I had to do quite a bit of work. Fitting the front arches so that the wheels looked good, and allowed them to turn full lock without binding on the air dam or arch took a lot of messing around. I think the 13" rotors fill the wheel nicely though!

Then it had to be painted, above left. note the cut out in the flare to allow the bumper to fit.
The paint was mixed to match the 1973 Datsun orange, the code is 918 orange for a 73, the auto body store had a book listing the color. As you can see the original paint had faded with age.
I recommended spraying the whole car with tinted primer-sealer to get a uniform orange/red shade to the car before applying the color, the color varies shade with whats beneath it otherwise.
You need to put plenty of clear coat on so that you can spend absolutely ages wet sanding it perfectly flat too! but its worth it.

INTERIOR
There are no pictures!
Well right now its used stock, I did all I could to make it look stock as I am not a fan of blue gauges etc.
The seats need recovering and I would like to have a real seat guy sculpt them a little more than stock so that they have the look and feel of a race seat, but will be practical for daily use still.
I also want to put in a roll hoop and a harness just for autocross days.
I will get my butt handed to me by anything I go up against in a competition, but I bet I'm grinning as much as anyone after each run!

MEASURED PERFOMANCE

I tried to calculate the mpg, and I think around town is 14 mpg and highway maybe 20 mpg.

Weight 2604 lbs with no driver: Corners weights are
647 : 655
622 : 680

Gtech pro measures the 0-60 between 4.6 and 4.8 seconds. Car and Driver say Gtech is a credible tool but I want to get a time from a track at some point.

Everything works except AC which will be hooked up over this winter.

I used a cableX to drive the original Z speedo from the T56s electronic output and calibrated it by programming the ECU. The CableX lives up under the dash and works well. The highest indicated speed I have seen is 150 mph, but it was pulling well so I feel 160 mph might be tops.

CALCULATED PERFORMANCE

Calculations from cartest 2000

Time to Speed sec,
0- 30 mph,1.80
0- 40 mph,2.39
0- 50 mph,3.76

0- 60 mph,4.64
0- 70 mph,6.35
0- 80 mph,7.61
0- 90 mph,9.03
0-100 mph,11.49
Top Speed 165 mph

Time to Distance sec,

0- 60 ft,2.15 @ mph,36.12
0- 100 ft,2.81 @ mph,46.10
0- 330 ft,5.63 @ mph,68.12
0- 500 ft,7.25 @ mph,77.19
0- 660 ft,8.58 @ mph,87.08
0-1000 ft,11.08 @ mph,97.82
0-1320 ft(1/4 mile),13.19 @ mph

Conclusion
I can't imagine going thorough all that again! but I just might for a clean silver body shell, this time I would stay with the stock arches and put in a smaller 4 /6 cylinder turbo.

It is a blast to drive, the acceleration shoves you into the seat as you snick through the gears, all the time getting a visual rush as the scenery rips past, and the orchestra plays a wonderful big v8 sound track. Just as much fun as womping on the go pedal is the stop pedal. which just tears speed off in a really impressive reassuring way.

It gets honks, thumbs up and smiles wherever it goes, and my fiance thinks its neat, what more could I ask for!