74_5.0L_Z

I too have been working on a 3D cad drawing of Z (260Z). I wrecked my z and destroyed the front unibody (firewall forward), but the rear of the car was untouched. Using the stock chassis drawing, I designed a new frame and cage (16 points) that incorporates all the stock suspension mounting points. I would be happy to donate the drawing to anyone who wants it, and would be happy if someone posted it. Certain elements of my cage design would be easily copied for a less extensive cage. The main hoop sits on the ledge behind the seat as close the rocker panel as physically possible, is tilted back 10 degrees, and runs so close to the B-pillar that a key will not fit between.

My philosophy of building a high performance car is to improve the brakes and suspension before getting too crazy with the power. On my car, I rebuilt all the stock brake system, and added coilovers(200 #/in on rear and 175 #/in on the front) to all four corners with Koni shocks. I then put my fuel injected 5.0L and T5 into the car. Even with the stock 5.0 the car ran like a scalded ape(mid 13's), but the stock brakes were insufficient. Before I added any more power, I added Mike Gibson's(username SCCA) stage II front brakes, my own custom rear setup, and an adjustable proportrioning valve; the car stops very well. After doing brakes, I added aluminum heads, cobra intake 24# injectors... I feel confident that the brakes will be sufficient even if I add two turbos and nitros Get brakes and live longer.

Several of us have already finished what you are proposing. The engine and transmission fit well, and the shifter will come out of the stock hole if the engine is positioned correctly. Your best bet is to use the search option of this forum. There is a wealth of info already posted. Try searching for my posts (username 74_5.0L_Z), or the posts by SCCA, Alsil, Dr Graham, ... We have addressed many of the questions you have, and many you don't even know you need to ask. Good luck, Dan McGrath

I pondered the idea of turbo(s) for a while. I believe that a single T04 would be pretty simple(at least as far as space). Two turbos would take some imagination (at least if you retain the stock wheel wells). I considered mounting the turbos in the wheel well area behind the front tires, and running the exhaust through to the turbos, The outlet of the compressors could run parallel to the tops of the fenders(over the tires) to an intercooler in front of the radiator. All it takes is time and a whole bunch of money. For my purposes(autocross), turbos are not the way to go. The 5.0L can be built up to 400+ horsepower without much effort, and the naturally aspirated torque curve is much more predictable. If you want to drag race it then turbos are hard to beat.

I was going to chime in about sway bar ends as well. What I want are ends that use ball and socket joints (not rod ends) to prevent binding. A site (http://www.8shark.com has them), but they are a little expensive.

With a stock 5.0L and T5 in my 1974 260Z, 3.55 gears and street tires, I ran a 13.70 @ 101. I added 1.7 roller rockers, 24# injectors, and 73 mm MAF and ran 13.20 @ 104. I added Edelbrock Performer Heads, Cobra Intake, Crower 15511 cam and 70mm TB and ran 12.60s @ 112. I haven't touched the bottom end; it probably has 200,000 miles on it. One of these days, I'll build a 331 stoker bottom end.

The front of my pan is slightly behind the crossmember. The harmonic balancer is centered above the rack, and the engine is centered left to right. The centerline of the crank is even with the top of the frame rails. The engine is tipped back at an angle of 2.5 degrees. I can remove the transmission with the engine in the car, but cannot remove some of the bellhousing bolts from the holes until the transmission is tilted downward in the back. If the engine were any higher, then the upper intake (fuel injected) would not have cleared the hood. I weighed the car last time I was at the track. The car weighed 2600 pounds with 16 gallons of fuel. 1320 pounds in the rear, and 1280 in the front. If you want optimal handling, install the engine as far rearward and down as you can.

Thanks Johnc, It is a street / autocross / hope to do the Silver State Classic someday car (Mostly AutoCross). I think I'll stick to paint. Any suggestion?

Last May, I wrecked my Z(sob). I totalled the front end (hood, fenders, unibody from firewall forward). The rear of the car(firewall back), drivetrain, suspension components, etc.. were unharmed. So I decided to put in a full frame extensive cage, and tube font end. I have finished the frame, and have all the tubes cut/ notched. The cage has been weled into sub assemblies that can be removed from the car(for coating before final assembly. What I am trying to decide is whether to paint or to powder coat the cage. I want to coat the sub-assemblies, install them in the car, weld the assemblies together and to the car, then touch up the welded areas. I would like to powder coat, but don't know how to touch up the welds after the stuff is in the car. Have any of you tried to do this. Is it easy to match powder coat with paint? Would I be better off just painting the cage?

I ran 12.70 @ 112 in my non-posi Ford 5.0L/T5 260Z on Street tires (Dunlop SP8000).

I suppose you could use the stock tank. I believe Scotty(GNZ) used one for a while. I removed the stock tank, removed the spare tire well and installed an RCI 16 gallon polyurethane fuel cell centered between the rear frame rails. I didn't use the stock tank for two reasons: First, my stock tank had sat for twelve years with fuel in it (yuk!). Second, I wanted to run dual exhaust(one out each side). If I had it to do again, I would use a better cell (ATI or Fuel Safe), as the poly cells tend to deform. I am using an MSD fuel pump (P/N 5252?). The pump is mounted low in the rear), and is powered by the EEC-IV computer and Ford Fuel pump relay. (important: the inlet of the pump should be at or below the bottom of the tank)

Yes, get a V8 T5, or if you run an automatic run an AOD. If you build a street driven Z that doesn't have overdrive, you will hate driving on the freeway. For example , 24.7" tire 3.545 rear gear, 0.68 5th: 2500 rpm = 76 mph , 3700 rpm = 112 mph, 4500 rpm = 137 mph, 4900 rpm = 150 mph 24.7" tire, 3.545 rear gear, 1 to 1 final drive: 2500 rpm = 52 mph, 3700 rpm =76 mph, and 6200 rpm = 128 mph. Choose wisely

Don't get the six cylinder T-5!!! It will not stand up to even a stock 5.0L. The World Class T-5 is marginal as is. I expect to leave mine in pieces on the track sometime in the future, and then upgrade to a Tremek.

Terry, My T-5 has the 3.35 ,1.99, 1.33, 1, 0.68 ratios, and I am running 24.7 inch tall Kumho Victoracers. I mainly autocross the car, so I spend most of my time in second gear(sometimes on the rev limiter). I would love to get one with ratios like yours. I have pondered the Ford Motorsports T-5 with the 2.95 1st gear, but it also has a 0.63 5th (yuk!!!). The Tremek like Jon has would be a step in the right direction, but I would like a 0.75 - 0.80 5th gear ratio.

I have a 1974 260Z with an fuel injected 5.0L and a T-5 transmission. I have driven the car for two years. When I first put it together, the car had a 3.90 gear. I hated it; first gear was useless. I then put in a 3.545 gear, and was much happier. If I could find one, I would use a 3.36 gear in the rear. With the 3.545 gear, I don't use 1st gear in normal driving. I can easily leave a stop light in second at part throttle, nail the gas when I get to about 20 mph, and roast the tires. In autocross trim,the car runs mid-twelve second quarter miles at 112 mph. So, here is my suggestion: get 3.36 if you can. Otherwise, use the 3.545:1 gears that are readily available in salvage yards.

A popular modification of the Z front end is to relocate the pivot point of the lower control arm upward by 3/4" to improve bump steer. Other side benefits of relocating the pivot point of the lower control arm is to give lowered cars some camber gain, and to raise the roll center. Further camber gain can be accomplished by adding caster so that the wheels gain camber as they are turned.

So far your list looks pretty good. The bump steer mod is 3/4" up, and 1/4" out(no more). If you go out too far out, then the sway bar ends will be misaligned with the hole in the lower control arm, and will cause binding. I modified mine as above, and love it. Bump steer has been virtually eliminated. As far as the 300ZX struts, I don't know. Are they the same diameter/configuration. Most people here are using MR2 strut inserts in their sectioned front strut housings, and 240Z fron inserts in the rear. Ground Control sells Konis that are the correct length for sectioned struts. Your spring rate selection looks good. I am using 250# rear and 200# front. What are you using for sway bars? If you have a posi rear, then use a small rear bar. If you don't have a posi rear, then use no rear sway bar. A rear sway bar will cause oversteer, and reduce traction off corners.

I have a 1989 5.0L/T5 in my 1974 260Z. I used only the engine portion of the Ford harness. The task of wiring it into the Z seemed daunting when I started. So, I bouoght a book to explain how the system works, and that shows the wiring for various years. The best book out is "Ford Fuel Injection & Electronic Engine Control, 1988-1993 "by Charles Probst. It is specific to the EEC-IV from 1989-1993. The book contains simplified wiring diagrams, and does a good job of explaining how every component functions. After reading this book, the wiring for the fuel injection turned out to be about the simplest part of the job. In the end, I used the harness that goes from the computer to the engine, and the harness that goes to the O-2 sensors. You'll need to supply power and ground to the relay that powers the computer. You'll also have to run a wire from the fuel pump relay to the fuel pump. As for a pump, I am using an MSD EFI pump. The pump is cheap (~$110.00 and so far has kept up with 350HP. Mount the pump so that the inlet is at or below the bottom of the fuel tank. These pump push fuel; they do not pull fuel very well. Good Luck, Dan

I used a fuel cell for two reasons. First, the stock tank had sat for 12 years with fuel in it (what a mess). Second, by switching to a cell, I made room for a dual exhaust. I cut out the spare tire well, and centered a 16 gallon cell between the rear frame rails. This gave me room to run a Flowmaster on either side. Also the cell is invisible from the rear because it is level with the bottom of the rear valance. If you get a fuel cell, get an aluminum one or better yet get an ATL ($$$). The polyeurathane ones deform.

The datsun flange uses tiny little u-joints. I started from scratch. I went to orlando driveline specialists. New Ford slip yoke, New Neapco adapter flange, New tube, New spicer u-joints, and balanced for $190.00. Don't scrimp here. Have a new driveshaft built.

Hey Scottie, The frame is welded in place (starts at rear crossmember goes all the way forward. The main hoop of the cage and the bars going rearward are tacked together. The door bars are notched(an x), and the holes are cut in the firewall. I now have to finish the tubing ahead of the firewall. I hope to have the car at the welder's in about 2-3 weeks for the final welding. The cage is 1 5/8" chromolly tubing. The main hoop and door bars are 0.120 wall the rest is 0.065 wall. From the welder, it goes to the paint shop. Dan

There are at least three of us on this board that have the late model 5.0L in our Z(Mike Gibson (scca), Alsil and myself). My combination is a 1974 260Z with a 1989 5.0L and T5 tranny. My 5.0L has edelbrock aluminum heads, Cobra Intake, 24# injectors, 73mm MAF, 70mm TB, Crower 15511 cam, FMS E351 1.72 roller rocker arms. My car has the Outlaw Calipers and Ground Control Coil-overs on all four corners. I use the car for Autocross mostly, but also run mid 12s at 112 mph. Look at Mike's (scca) site for good pictures of engine placement. Good Luck Dan

I recently built a complete frame for my 260Z. The bolt holes are at the edge of the frame as you and pete have already discovered. I built the front portion of my frame to the 260Z drawing, and ended up with the crossmember in the wrong place. The 260Z and 280Z drawings disagree. I believe the 280Z drawing to be correct (at least in the fore/aft placement of the crossmember). How far from the firewall are you placing the rear bolt of the front crossmember? I have had others measure and report a distance of 19 7/8" and 20". Pete, where did you place the crossmember holes? Dan

Thanks Guys, By your measurements, the dimension on the Nissan 260Z drawing is ~1.5 inches wrong, and the 280Z drawing is correct. I did consider going to a nonparallel, unequal length double wishbone suspension. Never heard it called SLA. However, I already have the complete adjustable coilovers, camber plates, konis, and Outlaw Brake setup, and wanted to reuse them. Dan

Anyone get a measurement yet?