74_5.0L_Z

This was my solution to the whole chassis reinforcement issue:

Thanks, Would you mind clarifying the last sentence? What kind of bad things?

I've been thinking of this topic for several weeks. The people on this forum always seem to read my mind. I began thinking in terms of doing the rear suspension to increase the amount of backspace available in the rear wheel wells. I drew up some ideas, and decided to analyze the suspension I currently had before making modifications. What I came up with is that the front needs alot more help than the rear. The front suspension gains about 0.75 degrees of negative camber per inch of bump, gains positive camber in a deminishing non-linear fashion as the wheel rebounds past the point where the LCA is level, and has a really high KPI (~13.5 degrees) The rear suspension gains about 1.7 degrees of negative camber per inch of bump, and is linear over the entire stroke of the damper. I decided that I will modify the front suspension rather than the rear. I may do the rear later after I have improved the front. What I am trying to decide is how much KPI to design around. I can run a longer upper control arm by using a smaller KPI (5 to 8 degrees), and I feel that a longer UCA is better because the roll center will move around less. I am also trying to decide how tall to make the upright. I am currently leaning towards going with the tallest upright height that will allow the ball joint to fit inside the wheel.

http://forums.hybridz.org/showthread.php?t=75442&highlight=Dynomax

Have you checked out the new XP class in SCCA. This looks like a perfect fit for our Hybridz cars in national level autoX.

I just measured, and my driver's side cylinder head is 1.125 inch from the fire wall. My firewall is unmodified, but you will have to remove the ears from the stock transmission mounts on the body.

I have a 1989 5.0L in my 260Z, and I have been driving it for over five years. The 1989 uses the rear sump type pan. In order to squeeze the engine in to the stock chassis, I had to do a couple of things: First, I moved the oil plug for the front sump from the front corner to the bottom. This gave me ~1/2" additional clearance, and made it possible to remove the drain plug from the front sump. Second, I put a 3/16" plate between the front crossmember and the frame. This created some more clearance. Third, I slightly notched the driver's side of the hood latch to clear the curve of the EFI intake. Fourth (this is important), I installed the engine at a 2.5 degree angle. This required me to adjust the angle of the differential to match. I raised the rear of the differential by removing the washers above the mustache bar. Since the original installation, I have wrecked the car and replaced the front end with a tubular chassis, but the engine is still in the same location (though now mounted using a front plate/mid-plate set-up). Here are some pictures that show the relationship of the harmonic balancer / pan to the steering rack/crossmember.

Just be careful that you have sufficient clearance between the frame and T/C rod after you relocate it. I redid my T/C rods before sectioning my struts, and had no problems for over a year of driving/ autocrossing. I then lowered my car and sectioned the struts. Unfortunately, I did not recheck all my clearances and my tubular T/C rod hit the corner of a plate that I had welded to the bottom of my frame rails(remnants of my old motor mounts). The result was that the dented T/C rod buckled and broke under hard braking on a very tight course. The following picture shows the results of a trip through the mangroves at the Bay Bottom Crawl. The left front fender, hood, and air dam were destroyed. The left side mirror, Quarter emblem, radio antenna, and rear side marker were ripped off the car (and are still somewhere in the mangroves), and left the driver's door with pressure dings. If you look on the ground in front of the car, you can see the failed T/C tube. I have nearly finished repairs (SubtleZ body kit), and have reworked my T/C rods for added clearance. I'll post pictures when I get some.

My 1974 260Z doors weighed 67 lbs each with all the hardware (glass, hinges, door panel, arm rest). I plan to get a second set that will be shells only.

Does this count? I have just a little over 300 hp at the wheels, and have 53.6 percent of the weight on the rear tires with me in the car. The tops of strut tower were moved backwards 3/4" to increase caster. The center of the distributor cap is still behind the center of the strut towers. The back of the driver's side cylinder head is less than one inch from the firewall. The harmonic balancer is just above the steering rack.

What type of distributor/ignition do you have? I have had similar problems to yours when using an old optically fired ignition. The problem was caused when the rotor tip was not properly aligned with the contacts in the distributor cap. At idle it would run fine, then as the engine was placed under a load (and the distributor advanced) the engine would run terribly. You can get into this scenario with crank fired ignitions and other types of ignition that use a distribitor. The way to diagnose this is to rotate the engine by hand with the key ON (ignition energized but not the starter), the distributor cap off, and find where the ignition fires. Mark that point on the distributor housing, and verify that the center of the desired cylinder's electrode on the cap is properly aligned with the leading edge of the rotor tip. If the trailing edge of the rotor is at (or slightly past) the edge of the electrode, then you will have problems when then distributor advances. On small diameter caps, the advancing distributor can cause the distributor to fire the wrong cylinder. Have you checked your timing at 3500 rpms? Is it stable?

When I built my replacement frame rails, I moved my T/C pivot up 3/4" and out 1/4" to mimic the relocation of the LCA pivot point. I replaced the entire front frame with 2.5" square tubing per the original frame dimensions (except the T/C pivot point. I made my clevises from 2" x 3" x 3/16" rectangular tubing. I scribed the outline on one side and located the holes, and had my buddy at the machine shop cut them out. The part that overhangs the inboard side of the frame rails is gusseted from above. I made a fixture to locate the clevises for welding. My reasoning was the same as yours: I didn't want to design an anti-anti-dive front suspension:)

The problem that you are encountering is one of the reasons that I don't like using the lower control arms to adjust camber. I use the camber plates for that. On my car, I have done the front crossmember mod(relocated the hole for the LCA up 3/4" and out 1/4"). This, with the stock length lower control arms, pretty much eliminated bump steer. As a side effect however, it also pretty much decoupled the camber and toe of the car (when adjusting using camber plates). By that, I mean that I can change the camber with very little effect on the toe. On a car where you adjust camber using the lower control arm, you have to realign the toe for even a slight camber adjustment. At one time, I had the eccentric bushing to adjust my front camber. I replaced them after one of the eccentrics rotated during an autocross event. My car all of a sudden went from 2 degree negative camber and 1/8" toe out to 0.5 degrees positive camber (on the RF wheel) and 3/4" toe out. These of course are my own personal opinions, and as such are no better than those of anyone else. Dan

I am glad that you are making some progress, but I see at least one thing that would spoil the final product (for me at least). That C-4 transmission will drive you nuts because it has no overdrive. If you are going to be driving this car on the highway at all, find a transmission that has an overdrive gear, or you will HATE it. My car has the 5.0L and T5 from an 89 Mustang cop car. I am running 3.55 gears, and 245/45/16 tires all the way around. With this combination, 2500 rpms in 5th gear (0.68 to 1) equals 76 mph and 5500 rpms equals 167 mph. In 4th gear 2500 rpms is 51 mph and 5500 rpm is 114 mph. Do you really want to rev that high on the highway? Do you want to be limited to about 120mph? If not, find a transmission with an overdrive. The overdrive will also save gas and reduce the wear on your engine.

My current set-up is pretty mild. I have Edelbrock Performer 5.0 Heads, 1.72 roller rockers, 24# injectors, C&L 73mm MAF, Cobra Intake, Crower 15511 hydraulic roller cam, BBK 65mm TB. The bottom end is bone stock as I recieved it out of a junk yard in 2000. I only replaced the oil pump. I have never even looked at the bearings. On the shelf, I have a PerformerRPM intake and some 30# injectors. I am wanting to put together a 331 stroker with some more compresion and a small solid roller cam (~.600 lift). Before then I am building some custom long tube headers and possibly a custom upper intake. I am contemplating a chip or getting the tweecer RT set-up. By the way, where in central florida are you? We ought to get together. Dan

I am running the stock 5.0L computer(A9P)and wiring harness from a 1993 Mustang. It was really not very hard to wire up. I had expected the installation to be difficult, so I bought Charles Probst's book about Ford EEC-IV fuel injection (great book), and learned all that I could before attempting the install. In hindsight, hooking up the fuel injection has been one of the easiest parts of building my car. If you look back at some of my earliest posts(circa 2000), I gave many of the details for the installation. I love my fuel injection set-up. The Mass Air version from 1989-1993 adapts automatically to most engine modifications.

I too use the Tilton hydraulic TOB and King Cobra clutch. I have about $400.00 in the TOB including a Tilton 7/8" master cylinder. You can see the specifics of my clutch set-up here: http://forums.hybridz.org/showthread.php?t=87797&highlight=Tilton Mike, how have you been? I haven't heard from you in a while. Are you still in the brake business?

Spend the money for a good set of heads. You get more bang for the buck on heads than any other modification. When I upgraded from my stock E7TE heads to the Edelbrock 6037 heads, I gained 10 mph in the quarter mile and dropped nearly a full second (13.20 @ 103 to 12.42 @ 113). I wish that I had spent a bit more and got the AFR 185 heads. The ported explorer heads won't get you the results that you are after. Heads are the first and most important choice for making power. Without a good set of heads, the rest of the modifications are pointless.

I built my tube front end with two criteria: First, I wanted it to be light and strong. Second, I wanted to use the stock (sort of) suspension attach points. Here is my take on it as stated in this thread: http://forums.hybridz.org/showthread.php?t=102715 " My strut bar and the two tubes connecting the main hoop to the strut bar are 1.625 x 0.083. The main hoop, the diagonal, and the bars from the top of the main hoop to the strut bar are 1.625 x 0.120. All of the tubing is 4130N (normalized chromoloy) and is TIG welded. My door bars are 1.625 x 0.120, the hoop at the firewall is 1.625 x 0.083, and most of the front end tubing is 1.625 x 0.065. My subframe is 2.5" square x 0.085 mild steel. All of the tube not specifically designated in this picture are 1.625 x 0.065 " I like to use several thin wall tubes arranged in triangles rather than put a thicker tube in bending. When I cut off the front of the car, I weighed all of the pieces (frame rails, inner fenders, strut towers, radiator core support, etc.). The stock pieces minus the fenders, hood, and headlight buckets weighed 95 lbs. The structure that I replaced it with weighs 45lbs, and is much stronger and stiffer than the stock front end. If you are interested, there are more photos of my cage/front end in my album. By the way, I was inspired by the work of tube80z when I began my tube chassis design. I have since lost the link that showed pictures of his tube chassis.