74_5.0L_Z

I used an EZ 14 circuit harness mounted on the top of the driveshaft tunnel near the firewall. Mine is strictly a race car (no radio, no Heat/AC, no windshield wipers, etc...). I use a modified ford engine wiring harness between the ECM and engine while the EZ harness supplies all of the other body functions (ignition switch, brake lights, tail lights, gauge illumination, etc..) as well as power to the ECM and fuel pump. I like the compact fuse panel and the 175 amp circuit breaker that come with the kit. It definitely made it easy to clean up the wiring.

Where are you getting contact? Tire to fender lip or tire to strut? With 17" wheels and coil-overs, you should be able to run more than -20mm offset. That equates to 4.46" backspace I run 8" springs, but my rear spring rate is 400 lb/in (probably not street friendly). With 15" wheels, I could run 5.5 inch backspace. With 17"wheels, you could get away with 5.75" backspace. Its always better to have more backspace than you can use because you can compensate with spacers. If you don't have enough backspace then there is no way to adjust besides getting different wheels. I use 5.25 backspace on all four corners, but only use spacers (1/4") on the front.

What are you using the car for (street, drag strip, track days,...)? What size tire are you trying to fit? If you choose the right wheel diameter and backspace, contact of the strut tube is not the limiting factor. On the rear, if you have coil-overs, you can run at least 5" of back space with a 15" diameter wheel. I run 15 x 10 wheels with 5.25" back space. With Hoosier 275/35-15 tires I have about 1/2" clearance at the strut tube. As you increase the wheel diameter to 17 or 18", you can increase the backspace of the wheel. The inner wheel tub is the limiting factor for modern (17", 18") diameter wheels.

Do you have the vacuum hose connected to the booster on the brakes? If so, disconnect it and plug it. You may have a big vacuum leak internal to the booster.

You will loose camber gain.

When I designed my new cross-member, I added notches to positively locate it laterally relative to the frame. The bolts don't take any shear load.

With the mount arranged horizontally like that, you are putting a bending moment into the side of the block. The lower bolts at the block are in tension, and the upper edge of the mounting plate is trying to push into the block. Typically, the mount is angled normal to the face of the block to assure that the mounts don't apply bending loads.

I haven't had issues with it, but I do want to add a locking mechanism to support lateral loads trying to separate the rack tube from the rack pinion housing. Right now the engine is out of the car, so it might be a good time to revisit. An even better solution would be a nice Woodward rack. Do you have one I can borrow😀?

You could try making your own cross-member like I did. The other thing that you can do is move the whole cross-member forward so that the engine drops in behind. This will also add caster and require custom T/C rods. crossmember.pdf

https://www.classiczcars.com/forums/topic/48621-steering-rack-disassembly-and-refurb/?&page=4#comments

It is offset toward the passenger side (I think the offset is about 3/4"). Duplicate that as much as possible to minimize driveshaft angle as seen from above.

My posts in the thread above show the fitment.

The dimensions for the bar above were for an S30. The original installation was in a 1974 260Z.

I think you would be better off creating an SLA front suspension rather than the double ball joint set-up. Alternatively, have you considered putting narrower front wheels / tire on the car and using longer lower control arms to push them out to the width of your fenders. You would of course have to relocate the top of the strut outboard by a distance similar to the added length of the lower control arms. The factory LCA is ~11.3 long center to center. You currently have 15x14 wheels with essentially a 4" backspace. I would go to a 15 x 11 with a 5.5 inch backspace and make some LCAs about 16 inches center to center. Which ever avenue you pursue, I am watching eagerly and would be willing to provide any help I am able.

I used the gorilla lugs for several years (black 7075 aluminum) and had no problem. I used P/N 44037B because I have replaced all of my wheel studs with M12 x 1.5 ARP. If you have stock wheel studs then you need M12 x 1.25 threads. However, when I started doing track days I bought a good set of steel lugs.

Unfortunately, it is really hard to get more than about 5 degrees on an S30 without major modifications. I'm at about 6.5 degrees and I have moved my cross-member forward and the top of the struts backward. Yes you do get benefit from the effort. Just know that there is a lot involved in getting it right. This is what 6.5 degrees looks like in side view.

For a street driven car, I would say dial in as much caster as possible without having clearance or binding problems. Unfortunately, adding caster is difficult to do correctly. If you add caster by lengthening the T/C rod then you have to have spherical bearings at the LCA to cross-member connection to avoid binding. You have to push the lower ball joint forward 1.25 " to get 6.4 degrees of caster. Because the LCA attachment to the cross-member is fixed, the LCA becomes angled forward pretty significantly as seen from above (See attached image). I used to set the car up with the control arms angled forward, but that causes other issues. The angled LCA causes loss of static camber. With camber plates you can compensate, but that is a band-aid. Another issue to deal with when you angle the arm forward is clearance between the tire and frame and tire and forward section of fender. Again, things that can be dealt with but have to be considered. In my current set-up, I moved the top of the strut back 3/4", lengthened the T/C rod to move the lower ball joint forward ~.5 inches, and made a cross-member that relocates the LCA attach point forward so that the LCA is perpendicular to the chassis center line at my desired caster.

I think there are a lot of variables. The factory ALWAYS designs cars to understeer at the limit. That means that they always want the front suspension to reach its traction limit before the rear. Many newer sports cars have an SLA front suspension and a strut rear suspension, or they have struts at all four corners with tons of front caster. The SLA will almost always have more camber gain than a strut set-up, so the designers may be adding rear camber so that the rear will be optimized relative to the front at the lateral limit. Likewise, the newer front strut designs utilize a ton of caster compared to older designs. The added caster adds camber gain to the front wheels as steering angle is applied. So again, the rear needs added camber to match the front when both ends are near their limit of traction. The S30 is different than the newer designs (at least in stock form). The rear struts have more camber gain than the front (the fronts have about .5 degrees per inch of travel, and the rear have about 0.75 degrees per in of travel). You can see this on a lowered Z with stock suspension: The rear gains a lot of negative camber, but the front gains very little. Also, the stock front caster is really low compared to newer designs (<3 degrees), so there is no camber gain as the wheel is turned. If you add significant caster to the front of an S30 (>6 degrees), then you get the benefits of camber gain as the wheel is turned. You can then run less static camber, and you can run almost equal camber front and rear. I run 6.5 degrees caster and -1.8 degrees camber up front. I run -1.5 degrees camber in the rear.

Thanks for the info. If I could time warp back to 1982, I could go buy one. It would be nice to find one someone has laying around.

I am looking for a 22 mm front sway bar. The bar can be originally intended for the S30 or from something else as long as it is compatible. I may have to modify it regardless.

Does anyone know of a readily available 22mm sway bar that fits the S30? I already have 18 mm, 20 mm, and 25.4 mm sway bars. I currently have the 20 mm bar installed and would like to add a little more front roll stiffness without adding additional spring rate. I know from previous use the 25.4 mm bar is too stiff for my needs.

Is the drivetrain (engine/transmission) installed? It will ride high if there is no weight in the front.

Here is a good link that covers the gear ratios and rated torque capacity of the mustang T5. http://www.allfordmustangs.com/Detailed/349.shtml You will notice that all the T5s for the 3.8 V6 were rated at 265 lb-ft of torque while the V8 World Class T5s were rated at 300 to 330 lb-ft. If you go with the GForce or Astro Performance gears and shafts then you can get 500+ lb-ft of torque capacity. Also the V6 T5s have the crappy 3.35 to 1 1st gear.

You need the V8 version period. At a minimum, you should get the T5Z transmission. You can buy them new or get a good one from Astro Performance. For the Z car, gear ratio selection is paramount to making a fun driving car. When I first built my car(circa 2001), I used a stock T5 from a Mustang police car and it had the following gear ratios: 1st: 3.35 to 1 2nd: 1.99 to 1 3rd: 1.33 to 1 4th: 1 to 1 5th: 0.67 to 1 It held up decently behind a stock 5.0L, but I hated 1st gear. At the time I had a 3.54 rear gear and ran 24.7 tall tires, but 1st was uselessly short. In street driving, I just generally started off in second gear. Later when I upgraded to a 331 stroker making 400 hp / 400 tq at the wheels, the stock T5 died a very quick death (during an autocross I sheared all of the teeth off second gear coming off a corner). When I pulled the transmission I discovered that I had also twisted the input shaft and output shaft as well as the stock slip yoke. So, I upgraded to Gforce gears and shafts. At the time I was only autocrossing, so I opted for the stock fifth gear. The new gear ratios were as follows: 1st: 2.94 to 1 2nd: 1.94 to 1 3rd: 1.33 to 1 4th: 1 to 1 5th: 0.59 to 1 I really liked the new 1st gear, especially with the new 3.36 rear end that I installed at about the same time. Unfortunately, when I started doing track days instead of autocross, I really hated 5th gear. The 4 to 5 shift dropped the rpms way too much and totally killed acceleration. So I pulled the transmission and installed the S80 fifth gear set from Modern Driveline (0.80 to 1). I now really love fifth gear. It pulls like a freight train all the way to redline in fifth now, but it might not be a good choice for a street car. My recommendation is this: If you plan to build any significant power then pony up for an Astro Performance A5 with the following gear ratios: 1st: 2.94 to 1 2nd: 1.94 to 1 3rd: 1.33 to 1 4th: 1 to 1 5th: 0.80 to 1 Be aware that the GForce and AstroPerformance T5s use a 26 spline input shaft and will require a different clutch disk. The stock input shaft is a 10 spline.

I have been considering building a cradle for the back of my car, and building a tri-link style rear suspension. It is one of the million things on my to do list....