74_5.0L_Z

Another place to check is the expansion tank behind the passenger side rear wheel well. A bad hose will cause gas vapors or gasoline to get into the car. Those hoses are often badly rotted.

Unless you are running high compression or boost, you don't need anything better than 93 octane unleaded. I have 9.5:1 compression and run 16 degrees initial timing(36 total) without any problem. The leaded should be no problem with the injectors, but the O2 sensors won't like it. I assume you are not runnings catalytic converters.

Unlimited Fiberglass has a direct replacement(bolt on)with no cowl and no louvers. It does however have the factory hump. Reasonably priced too.

Hey Guys, There is a Supra TT powered Z on E-bay. Sweet looking car currently at $9000. It has the later engine.

The mount didn't post like I'd hoped. Email me and I'll send you a drawing.

My motor mounts are different than Alsil's but I think our engines are similarly placed. My transmission mount is similar to the one in the JTR manual. Its made 3/16" x 4" flat stock that is bent as follows: ___ ___ / / ____/ _______/ ____ The two flat sections on the ends go under the floor pan and butt against the inside of the floor supports. Each side has four bolts that go though the floor, and through a doubler plate inside the car. The two humps allow the exhaust to sit level with the floor pan. I believe they are 3" tall by 4.5" wide(at bottom). The Ford rubber tranny mount sits on the center flat section, and is centered left two right. I use a 280z 3 core radiator in my set-up. It keeps the car plenty cool. I am also using the 5.0L clutch fan driven by the motor. The Datsun radiator requires long hoses(the inlet and outlet are on the wrong sides). I deleted my power steering pump, A/C, Smog(I only drive the alternator, and water pump. I still have the 5.0L reverse rotation pump. I would switch to the forward rotation pump to simplify the belts. If you don't you will need to catch the belt with a tensioner on the driver's side of the motor. Make certain you get the smaller 5.0L starter(89 and earlier had a huge starter that won't clear the headers(91? and later use a mini starter that is much smaller and lighter). I use Dynomax blockhugger headers. Some of the others are using different brands. Whichever you decide on, I suggest using the copper header and flange gaskets. Good Luck, Dan McGrath

I took the car the Orlando Speed World last night to see how it runs with the new parts (Heads, Intake, Cam). The first pass I spun hard off the line, backed off the gas, got back into it and ran a 12.97 @ 110.04. Second run, I again spun (not as bad) and ran a 12.82 @ 110.06. Not bad considering the car is set-up for autocross and not the quarter mile. My previous best was a 13.219 @ 103.7 mph with the stock 5.0L engine. With a little traction that speed should put me around 12.5. I weighed the car while there. 2600 total minus me. 1280 on the front tires, 1320 on the rear. That's better than 50% on the rear without me in it.

Pete, Here is where mass comes in. Ftot = m * a = M* dV/dt Ftot = Fr - (1/2* rho * V^2 * Cd * A + Csr * V) = M * a where Fr is the reaction force of the road on the tires Therefore, M * dV/dt = Fr - (1/2* rho * V^2 * Cd * A + Csr * V) or dV/dt = Fr/M -(1/2* rho * V^2 * Cd * A + Csr * V)/M which in the limit that dV/dt = 0 (top speed) reduces to Fr = 1/2* rho * V^2 * Cd * A + Csr * V but Fr = (Teng * GR_t * GR_diff)/tire_dia Your torque to mass ratio determines your acceleration, but doesn't affect the top speed. The only factors that affect top speed are Cd*A, Csr, and HP. These are the relationships I use in the excel application that I sent you. Any chance of posting it.

I have played with the Z car aerodynamic numbers a little bit, and would be interested in other peoples numbers. To begin with, I wanted to get values for the product of drag coefficient and frontal area, and a number for the static rolling resistance. I use the following equation for total drag force(Fd): Fd = 1/2 * rho * V^2 * Cd * A + Csr * V also Fd = M dV/dt where M is the mass of the car. Using this equation and a plot of the 240Z coast down data(1970 Road and Track), I solved for the unknowns Cd*A , and Csr. This is what I got: Cd*A = 5.2 ft^2 Csr = 1.92 Lbf/mph Using the above numbers, and the formula P=F*V, I get 336 RWHP to go 160 mph, and 390 RWHP to go 170 mph.

One thing you should keep in mind is that the mounting for the later ZXs will be different than for the early Zs.

My swap works very well, but I made it unnecessarily complicated. If I were to do it again, I would do some things different. I would place the engine exactly where I have it, but would do my mounts differently. Therefore I haven't wrote up the install. I have describe through various posts the position, and angle of my engine, which components I used for clutch actuation, and which headers, etc... If I ever get my mounts to a point where I think they are optimal, and easily copied then I'll do a write-up.

Scottie, I would love to join you, but all I have are my autocross tires(no street tires yet). I plan to get some new wheels and tires for the street soon. Right now it is only getting driven back and forth to the autocross events.

Thanks for the feedback guys, The engine still has the stock bottom end(untouched with umpteen bazillion miles), but now has Edelbrock performer heads, Crower 15511 cam, 1.72 roller rockers, port matched Cobra intake, 24# injectors, C&L 73mm mass air, and BBK 70mm TB. It probably only makes a little over 300hp(butt dyno) but moves this 260 real fast. You guys with the 400+ motors must really have scary rides. I haven't had the car to the 1/4 since adding the heads, cam, and intake but anticipate 12.20 to 12.30 time at ~112(It ran 13.20s @104 with the stock 5.0). I autocrossed the car the day after I got it back together with the new parts. I raced over a dozen cobra replicas(factory five, ERA, ...) many mustangs, turbo 944s, and others, and got my first Fast Time of Day. On inspection after the race, I discovered that I was running with 0 timing advance.

I have centerline 15 x 8 inch wheels with a 5 in backspace. The tires are 245/50/15 Dunlop SP8000. This combination fits all the way around with stock fenders and coil-overs.

I get to go home to a UPS delivery: New parts for the car . I am getting Edelbock Aluminum Heads, Cobra Intake, 70mm throttle body, and Crower Hydraulic Roller Cam. My car is going to be so happy.

I want to get the FMS RPM extender so that I can control the red line and WOT A/F ratio.

I wanted to match the angle of the engine to the angle of the differential. I settled on 2.5 degrees because any more nose up on the enginecaused the upper intake to hit the latch support. Thd differential angle was almost 5 degrees. To make up the difference, I removed the rubber washer/spacer from above the moustache bar and cut the tube that protrudes through the bushing. The moustache bar is mounted flush against the body, and the differential angle is 2.5 degrees. The tailshaft of the transmission is almost at the same height as the pinion flange, and is 1.5 inches off center to the driver's side(the pinion flange is off center in the chassis, and the output shaft of the tranny is exactly centered in the chassis). There is a side benefit to removing the spacer above the moustache bar and raising the back of the differential: The factory retention strap across the front of the differential is drawn tight. I have only the factory rubber pinion mount, and have no trouble with it tearing. With the differential at the stock angle, there is slop between the retention strap and the differential, and the rubber tears with even the six cylinder.

Dr. Graham, I put the car on stands and leveled it as best I could. I measured the engine angle by using a magnetic based angle finder(Sears $10.95). I place the angle finder on the bottom of the starter housing, and raised the tail of the transmission to get the desired angle. I then constructed the tranny crossmember to maintain that position. Dan McGrath

I have the Outlaw 2800 4 spot calipers on all four wheels. The front have 1.75" pistons, and the rear use 1.38" pistons. The front rotors are 11.5 x 0.81, and the rear are 10.75 x 0.81. I installed a Wilwood Proportioning valve in the rear line, and had to decrease the rear line pressure almost to the limit of the proportioning valve in order to prevent rear wheel lock up. With your set-up, I would install the proportioning valve in the line going to the rear. You just won't need to decrease the rear line pressure as much. When you install the adjustable proportioning valve, be sure to remove the factory propotioning valve. All I did was splice the line where the factory valve was with couplers

I've been autocrossing my car for about 6 months. I'm no expert, but here is my experience thus far. I have 200# springs in the rear and 175# springs in the front. I also have an open differential. The car also has the Suspension Techniques 1.125" sway bar in front and 7/8" in rear. I tried the combination with the rear sway bar attached, and the car easily spun the inside tire. I disabled the rear sway bar, and the rear traction improved dramatically; however, the car now has a slight push. My next step is going to be to go stiffer on the rear springs, and leave the rear sway bar disabled. This is what I suggest for cars with an open diff: 250# rear springs 175# front springs 1.125" front sway bar no rear sway bar

I am running in the Florida State Autocross Championships this weekend. At my local region, I run in Street Mod(SM). At the FSAC this weekend, I'll have to run E Mod(EM). EM is an all out race class. I'm going to get anihilated by the competition, but it should be fun. The course is set-up on the Gainesville Raceway Road course, and has some long straights and sweepers(for an autocross at least). In a few weeks, I hope to run a road course with some guys from the local Porsche club.

I am using the 2800 series calipers up front. I drilled the original holes on the strut and heli-coiled them for 5/16 x 20 bolts. I am using the stage II kit offered by Mike Gibson(scca) on the front of my car. The kit includes 11.5 x 0.81 vented rotors, 2800 series Outlaw calipers(1.75 in piston), and Hawk pads. If you go this route specify Hawk HP-Plus pads and not HPS. The HPS pads fade easily. I have also put 2800 series caliper on the back of the car. On the back, I use 1.38 " pistons). I use a 1985 maxima front rotor on the back. It is 10.75 x 0.875 in(cut down to 0.81). I remove the stock proportioning valve and use a wilwood adjustable unit.

The Pro-stocks may be limited in some aspects, but they are to be admired for the times they run given the rules they must obey. The pro-stockers are limited to 500 cubic inches and no power-adders, yet they run 6.80s at 200+ (consistently). The cars at the World Street Nationals were very impressive because of the variety and horsepower. Most of the cars had in excess of 600 cubic inches and some sort of power adder. The turbo cars were phenomenal. One car had four turbos. The fastest only ran slightly faster than a Pro-stock. The Japanese turbo-cars are impressive but should not be compared to Pro-stocks. There are plenty of NHRA and IHRA classes that are comparable. IHRA Pro-Mod comes to mind.

I have a 1974 260Z with a stock Mustang 5.0L and T5 tranny. The car only runs 13.20s at 104 in the quarter. My times are slow compared to many of the more modified cars on this site. But, a 13.20 quarter mile equates to a 4.6 sec 0 to 60. This speaks volumes about the capabilities of the Z car with even a modest V8.

1974 260Z 1989 5.0L mustang engine and T-5 transmission Stock 5.0 fuel injection Tilton hydraulic throw-out bearing Tilton clutch master C&L 73mm MAF 24# injectors 1.72 roller rockers dynomax block-hugger header dual 2.5" exhaust w/ 2 chamber Flowmaster RCI 16 gallon fuel cell centerline 15x8 (5in backspace wheels) Dunlop 245/50/15 tires GroundControl coilover springs(200#/175# R/F) Koni single adjustable struts Suspension Tecniques sway bars polyurethane everything 11.5 x.81 rotors w/ outlaw 2800 series calipers on front Maxima 10.75 x .81 rotors and outlaw 2800 series calipers on back. adjustable proportioining valve Soon to install Edelbrock Aluminum Heads, Crower cam, Cobra Intake.