74_5.0L_Z

I have 245/45/16 Hoosier A3S04 tires on my 16x8 wheels. They were an extremely tight fit under the stock fenders. They fit the wheel very well, but they are a canterlevered design. The car now has the SubtleZ body kit, and I am in the market for some 15x10 or 15x9.5" wheels so that I can run the new 275/35/15 form Hoosier.

Look at these links. They contain some really good info pertaining to the driveshaft parts, pieces, and build-up. http://forums.hybridz.org/showthread.php?t=86748&highlight=Neapco http://forums.hybridz.org/showthread.php?t=65652&highlight=Neapco http://forums.hybridz.org/showthread.php?t=75332&highlight=U-joint Pay special attention to the topic of U-joint alignment as discussed by PPARASKA. If you do not have correct alignment of the U joints, you will experience some bad vibration issues.

Oh come on Rick! You are an instrumetation type guy. Are you so selfish that you are unwilling to put a few small holes in your hood? Hell, look at the hole I put in my hood. You wimp.

The vacuum advance will wake up the engine at low rpms. Generally you just run a vacuum hose from the distributor to the timed spark advance port on the front of the carburetor.

I don't understand why you need spacers if the wheels have a 5" backspace or less. I have two set of wheels for my car 16 x 8 and 15x8. Both sets have 5" backspace. One set has 245/45/16 tires and the other has 245/50/15 tires.

Two years ago we dynoed my buddy's 289 NHRA superstock engine. In his class SSMA he has to run the factory heads and compression (9.0:1). He can however run a huge cam (0.790" lift and 102 degree LCA). On the dyno with race gas we found that 39 degree total was best for our set-up. A street 302/289 would probably also benefit from more than 36 total. Un fortunately, the pump gas will cause the engine to ping/detonate beyond 36 degrees total.

I run mine at 16 initial and 36 total. I have aluminum heads so I can get away with more timing on 93 octane pump gas. When I had the stock iron heads, I ran 14 initial and 34 total. Does you distributor have vacuum advance?

I have been gathering parts to build some 180 degree headers. Terry and I have an advantage because our motors are mounted using a front plate/ mid-plate. The advantage is that the entire under side of the engine is clear. I plan to run the center two tubes from each side under the oil pan to the opposite side collector. By placing the collectors fairly far forward (about even with the starter), I believe that I can get equal length tubes. The tubes that cross under the pan will run parallel to each other in the space between the front and rear sumps of the oil pan. For ease of assembly, I plan to make the section of tubing that passes under the engine removable. The only real downside is that the tube may be a little long (36" -39).

Michael, Variations in the velocity between one run and the next makes sense for the variation in Q(psf). Further, it may be that the spreadsheet whose snapshot I am using as a reference always reports Q(psf) for the velocity of the original test and not for the extrapolated speed. Have you looked at the excel spreadsheet that I put together? Thanks

Michael I ran the numbers for a few test cases. Like you said : Q is the dynamic pressure, 0.5*density*V^2. If the testing were at 80 mph (=117.3 ft/s), at "standard" conditions Q comes out to 16.3 Lbf/ft^2, in the usual engineering units. However, the snapshot that is posted here is for an extrapolated 120mph, and each test configuration listed has a different value of Q(psf). By that I mean test configuration 1 average has a Q(psf)=16.294, test configuration 2 average has a Q(psf)=16.246, test configuration 18 average has a Q(psf)=15.865, etc... If the Q(psf) were as you stated then it would be constant for each configuration because the dynamic pressure is only dependant upon velocity and air density. Thanks for trying though. If you or anyone else are able to discern the physical relationship of Q(psf), let me know and I will incorporate it into the spreadsheet. I should also point out that I was not part of the team that did all the work at the windtunnel. I only endeavored to put this spreadsheet together so that the data would be a little easier to visualize for everyone in the HybridZ community. By doing this, I feel like I am contributing to the aerodynamics effort(I too wish that I could have been there). Thanks, Dan McGrath

Thanks Michael for pointing out what should have been obvious. I was thrown by the definition given in the initial posting of the data: "Q down pressure on entire car measured near center of roof ". I didn't realize that Q was just the denominator of all the Cd,CL, ... equations divided by the area. I was using it all along without using knowing it.

From the snapshot of the aerodynamic results and some basic aerodynamic relationships I was able to reverse engineer all of the lift, and horsepower numbers from the coefficients and vice versa. After I was sure that I had established relationships based in physics that work for all the data, I built a spreadsheet that allows the user to vary the velocity, air density and frontal area and see how it affects all of the test cases. The relationships that I used to go back and forth between the coefficients and the forces are as follows: CL=L / (1/2 x rho x V^2 x A) CD=D / (1/2 x rho x V^2 x A) Cs=S / (1/2 x rho x V^2 x A) CPM=M / (1/2 x rho x V^2 x A x WB) where M = (Lf - Lr) x WB/2 HP = D x V From the data given, I don't have enough information to calculate CYM, CRM and Q(psf). These bits of data would be nice, but they are almost inconsequential to the tests that were performed. The data and graphs are in an excel file that includes an interactive graph. By that I mean that you can select the data that appears on the graph through the use of some dropdown menus. In order for this feature to work properly, you must set your Excel Macro security to medium and allow the application to run the macros. If you don't know the current level of your Excel Macro security, set it to medium as follows: From Excel Select Tools -> Macros -> security and select medium. Do this before trying to run the new spreadsheet. I will gladly accept any feedback for improving this tool and will respond to correct any errors that anyone discovers. Here is the link to the file. It is compressed as a .rar file which is like a .zip file. http://forums.hybridz.org/attachment.php?attachmentid=2961&d=1181700792 The following link is to an application that will open the .rar file. Download winrar http://www.download.com/WinRAR/3000-...ml?tag=lst-0-2 I originally posted this elsewhere but the spreadsheet was buried in the middle of the thread with various pertinant info spread throughout. I felt that it would be more visible and convenient if I started a new thread.

I have made extensive improvements to the excel file, and I have replaced the file above with the new version. It now includes an interactive graph. By that I mean that you can select the data that appears on the graph through the use of some dropdown menus. In order for this feature to work properly, you must set your Excel Macro security to medium and allow the application to run the macros. If you don't know the current level of your Excel Macro security, set it to medium as follows: From Excel Select Tools -> Macros -> security and select medium. Do this before trying to run the new spreadsheet. Again, I will gladly accept any feedback for improving this tool.

I'll fix that. Also, I am working on an improved version that features interactive graphing. I'll post it tonight.

OK guys, I have attached a .rar file with the spreadsheet in my post above. If anyone finds any errors with it, let me know and I will fix it. Thanks, Dan McGrath

From the snapshot and some basic aerodynamic relationships I was able to reverse engineer all of the lift, and horsepower numbers from the coefficients and vice versa. After I was sure that I had established relationships based in physics that work for all the data, I built a spreadsheet that allows the user to vary the velocity, air density and frontal area and see how it affect all of the test cases. I will post this here, and if you inspect it and determine that it does not truly represent the data, I will not be upset if you delete it. The relationships that I used to go back and forth between the coefficients and the forces are as follows: CL=L / (1/2 x rho x V^2 x A) CD=D / (1/2 x rho x V^2 x A) Cs=S / (1/2 x rho x V^2 x A) CPM=M / (1/2 x rho x V^2 x A x WB) where M = (Lf - Lr) x WB/2 HP = D x V From the data given, I don't have enough information to calculate CYM, CRM and Q(psf). These bits of data would be nice, but they are almost inconsequential to the tests that were performed. Wind Tunnel Results.rar

I have nearly finished a spread sheet that will allow the user to vary the velocity, air density, and such and see how each of the test configurations respond. I have completed all of the columns except CYM, CRM, and Q(psf). At first glance, I did not think that I had enough info to complete those columns. Then something occurred to me. So my question is this: Do the numbers in the Pt column correspond to the left and right wheel, and which is which? If that is the case, I will have enough info to complete the spreadsheet. Mikelly, Can I post it here when its complete? I don't think we want it on the downloads page for everone, do we? Would you like to review it first? Oh yeah, for Q(psf), I assume this represents the entire lift force over some reference area. What was the value of the reference area and what is its significance?

Terry, I have Two Romac Dampers. The first is a 0241SA/50 on my current engine, and the second is an 0241SA/28 for the 331 that I am building. I am using the factory bolt/washer to retain them both. The factory washer is 1.75" in diameter and fits into the cavity onto the only flat that is present on either of mine. I would definately reduce the washer such that it sits on the suface nearest the end of the crank. Otherwise, the washer will deform and place radial force on the balancer.

With the velocity and the frontal area known, lift and drag were measured. Then they were able to calculate the lift and drag coefficients from the measured lift and drag as well as the known velocity, air density, and frontal area. The coefficients, frontal area, and how they were affected by the various vehicle configurations is the information that was gathered. With some relatively minor changes, the crew took the Z car from a stock configuration that produced 288 lbs of lift and 309 lbs of drag at 120 mph (set-up 19) to a configuration that produced 108 lbs of downforce with only 275 lbs of drag (set-up 28). And they did all of this with minor add-ons.

The lift coefficient CL relates the Lift to the available momentum of the fluid in a unitless fashion. CL=L/(1/2 x rho x V^2 x A) where L is lift rho is the density of air V is the free stream velocity of the air A is the frontal area As an example from our data, Run 1 lists the following values: L = 323.528 lbf rho at STP = 1.225 kg/m^3 (0.076 lbm/ft^3) V = 120 mph A = 18.5 ft^2 From these values and proper conversion of units, you can solve for CL CL = 323.528 lbf / (1/2 x 0.076 lbm/ft^3 x (120 mph)^2 x 18.5 ft ^2) The numerator of the equation has units of force and CL is a unitless value, therefore the denominator must be manipulated to get units of force. We can do this as follows: (1/2 x 0.076 lbm/ft^3 x (120 mph x 5280/3600)^2 x 18.5 ft ^2 / 32.174 = 678.5 lbf Therefore CL = 323.528 / 678.5 = 0.476 The important thing to realize is that CL is constant, so once determined it can be used to extrapolate values of lift for other velocities. L=CL x (1/2 x rho x V^2 x A) So say we want to know what the lift will be at 150 mph L = .476 x (1/2 x 0.076 lbm/ft^3 x (150 mph x 5280/3600)^2 x 18.5 ft ^2 / 32.174 = 505 lbf The lift at 150 mph for the vehicle in test set-up #1 will be 505 lbs and at 200 mph would be 899 lbs. The other unitless ratios Cd, Cy relate the drag force and yaw force to the same denominator used in the equation for CL.

That water pump has the same pilot diameter as the stock 5.0L. Therefore you should have no problem in that area.

It looks like that water pump will work quite well. It is designed for forward rotation and serpentine pulleys. Go to bed.

The 302 is a 5.0L. Until 1982 all of the 302/5.0L were v belt forward rotation. After 1982 Ford and most other manufacturers went to the serpentine system. The post 1982 water pumps rotate counter-clockwise(opposite direction of the crank). The earlier 302 rotated clockwise (same direction as the crank). If you get the water pump from fordracingparts/summit you will be able to keep your current belt configuration. I believe that will also go a long way toward curing your overheating problem. BTW: What time is it in Kuwait?

On a reverse rotation set-up, the engine rotates clockwise, and the water pump rotates counter-clockwise. If you get an older water pump (1969 ish) and timing chain cover, you can keep your current belt arrangement. Try this: http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=5723