bjhines

Here are some pics that really show how far you can go to lighten a chassis like ours.. If you look carefully at the painted pictures.. you can see where tape and paint are sealing some holes... ...

You have to consider where the weight is in the car... I would leave the weight in the bottom of the chassis and start thinking about how you can shave weight off the top... Replace all glass with plastic... Loose the hatch all together... replace with a large thin sheet of poly with aluminum reinforcement...get rid of the top hinges and hinge plates as well.. Most people have to cut some holes in the roof to complete some of the top welds on the cage... you could vac. form a sheet of prepreg CF over the original roof and then cut out all of the sheet metal leaving only the drip rails and the window frames... then bond the CF roof onto what is left... seems easy enough... The doors can be significantly lightened... in many stages... until you just pin a CF door skin to the cage... In fact all of the outer body sheet metal can be replaced with CF skins... trim all of the sheet metal away leaving a "halo" of the original panel to fasten the skin to... Aluminum hardware is light.. but it will cold weld itself eventually and must be drilled out to remove... but many of the bolts can be shortened and lightened... When you get into frame and unibody work... you can pull a lot of reinforcement out of the bumper and front clip areas... Front bumper mount doubler plates and their weld nuts can all be removed... the front lower tie down hooks have LARGE 1/4" thick steel plates welded into the bottom front of the frame rails.... The rear clip can be lightened by removing all of the bumper mount gussets and the center gusset... Remove the hood hinges, door hinges, hatch hinges, rear cargo doors, remove the hood latch plate and the firewall mount, swiss cheese everything.. and then re-seal the body of the car with poly tape and paint... some example pics.. anyhting you add should be lightened wherever possible...

Here you go.. some pics of the mods... I'll add some more later... I used 5/8" HIGH$$$$ rod ends... left and right threads...I hacked off the ends of some old factory tie rods... I machined them down to fit inside the swedged tubes... and I drilled the steering knuckles out for 5/8" bolts... Lemme tell you.. those factory parts are FORGED steel... It took me over an hour to drill those arms out.... It took a while to machine down the ends of the factory tie rods too....

We are shooting for the end of January... with the ability to carry this test out at later dates.. ie. Feb, March... We are hoping for sufficient funding to allow for further development dates later next year... My dream would be a satisfying and promising first date... with follow ups to allow for some pretty sophisticated developments... I think it will take more than one date with our Fairlady to get all the way to home base...

My speedo reads 5 mph over at 35 MPH, 10 over @ 70MPH, 20 over at 140, etc.... That is with stock 1972 240Z drivetrain and speedo gearing on 15x7" rims with 225/50/15 Toyo RA1s... IIRC... my speedo on that run down the Roebling straight is getting to around 145MPH... That is why I called it redline 4th gear... I know it is around 125MPH max... That is with an engine that puts out 160RWHP at 6800RPM... You notice that I am still accelerating fairly rapidly all the way to redline... taller differential gearing with a 5 speed would be the ticket for my car... I do not feel like the car is moving that quickly(125MPH).. it does not feel unstable... Wind in the cockpit with the windows open is not very bad at all... I can just begin to detect lift in the rear over 100MPH... the rear end does not follow the movements of the front end as well at high speed... like it is getting light in the back... as you can see fomr my sig. ... I have no rear spoiler at all... My V-8 track car will be highly modified...

I don't think I am going to quicken my steering for my race car... If I did though... I could buy the factory style forged knuckles.. and then drill them out to 5/8" and use my newly minted custom bumpsteer adjustable tie rods... Or I could buy AZC knuckles and go back to factory tie rods... I am building adjustability into my set up.. I would be stuck with whatever Dave recommends with his set up...

Which leaves this "rebuilding" thing still up in the air... There is a way... we have not found it yet... yet...

This still leaves the problem with matching any new U-joint to the rack pinion... 28 spline 15mm... not gonna happen... unless you make it yourself...

How are you going to attach a newer style joint to the rack input-stub...??

I have pics of my car at speed... My reinforced urethane air dam holds as stiff as any fiberglass dam... I have only the airdam... no other aero mods.. and my car tracks realatively well at 125MPH... This is redline in 4th gear with a 3.54 diff on 225/50/15 tires...

S-30 240Z has 28 spline 0.590 dia. shaft.. this is very close to 19/32" or 0.5937.. I have not found replacement joints yet... but I thought I would stick this in here... I called Borgenson... they have a 15mm 29 spline joint that fits Nissans and Toyota Landcruisers... unfortunately we need 28 splines...

I'm painting mine Ford Mustang Lime Gold Metallic...

The S130 nose is more or less like an S-30 with a Gnose... much lower hood line.... much less air goes into the S-130 nose

Tony D... You have some experience with body modifications for all out speed... What have your experiences told you about the various available parts for the S-30 cars...???

Good Article...... WHY ARE WIDE TIRES BETTER? It has been recognized for about 40 years now that wide tires provide more grip, at least when we are not limited by aquaplaning. One might suppose that this effect would be be well understood by now, on a theoretical level as well as a practical one. Yet the matter seems to be receiving a lot of attention from various authors lately. This seems to be due in part to the need for mathematical tire models to be used in computer simulation. I have encountered the question at least twice in the past month, once in a seminar presented by Paul Haney, based on his recent book about tires, and once in Paul Van Valkenburgh’s November Racecar Engineering column. The issue has also come up in my work as an advisor to the UNC Charlotte Formula SAE team. On the face of it, one might wonder why there is any controversy about this, and also why it took people until the 1960’s to try wide tires. More tire, more rubber on the road. More rubber on the road, more traction – right? Why wouldn’t this be obvious? Essentially, there are two reasons it wasn’t obvious. First, according to Coulomb’s law for dry sliding friction, friction is independent of apparent contact area. It depends instead on the nature of the substances in contact, the normal (perpendicular) force, and nothing else. Second, a tire’s contact patch area theoretically doesn’t vary with its width anyway. If we widen the tread, the contact patch just gets shorter, and the area theoretically stays the same. Let’s consider each of these notions. Coulomb’s law applies quite accurately to hard, dry, clean, smooth surfaces. However, a tire tread is a soft, tough, sometimes tacky substance in contact with a hard, rough surface. When two hard, smooth surfaces are in contact, they actually touch only at a small percentage of their apparent or macroscopic contact area. Friction depends on molecular bonding in the small microscopic contact zones. As normal force increases, the microscopic contact area increases approximately proportionally, and consequently friction is directly proportional to normal force. With rubber on pavement, however, there is not only the usual molecular bonding but also mechanical interlock between the asperities (high points) of the pavement and the compliant rubber. Sliding then involves a combination of shearing the rubber apart and dragging the asperities through it as the rubber reluctantly oozes around the asperities. The interface somewhat resembles a pair of meshing gears. With gears, when we increase the size and number of teeth in mesh, we increase the force required to shear off the teeth. It would be reasonable to expect a similar effect with the interlock between the tread and the pavement. With increasing normal force, this interlock gets deeper, as the asperities are pushed further into the rubber. However, we might reasonably expect that at least beyond a certain point, the asperities are pushed into the rubber to pretty nearly their full depth, and further increase in normal force does not proportionately increase the mechanical interlock. With greater macroscopic contact area, it should take a greater normal force to reach this region of diminishing return. A tire typically does show characteristics that would match this hypothesis. It will often have a range of loadings where its coefficient of friction is almost constant; where friction force is almost directly proportional to normal force. Above this range, the tire exhibits much greater load sensitivity of the coefficient of friction. The curve of friction force as a function of normal force goes up almost as a straight line for a ways, then begins to droop at an increasing rate. Of course, the contact patch does not remain the same macroscopic size as load increases. It grows as we add load. Nevertheless, this contact patch growth is evidently not enough to keep the coefficient of friction constant. The contact patch growth is interesting in itself, and a bit counter-intuitive. A tire can be considered a flexible bladder, inflated to some known pressure, and supporting a load. If such a bladder is extremely limp when uninflated, like a toy balloon, and we inflate it, place it on a smooth, flat surface, and press down on it with a known force, the area of contact with the surface is equal to the normal force divided by the pressure: A = Fn/P. If a tire approximates this behavior, then it follows that the contact patch area depends only on the load or normal force and the inflation pressure. If we make the tire wider, then at any given load and pressure the contact patch doesn’t get bigger, it just gets wider and shorter. Accordingly, much discussion of the reasons a wide tire gives an advantage focuses on reasons we might expect a wider tire to yield greater lateral force than a narrower one, assuming similar construction and identical pressure, tread compound, and load. One theory, advanced by the late Chuck Hallum and evidently picked up by Paul Van Valkenburgh in his recent column, is that a tire is primarily limited by thermodynamics. It generates drag when running at a slip angle. The drag times the speed equals a power consumption, or rate of energy flow. This energy is converted into heat. For the system to be in equilibrium, the heat must be dissipated as fast as it is generated. Even short of the point of true equilibrium, the tread compound needs to be kept below a temperature where it softens to the point of being greasy rather than tacky. If the contact patch is shorter, that means that each square inch of tread surface spends less time getting heated and more time getting cooled. Also, when a tire is operating near its lateral force limit, the front portion of the contact patch is “stuck” to the road and the rear portion is a “slip zone” in which the tread moves across the pavement in a series of slip-and-grip cycles. The slip zone grows as we approach the point of breakaway. Beyond the point of breakaway, the entire contact patch is slip zone. The slip zone generates less force and more heat than the adhering zone. A shorter, wider contact patch is thought to have a larger adhering zone and a smaller slip zone at a given slip angle, and wider tires are also known to reach peak force at smaller slip angles. Therefore, a wider tire is not only better able to manage heat, but also generates less heat at a given lateral force. This all makes sense, but it fails to explain why wide tires give more grip even when stone cold. There is little doubt that they do. If you have a street car with four identical tires, and you replace the rear tires and wheels with ones an inch wider, using the same make and model of tire, with no other changes, the handling balance will shift markedly toward understeer. You will see this effect at all times, from the first turn in a journey to the last. Surely this effect is not coming from heat management. Paul Haney explains this by the larger-adhering-zone theory described above. The tire makes more efficient use of its contact patch, even if the contact patch isn’t larger. As much sense as the above theories make, they ignore some real-world effects that have a bearing on the situation. First of all, the degree to which tires follow the A = Fn/P rule varies considerably. A very flexible tire, at moderate load, may have a contact patch as large as 97% of theoretical. A fairly stiff tire may be well below 80%. We are all aware of run-flat tires currently being sold, which will hold up a Corvette with no inflation pressure at all. As P approaches zero, Fn/P approaches infinity. If A does not approach infinity, and the tire does not go flat, the contact patch area as a percentage of theoretically predicted area approaches zero. One might suppose that the effect of carcass stiffness would be significant mainly in street tires, with run-flats being an unrepresentative extreme. Yet I have seen dramatic differences in carcass rigidity in different makes of racing tires intended for the same application. The Formula SAE car run by the University of North Carolina Charlotte uses 10” wheels. Hoosier and Goodyear both make 6” nominal-width tires for the application. The stiffnesses of these tires differ dramatically. The Hoosiers are much more flexible than the Goodyears. The Goodyears are so stiff that they will support the front of the car (without driver), with little visible deflection, when completely deflated – run-flat racing tires! How closely do these tires approximate A = Fn/P in this load range? Not very closely at all. My point here is that tire stiffness, vertically, laterally, and otherwise, is not purely a function of inflation pressure, so it is a bit risky to try to infer contact patch size from pressure and load. Therefore, we don’t necessarily know that two tires differing only in width do have the same contact patch area at the same inflation pressure and load, or even that tires of the same size do. Anyway, if it is approximately true that A = Fn/P, it follows that a wide tire will have greater vertical stiffness, or tire spring rate, than a narrow one, at any given inflation pressure. It will also have a smaller static deflection at a given load, which is why the contact patch is shorter. The flip side of this is that for a given static deflection or tire spring rate, a wide tire needs a lower inflation pressure. Consequently, if we compare wide and narrow tires at similar static deflection or tire spring rate, rather than similar pressure, they will have similar-length contact patches and the wider one really will have more rubber on the road, just as we would intuitively suppose from looking at them. As we make a tire wider, not only does vertical stiffness increase for a given inflation pressure, so does the tension in the carcass due to inflation pressure. A tire is a form of pressure vessel. We may think of it as a roughly cylindrical tank, bent into a circle to form a donut or torus. Borrowing from the terminology of pressure vessel design, we may speak of the “hoop stress” in the walls: the tensile stress analogous to the load on a barrel hoop. For a given inflation pressure, the hoop stress is directly proportional to the cross-sectional circumference, or mean cross-sectional diameter. When the carcass is under a higher preload, the tire acts stiffer laterally. This effect can easily be seen in bicycle tires. A fat bicycle tire will feel harder to the thumb than a skinny one, at any given pressure. If we try to inflate a mountain bike tire to the pressure we’d use in a narrow road racing tire, the tire will expand its bead off the rim and blow out. So when we compare narrow and wide tires at equal inflation pressures, the wider one will be stiffer laterally as well as vertically, and it will achieve this at no penalty in contact patch size. Finally, there is the question of tread wear. As we have noted, if the contact patch is longer, it has a larger slipping zone near the limit of adhesion, and it also spends a greater portion of each revolution in contact with the road. Not only do these factors influence how hot the tire runs, they also influence how fast it wears. Therefore, assuming good camber control, a wide tire should last longer than a narrow one, with similar tread compound. The astute reader will see where I’m headed with this. If we need to run a given number of laps or miles on a set of tires, then with wider tires we can trade away some of the inherent longevity advantage, and run a softer compound. Okay, summing up, what does a wider tire get us? 1. It runs cooler, and/or 2. it makes more efficient use of its contact patch by having a greater percentage adhering, and/or 3. it can run at lower inflation pressure and therefore actually have a larger contact patch, and/or 4. it can have greater lateral stiffness at a given pressure and therefore keep its tread planted better, and/or 5. it can use a softer, stickier, faster-wearing compound without penalty in longevity. Note that most of these effects in turn play off against each other. We can blend and balance them, and get a tire that is somewhat cooler-running, has a somewhat lower operating pressure and somewhat larger contact patch, has somewhat greater lateral stiffness, and survives long enough with a somewhat stickier compound, all at the same time. That would explain an improvement in grip, wouldn’t it?

I never said they weren't neat... But I am much less inclined to own something because it is rare... in fact as cars become "free" I tend to start aquiring them and messing around with what they can do... Z cars were printed like newspapers... they were all the same except paint color... there are no rare versions that had any real advantages... My perspective matches this site perfectly... I am inclined toward bang for my buck... The Z car is old enough to forgo inspections when liscensed as an Antique... It is sophisticated enough to hang with much newer and more expensive cars... and it has a hood the size of a soccer field.. which means I can easily give it rediculous power... My latest project will be a snarling beast that I can tear up tracks with and still drive to Wal-Mart... LOL... If the Z-car gets hit or finds some Armco barrier.. I can throw another swap meet fender on it for the cost of paint and filler... The thing about the Z cars is.. they have all the benefits of an old car.. with none of the expenses involved... I can still get all the parts.. and we all rob stuff off later cars anyway... The S-30s were light years ahead of the European "classics"... If I had any car to choose to do what I do... there is simply no other choice other than the Z car...

I can't vouch for any marketability of this information... Many publishers test products to draw readership with no involvement from the manufacturers or the distributors of those products... It will be documented with video and pictures... as well as data from the wind tunnel facility... We will document each test accordingly... Remember... this is a test for comparison... any actual data may vary slightly from one wind tunnel design to another... they are all approximations of real world circumstances... so there is only so much hard data to compare against different results at different facilities... To give you an idea of development time that can be involved... many race teams budget for 100 hours of tunnel development at much more expensive facilities... I have talked with the operators at length about what we are trying to accomplish... they feel confident that we can test and compare many of the available options for our cars... We are currently trying to get the logistics sorted out to allow tests on as many different pieces as we can... There are many approaches to aero design... We may try to group our modifications into a street class and a race class... that seems to be the most appropriate way to ensure a large number of people benefit from this experiment...

HS-30H... I have to say that we have all types and years of Alfas running at several of our events... Some are race built.. almost all are modified to at least B-street standards.. all of them seem to miss a lot of sessions... or entire days... The few race built cars are historic racers... they dust em off and run a few laps and then bring em in after 15 minutes to cool off... granted they are EXPENSIVE little hand made things... considering parts are practically nonexistant... I have never had one pass me.. or even stay with me before... not even close.. I can lap most of them several times in 30 min. if they even stay out that long... They do bear the brunt of a lot of jokes.. but they get slaps on the backs for sticking with the neat little things... The Jag 13 was pourpose built to run the Lemans course.. They never won a race at another course... because they could not turn. I do not want to hurt feelings... but I am always surprised at how slow the little BMW2002s and the Alfas, and the Triumphs really are... I guarantee I could smoke em with amost any modern V-6 midsized sedan...

If you have a specific piece you would like us to test... then please prepackage it in some mountable form and we will arrange to have it tested... If you want VGs.. then I suggest you mount them to a sheet of plastic that can be easily attached to the roof or wherever you intend to place them... then I can simply tape it to the test car.... I will be video taping this event... I am trying to talk a professional videographer into helping out for Zero Cost... or just his tapes and comsumables at least...

I can't get to the bottom of mine without removing the drip pan/heat shield... drain or not... It is just as easy to remove the 4 screws and slap a new gasket on there... get the rubber gasket kit if you do this a lot... A proper air cleaner will greatly reduce amount of debris that gets into the float bowls... ...

I figured I would post some pics of the facility.... Aerodyn in Moorsville NC... NASCAR territory... http://www.aerodynwindtunnel.com/ http://www.a2wt.com/ this is the tunnel we will be renting initially... It is their second unit... ....

Hmmm... pictures... You should set your Zoom to full tight(longest distance)... Back away from the car as far as you can to get the front to fill the entire width of the viewfinder... If you have a high resolution 5Mp or better... then you can back up even further until the car only fills half the width of the frame... Shots like this REQUIRE a tripod... set it up and shoot with the timer to avoid disturbing the mount when pushing the button... To make things easier you should use a contrasting backdrop.. this can be done with lighting, placement, or drapery... You will need a FLAT level parking lot and you need a vertical point of reference... like the lower edge in the middle of the windshield... level the car and use a laser level to set the tripod height... set your camera veiwfinder to display the grid... use the grid to level and center your shot on the lower windshield lip... alternately you can use the level bubble on the tripod by roughly setting tripod height and then using the level bubble and height jack until the bubble reads level with the camera lined up on the lower lip of the windshield... By using this method you reduce the angular distortion of the image... this nets good returns up to about 5 car WIDTHS away... any more than that and the distances get much further for similar gains... Getting even more scientific and detail oriented you could grid the front of the car with tape... divide it into 2, 4, 6 or even more individual shots and then spend a lot of time piecing them back together...

Those joints are typical of the type that "beat out"... they must be constantly adjusted and rebuilt... The other consideration is that they are made to give a little... they are designed to allow freedom of movement in all direcitons... they were not designed to maintain race car alignment... And considering they do not use the typical 5/8" and 3/4" bolt sizes that most >2500lb race cars use... they are not very tough... they are probably depending on them breaking to avoid frame damage... the last thing you want on a race car is breakaway suspension parts...

Roodypooh, Thanks for those very well thought out estimates... I need some input on these details... for as many factors as you can come up with... Factor in the addition of a 2.5" dropped body and an airdam, with 10" wide, zero-offset wheels, 275/40/17??? on 17x10 Medium sized sport mirrors on both sides, Mild fender flares (ZG or round)... That would be a good baseline for our ~typical~ car... frontal area is really the most important for this test.. but we need some initial numbers to plug in...

The Lambo is one of my favorites... just because it is so rediculous on the street... I couldn't swear to it.... But I asked the owner what he had done to the fuel injection system...??? IIRC... He told me that it was a Megasquirt system... I know he picked the car up for around $70,000 and spent relatively little $$$ getting it into trackable shape... I do believe he ended up with a BMW a couple of years later... ....