rudypoochris

You are talking about modifying the mu of the two materials. I am talking about widening the area of contact between the two materials. John, sorry I should have been more clear. I am refering to tire width only. Same OD. The tires for this debate are meant to have no effect on aerodynamics.

BJ I am not qualified to tell you how much frontal area there is on a Z simply because I asked someone to take a FSM picture which may or may not be correctly scared and basically count squares (using the comp) with AutoCAD. The result is posted in post #17 of this thread thanks to JIM. The numbers seem high, 17.78 for no wheels just car. With airdam the guestimate is somewhere between 20-21. Multiply that by .43/.46 not even sure which it is, and your answer is recieved. Ah HA! It is not that simple though. Since when you add on an airdamn and such the coefficent of drag is infact changed. Not sure if the number goes up or down. Now that is all up to you.

This is a harry one. So does having a larger tire and pulling 1.0g's compared to smaller and pulling .8g's mean there is more friction? Or is it the same? Thats basically what it comes down to. Or is that just a question that us mere mortals cannot solve at the moment?

Thats some good insight. The majority of the debate comes from the approximation for friction where: F = mu*R Where F is the frictional force, mu is the coefficent, and then R is the reaction force normal (I believe its called). Basically one argument is that contact area does not matter because there is no area in that equation. The other argument is that that function only works for non static friction and that that formula is an inaccurate example when it comes to tires. If one car pulls 1.0g's with large tires, and then pulls .8g's with smaller tires, can it be stated that larger tires create more friction with the road surface since they resist more force?

So basically my friend and I are having a debate whether or not the size of a tires contact patch affects friction when not sliding. At full grip is friction more with a larger contact area than with a smaller one? wikipedia says that contact patch does matter when not sliding, but can someone please verify this or add some insight, thanks!

Maybe someone can CAD in a picture of the Z's frontal area from the FSM (http://album.hybridz.org/showphoto.php?photo=2123&size=big&cat=) and somehow calculate the total area in sqft. I could put it into AutoCAD, but I don't know how to count the units up. 14-15 units looks like a good guess though, in any case it still is not as bad as one might initially think.

I believe the heat build up and the aero have alot to do incommon. Simply because the air under the hood is not evacuated effectively which causes it to back up the flow infront of the radiator and create a high pressure zone under the hood. High pressure means the air isn't going to want to flow through the radiator as easily and to an extent lift will be created. Atleast thats what I gathered. As for the S130, it has a much lower Cd, somewhere in the high 3's. I found a post on Zcar.com that says 79 models were 3.9 and 75-78 was 4.3. Not sure I trust it, but the 280zx had a better Cd by far. Not sure about the frontal area though.

I have read that Z's do not evacuate heat very well from the engine bays. Could be wrong though, as it may seem.

Time to search it up big time. I am not too far from you though and am doing a Ford V8 swap.

I have been doing a little research about the aerodynamics of the Z. It deffinately falls down alot on the amount of lift generated, heat build up, etc. I am focusing on the Cd though, which was reported to be around .43 to .46. That is not exactly good considering .28's-.32's are becoming the standard for the average car/sedan. Is our .46 really that bad though? Nah. From what I can gather CdA is more important than Cd when talking about overall drag. Cd - Simply refers to the amount of drag per sq unit CdA - Takes into account the square units (frontal area) which is a much better representation of what is going on. The CdA of an S30 is 6.169 using ft^2, as stated in the QUARTER2.xls program that can be downloaded from here. Meaning, for those that care, the frontal area is 13.41-14.35 sqft. Since the Z is much smaller in frontal area than most modern sedans, the drag really isn't that bad. To put it into perspective, here is a list (from wikipedia.org) detailing some modern cars CdA's using ft^2 aswell: 5.10 - 1999 Honda Insight 5.71 - 1990 Honda CR-X Si 5.76 - 1968 Toyota 2000GT 5.80 - 1986 Toyota MR2 5.81 - 1989 Mitsubishi Eclipse GSX 5.88 - 1990 Nissan 240SX 5.92 - 1994 Porsche 911 Speedster 5.95 - 1990 Mazda RX7 6.00 - 1970 Lamborghini Miura 6.13 - 1993 Acura NSX 6.17 - 1995 Lamborghini Diablo 6.27 - 1986 Porsche 911 Carrera 6.27 - 1992 Chevrolet Corvette 6.54 - 1991 Saturn Sports Coupe 6.40 - 1990 Lotus Esprit 6.57 - 1985 Chevrolet Corvette 6.77 - 1995 BMW M3 6.79 - 1993 Toyota Corolla DX 6.81 - 1991 Subaru Legacy 6.90 - 1993 Saturn Wagon 6.93 - 1982 Delorean 6.96 - 1988 Porsche 944 S 6.96 - 1995 Chevy Lumina LS 7.02 - 1992 BMW 325I 7.04 - 1991 Honda Civic EX 7.10 - 1995 Saab 900 7.14 - 1995 Subaru Legacy L 7.34 - 2001 Honda Civic 7.39 - 1994 Honda Accord EX 7.48 - 1993 Camaro Z28 7.57 - 1992 Toyota Camry 7.69 - 1994 Chrysler LHS 7.72 - 1993 Subaru Impreza 8.70 - 1990 Volvo 740 Turbo 8.70 - 1992 Ford Crown Victoria 8.71 - 1991 Buick LeSabre Limited 9.54 - 1992 Chevy Caprice Wagon 10.7 - 1992 Chevy Blazer 11.7 - 1993 Jeep Grand Cherokee 16.8 - 2006 Hummer H3 17.4 - 1995 Land Rover Discovery 26.3 - 2003 Hummer H2 Yes, we did best the H2. We are mroe aerodynamic than any of those cars in bold. Feel free to PM me CdA's to add to the list.

I know the 200zxR had the normal 45lbs breakaway and the same size clutches as the Z31t we got here. Are you sure that the R31 units had beefier clutches. For some reason i doubt it from what I have seen so far.

There was a movie I had to watch in high school that showed an S30 280z I believe running into a semi and the guy basically learned to value life more and he lost his girlfriend or something. I will think on the name.

I see. Apparently the setup is some kind of mechanical electronic mix. It is a central injection where some kind of restrictor plate blocks off air. When you accelerate, it opens the plate more and the injectors spray more I do believe. How they know how much to spray I am not sure, it may be mechanically linked to the throttle opening.

Is the MAF usually already maxed out at stock? If so, can a resistor simply be put inbetween it and the computer. Then the computer sends lean for a couple seconds and compensates at the o2 sensor, or does it not work that way? Thanks! This is all in reference to modifying a 1988 central fuel injection Audi 80 Quattro. I was wondering if it could be turboed using the stock computer or simply ported, cam change, and larger injectors.

This is not necessarily Z related. Assuming the car is a mass air flow based car, what can be done using the stock computer as far as turbo charging. 1. Will the computer realize there is a turbo and compensate with more injector time? 2. Can the injectors be substituted for larger ones with out reprogramming the computer (as in will it learn through what the o2 sensors are saying, that the fuel mixture is rich)? 3. Do injectors use a univeral.standard harness type or would injectors from a different brand car need to be rewired to fit another. Thanks!

http://www.ronalusa.com

Thats how I do it. Still need to keep refilling the master though. But thats a given in either case.

http://www.race-cars.com/engsales/cosworth/1126773358/1126773358ss.htm Heres a $170k ish F1 V10. Rebuilds are only $17k a pop. Lifetime is a whole 700km... more at reduced rpm!!

bump. I am getting antsy

Why not use the 300zxt shafts? I think they are 6 ball CV instead of the tripod design on the 280zxt.

You should have gone vented or not at all unfortunately. Even then I heard it isn't that phenomenal, but it should help your fade alot. Anyway, you are lucky. They (Coldffusion and sparky I believe) are making a wilwood install kit to use 12.2" rotors and calipers and such. Basically they supply the hats and caliper brackets and you source pads, rotors, lines yourself. Total cost is projected to be around $500 maybe less. http://forums.hybridz.org/showthread.php?t=113936

Phantom grip it. Just kidding, but that might acctually work provided you put in some aggressive springs.

Wow, thats cool. Wish they had more pictures of the wheels and possibly weights as well. Do you have the link to the halibrand wheeled g-nose 240z?

I thought that the tokico Illuminas wern't good for rates above 275lbin, are these HP's going to last? What size bar are you running F and R? That is a pretty clean coilover install though, good job!

NZeder just wondering what pattern are you going to put those washers in? As far as this OBX helical unit vs a 300zxt 87-89 clutch pack unit, which would be superior for road racing or autocross? Is a 1 way or a 2 way superior or is that up to the drivers tastes. Which diff distributes torque better on the turns?