vega

post please?

Good point, although to add to what you said... Where are you making that hp on the curve(rpm)? What amount of tq are you making and where is that coming in at? v8? l6? what transmission gearing do you have? Rear differential gearing? What kind of suspension? Also out of curiosity with have you run in the 1/4 mi with that car to date? (just to compare power to weight to your setup etc) Great info you guys, its much appreciated, it is quite obvious why you guys are admins.

It not an "atypical" name- no racial/political/religious intent behind it. Just thought it was interesting. I enjoy names, I have been writing books for a myriad of years- I have a certain affinity toward names such as these. Also for future reference, all that politically correct "stuff", may as well through it out the window. There is too much emotion for me to even remotely care. People will be offended by a couch if they want to. If someone wants to be offended by something they will choose to be offended. THAT sounds like a personal problem that they need to seek out psychiatric help for which is beyond more than I personally care. Just for future reference.

Thank you for the recommendations fellas, without buying the books yet have we figured out a general idea of what a z car NEEDS for tire to hook with 400whp (2800 lbs)? I can't really run slicks on a road course (i know there are auto x tires) and I would like to drive the car on the street as well.

He sounds very american

they are the same image

Is this guy on hyridz? Do we know his setup? Ie; motor, trans, diff, aero, tires, rims, suspension, etc?! I would really like to know what is going on with this car. -vega

JohnC what books? I would really like to read them. I have been studying these things for a while and it is difficult to find definitive answers.

I would agree, if one were to stay the same weight same suspension setup, same (comparable) compound as factory. would the 130 (whp for a z) and the 195mm be a way to try to factor that in? 130/195=0.666666667. So every 1hp needs 0.666666667mmm of width for the tire. so a 450whp z would need a 300mm tire- etc.

how do manufactures figure it out then?

How does one calculate how much tire is needed for a given amount of power (from a dig) then? If you have a 80hp fwd crx and you have 305s (modded to fit of course )on it i am betting this isn't going to help. So how much is needed based on power?

Your contact patch will remain the same if you run a 175mm wide tire or a 235mm wide tire IF, and this is a big if, you use the same make and model tire and same tire pressure in this comparison. Now if you would run a wider tire with lower tire pressure, your contact patch would increase also increasing your static traction. Now before all of you either start arguing with me or go out and buy super wide rubbers and stuff them under your cars, hear me out further. Narrow tires will not roll as well as wider tires. Wider tires will distribute your vehicles weight across the wider contact patch, deforming the tire less. The more tire deformation will result in more rolling resistance of the tire. But, wider tires are less aerodynamically efficient at high speeds and add extra drag to the overall vehicle. Taller tires have more affect on tire traction than wider tires in pure lateral movement (i.e. drag racing). But as a result of running taller tires, you increase the torque on your entire suspension and drive train systems, causing potential for component failure. In the case of tires, although traction increases with load, it increases less than linearly, and coefficient of friction decreases with load. A larger contact area reduces the load per unit area, resulting in more grip. There is a point of diminishing returns, such as weight and aerodynamic drag. It's also true that a larger tire dissipates heat and with a lighter load involved, it wears less. Another reason for a larger contact area is to compensate for debris or track imperfections interfering with the tire and pavement contact. Note that load sensitivity is commonly used to adjust the understeer or oversteer of car. When a car turns, the down-force on the outside tires is increased and the down-force on the inside tires is decreased. The body of a car also rolls a bit, and the suspension can be used to unequally distribute the load between the front and rear tires. If the front end is relatively stiffer, then more of the down-force is exerted on the outside front tire, and the relative grip is reduced because of tire load sensitive. A stiffer front end causes the front end to lose some grip in turns, resulting in understeer. A relatively stiffer rear ends results in oversteer. Street cars are generally setup with understeer, while race cars are setup with a small amount of oversteer. For a variety of reasons, such as deformations, molecular bonding type reactions as well as surface roughness, real world friction isn't the simple thing described in physics books. Now to sum up everything rather than starting an endless rant… Going wider will not always give better traction. If you want an all sweeping statement that is roughly true. Wider contact patch sacrifices linear traction for lateral, narrow tires sacrifices lateral for longitudinal traction. And the most important thing about tires is not contact patch area but that they are at correct working temperature. Wider tires are not always better. They don't always give better traction. It depends on the car, the situation, the conditions. Eg. Rally cars use wider tires when on tarmac rallys, and use (surprisingly) very thin tires on ice rallys. F1 cars used to use narrow tires until aero began to be used in the 60's. Drag racers actually want tall tires, width is there to stop the tire being destroyed. An example I can think of is formula student cars, they used to use 8 inch tires but couldn't get them up to temperature. They switched to 6.5 inch and got more grip because they can get them up to temp. So before you go out and buy some super wide meats and cut the crap out of your fenders to stuff them in there…. Sit back and consider some factors. What temperatures are you going to be driving in? Are you only accelerating in straight lines like drag racing or are you autocross racing and need more lateral stability? How long do you want your tires to last? Obviously sticky tires don’t last as long as hard compound tires, but have a much higher coefficient of friction. And running tires with lower tire pressure can put too much heat into the tire. Lastly, if you are using your car as a DD, running 235mm wide tires when the stock size is 195mm, probably isn't helping you at all. Instead of modifying your car to fit these tires and paying higher prices for these wide tires, really isn't worth anything to you unless you plan on whipping it through your local neighbor hoods like a rally driver on a daily basis (which I will never encourage or think is “cool†to drive like an idiot on public roads)the point is though the mentality that wider always = better is wrong. There is an optimum limit even on drag racers. Basically though, there are just so many factors to consider when choosing a tire that one post cannot cover all of them. Gearing, suspension setup, driver preference, car classing rules, car style/power-train layout, car weight, wheelbase, wheel width/diameter, compound, heat generated, tire aspect size, power of car, overall width of setup, ...the list goes on. The theory all summed up sometimes a narrower tire will be faster than a wider tire for a variety of reasons.

Put that up on you tube and post the link!

Not one person?

There is a guy in anoka mn that claims he had a shop in the oc in cali his name is gregg allred. The shop in mn is called "oldschool horsepower". Has anyone heard of this guy? Dealt with him, or know anyone who has done work with him? he had a video he showed with a z doing a high 9 he claimed it was a l28 with 50mm webbers (claiming to be an old car of his he did up). I am trying to find if he is a reputable person. I have a 327 i need some work done to. Everyone I know around town has never used him nor do they know anyone who has. He has beeen in mn for "3 years" according to him. Please help!

done that- they don't allow for different intake port sizes they are very very limited. i have been able to get through a lot of basic crap though.

I think i will be going with a 195 or 200cc intake runner with a cam that runs a bit higher rpm. I am not sure what lift is reasonable. As in what is too high or what is too low. http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=227&sb=2 or something lower lift? http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=232&sb=2

Genius thread I will be pming you soon with my current setup. I would like to hear or read a critical view in your opinion.

all blowers like rpm they do have a limit before they get too hot depending on how they cool but the same can be said for turbos.

anyone got any others?

I am sticking 327 i have a forged crank for it already hence the 327 its already machined etc. eventually (not with these cams) i will be using a centrifugal supercharger blowers like rpm.

Crane cam 110931 (duration 228/238) http://www.cranecams.com/72-77.pdf Or Comp cam 12-677-4 (duration 236/242) http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=226&sb=0 With a lower duration and a bit more tq producing at lower rpms these are the two I am stuck between, with lunati, comp, crane, and isky in mind. I just went through all of their catalogs again and compared them all.- again (fml) I can advance the the cam on either of these to bring the rpm down a bit too if needed. Thoughts?

I will be cutting the firewall, with that cam I should see ALL of my tq before 5500rpm it will really kick in at about 2500rpm, the hp shoots up pretty fast at 3400rpm-ish. Modified 700r4 trans r200 rear diff (3.545) Road race car that is (Sorta) street-able.

maybe eventually with efi

For my road race car (78' 280z) the engine that is being put together goes as follows. small journal 327 bored 40 over KEEPING the 3.25 crankshaft making it a 333ci motor. I am also having the mains splayed. Full arp studs for heads and mains. 5.7 rods (i already have them) 800 holly double pumper carb The heads (i was told the springs would be perfect for the cam?) http://www.jegs.com/i/JEGS-Performance-Products/555/514032/10002/-1?parentProductId=1593012#moreDetails The intake (i will be having it gasket matched to the heads which should up the operating range also) http://www.jegs.com/i/Weiand/925/7547-1/10002/-1 The rockers (i have yet to determine if i should go the extra mile and get a girdle as well) http://www.jegs.com/i/Harland+Sharp/851/1001/10002/-1 The Forged pistons (should be around 10.4-10.5:1 compression) http://www.jegs.com/i/Sealed+Power/844/L2166NF40/10002/-1 The cam (i think i am going to degree the cam to 110 instead of 108) http://www.compcams.com/Company/CC/cam-specs/Details.aspx?csid=232&sb=0 head gasket(.41 i didn't want too big because of the quench squish affect) http://www.jegs.com/i/Fel-Pro/375/1142/10002/-1?parentProductId=758649 Headers(180 degree header part#180-1) http://www.schoenfeldheaders.com/180_crossover.htm I am also considering this unit http://www.jandssafeguard.com/MarineRacing.html Just wanted a quick update to those of you that know me for 1 and 2 to see if there are any rebuttals to what is going together here.