dsommer Posted November 7, 2004 Share Posted November 7, 2004 15MPH in the drive way. Throttle stuck hit the back garage wall, all while I was hanging out the window trying to pull the e-brake. With the 350 installed no way, don't want to know. Quote Link to comment Share on other sites More sharing options...
Sven Posted November 7, 2004 Share Posted November 7, 2004 141 mph and change. This was 10 years ago in my '74 260Z with a 2.6l, early "smogless" carbs, Supertrapp (yuck), and an MSD coil. -Pretty much still a stock Z. The secret weapon was a Nismo close ratio 5 speed from a FairladyZ, with a .8 5th gear. Speed was calculated from RPM/tires/diff/trans ratio. The formula was tested several ways and accurate, to include the police's own radar trailer/signs. At any speed greater than 90mph the speedo bounced way too much, courtesy of a really chewed up speedo gear. The only aero trick on the car was headlight covers. The car was surprisingly stable at that speed. I never expected to get it that fast. I anticipated the dreaded rear end lift, which I never noticed. Was this stupid, with a 21 year old car and no suspension mods other than urethane bushings? Yes, but I became obsessed with seeing just how fast it could go. Having unpopulated roads nearby with several mile straights helps too... -How did I live to be 30? Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted November 8, 2004 Share Posted November 8, 2004 Of course those who went faster than 155 cannot currently report it. RIP. One of two things will happen near this speed and above in a stock 1970's Z-car body. 1. The front "floating" will turn into flying catch air and could flip the car. If it doesn't flip then when the back of the car hits dirt it will slam the front back down and probably wreck. 2. The rear tires will lose traction when the force of the air on the front of the car exceeds the traction in the tires. If you maintain control of the car (nearly impossible at that speed without airfoils) you will possibly spin, possibly flip, possibly catch air sideways and take off (notice the air flap which opens every time the race cars are sliding sideways, without that the car could become a crude wing and actually lift off .) They don't put those truns on a track for looks, they're for safety. So be careful when checking this on your car. And if the front end feels "floaty" you're at your limit and you've probably just cheated death. Quote Link to comment Share on other sites More sharing options...
johnc Posted November 8, 2004 Share Posted November 8, 2004 1. The front "floating" will turn into flying catch air and could flip the car. If it doesn't flip then when the back of the car hits dirt it will slam the front back down and probably wreck. Uuuhhh, no. As someone who's repeatedly driven close to 150mph is a 1970 240Z I can assert that the front was not even close to coming up off the ground. You would need about 1,000 lbs of lift for that to occur and you would run out of horsepower long before you would be able to generate those lift numbers. The rear tires will lose traction when the force of the air on the front of the car exceeds the traction in the tires. Depends on the surface. Its possible on salt and on dirt. Impossible on asphalt or concrete. If you maintain control of the car (nearly impossible at that speed without airfoils) you will possibly spin, possibly flip, possibly catch air sideways and take off (notice the air flap which opens every time the race cars are sliding sideways, without that the car could become a crude wing and actually lift off I agree. They don't put those truns on a track for looks, they're for safety Well, no. The turns exist so that the cars come back to the start and also to keep the cars within sight of the paying spectators. They also add a great deal of excitement to the racing. Quote Link to comment Share on other sites More sharing options...
dsommer Posted November 8, 2004 Share Posted November 8, 2004 Quote: They don't put those truns on a track for looks, they're for safety Well, no. The turns exist so that the cars come back to the start and also to keep the cars within sight of the paying spectators. They also add a great deal of excitement to the racing. ROTFLMAO Quote Link to comment Share on other sites More sharing options...
Mikelly Posted November 8, 2004 Share Posted November 8, 2004 Thanks John for jumping on that... I needed a good laugh! Mike 8) Quote Link to comment Share on other sites More sharing options...
WickedWild Posted November 8, 2004 Share Posted November 8, 2004 Quote Link to comment Share on other sites More sharing options...
dr_hunt Posted November 9, 2004 Share Posted November 9, 2004 I've never heard of someone "maintaining control" and possibly spinning, flipping, catching air sideways and taking off. The force of the air on the front of the car exceeding the traction limits is an impossibility at even 200mph plus. Think about it, the Cd is around .35, frontal area is what, 19 square feet if that, air density at STP, using dynamic mu for asphalt and a normal force of 1500 lb on the rear tires (2), do the math. Quote Link to comment Share on other sites More sharing options...
zguy95135 Posted November 9, 2004 Share Posted November 9, 2004 When me and my dad were coming back from LA once we hit 125 in his old 78 2+2 (5 speed) and was still pulling at about 5000 RPM. The aerodynamics must be dynamically better then the 2 seaters because even with a worn stock suspension there was no lift or wandering. Or it could have been the huge bumpers holding it down Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted November 9, 2004 Share Posted November 9, 2004 There, I'm glad I got those out, now I know my source is not necessarly correct 100% of the time. I've been watching salt flats races too much maybe, sorry. But the truth is, it's dangerous above 150. So just say no. Hey, laughing with me, laughing at me, what's the difference. I obviously need attention. Hopefully my B.S. is exceeded by my words of wisdom. Remember a 10ton plane can still fly, don't think that the 1000 lbs of front end will keep you grounded, but when you've gone 175 in your Z and your "floaty front end" is still on the ground, I'll personally send you a free gift certificate to Oscars (worth $5.00 off with meal). And what happened to the emoticons? I lost half of them! Quote Link to comment Share on other sites More sharing options...
gramercyjam Posted November 9, 2004 Share Posted November 9, 2004 butlerz I am very interested in your setup. How in the world did you get the 260 to 150+. How long did it take to get to 150+ Tranny? Gearing? TIRES? I know my race prepped motor n/a at 13.5:1 did not have enough HP to get over 7900 rpm in 4th gear. So I am very interested in any secrets you could share with the rest of us. Thanks Speedometer error? According to the speedometers, my stock 240Z had a higher top speed than my 340 RWHP Corvette. The Z was also magically invisible to radar as I could zoom by the state police going 90 and never get a ticket. Quote Link to comment Share on other sites More sharing options...
patzky1 Posted November 10, 2004 Share Posted November 10, 2004 The Z was also magically invisible to radar as I could zoom by the state police going 90 and never get a ticket. Laughing Haha, I have the same thing going on currently in my car! 60 indicated ~ 40 real and 90 indicated ~ 60 real. Yes, I have timed these speeds to make sure. Wouldn't you think it would be easier for me to just get the right driven gear? LOL. The car does peg the speedometer past 160, but that is just 107 mph. I have calculated the top speed to be 118, based on no overdrive and my redline of 5500 with 3.54 gears and 225/60/15's. With an overdrive of, say, .8, I could get 148. http://pw1.netcom.com/~sgalaba/mph.htm Quote Link to comment Share on other sites More sharing options...
Mikelly Posted November 10, 2004 Share Posted November 10, 2004 Look Brandon, Not sure where you come from, or what your background is... But we do have some rather intelligent people on this site who are REAL engineers for a living... and even a few of NASA's Rocket scientists contribute here... So you're going to have to back up your claims with some facts... I've personally driven my Z at well over 150mph with ZERO issues... A BONE STOCK Z with a BONE STOCK suspension will get floaty at anything over 110. But lets face facts... Throwing on some lowering springs, a front spoiler and rear spoiler, and you can significantly calm things down. Add some stiff bushings and proper alignment and it is VERY safe and stable at speed. So I suppose next you will tell me that IF I lift my helmet outfrom under my windscreen on my ZX9R, that I'll be blown off my Motorcycle at 140mph... Seriously, not trying to bust chops to hard, but you have to back your comments up with facts... I hate to ask, but Are you an engineer (As your sign in indicates) and do you own a Z? Next question is HAVE you driven it on the salt flats, and on roads at speeds above 90mph? Mike 8) Quote Link to comment Share on other sites More sharing options...
jgkurz Posted November 11, 2004 Share Posted November 11, 2004 Fact: A stock bodied 280ZX lowered several inches has hit 226MPH at Bonneville without flipping or spinning. It was actually determined that the car went faster with the hood popped because the aerodynamics changed for the better. Here's a picture of the car, and yes it's an L28. Personally I've had my Z up to an indicated 142. That's as fast as I thought my tires or guardian angel could go. It's my opinion that high speed stability can be greatly improved on an early Z by lower the car and installing a functional airdam. A G-nose is another proven method to help aerodynamics. Quote Link to comment Share on other sites More sharing options...
Guest trickz Posted November 11, 2004 Share Posted November 11, 2004 I've had my 72 over 150 this was in the early 80's large air dam/spoiler (2 1/2" off the deck) lower springes,bars,shocks,large rear spoiler,327/4 speed,3.36 gear,very stable.The next time I got a huge ticket but I'LL BE BACK!!!!!! 8) I love a late night moon lit hi-speed cruse Quote Link to comment Share on other sites More sharing options...
BrandonsZ Posted November 11, 2004 Share Posted November 11, 2004 Thanks for the PM Mike, I consider my chops busted from this string. Hopefull you got my responce, I saved it in case you didn't get it. I truely believe there are extreamly knowledgeable people here. I don't trust too many engineers, . They tend to make claimes without backup. True or not. BTW, please keep your helmet on when going over 140 on a MC, you'll probably regret it, although you might not fly off that's not too fast. But above 150? Watch out for that swarm of lucusts or the bottlecap in the road. OUCH! Point being, be careful out there before some kids on this site try it and hurt themselves or others. I don't think there is any road in the continental us that you can go over 100 and not get arrested on the spot. They shutdown the open roads in Big Sky Country I heard. Quote Link to comment Share on other sites More sharing options...
JBSRace1 Posted November 12, 2004 Share Posted November 12, 2004 158 in the 1/4. no front spoiler, short rear spoiler. 4.86 rear gear with 32" tall tires 8,100 rpm. SBC. What kind of ET are you turning with that MPH? JB...158 is turning it on in the 1/4 Quote Link to comment Share on other sites More sharing options...
jap tin Posted November 12, 2004 Share Posted November 12, 2004 Normally 8.50's with a best of 8.46. Quote Link to comment Share on other sites More sharing options...
Guest zfan Posted November 13, 2004 Share Posted November 13, 2004 I have gone 140 mph if my speedo is accurate. 120 plus in the 1/4 mile..do that all the time. Mike Quote Link to comment Share on other sites More sharing options...
Guest racerbob Posted November 15, 2004 Share Posted November 15, 2004 GPS,time slip or do the math.Speedos are usually wrong.BOB Quote Link to comment Share on other sites More sharing options...
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