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I know most of us have speedometers that are 130 and 85 mph but has anyone pushed the limits of top end? I ran 134 with our 5 speed, could of pushed harder but didn’t want to get killed or blow up the engine. I also understand not everyone has a track close buy, but for those that have what has your car done.

Madeline Michele
M&M
Hollywood, FL
 

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I have a basically stock 83 280ZXT with five speed and I think my rear gear is about 3.54. Up here in Canada my speedo goes to 210. Unfortunately that's kilometers per hour. Translated about 131.

I have pegged the needle in 5th at 4500rpm ( about 131). I have also pegged the needle and gone to 6000rpm. Not completely sure of the math (re: air drag etc.) but in simple terms I feel that translates to about 138 to 140mph. It seems reasonable that 1500 rpm, taking into consideration drag, wind etc. would generate 7 to 9 more miles per hour.

At Shannonville, Kingston Ontario I reach 110mph on the back 3/4 mile straight after leaving a hairpin turn at about 20mph.

How does this compare to yours? BTW the motor has 290,000 K's (181,250miles) on it.

Kevin
 

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i have taken 2 different basically (other than the tires) stock 280Zs up to 125-130mph. Nothing left on basically flat roads. I know that both speedometers were really accurate (probably because of the slightly taller than stock tires). The second car (my current 280Z) has quite a few mods. I have not actually checked top speed though. It gets to 125mph really easily though. The 280ZX has quite a bit more aerodynamic body than a early Z and most have better stock gearing (5spd with shorter diff. gearing). I would think that they go a bit faster, stock, under the same conditions. I recently purchased a 79ZX coupe. I am looking forward to driving it this winter. I am sure it's not as quick (has all the options) but I think it will be a lot more torquey than my 75 with the big cam.

Anyway, 134 sounds realistic for a stock 280ZX.
 

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Down hill with a tail wind might be cheating

There is a site where you can key in your information. Tire size, trans ratio, rear end and redline that will draw a graph of your top-end... Mine comes out to 208 MPH but seeing how the 1st gen stock Z's only have a CF of about .43 I don't see that happening anytime soon. Problem # 2 no place to open it up all the way (cops don't like you going 90+ MPH over the 70 MPH Speed Limit, DOH) While current ZR tires are rated to 149 MPH I can't even run that at the State Open Road Race (48 Mile one way and back) cause anything over 125 MPH entered have roll cage, plus other gear that I don't want to put in my little sleeper and DPS is on the course and will give you a ticket if you go over the speed in the class you entered. But it can still push 130MPH in the first 1/4 mile in 3rd gear... Doh is that cheating...

Z U V8ter
 

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Re: Down hill with a tail wind might be cheating

Guess you did not watch the cartoon show with Homer! It's not a who (who is on first base) it is a saying when you do something really dumb... Like come home and look at the 2 grand of front brake hardware on the floor that should be on the car to make it stop from those kind of speeds....
 

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Re: Down hill with a tail wind might be cheating

M&M was not ment to be sarcasm at all... I hybrid all the way running 450 RWHP (not a true daily driver because C12 Racing Fuel goes for $4.50 / gal.) While it could be 12.5 to 1 CR loves LEAD to hit 7200 RPM's through the gears. Most street races don't last more then 4 sec, before they see my tail lights getting smaller and a jump to the right as it starts to light up the tires again @ 60 MPH. That is why you never see me post on how fast is? beat a honda! or other post like that... I do answer many other question on here and try to be helpful when I can as well as on other Z sites. It was just when I saw the post about running 140 down hill was that cheating... I could not help the tail wind comment...

I'm looking for a twin in stock form if I can find one in the same condition mine is in... and if I do it might become a daily driver and I park the 4x4 as a back-up... But it is hard to find an early 77 280Z (1/77) with only 83K on it... While my site is lame and has not been updated in the last two years but you can check it out if you want to. Or I could e-mail you some more current ones like the brakes laying on the floor... They almost look to good to put on the car... It is just working on computers all day long and surfing the web all night long for more Z information the last thing I want to do is write web pages and FTP up to my host server...

BTW: How did your first club meeting go, I don't recall you posting anything after it... Also did you ever get my email about your club site that I sent you? You need to put your picture of your Z in a second frame it covers your buttons until you reduce the size of the page... I run 1600x1280 res on my 19" monitor and I had to make the page size about 1024x768 to see it right... Just FYI

You have a great day yourself...

Hope I didn't get in more trouble, DOH

Z U V8ter
 

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LOL bondo, sorry but your speedo's broken....

However....

280Z Destruction-level-boost run. (16PSI) Yes we killed the motor, Buuut...

We hit the M. Think about that for a minute.

Thank you Alice...and Goodnight!
 

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My 240Z with ZXT engine taching 6500 rpms with a .86 5th gear and 225/45 ZR16 rims/tires hits 138 mph with ease.

I am swithing the rear to a 3:70 LSD this weekend which will give me a top end of 145 mph.

I realize that calculated speed based on gear ratio's don't always tell the true story if you can't get your car does not have the torque/HP to overcome the air resistance. But in my case the engine so freely revved up to 6500 rpms in 5th with my 3:90 rear, that I can't imagine having any problems getting to the 145 mph mark.

KEY is Power/Weight: (2300 pound car with 280ZX Intercooled, Turbocharged, cold air induction, 3" free flow exhaust L28 engine)

The only thing I am not sure of is if I went with a 81-83 N/A 280ZX 5 speed with .74 5th gear, would I get to 160+ mph.

I think a G-nose, headlight covers, 18 pounds of boost, small lip spoiler in the rear and a comprehensive safety check would have to be in order to even come close.

Chas
 

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Stock 72 240Z drivetrain...Zenon front air **** and rear deck lip I topped out at 4,500 RPM and about 125Mph on the interstate in Wisconsin. Since then have changed to a Pertronix Ignition and it seems to be pulling right up to redline. Also dropped in a 5 Speed from a 77 and a 3.54 diff. Hoping to do 150Mph...and get there mighty quick
 
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