What's my speed?
09-20-2002, 11:35 PM
#2
The Evil Twin
Join Date: Mar 2001
Location: Seattle, WA
Posts: 9,294
Re: What's my speed?
On a dyno, it tells you how fast you are going. My 82 280zx was running at 100mph at 5,300 rpm in 4th gear. When you shift to 5th it drops to about 4 grand. So you were going 100-110 mph. Wohoo!
09-23-2002, 09:05 AM
#4
Guest
Posts: n/a
Re: What's my speed?
ought to be around 115 to 120 shouldn't it BleechZ?
Jamie Shelly
kd5izq@msn.com
ICQ - 159705433
IZCC Number is #12402
Jamie Shelly
kd5izq@msn.com
ICQ - 159705433
IZCC Number is #12402
09-23-2002, 02:14 PM
#5
The Evil Twin
Join Date: Mar 2001
Location: Seattle, WA
Posts: 9,294
Re: What's my speed?
Actually, at 4000 rpm in 5th you'd be at 100mph.
At 5700 in 5th you'd be at 145mph. That's higher than the 280zx's top speed rating. I don't think you have enough power to go that fast.... or you must of found a very long downhill slope!
Mine stops at about 4500 in 5th gear, but the freeway isn't all that level either.
At 5700 in 5th you'd be at 145mph. That's higher than the 280zx's top speed rating. I don't think you have enough power to go that fast.... or you must of found a very long downhill slope!
Mine stops at about 4500 in 5th gear, but the freeway isn't all that level either.
09-23-2002, 06:28 PM
#6
Guest
Posts: n/a
Re: What's my speed?
That is pretty fast, one time It was about 2 am and the freeway was empty and I was going about close to 5000 rpm. Then suddenly I see some lights coming behind me. Yes, it was a trooper. He had been chasing me for 6 miles. I did not know. I had the radio full blast. and I was not looking back. Actually that is what I told him. When he asked me if I had seen him. I told him no since I pass people I don't bother looking back. he showed me the speed gun and he clocked me at 125mph. Well, here in Texas you don't get a ticket it is automatic arrest. But he talked to me about when he had a Z himself. So I listen. He kind of gave me a break. He did not arrst me, but gave me a ticked saying I was going 80 on a 60mph. zone. I was able to get defensive driving. I thought that was a good break. Have I slowed down not really. but only when traffic is heavy I slow down. but when there is no one. I'm gone. Hope you enjoyed the story. good luck people.
"It can't rain all the time"
"It can't rain all the time"
09-23-2002, 08:05 PM
#7
Guest
Posts: n/a
Re: What's my speed?
It was a 50 mile stretch of pretty flat straight interstate. At 2 am the only thing to see on this road are maybe a deer or two. So I ran full open for a while before she hit 5700. It was very hard to keep the car on the road i had severe body lift from the aero package that are factory. The front end was floatty but the *** end seamed ok. I backed down to 4500 it is a lot more comfortable at that rpm range.
Z for go Z for show
Z for go Z for show
09-24-2002, 07:30 AM
#9
Registered User
Join Date: Mar 2002
Posts: 646
Re: What's my speed?
Hey Guys,
Most of your experiences of high MPH are based on your
factory tachs and speedometers. It doesn't take into consideration equipment error , tires size or other factors.
I would think a ZX is good for somewhere in the 125 MPH
plus range and a bit less for the 240. Thats just from the info
I have seen from actual track tests.
Mike
Most of your experiences of high MPH are based on your
factory tachs and speedometers. It doesn't take into consideration equipment error , tires size or other factors.
I would think a ZX is good for somewhere in the 125 MPH
plus range and a bit less for the 240. Thats just from the info
I have seen from actual track tests.
Mike
09-24-2002, 10:12 AM
#10
The Evil Twin
Join Date: Mar 2001
Location: Seattle, WA
Posts: 9,294
Re: What's my speed?
ShaneZ's profile says that his Z is running 205/50/15 tires. That is undersize. That is like swapping from a 3.5 to a 3.9 rear or 3.9 to 4.11
Plus, his 280z 5-speed has a lower (more torque) 5th gear than the 280ZX. The speed rating I said was if you had the 81-83 non-turbo 5-speed (highest 5th gear possible) and a 3.9:1 rear end running stock tire size of 205/60/15. (or 195/70/14)
With his tire size and going 5700rpm he would only be at 127mph with a 3.54 rear or 116mph with a 3.9 rear.
:-D
Plus, his 280z 5-speed has a lower (more torque) 5th gear than the 280ZX. The speed rating I said was if you had the 81-83 non-turbo 5-speed (highest 5th gear possible) and a 3.9:1 rear end running stock tire size of 205/60/15. (or 195/70/14)
With his tire size and going 5700rpm he would only be at 127mph with a 3.54 rear or 116mph with a 3.9 rear.
:-D
09-24-2002, 03:58 PM
#11
Guest
Posts: n/a
Re: What's my speed?
There are several things to consider when calc top speed.
tire diameter, gear ratio of diff, gear ratio of tranny, and rpm of motor.
factory z guages are not all that accurate at high speed...They are pretty good at lower speeds.. Remember that it is gear driven, and because of that is not perfect...(wear and tear etc..)
There are formulas for calculating top speed on the web, just need to put in the ol "+ or -" 5% or so for error..
I ran 7400 rpm in 5th with my 280 (highly modified) it worked out to 148mph.. yet I drove it years earlier when it was dead stock the stock guages read 150mph on a nice stretch of highway one night. Trust me the car was faster after..
tire diameter, gear ratio of diff, gear ratio of tranny, and rpm of motor.
factory z guages are not all that accurate at high speed...They are pretty good at lower speeds.. Remember that it is gear driven, and because of that is not perfect...(wear and tear etc..)
There are formulas for calculating top speed on the web, just need to put in the ol "+ or -" 5% or so for error..
I ran 7400 rpm in 5th with my 280 (highly modified) it worked out to 148mph.. yet I drove it years earlier when it was dead stock the stock guages read 150mph on a nice stretch of highway one night. Trust me the car was faster after..
09-24-2002, 05:41 PM
#13
Guest
Posts: n/a
Re: What's my speed?
Motor is in final stages.
Car heads for the shop later this week for the install. I hope to have it running in a week or two, and broken in for next season.. The way the weather is around here, it won't be hard..I made it till Dec last year.. no snow..
Mwahahaha motor looks totally evil. Gonna feel down right rediculous now..
On a side note I'll tell ya about a little street race a few weeks back... uhhh hold on. I'll start a new topic so everyone can read it..hehe
Car heads for the shop later this week for the install. I hope to have it running in a week or two, and broken in for next season.. The way the weather is around here, it won't be hard..I made it till Dec last year.. no snow..
Mwahahaha motor looks totally evil. Gonna feel down right rediculous now..
On a side note I'll tell ya about a little street race a few weeks back... uhhh hold on. I'll start a new topic so everyone can read it..hehe
09-24-2002, 08:17 PM
#14
Guest
Posts: n/a
Re: What's my speed?
I am currently building my motor out of my 79. This one is going into my 78. I am torn between carbs and fuel injection. I thought of doing the triple weber thing. then I thought of doing injection with a supercharger.
Any ideas I have about 15,000 budgetted for this project.
Have you Zeen me Lately.
Any ideas I have about 15,000 budgetted for this project.
Have you Zeen me Lately.
09-30-2002, 08:30 PM
#15
Registered User
Join Date: Jun 2002
Location: Alameda, CA
Posts: 903
Re: What's my speed?
I have an '83 ZX na. When it was running top notch (stock), I asked my brother 'n law to call hit trooper friends and tell them we want to blow out our cars. He has an '86 Ferrari Mondial. To make a long story shorter, he started pulling away from me and I was running close to 6k ( I have a digital dash too...), so I flashed my lights at him. When it all was over, he told me that we were going 130 when I hit my lights.
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