stock vehicle...over 100 mph

[1967k10]

Thanks,Greg .

1967K10,

If nobody responds to your question by the time I get back from lunch, I'll run your numbers and post them up.

 

[Xtremjeepn]

.... took it all the way to 3700rpm . My buddys GPS couldn't keep up .

WTF is it an abacus based GPS?

My old Garmin keeps up fine on an airplane doing over 600mph.


I am currently running a Nordskog GPS Driven Speedo in my truck and it keeps up fine at any speed too.

 

[Greg72]

I'll add my .02 cause I too am looking for the accurate way to figure this.
My 01 D-Max runs 2000rpm @ 77mph and 2700rpm @ 100mph with 33" tires,3.73 gears, 6spd manual,and the speedo recalibrated for the 33"s.
We were out one night in BFE and pegged 100 and punched it. took it all the way to 3700rpm . My buddys GPS couldn't keep up but we figured it was in the neighborhood of 140. I know D-Max's with 5spd Ally's are capable of 140mph and I have a higher OD. Any thgoughts that will help us both figure accurate speeds.

Here are the numbers, based on your 77MPH @ 2000RPM assertion:

With 33" tires and 3.73 gears, your overdrive gear is in the neighborhood of 0.68:1

2000 RPM = 77 MPH ( your original measurement)

2700 RPM = 104 MPH
3000 RPM = 115 MPH
3700 RPM = 142 MPH
4000 RPM = 154 MPH
5000 PRM = 192 MPH
6000 RPM = 231 MPH (Just a bit slower than a Bugatti Veyron!)

Your observed speeds at 2700 and 3700 RPM turned out to be pretty close to the calculated values, so I'd say the speedo is reasonably accurate in your truck. I also threw in a couple of extra conversions at the x1000 marks so that you could know "at a glance" what your speed is...

 

[1967k10]

Thanks a lot Greg. Seems I better not try it again let alone with the 8ply M/T's I had on it at the time .

 

[blazin_blazer]

ok at 2000 rpm's its dead on 80 mph at 3000 rpm's it's 105... any mathematicians? but remember i have to take it out of od to get it above @122mph at 3700-3800rpms

 

[slyguy_22]

Here's a homework exercise for anyone interested....

Greg is traveling across Utah on a wide open (and empty) highway and is traveling 100MPH in top gear. To alleviate the boredom, he snaps a photograph of his progress.

Based on the photograph below, what is the vehicle's calculated top speed?

Hint: This vehicle has much less wind resistance than a Nissan Pathfinder!

So what is the answer for the question that you put up and what vehical is it?

 

[blazin_blazer]

looks like it says ''Porsche'' in middle of steering wheel

 

[78Buford]

After seven pages (with several technical facts thrown in), let me simply state this:

The only way that Nissan is going to "legitimately" read 140+ mph on the speedometer is if it were sitting on jackstands in your garage.

 

[Greg72]

ok at 2000 rpm's its dead on 80 mph at 3000 rpm's it's 105... any mathematicians? but remember i have to take it out of od to get it above @122mph at 3700-3800rpms

Something's not right....

If you are really reading 80 MPH at 2000RPM, then at 3000RPM your ACTUAL speed would be 120MPH, not 105. (did you drop out of OD for that one?)

Take a couple of readings at lower speeds. We are all suspicious that the speedometer at higher speeds isn't accurate anyway.... Do something like 60MPH in OD and then take it out of OD at the same speed and take note of the RPM again. With those two numbers things will make a lot more sense.



Slyguy - That calculated speed of ~155MPH would be correct, however the actual top speed (with drag) is only 149MPH. The car is a 3.2 liter 911 Carrera.

 

[blazin_blazer]

no both of those(80@2000&105@3000) are in od..it stops @ 122 in od, turn it off and it will go on up...i try find a gps

 

[79k20350]

no both of those(80@2000&105@3000) are in od..it stops @ 122 in od, turn it off and it will go on up...i try find a gps

If thats both in od, theres an issue, or you dont have a lockup convertor.


It is a linear scale, so it would be 120 at 3000 rpm, not 105. Period- no arguments. (without slipping)

As for having to turn od off, that means youd be 1:1...

What size tires do you have? You can do the calculations without gears, but with tire size.

Just rough esitmates,

With 31" tires, (.72 overdrive) 2000 rpm, and 80 mph, youd have 3.23 gears

Now I figured that out to do the rest.

Again, 31" tires, 1:1 (for lack of overdrive at high speed), 5000 rpm you'd be at 141.

Now I doubt it even got that fast... Thats also not taking into consideration slippage if theres no lock up converter.

With no lockup and 7% slippage 5000 rpm is 131, which is much closer to the actual reported top seped of the vehicle.

Then again, these are all guesstimates.

 

[79k20350]

Ok diving a little deeper (more accurate)

Stock pathfinder tires size is 255/65r16= 29.26

So again, same calculations,

No slippage = 134 mph

With 7% = 125

 

[Greg72]

Take a look here....

http://www.nissanhelp.com/Models/2005/Pathfinder/Specifications.htm


There are a few potential tire sizes depending on the particular model (XE, SE, OR, LE), and two different rear end ratios depending on if it's a 2WD or 4WD version. (3.133:1 vs 3.357:1)

My guess is that this is a 2WD version, the numbers aren't even close to possible with the deeper axle gears of the 4WD. Knowing which trim level the truck has will tell us the tire size, and at that point the mystery should be over.

 

[DR]

160 in a quad cab F150!









Well, Actually A Ford Lobo not an F150... And it might have been KMH... But still.

 

[BKinzey]

Traveling downhill would help some, maybe a lot? So who's got a long straight downhill run. Like 2 or 3 miles.

If you suggest a cliff that's fine but you gotta drive it

 

[BlazerBud]

After seven pages (with several technical facts thrown in), let me simply state this:

The only way that Nissan is going to "legitimately" read 140+ mph on the speedometer is if it were sitting on jackstands in your garage.

Or floored with the pedal to the metal as it is falling to the ground after being dumped out of a C-130 Hercules

 

[justwhatido]

Wife's Sequoia shuts down at 100

 

[carpeonnel]

when did gm started putting the governors on vehicles? Cuz my 96 S10 Blazer will peg out the speedo and keep going. Don't think it's gonna break any speed barriers but I know it doesn't stop at 94

And GSXrmike, I'm a big fan of GXSRs too. I had a 03 1000 and I know the speedo stops at 183 It would redline @ 12500. I know it would peg out the digital speedo at 183 just under 12000 and keep going til the rev limiter hit. I know it did 100mph at 6000 rpm in top gear, so I think it's speedo is pretty accurate.

And Blazin I hope your wife's alright. I'm a paramedic, Im actually working tonight, but an unexplained tach is never good. She have any other medical problems?

 

[reddog64]

I call BS...

That is all...

 

[blazin_blazer]

ok greg, you were right sum'n was wrong 2000 rpm=70 mph not 80,..i made a chart today so we can see how bad the speedo is off...tires are 245/70/16...heres what i got today....sometimes the tach needle wasnt on a graduation, but i believe i read it within 50-75 rpm's...its graduated in 250 increments


RPM MPH
OD NO/OD
1100 1500 40
1350 1900 50
1750 2200 60
2000 2500 70
2250 2900 80
2600 3075 90
2900 3600 100
3200 4100 110


is that enuff info to disappoint me? :-)


edit: update on wife, they say she has hyper-thyroidism, causing the tachycardia, they have to run more tests(iodine test ) to see if she has any nodes or tumors on thyroid or possibly graves diasese, again thats a either way they said she prolly have to be on med rest of her life...i don't get it, i thought hyper-thyroid was what caused gigantisism, shes tiny 5'1'' 110-115 lbs. i'm going to go google this grave diesease see what it is....they said since they found her thyroid problem they can treat it and her anxiety will prolly go away(she been on xanax for it for yrs) and she will fill like a new person...1 thing i kidded her about...1 of the meds shes on has a side effect..it increases sex drive :-)