Max MPH

[9DSX_DRVR]

This post is not about TOP END MPH. I am interest in mph in each gear.

This is the info I found out

1st gear = 3.321
2nd gear = 1.902
3rd gear = 1.308
4th gear = 1.0
5th gear = .759

rear gear =4.083

Ok using the varios calculators, I came up with the following:

with stock wheels size 195R 15s = 24.2 in dia.

so with 6k RPM shift I would get max MPH for the following:

1st gear = 31mph
2nd gear = 56 mph
3rd gear = 81 mph
4th gear = 106mph
5th gear = 140mph

I don't have a working tach. So can anyone verify this info for me?

Thanks

[DoriftoPnoy]

cool. wanna show your calculations? kinda curious as to how you figured this out on paper.

[mrmephistopheles]

There are online calculators for this sort of thing if you can use google.

Out of curiosity, why the need to know?

You shouldn't really be going over 75 or so on public roads. Def. not over 100, and especially not on stock tires.

[irax]

acording to the calculator i did 152 in my s13 automatic
this may or may not be correct accounting for windspead and resistance i was probably realisticly doing 145

[womenbeshoppin]

realistically a stock 240 can only hit a lil above 120 i believe.

[s14dude]

i dunno ive done 145.

[Wei240]

if it's downhill and you have aero, you can probably go for more,

change to a vlsd from j30 which i believe has a different gear ratio that'll net higher mph, forgot,

but in any case, we're not going to beat any land speed record... i can only picture the bolts on our car slowly unscrewing itself once it hits 90 mph, lol

[s14dude]

if it's downhill and you have aero, you can probably go for more,

change to a vlsd from j30 which i believe has a different gear ratio that'll net higher mph, forgot,

but in any case, we're not going to beat any land speed record... i can only picture the bolts on our car slowly unscrewing itself once it hits 90 mph, lol



I have an R32 vlsd. Do you have any idea on specs of this? When i do a Wangan Run....my car tops out at 145......i feel like the engine has a little bit more power......but it seems im limited....maybe my diff? possibly wind resistance?

LOL at stuff unscrewing......i dont doubt it haha.

[!Zar!]

s-chassis and wangan in the same sentence is lol.

[bardabe]

I have an R32 vlsd. Do you have any idea on specs of this? When i do a Wangan Run....my car tops out at 145......i feel like the engine has a little bit more power......but it seems im limited....maybe my diff? possibly wind resistance?

LOL at stuff unscrewing......i dont doubt it haha.
heybrandon its called a speedcut. i've done that a few times. Owned a turbo RX-8 untill i hit speed cut and it still took him a few seconds to catch me. :bigok: and ure LSD has nothing to do with it. :loco:

[9DSX_DRVR]

There are online calculators for this sort of thing if you can use google.

Out of curiosity, why the need to know?.

I used a calculator online. But, I wanted to verify what the "numbers" say and what you get in reality. So here is the BIGGEST reason. I want to know the max MPH in each gear. ie what is the fastest I can be going in a gear and can down shift. So If I am in 5th gear I don't want to downshift if I am going over 106mph. So I am not really interested in the top end like everyone thinks this post is about.

Another reason is I don't have a working tach yet. Tachs in the SOHC cars won't work with the sr20 motor.


You shouldn't really be going over 75 or so on public roads. Def. not over 100, and especially not on stock tires.

I am not sure if you mean anyone not going over 100mph or just the 240sx doing over a hundred. Because a recent car cruise I went on (not mentioning any names) consisted of about 28 cars and they were all doing over 100mph. I also meant stock size not stock tires.

[9DSX_DRVR]

realistically a stock 240 can only hit a lil above 120 i believe.

Stock ECU cuts you off at 115mph I believe. However, I have an RPS13 ECU which I can tell you for sure lets you go at least 125mph.

[s14dude]

nah its not speed cut because the engine is still moving strong...just wont gain anymore speed.

and yes S-Chassis Wangan!

[irax]

Automatic s13's dont have a speed cut

SOHC 5 speeds cut at 115
DOHC 5 speeds cut at 120

SR SHOULD be the same but I DON'T KNOW

And that is based off of stock speedo, different tires = different actual speed cut off

[jrmiller84]

i can only picture the bolts on our car slowly unscrewing itself once it hits 90 mph, lol

Exactly, you're passenger side floor panel will unscrew and fly out from underneath your car at those speeds :keke:

:2f2f: :2f2f: :2f2f:

[irax]

Nah I had a 'danger to manifold pressure' warning light before hitting 90 I decided to back down then

[krazyfil]

realistically a stock 240 can only hit a lil above 120 i believe.

haha... thats a joke... ive been clocked doing 147 before with a radar gun... and i was only at abour 6200 rpm.... so yea u can go faster... 120...lol.. your funny

[s14dude]

yeah no speed cut here......i think if i had a more straight and smooth road i might be able to do 147+

[projectRDM]

Scott Avoy ran his SR all the way out on a dyno, 5th gear redline was 172MPH. Realistically with drag and windspeed that's maybe 155-160. I've had my old car to 148MPH before, verified by the MDM-100, which receives signal directly from the VSS. Accounting for tire size that's about 145MPH.

The numbers above are good to use only if you're still running OE tire sizes, after that you can probably add another 5-10MPH on each one. I want to say my old car would do 35 in 1st, 65 in 2nd, 90 in 3rd, 115 in 4th, and 5th was whenever I let off.

[9DSX_DRVR]

The numbers above are good to use only if you're still running OE tire sizes, after that you can probably add another 5-10MPH on each one. I want to say my old car would do 35 in 1st, 65 in 2nd, 90 in 3rd, 115 in 4th, and 5th was whenever I let off.

Thanks. Thats the answer I was looking for.

Its kinda hard to speed shift w/out a tach. But at least if I know the speed limit in each gear I can guess.

Damn, I need to get that tach soon!

[reflexdb]

So....here's the math:

Speed[mph] = (RPMengine)/(Gear ratio)/(Rear end ratio)*pi*(diameter of tire[in])*7.33

I don't know for sure if there is or isn't a primary reduction in the tranny or not. But if not, this will be your ground speed. Also, wind resistance is not going to change this number. The force from wind resistance will slow down your acceleration to this speed, and will limit top speed if your engine doesn't have enough power to overcome it. But if your going a set RPM in say 4th gear, do the math and that will be your vehicle speed.

[s14dude]

yeah im running the stock 15's. 148 sounds about right....i think ill top out around there if i get the change to drive on a longer straight.

[s13silvia123]

realistically a stock 240 can only hit a lil above 120 i believe.


i've done 140 on mine

[steve shadows]

Scott Avoy ran his SR all the way out on a dyno, 5th gear redline was 172MPH. Realistically with drag and windspeed that's maybe 155-160. I've had my old car to 148MPH before, verified by the MDM-100, which receives signal directly from the VSS. Accounting for tire size that's about 145MPH.

The numbers above are good to use only if you're still running OE tire sizes, after that you can probably add another 5-10MPH on each one. I want to say my old car would do 35 in 1st, 65 in 2nd, 90 in 3rd, 115 in 4th, and 5th was whenever I let off.

Its all about wheel speed sensors and standalones.

Im planning on hooking one up. HWY runs are more dangerous to your bank account and driving record and your own personal life when its 330 AM then other people typically.

I have always had the personal policy of aiming for something hard and killing myself if I start to lose control than hitting some innocent person.

but yeah, depends. I’m running a 4.36 final with a sr 5 speed gear box.

Who knows how fast i'm going after _____ rpm in 4th gear for example.

Really really fast im sure.

I mean what does an E46 M3 top out at? I kind of pooped all over his investment.

When I get the wheel speed sensor iir to come back on here, ill let you know haha.

PS. the stock Nissan S13 SR Speed sensor is worthless after 128 mph or so as in drawing any sort of usable signal or speed reading.

Not sure if the s15 is better or s14 etc.

BTW I've done top speed pulls with the 3.90 LSD, the 4.10 and the 4.36.

The 3.9 was definitely longer however the 4.08/10 was better overall.

The 4.3 is nice and feels longer than I expected overall and is better for a car that sees lots of joshin-off and not just a specific straight line run.

It all depends on what your trying to do. I think the 3.5 is way too long unless you have a custom gear set and then it would be applicable for drag (using a nice gear with an auto tranny and good stall + 200 shot etc) for lots of traction etc.

Its all up to you folks im just rambling now. :blah:

[womenbeshoppin]

srry, i didnt know stock 240s top out that high.

[mrmephistopheles]

Another reason is I don't have a working tach yet. Tachs in the SOHC cars won't work with the sr20 motor.

I am not sure if you mean anyone not going over 100mph or just the 240sx doing over a hundred. Because a recent car cruise I went on (not mentioning any names) consisted of about 28 cars and they were all doing over 100mph. I also meant stock size not stock tires.

So get a DOHC tach. They're about $20 and take 15 minutes to install.

I meant anyone, not just 240sx. Essentially one of those 'just because you can doesn't mean you should' deals. I won't lie, I've taken my car to over 130mph, but it was a stupid immature thing to do. I put myself and others into a risky situation, and could've resulted in a grave outcome. Putting yourself in danger is one thing. I don't really care much about that - but when you jeopardize the well-being of others, you're in the wrong. That happens any time you drive recklessly on public roads. People frequently don't grasp the gravity of the responsibility of driving a car and how one error can lead to a lifetime of pain or death. So far, I've been lucky. I've been in one crash, and it's been on a closed circuit - completely my fault (overconfidence), and I never put anyone into danger that wasn't doing what I was doing.

I know 240s can go fast, but it's dangerous to others to do so, and not worth the brief thrill associated with it.

[DJ_Sunrise]

154mph before cop clocked me.. and gave me a seatbelt ticket. somewhere around 5200ish rpm i want to say? J30 LSD. had plenty of room left to go faster. ran 130mph almost entire trip to penn state university from nj, normally 5 hr drive.. but popo caught me half way through. cock suckers, therese nobody on I80.

1st gear 35
2nd gear 67

after 2nd, i watch the road, not the gauges... :)

[Motorhead]

*happy dance*

Yeah baby. GT-R rear end, 3.63 ratio and a RB25 transmission.

Thank god for looooooooong legs.

[s14dude]

So is the R32 a 3.63? Anyone know what the ratio is for the R32 diff?

Im glad i have my GReddy TT, shows me digitally how fast im going. ^_^

[steve shadows]

So is the R32 a 3.63? Anyone know what the ratio is for the R32 diff?

Im glad i have my GReddy TT, shows me digitally how fast im going. ^_^

the digital signal fromt he two wire snesor - its useless over 130 mph as I stated.

[9DSX_DRVR]

So get a DOHC tach. They're about $20 and take 15 minutes to install.

Do you mean the stock DOHC tach?

I meant anyone, not just 240sx. Essentially one of those 'just because you can doesn't mean you should' deals. I won't lie, I've taken my car to over 130mph, but it was a stupid immature thing to do. I put myself and others into a risky situation, and could've resulted in a grave outcome. Putting yourself in danger is one thing. I don't really care much about that - but when you jeopardize the well-being of others, you're in the wrong. That happens any time you drive recklessly on public roads. People frequently don't grasp the gravity of the responsibility of driving a car and how one error can lead to a lifetime of pain or death. So far, I've been lucky. I've been in one crash, and it's been on a closed circuit - completely my fault (overconfidence), and I never put anyone into danger that wasn't doing what I was doing.

I know 240s can go fast, but it's dangerous to others to do so, and not worth the brief thrill associated with it.


The original purpose of this post (I don't think anyone caught it except R240NA) was to findout my shift speeds were. As far as driving fast, We were out in the country were there was nothing but farmland. It was also an older crowd, so no inexperienced teenagers driving fast. But, I agree it only take one fatal crash to ruin someones life.

[s14dude]

the digital signal fromt he two wire snesor - its useless over 130 mph as I stated.


what 2 wire?


i tap the wire of the ECU.

[projectRDM]

The OE VSS is a 2wire sensor, it's signaled at the speedometer and sends a reference to the ECU through the single yellow/green wire. What was pointed out is that the S13 VSS becomes less accurate as speed increases, and above 130 it's radically inaccurate.

OE DOHC tachs can be found cheap as hell, but for an OE car with OE tire sizes I'd suggest:

30
60
80
110


for shift points. Even that's being aggressive since the KA doesn't make much power above 6200RPM.

[swift_style]

haha... thats a joke... ive been clocked doing 147 before with a radar gun... and i was only at abour 6200 rpm.... so yea u can go faster... 120...lol.. your funny

147 on a stock 240? Damn, I didn't know that I could go that fast. If I knew then I would've just kept on flooring it till my motor fells like it's gonna blow, but right when I hit 120 I stop. I didn't notice where the rpm was at that time. I was kinda nervous making her break 120 for the first time.

[Motorhead]

Again I say. W00t for me.

I suppose I should have clarified.

3.63 GTR rear end + rb25 transmission + PowerFC + RB26 = Pwnd

[srblacks13]

1st 30
2nd 60
3rd 90
4th 120
5th.....

My first car was an SR and the tubo timer said 270khm and I was turnin like 6800rpm in 5th. SO that equals out to like 160ish mph

[s14dude]

The OE VSS is a 2wire sensor, it's signaled at the speedometer and sends a reference to the ECU through the single yellow/green wire. What was pointed out is that the S13 VSS becomes less accurate as speed increases, and above 130 it's radically inaccurate.




ahhh.....gotcha. thanks for the info i didn't know that!


ill have to check my shift points today and update. working with..

redtop SR + GTR LSD + stock SR tranny + 15"

[Mdl_Pin0y]

Exactly, you're passenger side floor panel will unscrew and fly out from underneath your car at those speeds :keke:

:2f2f: :2f2f: :2f2f:

hey thats from fast and the furious

[Motorhead]

Wow. Picked up on that? :)