top speed

[kansas240]

150mph? any accurate record of this? is it stock motor with stock gear ratio?

theory is one thing, reality testing is another

Is a BONNEVILLE record holder not worthy of your respect? follow the link posted above. Documented Proof is one thing, theory on a forum is another.

[Edub1]

I took my 89 till it hit the wall. A little car left but she was floating so bad I was laughing. What the hell good is it if the car turns into a hovercraft?

I suspect that aerodynamic improvements are needed in front and back before top end even needs to be discussed. In fact, I'm going to start a thread on that right now.

[titanium240]

Seriously, the 240SX is not a car anybody would want to sustain high speed in for any amount of time, it just gets way too unstable to handle (yes, that's redundant, I know)... On the other hand, I saw a thread once...oh here it is: zer...ote=1

A quote:

I actually got bored and wrote a program for this a few months back. I got into it the other day and revised it to make it more friendly. This is what it reported on a stock S14 at 5800 rpm.

Speed: 130.624mph

For a maximum speed it reported:

Mechanical Top Speed: 157.649mph

Aerodynamic Top Speed: 145.127mph

It doesn't consider tire friction. Someone correct me if I am wrong in this assumption. But I believe that the car will travel at whatever speed the engine is spinning up to a point where the car will no longer accelerate because the drag force is equal to power the engine is producing. Anyway, it gives a reasonable approximation I think.

So, if the car was aerodynamically stable enough and these computations were accurate, 160 still wouldn't be made, but it's pretty damn close mechanically.

I'd rather track and rally these cars myself, so top speed's really not that important to me as long as the suspension's set up right.

[TrueSlide]

I do not think mechanically a KA will support those speeds, just because of the way the KA is designed. You would have to change and build the KA pretty good and mess with transmission, etc. etc. Look at the dynos of a KA, its power drops off pretty good at around 6k. The long stroke/bore of the engine keeps the rev to around a 6.5k, which reving the motor in 5th to 6.5k will not be 158.

Sorta just cliff notes, too tired to get into detail with the numbers.

[Edub1]

What about the turbo cars?

[91RMKS13]

almost all of you are thinking in terms of stock cars. i would like to see a show of hands for those of you that have a stock engine.

ok now if your hand is up is it up because you are financialy challenged and pour all of your money keeping the car on the road.

also one thing i have not heard any one talk about is tire LIMITS. My tires are 17's and are speed rated to 186mph. i have taken my car to 115 with cheap tires on stock wheels very scary those things were just not made to fast. But on the 17's the car was very stable also lowering the car will help because less air will travel under the car lifting it (also like the stock wheels and tires your suspension was never made for those speeds).

[kansas240]

I am simply stating the possibility of a mild motor to push this shape (c.d.) to a proven speed. of course the tires, wheel bearings, brakes need to be up to spec, and for salt flats, speed rated tires are a must.

a really hot flatty is around 200 horse, so with highway gears, and a solid 220 horse mill, it can hit 150. a ka motor can make 220 horse with a few bucks in machine work and cams. an air dam and small spoiler will help to stabilize it, keeping it from floating.

simulations, theories, banter can't be proven.a stock bodied 240 running through the speed traps at 150 has been.

This class encompasses coupe or sedan bodies, 1928 or later, unaltered in height, width, length or contour, mounted in the conventional manner with all panels mounted in the original relationship to each other

that means a stock bodied oem spec chassis with a motor swap, very small front air dam, lowered no more than 1.5" from stock.

thats all i'm sayin

[TrueSlide]

You would have to change the transmission and/or the design on the motor. The KA is NOT a high reving motor and does not make good power at high rpms without some work.

[djsnoopert]

If I haven't said it already, I have had mine to 135, but then the body goes nuts and starts shaking. It was getting wind underneath it, and with no spoiler, I decided to let off the gas. I expect I was pretty near the threshold. I could have had a higher top speed if I had the spoiler, but that then affects acceleration. But neither here nor there, they look better with my wangan (I know, it's a little rice). i had the same thing happen in my 91 se. we where going 138 according to my cousins digi tack in his mustang!

[TrueSlide]

where was your 5th rpm at? Iam positive it was running at redline or very damn close.

[Kouks]

the ka transmission has a longer 5th gear than the ca. On GT4, the ca transmission + ca diff4.3.... will go 146. mechanical gearing.With the ca motor transmission and ka diff..156 was possible at like 7500rpm.

the ka has a lower redline, but a longer 5th gear. So as bcar240 said it has mechanicals to go 157, i believe it with stock diff. With proper aero's, ie (proven bodykit to reduce drag(CWEST or INGS maybe) and all the power in the world... and coilovers i believe it would be stable enough to go that fast. Also good tires help.....

Ca transmission would help most ka people looking for better 5th gear acceleration(.830 vs .738 i believe) plus the ca's diff(4.360 vs. 4.080. con would be about 130-135mph top speed, GUESSTIMATE.

[TrueSlide]

KAThe KA would have to be able to produce good HP ratings @ above 7k. How many KAs do that?

But the KA normally has the redline at 6200 which would support a top speed 137MPH. And we all know without work the KA does not breath and produce power well above that RPM range. Make the KA able to produce power and reliablity at 7100 RPMs and your KA can bring you to 157 granted it has the power/aeros and suspension to take you there.

KA fifth gear is .759

[ArticDragon192]

Pardon the dirty dash.

Haha, I got you beat. I've hit 5800 rpms in 5th

[Florida240sx]

Took the pic before I started slowing down. Was coming up on a turn.Where cops like to sit....

[rsmithdrift]

Just so you guys know. All you have to do is find your rpm in each gear at a slow speed and do the math to find out how fast a car will go.

At 1k rpm in 5th the 240sx and 300zx (same ratios) are going 24ish mph. At 3k rpm they are both going 72.5 mph.

This is a consistent ratio of 24.16 mph per 1k rpm.

SO............To find top gear speed all we have to do is find out what 24.16 x 7 is. It's 169.12mph. Of course no car with 160hp will do that so to find out go drive to the limit with good rated tires and see how many rpm you can get.

On flat ground, I can only get 5,500 rpm in 5th gear out of the 240. That's 132.88 mph. My car has a stock motor and body and needs a coolant temp sensor so it runs a little ritch.

My Z tops out at 145......what the speedo says. It will only do 125 on flat ground due to the extra weight and larger less areo body compaired to the 240, however, I've done 145 in it going down signal mtn. Highway 111 has an 8% downhill grade with a 2 mile perfectly straight stretch of 3 lane highway at this grade. It was very stable and didn't float AT ALL. It actually squated quite a bit. I then entered a turn at 110mph and started sliding around alot but managed to keep it on the road (though I broke the front sway bar link in the process)

The 240 is just as stable at those speeds. On that same stretch of road I hit aproxamately 149mph. (6200 rpm, 5th gear) I took that same turn at 105 in the 240 and it held the turn perfect.

My 300 is an 84 2+2 (with wieght reduction) and the 240 is a 93 fastback SE with strut bars and that is it.

Modified by rsmithdrift at 2:35 AM 2/12/2006

Modified by rsmithdrift at 2:36 AM 2/12/2006
Modified by rsmithdrift at 2:37 AM 2/12/2006

[ArticDragon192]

Just so you guys know. All you have to do is find your rpm in each gear at a slow speed and do the math to find out how fast a car will go.

At 1k rpm in 5th the 240sx and 300zx (same ratios) are going 24ish mph. At 3k rpm they are both going 72.5 mph.

This is a consistent ratio of 24.16 mph per 1k rpm.

SO............To find top gear speed all we have to do is find out what 24.16 x 7 is. It's 169.12mph. Of course no car with 160hp will do that so to find out go drive to the limit with good rated tires and see how many rpm you can get.

On flat ground, I can only get 5,500 rpm in 5th gear out of the 240. That's 132.88 mph. My car has a stock motor and body and needs a coolant temp sensor so it runs a little ritch.

You're forgetting tires expand with more speed due to the increase in heat. You should be able to hit 6k on flat ground with the KA. Even more with a downgrade road.

[tonynalli]

Top speed is between 134-138. Maybe on the salt flats you can acheive more.I woukldn't say over 145mph because of wind resistance. Gearing is only to 155-160. I have gone 134-138mph but was clsoe to a 2mile run maybe a little more.

actually ive been in 5th gear and at redline in my car not to long ago..but hey i wish i had a gps to see how fast i was going...but it took my a moderate amount of time but...not to long.. and the windows were down for most of it..

[rsmithdrift]

You guys are confusing me. Is the 89-90 s13 with the SOHC geared different than the 91-94 DOHC???

Cause mechanical gear ratio will get you to 169.12mph @ 7k rpm in a stock 93 hatchback. Not that it'll go that fast, but it is possible with more power and less drag.

[tonynalli]

the red line is different...nothing more

[Edub1]

You guys are confusing me. Is the 89-90 s13 with the SOHC geared different than the 91-94 DOHC???

Cause mechanical gear ratio will get you to 169.12mph @ 7k rpm in a stock 93 hatchback. Not that it'll go that fast, but it is possible with more power and less drag.

They are the same. But, double check your math.

[rsmithdrift]

Here is my math. Is this not right?? It's from the above post and 24.1666666666 x rpm is how fast you are going in 5th gear. from my calculations.

[naed240sx]

You guys are confusing me. Is the 89-90 s13 with the SOHC geared different than the 91-94 DOHC???

Cause mechanical gear ratio will get you to 169.12mph @ 7k rpm in a stock 93 hatchback. Not that it'll go that fast, but it is possible with more power and less drag.

your saying that 1.5k rpms will get you from 112 to 170? No way.

[240crawler]

My mostly stock 91 will only hit 4900 in 5th. No idea about speed, HUD is broken. Faster than a 01 Ecotec Cavalier. His shutoff is 112, GM spec, and his speedo said 114. I had to baby my car past 80 for him to keep up, though.

[rsmithdrift]

your saying that 1.5k rpms will get you from 112 to 170? No way.

No. Im saying that for every 1k rpm in 5th gear you are gaining 24.16666666 mph.

redline 5th is 7k rpm, so 7 x 24.16666666666666 = 169.12.

fuel cut off at 5k rpm is at 120.8333333 mph. That is where it used to hit in my 93 hatch before I cut the wire.

5th gear rev limiter at 5.2k rpm is at 125.6666666 mph. That is where it used to hit on that same car before I disconected the sensor on the transmission.

fastest I've gone on flat ground is 5.8k rpm, which is 140.16666666666 mph. That was with some drafting help. Usually it stops at 5.5k rpm which is 132.9166666666 mph.

I get this ratio of 24.16666666 mph per 1k rpm by seeing that at 1k rpm in 5th I am going 24/25 mph, at 2k rpm I am at 48/49 mph, at 3k rpm I am at 72.5 mph and and at 4k rpm I am at 96/97 mph. If you find the rpm/speed ratio it turns out to be 24.1666666666 mph/1k rpm. Which is consistent and therefore must be right.

Maybe you guys should check your math.

[hada240]

i would say about 130. if u use the ecu from an automatic 240 and switch it with the manuel ecu. i had a 1990 240sx and it would stop at 115. but the with the auto ecu you would fell the diffrence

[Edub1]

I'm not sure where you're getting these numbers but they are wrong. I'm fairly sure my car is at 4000RPMs at 85MPH and I have slightly oversized tires.

That gives 21.25 MPH which at 6000RPM = 127.5MPH

This is irrelivant though as you will need aerodynamic improvements to have controll at this speed.

[91RMKS13]

http://www.csgnetwork.com/speedcalc.htmlmaybe that might help.

[Edub1]

5th gear is .76

Differential is 4.08

Stock tires are 24.7"

Top speed should be 142.24

Seems like my speedo is a tad bit slow. Anyway, 6000rpm is to high to sustain and the aerodynamics of the car are limiting.

A taller rear end and some aero work is the key.

[hsckris]

A completely stock 240 wont hit 160. It does not have the horsepower to push it that fast. Theoretically, it has the gear for it, and with enough power it might, but then you will have to factor in heat and wear.

my brother hit a confirmed 153mph in his mostly stock s13. has intake, plugs/wires, cat and catback exhaust, and wheels & tires... thats it. its a KA DOHC w/ an auto trans.

[rsmithdrift]

The answer to all your questions......zerothread?id=160333
Modified by rsmithdrift at 1:14 AM 7/3/2006