Kill storie...Supra

[JDMEddie]

Dude...Launch at 5000RPM and switch gears @ redline....Trust me

Tell'em how to do it Karezza666

[J SPEC SilEighty]

Originally posted by JDMEddie
Dude...Launch at 5000RPM and switch gears @ redline....Trust me

Tell'em how to do it Karezza666

If you launch at 5000 RPM then your already past the 240's peak torque and it's just losing torque after that. If you launched at something like 3200 RPM then you would have all that high torque to pull you along quicker. If you launch at 5000 RPM then your almost at redline and will have to shift right away like tatII said and it will just take away time from your 0-60 or 1/4.

[JDMEddie]

ok you've had your car a month now??? Have you raced it yet??? It doesn't stay at 5000rpm when you slip the clutch; RPM drops to about 3500 when the clutch gets engaged...duhhh...before you say its a bad idea, try it.

Racing is about taking it to the red-line, so you run out of torque, if you push it higher then shift your rev is higher in the next gear...understand yet??? Still don't, pull up to a B18 non-Vtec both going 40MPH...get ready...try and keep up when you shift at 5500rpm, wont happen. But when you shift at 7000 like my S13 its bye bye teg.

Racing is beating your car down(or did you think parts last forever). If you want to drive normal everyday I'm sure your car will last for a long long time; till then PARTS WILL BREAK!

you do too much reading...get out there and kick your cars ass!

[JDMEddie]

You will never get better times than me...You prolly never seen a track. I'm going to ESTA DRAG STRIP! its about 10 minutes from my house. Post your times...we will see what happends. I forgot to mention I think our boy Karezza666 is rocking a turbo in his ka24e. I think he also is buying a skyline motor...you will never catch him. Happy chasing=)

[J SPEC SilEighty]

Originally posted by JDMEddie
You will never get better times than me...You prolly never seen a track. I'm going to ESTA DRAG STRIP! its about 10 minutes from my house. Post your times...we will see what happends. I forgot to mention I think our boy Karezza666 is rocking a turbo in his ka24e. I think he also is buying a skyline motor...you will never catch him. Happy chasing=)

Buying a skyline motor huh? Just like the other guys here in the 240 forum that have a skyline motor in their cars but no pics to prove it? I'll believe it when I see it. That's just how I am, I've got to see it to believe it.

I've never seen a track? In my 240, no. In my GSR I had before my 240, yes. I went up to Virginia Motorsports Park almost every weekend and ran just for fun. So don't say I've never seen a track when I'm there all the time.

And yes, slipping your clutch will give you better launches but you better have the cash ready to fork out because that shit wears down your clutch fast as a bitch and if you're doing that at every light when you want to race some riced out civic that it's not even worth racing, then your going to be replacing your clutch quite a bit.

I sold my Integra about a week before I got my 240SX. The last time I ran the Integra I got the following:

15.845 @ 90.16mph
2.305 60ft
.949 R.T. (Yeah I know it's a bad RT)
ZERO mods done to my car with full interior plus spare tire. probably would have done a little better with a few more runs.


.

[J SPEC SilEighty]

Originally posted by JDMEddie
Racing is about taking it to the red-line, so you run out of torque, if you push it higher then shift your rev is higher in the next gear...understand yet???

I don't feel like doing all the math that's involved right now but I may do it tomorrow or something if I have time. Here's a little piece taken out of a horsepower definition on finding the optimum shift point.

"So, how do you work out the shift points in order to achieve maximum acceleration? Well, to do this, you need a performance graph for the engine (showing torque against rpm, which you get from a rolling road session) and you need to know the gear ratios of the car.

At this point it's important to note that the table below does not take into account the final drive reduction, nor the transmission losses that would be experienced. This is because the table is purely showing the performance difference between gears, and the above factors would apply similarly to each gear.

This is based upon a standard Mk2 Vauxhall Astra GTE 16V, and the data is from the official brochure. I'd like to point out that due to the quality of the graph, these values are approximate, and may differ slightly from actual figures.

Torque 1st 2nd 3rd 4th 5th

RPM (ft-lb) 3.55 2.16 1.48 1.13 .89

1000 97...... 345 210 144 110 87
1400 108..... 382 233 159 122 96
1800 115..... 408 248 170 130 102
2200 120..... 427 260 178 136 107
2600 125..... 442 269 184 141 111
3000 130..... 461 280 192 147 116
3400 134..... 476 290 199 152 119
3800 141..... 500 304 209 159 125
4200 147..... 521 317 217 166 131
4600 148..... 526 320 219 167 132
5000 149..... 529 322 221 169 132
5400 148..... 524 319 218 167 131
5800 141..... 500 304 209 159 125
6200 131..... 463 282 193 148 116
6600 117..... 416 253 174 133 104

The first column in the table is the engine speed in rpm, followed by the torque output at the respective engine speed. The following columns have been calculated by multiplying the given gear ratio by the torque output. This calculates the actual amount of torque that is being sent to the final drive.

So, what does this table tell us? To make any use of it, you need to know the formula for calculating the change in engine speed going from one gear to another.

The formula is;


NEW RPM = CURRENT RPM X (NEW RATIO / CURRENT RATIO)


So, for the above car, if you were doing 3000rpm in first and you changed up to second, your new engine speed should be 1825rpm.

This formula is very important as it allows us to see the difference in torque based on gear changes. Now, lets say we were to take the advice that you should change at the torque peak. For this car it's at 4800rpm. So, we're in first gear at the torque peak, and the gearbox is sending 530Lbs-ft of torque to the final drive. We change into second, we're now at 2920rpm, and it's sending 279Lbs-ft to the final drive. Immediately we can see this was bad advice. If you look at the table, even if we left it in first for an extra 1000rpm, at 5800rpm 500Lbs-ft would be sent to the final drive. Yes we are past the torque peak, and yes the torque is dropping, but it's still sending more torque to the final drive than at any point in second gear.

This car happens to have good torque throughout the rev range, and it is apparent from the table that, with this car, in order to get the greatest acceleration you need to change as late as possible, about 6600rpm being the optimum.

Not all cars have such a good torque spread, and shifting may take place before the redline. However, the rule is that if you could be sending more torque to the final drive in a higher gear than the one you're currently in (by using the rpm formula), you've missed your shift point. As long as you shift at the optimum rpm, then your car will be accelerating at its maximum rate.

the water is now clear"

[JDMEddie]

Originally posted by J SPEC SilEighty


If you have ever bothered to check out the dyno chart for the KA24DE then you will see that the torque starts dropping off around 4.5K RPM and at about 5k RPM the torque is as low as it is back at 2k RPM so it is pretty much usless to take it past 5.5k RPM or so and you definatley don't need to take it up past 6.3k RPM at all. So while your out shifting your car at 7k RPM or so, us experienced and knowledgeable drivers will shift at the optimum point and get better acceleration and better times than you. Ok?

Originally posted by J SPEC SilEighty


I've never seen a track? In my 240, no.

And yes, slipping your clutch will give you better launches


.949 R.T. (Yeah I know it's a bad RT)

I think you should take your S14 to the track...what does it cost to run in PA? It cost $37 @ ESTA---

Its getting colder and you should be able to run pretty well. Try shifting @ 5500-6300 & @ red-line...I'm going to do the same thing...just to be more educated about how to drive. That reaction does suck...you could of gotten a killer time...watch your tree=)

I really know nothing about you, but you seem like you know what you are talkin about, you read alot into things...like that guy who drives the FC RX-7 in initail D. I think you should go run your 240...I'd like to see the results. I will post my slip

[JDMEddie]

Originally posted by J SPEC SilEighty

WOW this is for your car I couldn't find mine to fast:

http://plaza.ufl.edu/briand/240sx%20info.htm

Transmission Gear Ratios(1995 - 1998):

Manual Transmission -FS5W71C:

1st 2nd 3rd 4th 5th
Gear Gear Gear Gear Gear

3.321 1.902 1.308 1.000 0.759


NEW RPM = CURRENT RPM X (NEW RATIO / CURRENT RATIO)

1st to 2nd:

3152 = 5500(1.902/3.321)
3608 = 6300(1.902/3.321)
4009 = 7000(1.902/3.321)

2nd to 3rd:

3782 = 5500(1.308/1.902)
4332 = 6300(1.308/1.902)
4814 = 7000(1.308/1.902)

http://plaza.ufl.edu/briand/240sx%20info.htm

I did the math I am enlightened...can you find a link for a 91-94 gear ratio...i'm soo tired from 3 gears of math.

[J SPEC SilEighty]

Hey, I did the math as well and from what this says you are pretty much right about shifting at redline. Here are the optimum shift points
1st to 2nd - 6500 RPM
2nd to 3rd - 6000 RPM
3rd to 4th - 5600 RPM
4th to 5th - 5400 RPM
Here's the math that I did, sorry it's so sloppy.

For anybody else reading this, here is how to read my work and know when the best point to shift is. When you put in the new gear ratio divided by the current gear ratio and then multiply is by the current RPM, it will give you the new RPM in the gear you are shifting to and it will give you the Lb-Ft that is going through the transmission. When you are shifting to a higher gear, you want the lb-ft in that gear to be as high as possible. You can look at my first pic that I have and you can see what the highest amount of torque will be and what RPM it will be at. So you want to shift at the RPM that will put you at the highest torque for the next gear. I can't really explain it very good so just take a look at the work.

JDMEddie, it costs $40 to run all day here. There is a show at the track this weekend called Battle of the Imports and I think I'll take my 240 to the track for that just to see what it will run. If I do go up there then I'll post the results when I get back. Also, sorry if I sounded like a dick before.

[TatII]

j spec holy shit!!! i go to an engineering school myself and i remembered learning this last year. but when i look at your formula i cn'at remember any of it. damn~ how did you remmeber all this stuff? but thanks the info. now i know the optimum shift point for my car. now i'm gonna go give it a shot. but about the launching thing. i'm too broke now to keep on changing clutchs. sooo i'll to launching.

[TatII]

and also jdmeddie. what do you run in the 1/4? i want to know what a S13 runs. i know that its definitly faster then the S14 though.

[Karezza666]

I am kinda getting a little edgy now. I do know what I am talking about JSPEC...........I HAVE BEEN RACING MY CAR FOR MORE THAN 5 YEARS ........and that is the best way you can launch. I have tried many different launches. I have raced over 150 races at the track. I will post my time slips when I get done with work. HAVE YOU EVER HEARD OF FEATHERING YOUR CLUTCH, CUZ IF YOU HAVE THEN THAT IS PRETTY MUCH WHAT YOU DO WHEN YOU LAUNCH. My best possible reaction time was .505 and that was reving it up to 5000 and feathering it. Damn dude I thought you knew. And if you have any questions about the 240SX, Silvia ask me, and see if I am F**king stupid. And I rarely ever get a rt over .800. I am going to try and plan a trip next summer (cuz I broke my tranny) to Virginia Beach and give you a ride and show you was up! I really do know how to drive, man so don't be talkin smak! I was hitting 15.7 with intake and Exhaust, that is it, the only mods that I had for a couple of summers.

[Karezza666]

OK HERE IS A PICTURE OF MY CAR............................................... .................................................. . by the way I don't have a turbo yet or a skyline motor yet, but this winter a RB25DET is goin in. I already ordered the engin, tranny, ecu, harnesses, mounts, drive shaft, and axles. I am starting to rip out my engin, tranny, drive shaft, axles, ect. But I do have a Zex Nitrous Kit in there though.
P.S. I have had the Minneapolis fire department show up a little after a brakestad I had done for about 3 min. straight, at a huge car cruise we where at there

[Karezza666]

My race track is called Rock Falls Raceway. We also have an import day too. You guys also have to remember a couple of huge key things that help and hurt your times. Like we all know Weather, Temp, and Altitude, just to remind you. AND ALSO I DIDN'T HAVE A PIC CUZ, I DON'T HAVE ONE THAT IS SAVED UNDER JPG FILE.

[J SPEC SilEighty]

Hey Karezza666,



Ok, first off, where was I talking smack to you? Are you talking about where I was talking about when to shift? Personally I think your some 10 year old kid who just learned all of the cuss words. Nobody here is yelling or anything and then you start calling me names like a "FAG" and a "BITCH"?

Anybody can be whoever the hell they want to on the internet because rarely is anybody ever going to find out the truth. And that's what I think we have a case of here. First off you say that you have raced over 150 times and you have the timeslips to prove it and that you will post them when you get home from work. Then later you say that you can't post them because they aren't saved as a JPG file. So haven't you ever heard of changing the file type?

Right now, I don't believe 1 thing that you have said. Put up some more pictures of your car (ones that don't look like you took them off somebody's website and claimed them as your own ) and then change those timeslips to jpg files, then I'll believe you.

Go ahead and drive on down here to Virginia Beach, because I would LOVE to see "your" car and for you to show me up. So go ahead and come on down.

How do ya like 'dem apples? :finger4: