Wut's the best time to shift gears for the fastest

[KyoLo]

I'm just wondering when is the best rev to shift from 1st gear to 2nd gear, and 2nd to 3rd for the best 0~60mpg performance? i just got my 97 240SX SE ...and i am still not familiar with the car, so i wanna ask you guys' experience for the quickest and the fastest 0~60mpg way of shifting gears...
because today i actually lost to an integra by 1/3 of integra's body...and it's AUTOMATIC...i know my skill sucks but ppl learn from mistakes and i wanna learn that from you experienced 240SX drivers =) for 1st gear..i was in the lead for half of integra's body ...but after 2nd gear..BLAH...i started to lose...damn it...then 3rd gear...going so so ...sigh..
I hate to lose to an integra...especially automatic..damn it...it's a RS btw ...

Kevin

[whateverjames]

if anyone unlocks the secret of getting 60mpg (miles per gallon) by shifting at a certain RPM, tell me! <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'>

i'd shift at 6000-6125.54984946465 RPM

[drifting240sx]

i shift at 6200 after that it feel there is no more power

[zephyr]

fastest way to go from 0-60 mpg would be to buy a hummer with upgraded injectors running really rich then sell it and buy a honda insight

[guidot]

I have a 96 non SE and I shift around 5900-6000. &nbsp;This is with an Injen SRI tho. &nbsp;I just drove my friends 92, which has the higher redline (bone stock too) and it just runs out of power around 6200. &nbsp;Stick to the 6k range and shift quick...you should be back into the highest torque range once you get to the next gear.

[KAMRAN]

shouldn't u shift at redline?? no?

[guidot]

Redline is nice, but theres no power there. &nbsp;Your max horsepower at stock is 5800rpm, so there's no reason to go any higher. &nbsp;Once you shift at that point, the revs will go back to 4k; right where your peak torque band starts. &nbsp;That is "good" shifting practice. &nbsp;Just try it off stop lights, you will feel the power drop sharply after 5800 or so.

[DSC]

I will usually shift between 5800-5900rpm
Just feels the fastest. &nbsp;If I go into the 6000 range my power feels like its just gone.

[thewholefnshow]

Shifting point will depend drastically based on your car. I cleaned my throttle body last weekend and usable power was bumped 400 rpms, so it can depend on lots of factors. Generally a 240 that is running like a million bucks will be shifted around 6000, cause the shift puts it right at the peak torque and it takes no time to get back up to peak hp output. But like I said, your exaust, bacckpressure whatever could change all that dramatically.

[mrdirty]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KAMRAN @ May 27 2002,09:36)</td></tr><tr><td id="QUOTE">shouldn't u shift at redline?? no?</td></tr></table><span id='postcolor'>
Redline has more to do w/ the physical limitations of the engine ie. valve spring float and such. An engine's efficiency drops of at a faster rate than it's little shot's of power from the cylinders is rising at some point so net power goes down.

Basically each cylinder is firing more often but they're hitting w/ less power because efficiency has dropped off. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/cry.gif" border="0" valign="absmiddle" alt=':cry:'>

[tnord]

about 6k, depending on modifications done to the car.

[wherezmytofu]

100-300 passed peak hp &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/cool.gif" border="0" valign="absmiddle" alt=':cool:'>

[DuffMan]

You are all wrong. The ideal shift point for a lightly modded (ihe) 240 is arround 7000rpm on the 1-2 shift.

[tnord]

what are you basing this information on duff?

[DuffMan]

Formula for ideal shift point: 1st gear ratio/2nd gear ratio = Torque after shift / Torque now.

Since the 1st gear ratio is 3.321 and 2nd is 1.902 so you want to shift at about 57% of the amount of torque you'll end up with. Since shifting at 7000 will put you at about 4000, take a look at a dyno of a lightly modded KA and I bet torque at 7000 will be at least 57% of torque at 4000rpms.

The other shifts don't have to cover such huge gaps in gear ratio, so you wouldn't want to shift as late.

[KyoLo]

for a moment i thought my topic was dead, coz last time i checked there weren't any replied, then 3 ppl ...then i couldn't find my thread...now that's great, i got my answers...2 answers..so shift around 5800~6000rpm each gear? or as Duff said, 1st to 7000rpm and 2nd to around 4000rpm(where the peak torque is) ..?

[DuffMan]

No shifting out of 1st at 7000 will make you start 2nd at 4000. Ideal shift point for the 2-3 and 3-4 is in the low to mid 6000s.

[NutzDrifta]

I don't know about you guys, but I have a 93 240sx that redlines at 6900. So reaching 7000 wouldn't be possible unless I remove the rev limiter. &nbsp;I'm pretty sure that the rev limiter should be the same on a 97; they are the same engine with the same limitations right? &nbsp;Not sure about that one. &nbsp;So shifting at the highest point possible would be ideal for first gear? &nbsp;I'll try that next time.

[mrdirty]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (DuffMan @ May 28 2002,01:08)</td></tr><tr><td id="QUOTE">Formula for ideal shift point: 1st gear ratio/2nd gear ratio = Torque after shift / Torque now.

Since the 1st gear ratio is 3.321 and 2nd is 1.902 so you want to shift at about 57% of the amount of torque you'll end up with. Since shifting at 7000 will put you at about 4000, take a look at a dyno of a lightly modded KA and I bet torque at 7000 will be at least 57% of torque at 4000rpms.

The other shifts don't have to cover such huge gaps in gear ratio, so you wouldn't want to shift as late.</td></tr></table><span id='postcolor'>
Is this w/ or w/out stiffer valve springs?

[guidot]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (NutzDrifta @ May 27 2002,06:48)</td></tr><tr><td id="QUOTE">I don't know about you guys, but I have a 93 240sx that redlines at 6900. So reaching 7000 wouldn't be possible unless I remove the rev limiter. I'm pretty sure that the rev limiter should be the same on a 97; they are the same engine with the same limitations right? Not sure about that one. So shifting at the highest point possible would be ideal for first gear? I'll try that next time.</td></tr></table><span id='postcolor'>
The rev limiter changed from year to year, because of mild engine modifications. &nbsp;My friend has a limit of 6700 with a 92 KA24DE, but mine is only 6200. &nbsp;The cam profile is different and that can affect redline.

[mrdirty]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (DuffMan @ May 28 2002,12:24)</td></tr><tr><td id="QUOTE">You are all wrong. The ideal shift point for a lightly modded (ihe) 240 is arround 7000rpm on the 1-2 shift.</td></tr></table><span id='postcolor'>
I was under the impression that ideal shift rpm was based SOLEY on specific information from a dyno run. I've never heard of your 57% rule, and don't think "rules of thumb" w/out looking at the dyno is accurate enough to say: "everyone here is wrong but me"

BTW: I don't remember seeing anything about his car being "lightly modded"; especially to the point where he can rev past the limiter.

I'm not trying to shit on you, I'm sure u know your shit, but when you suggest something potentially detrimental to the engine w/out anything to back it up, it gives people the willies.

[Zemus]

All i can really tell you is that I shift at 6000 when i race, but my car is almost stock, so i cant even compare to half of you in that respect

[240sBoMex]

have any of you ever tried the 'CarTest' (Special car program found on z31.com) Optimal shift points?? I think that thing's extraordinary accurate, but it does feel like I lose power when I shift all the way to Redline on 1st gear.

[Scylla]

How come these engines rev low? &nbsp;Compared to Hondas/Acuras (maybe others, I have no idea), the redlines are pretty low. &nbsp;Just wondering, potential 240-buyer here!

[KyoLo]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (240sBoMex @ May 28 2002,09:08)</td></tr><tr><td id="QUOTE">have any of you ever tried the 'CarTest' (Special car program found on z31.com) Optimal shift points?? I think that thing's extraordinary accurate, but it does feel like I lose power when I shift all the way to Redline on 1st gear.</td></tr></table><span id='postcolor'>
i can't find it~ where is it?

[240sBoMex]

Its on www.Z31.com, then under the Section TECH, click on Software. &nbsp;Says 'CarTest' and with it u can analyse and adjust any of the data to fit your specific car and Run It! ANyway, they suggest 6500RPM on '95 240sx, (which is prettymuch same as '97 240sx?) and that would be Redline.

[guidot]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (240sBoMex @ May 28 2002,11:06)</td></tr><tr><td id="QUOTE">Its on www.Z31.com, then under the Section TECH, click on Software. Says 'CarTest' and with it u can analyse and adjust any of the data to fit your specific car and Run It! ANyway, they suggest 6500RPM on '95 240sx, (which is prettymuch same as '97 240sx?) and that would be Redline.</td></tr></table><span id='postcolor'>
6500rpm on a 97 is well over redline (6200), you'd be pingin off the revlimiter before you shifted...not good...

[guidot]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (Scylla @ May 28 2002,12:16)</td></tr><tr><td id="QUOTE">How come these engines rev low? Compared to Hondas/Acuras (maybe others, I have no idea), the redlines are pretty low. Just wondering, potential 240-buyer here!</td></tr></table><span id='postcolor'>
The engines run low rpm because of the profile of the engine. &nbsp;It was made for torque not high rpm. &nbsp;The cams and head are manufactured in accordance with that. &nbsp;I'm sure if you rebuild bottom and top end you could get 8-9k out of a KA if you really wanted.

[240sBoMex]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">6500rpm on a 97 is well over redline (6200), you'd be pingin off the revlimiter before you shifted</td></tr></table><span id='postcolor'>
yah but 6500rpm on a '97 Is exactly Redline...thats what mine says and also the 'CarTest' and other places too. (maybe just looks like 6200 but its halfway to 7000) <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/eh.gif" border="0" valign="absmiddle" alt=':eh:'>

[sykikchimp]

There is a Difference b/w REDLINE and your REV-LIMITER (aka Fun Limiter lol). &nbsp;I think the REV-LIMITER on the S-13 KA is somewhere around 7200 rpm. &nbsp;It is governed by the ECU, not the red mark on your tach.

[drifting240racer]

i don't know about that chimp but i know that there is a limiter at speed in 5th gear. 7k is above redline for my '93 240 so i don't know why they would put the rev limiter above the redline unless that is not the redline. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>

[basemies]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (drifting240racer @ May 30 2002,03:00)</td></tr><tr><td id="QUOTE">i don't know about that chimp but i know that there is a limiter at speed in 5th gear. 7k is above redline for my '93 240 so i don't know why they would put the rev limiter above the redline unless that is not the redline. <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'></td></tr></table><span id='postcolor'>
redline is just the recommended rpm limit that you should rev your engine to. &nbsp;it's just a red line, the rev limiter just prevents you from revving your engine up to like 8000 rpm and causing serious collisions of valves and pistons.

[sykikchimp]

there is a speed limiter too.. &nbsp;but like I said.. &nbsp;the red mark on the gauge doesn't do anything

[sykikchimp]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (basemies @ May 30 2002,04:08)</td></tr><tr><td id="QUOTE">redline is just the recommended rpm limit that you should rev your engine to. </td></tr></table><span id='postcolor'>
or rather.. should not rev your engine Past.. &nbsp;


The key is Should. &nbsp;You can rev past it, till you hit the electronic limiter but you risk engine damage.

[KyoLo]

odd...i remember last few days i visited www.z13.com. Now it says you can own z13.com ?!!? does that mean the website is closed, or ..DEAD? ya..i think so.

[ca18guy]

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote (KyoLo @ May 31 2002,11:02)</td></tr><tr><td id="QUOTE">odd...i remember last few days i visited www.z13.com. Now it says you can own z13.com ?!!? does that mean the website is closed, or ..DEAD? ya..i think so.</td></tr></table><span id='postcolor'>
it's Z31 &nbsp;not 13 &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/crazy.gif" border="0" valign="absmiddle" alt=':crazy:'>