Not reaching redline - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

240sx2Nur · 03-01-2003, 11:27 PM

I noticed after a few trials thats my car does not hit the redline (automatic transmission), rather it shifts at 6000rpm instead of 6500rpm. What can be the possible causes of this? How can it be fixed?

/etc/shadow · 03-02-2003, 12:36 AM

Not sure if this free mod will increase the shift RPM, but it should help auto shifting in general:

Quote:

2) Automatic transmissions ONLY: _On both s13 and s14 auto trannys, there is a circuit, that when broke, removes some fluid weight from the tranny and shifts faster and harder. _GTech meter shaved .2 seconds off.... but then again, GTech sucks. _This has been said by Nismo to not cause any harm, and said by people that anything harder is going to lead to broken stuff.
_ _ _How To: On the right side of the engine bay, near the strut tower, really close to the fender, there is a grey connector. _Unclip that. _There is only one, and yes, it is a pain to unclip. _Turn on your car, and drive away. _
Please note: This will cause an s14 check engine light to come on. _Read the FAQ about ecu resetting to clear the code.

http://www.zilvia.net/f/showthread.p...923#post205923

AKADriver · 03-02-2003, 01:12 AM

That connector is for the dropping resistor for the transmission fluid pressure regulator. Unplugging it increases transmission fluid pressure, which leads to harder, faster shifts.

But the upshift RPM isn't regulated by fluid pressure. In these cars it's regulated by the automatic transmission's computer.

6000rpm is a pretty good shift point, actually, considering the KA's stock powerband. But barring that... If you want the car to go to redline, shift it manually.

240sx2Nur · 03-02-2003, 02:57 PM

Unplugging the regulator makes the transmission feel horrible, considering it already is a bit clunky. Behind the gas pedal there is a plastic piece. If removed will should increase pedal travel, correct? Are there any side effects to removing it?

mrdirty · 03-02-2003, 03:26 PM

broken throttle cable.

240sx2Nur · 03-02-2003, 08:07 PM

that only seems tangible if the stock slack has been taken up from the throttle cable.

mrdirty · 03-02-2003, 08:09 PM

Quote:

Originally posted by 240sx2Nur
that only seems tangible if the stock slack has been taken up from the throttle cable.

what?

mrdirty · 03-02-2003, 08:12 PM

You should be @ WOT w/ the pedal fully depressed, if you're not you need to adjust. Pulling the throttle cable more will only spin the throttle plate back into the intake stream (therefore less than WOT).

You can't get the throttle body any more open then WOT.

Not that this would effect shift RPM anyway...

240sx2Nur · 03-03-2003, 02:29 PM

The computer controls the shift points correct? Therefore possibly something to do with the codes may be faulty. How can I check for faulty codes?

AKADriver · 03-03-2003, 02:59 PM

Nothing is faulty! That's exactly what it's programmed to do!

andrave · 03-03-2003, 03:32 PM

I hate to break this to you man, but your car has a truck engine in it. If you are shifting higher than 5500 rpm you are probably shifting too high. It makes its torque down low and its done by 6000 rpm. I have a manual and I don't shift higher than that, there isn't any point. The automatic computer is trying to shift at the optimal points for your car, and at redline isn' t optimal for acceleration or engine life, so it doesn't shift there. Sorry. Performance chip might let it go up higher, but like I said... no real benefit unless you are running cams or something that moved the power band towards redline.

GlacierFreeze · 03-03-2003, 03:49 PM

I'm sure there are a lot of ppl who could argue with you about that "truck engine" statement.

mrdirty · 03-03-2003, 05:18 PM

Quote:

Originally posted by andrave
I hate to break this to you man, but your car has a truck engine in it.....

you and your ignorance are going to make enemies fast here...

240sx2Nur · 03-03-2003, 06:23 PM

Thanks for the help.

andrave · 03-03-2003, 07:43 PM

Quote:

quote:

can you say "wah?"
do a little research mr blah, and check it out for yourself. Where did the handy little KA24 come from? Why does it make so much torque down low? oh, thats right. its a truck engine. flamers online are flamers in real life.

03-01-2003, 11:27 PM	#1
240sx2Nur Leaky Injector Join Date: Jul 2002 Location: Chicago Posts: 125 Trader Rating: (0) Feedback Score: 0 reviews	Not reaching redline I noticed after a few trials thats my car does not hit the redline (automatic transmission), rather it shifts at 6000rpm instead of 6500rpm. What can be the possible causes of this? How can it be fixed? __________________ Nico

03-02-2003, 02:57 PM	#4
240sx2Nur Leaky Injector Join Date: Jul 2002 Location: Chicago Posts: 125 Trader Rating: (0) Feedback Score: 0 reviews	Unplugging the regulator makes the transmission feel horrible, considering it already is a bit clunky. Behind the gas pedal there is a plastic piece. If removed will should increase pedal travel, correct? Are there any side effects to removing it? __________________ Nico

03-02-2003, 08:07 PM	#6
240sx2Nur Leaky Injector Join Date: Jul 2002 Location: Chicago Posts: 125 Trader Rating: (0) Feedback Score: 0 reviews	that only seems tangible if the stock slack has been taken up from the throttle cable. __________________ Nico

03-03-2003, 02:29 PM	#9
240sx2Nur Leaky Injector Join Date: Jul 2002 Location: Chicago Posts: 125 Trader Rating: (0) Feedback Score: 0 reviews	The computer controls the shift points correct? Therefore possibly something to do with the codes may be faulty. How can I check for faulty codes? __________________ Nico

03-03-2003, 06:23 PM	#14
240sx2Nur Leaky Injector Join Date: Jul 2002 Location: Chicago Posts: 125 Trader Rating: (0) Feedback Score: 0 reviews	Thanks for the help. __________________ Nico

03-02-2003, 01:12 AM	#3
AKADriver Post Whore! Join Date: May 2002 Location: Springfield, VA Age: 43 Posts: 3,517 Trader Rating: (1) Feedback Score: 1 reviews	That connector is for the dropping resistor for the transmission fluid pressure regulator. Unplugging it increases transmission fluid pressure, which leads to harder, faster shifts. But the upshift RPM isn't regulated by fluid pressure. In these cars it's regulated by the automatic transmission's computer. 6000rpm is a pretty good shift point, actually, considering the KA's stock powerband. But barring that... If you want the car to go to redline, shift it manually.

03-02-2003, 03:26 PM	#5
mrdirty Zilvia Addict Join Date: Mar 2002 Location: Thunder Bay Ontario Age: 47 Posts: 650 Trader Rating: (0) Feedback Score: 0 reviews	broken throttle cable.

03-02-2003, 08:12 PM	#8
mrdirty Zilvia Addict Join Date: Mar 2002 Location: Thunder Bay Ontario Age: 47 Posts: 650 Trader Rating: (0) Feedback Score: 0 reviews	You should be @ WOT w/ the pedal fully depressed, if you're not you need to adjust. Pulling the throttle cable more will only spin the throttle plate back into the intake stream (therefore less than WOT). You can't get the throttle body any more open then WOT. Not that this would effect shift RPM anyway...

03-03-2003, 02:59 PM	#10
AKADriver Post Whore! Join Date: May 2002 Location: Springfield, VA Age: 43 Posts: 3,517 Trader Rating: (1) Feedback Score: 1 reviews	Nothing is faulty! That's exactly what it's programmed to do!

03-03-2003, 03:32 PM	#11
andrave BANNED Join Date: Apr 2002 Location: Burton WV Posts: 2,350 Trader Rating: (0) Feedback Score: 0 reviews	I hate to break this to you man, but your car has a truck engine in it. If you are shifting higher than 5500 rpm you are probably shifting too high. It makes its torque down low and its done by 6000 rpm. I have a manual and I don't shift higher than that, there isn't any point. The automatic computer is trying to shift at the optimal points for your car, and at redline isn' t optimal for acceleration or engine life, so it doesn't shift there. Sorry. Performance chip might let it go up higher, but like I said... no real benefit unless you are running cams or something that moved the power band towards redline.

03-03-2003, 03:49 PM	#12
GlacierFreeze Zilvia Member Join Date: Feb 2003 Location: Hattiesburg, MS Age: 42 Posts: 209 Trader Rating: (0) Feedback Score: 0 reviews	I'm sure there are a lot of ppl who could argue with you about that "truck engine" statement.