Removing the Top Speed Governor

[MrMigs]

Is there a way to remove the top speed governor on a '97 240SX by modding the stock ECU somehow? Maybe by cutting off a wire? Or is there another way to do it besides by getting a JWT ECU.

---> 1997 240SX SE

[gt7152b]

I think you can disconnect your VSS (vehicle speed sensor) but your speedo won't work and it may not be compatable with ABS or an auto. tranny.

[West]

Only way I know of is to get the JWT ECU.

[gt7152b]

Found this on 240sx.org faq:

"After reading the first solution I looked into finding a simpler solution. Best of all, everything can be done at the computer. My car is a 89 with a 96 ka24de, but all the wiring and computer is 92. On my computer, there is a yellow wire with green stripe, 8th one over from right on harness. This is the vehicle speed sensor signal. Cut that wire. That is it. If you have a California car I think it will trigger a code, but for the rest of us, it is an easy trick. Your speedometer will still work because the signal comes from the tranny, goes to the gauges, THEN feeds the computer. I had to find a solution because my car comes very close to the speed limiter at the end of the 1/4. If anyone can beat the revlimiter let me know. I'm working on it.

Name: Steve Kovacs
Email: [email protected] "

I would check a wiring diagram of your car to make sure you have the right wire. Remember that it might not be a good idea for ABS or auto tranny.

[MrMigs]

ah ha... I see... hmm...

I'll try to find a wiring diagram and repost whatever happens <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wink.gif" border="0" valign="absmiddle" alt=';)'>

[jonvolk]

Will this work with a 95+ 240?

[tkrolo]

There is a faq up on the 240.org site that states something about a wire from speedometer to the ecu; if you cut it, it supposedly removes the limiter. &nbsp;The reasoning is that the information travels from the tranny to the speedo, then to the ecu.

[drifterx]

yeah i heard cutting a wire works
but just dont know which one....

[matic 240sx]

i did it with my 97, same story from 240sx.org, yellow wire with green strip... worked fine! <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'>

[matic 240sx]

&quot;oh yea, your speedo is going to stop at your trip meter reset now&quot;

my mistake, your clock button... my hits it and stops

(Edited by matic 240sx at 5:29 am on Oct. 24, 2001)

[supervasil]

testing

[kandyflip445]

Here is a wiring diagram....hope it helps some.

[kandyflip445]

Here is another one. The first one was #2 of 2 and this is #1 under Engine Performance Circuits.

[kandyflip445]

If anyone needs any more wiring diagrams just pm me. I'll try to find what you need.

[92s13]

Can anyone take a picture of the ecu/wire that you guys are talking about?

[240Stilo]

Originally posted by gt7152b
If you have a California car I think it will trigger a code

Correct me if I'm wrong but I don't think they made cars for specific states.

[RedlineRacer]

Where is the ECU located? I've never even bothered looking for it. Is it on the passenger side?

[Phlip]

Originally posted by 240Stilo
Correct me if I'm wrong but I don't think they made cars for specific states.

I don't know that they did when our cars were manufactured, but I know for sure that california cars answer to stiffer emissions laws and that DOES vary state to state, even to the county in some states, like here in NC... If I lived 3 miles down my street, I wouldn't have to answer to the sniffer.

Originally posted by RedlineRacer
Where is the ECU located? I've never even bothered looking for it. Is it on the passenger side?

Yeah, in the passenger footwell, on the right by the door behind the panel.

[DuffMan]

The vss signal goes the speedometer/odometer first and then to the ecu, so if you cut it between the ecu and cluster, the cluster should still work, in theory anyway.

Also you have to cut the 5th gear sensor, becuase there is a lower rev limit in 5th gear. Try reving the car while stoped. If you put it in 5th and keep the clutch in and rev, it will cut at arround 5000rpms.

[Tekryder]

I clipped this from a thread off nico i think it was. .. Give special props to the guys I am qouting here. This was for s130

"if you get to the ecu and look at the harness its a green and yellow wire. start all the way from right and count 8 and go left 8 wires, mines was on the top row, but according to the chart from apexi depending on the ecu you have it could be on the top row or bottow row of the harness but it will always be green and yellow and 8 wires from the right, Just cut it put some electrical tape on the ends and put everything back and your set."


"You need to disconnect the two middle sensors on the tranny too (4th and 5th gears), otherwise it'll still cut you off at 5100 rpm. Without the sensors and the cut wire, I got up to 5900 rpm. That's about 140 mph with slightly bigger wheel tire combo."


And is stated that this will save u gas millage too, becuase nissan cars run full fuel capacity when above 70mph at any throttle range, and doing the above mod only allows full cycle at wide open throttle.

[Tubed4evr]

I assure you this "mod" works on 91-93 240's. Instead cutting the wire I hooked up a switch. Everything still works and the only thing you will notice is a check engine light (because the speed sensor isnt giving info to the ecu anymore). So whenever I want to check to see if anything is actually wrong with the car I just flip the switch and reset the ecu to clear the speed sensor code. And then check to see if anything else pops up.

I did this about 2 and half years ago and no problems. I have only tried it out once though, I don't like cruising over 100 on the street . . . just too many unknowns.


Ryan

[AceInHole]

Originally posted by 240Stilo
Correct me if I'm wrong but I don't think they made cars for specific states.

The chilton's manual definitely notes differences for California cars. Never saw anything on that in my S14 FSM though.



As for the speedo cut: it worked perfectly on my 1992 S13. I took a quick look on my S14 FSM and the speedo wire at the ECU seems to be in a different location than the S13's.

As a side note: has anyone noticed a stalling problem coming off of revs while the car was moving after cutting the speedo??

[formeRiceR]

OFF TOPIC BUT DOES THE APEXI RSM'S SPEED LIMIT ELIMINATOR FUNCTION WORK ON THE 240SX ????

[fogleroller]

Originally posted by formeRiceR
OFF TOPIC BUT DOES THE APEXI RSM'S SPEED LIMIT ELIMINATOR FUNCTION WORK ON THE 240SX ????

Yes, mrmephistopheles has one on his car.