Removing speed limiter on 93 KA24DET

[SloS13]

I can't seem to find a straight answer on removing the speed limiter. My car is cutting off at 107mph and I'm going to the track tonite.

Do I have to unplug the sensors from the trans, or just put a switch on the VSS to ECU wire?

[Biggamehit]

4600rpms = 115mph (on s13)
5800rpms ~ 145mph (thats my top speed that i achieved)

THIS SHOUD BE DONE ON YOUR OWN RISK.
TESTED AND APPROVED FOR 1991 - 1994 240sx. but it should be the same for all models of 240sx and 180sx.


ok, here is the trick. (i think i should make a profit out of this, lol)

1. locate the speed sensor on your tranny. its not like all other 4 sensors that go in your tranny. its much bigger then others, and its round.
2. follow the wires from the sensor... they go in the engine bay
3. as soon as the wire reached the engine compartment, the wires endup in plug that plugs in other plug.


now you can choose wat you want to do next:

***EASY WAY*** (not recommended though) - speed will never show, miles never go up, no speed governors.

4. Dont cut anything. just follow the wires from the speed sensor that go in a connector and unplug it. (look at diagram) and if you do, make sure the wires that are unpluged dont touch the ground.
= the speed will not show unless you connect the plug back.

***HARD WAY*** - as soon as you go over 110 mph or at any speed, you can turn off the switch, and then you speed dies, and governor. very usefull. thats the mod i got. lots of wireing. speed will show and governor will be active unless you turn the switch off.

4. there are 2 wires coming from the speed sensor. i think its green and black. but it doesnt matter.

5. Cut one of the wires (any). so now you have one wire that is uncut, and the other one is cut and has 2 connectors. you should clean the 2 connectors of the plastic surrounding and make it neater.

6.go and buy about 4 - 6 feet of double wire. (2wires that i glued together)

7. take the double wire. ( you sould have 2 wires hanging at one end of the double wire) and connect those 2 wires from the one end to the 2 connectors from the cut wire from the speed sensor. (look at diagram)

8. take the other end of the double wire and somehow manage to take it inside of the car. there should be a whole in the fire wall on the driver side.

9. put an on/off switch at the end of the doublewire that is in the inside of the car.

10. you are done. whenever you turn the switch off, there is a break in the wire, and therefore, there is no electronic circulation, and thats why your speed sensor goes offline, and you can go as fast as you want. turning the switch on, will make the sensor alive, because now there is a electronic circulation.


***VERY IMPORTANT***
on s13 (and i think on any model of 240's).. there is a 5th gear, rev limiter, that does not allow you to push the engine rpms more than 5000 in 5th gear! if you turn the switch off, and reach the 5OOO rpms line in 5th gear, (approx. ~ 128mph) you will not go anyfaster.

BUT, that will not stop us from reaching top speeds. there is a way to bypass that too. here is how:

all you have to do, is go under the car again, there should be 4 sensors other then the speed sensor. Unplug the 2, and 3 sensor that stick out from the transmission.(look at diagram) one of them is the 5th gear sensor. that sensor tells the computer that you are in the 5th gear, and therefore, the computer limits the rpms to 5000. try to unplug both, because i am not sure which one exactly is the 5th gear sensor out of those 2.

TEST IT FIRST:
after you unpluged both, try it out. start the car, pull the EBrake! put in the 5th gear (DONT release the clutch!!!) and rev it up all the way...

if the rpms go higher then 5000, then you did everything correctly.
NOW is the time to take your little 240 for a test drive on the highway. I find it better to speed in the mornings (like 10 am) thats when theres not too many cars.

TROUBLESHOOT
if the rpms stop at 5000 (you will hear it), disconnect all 4 sensors from the tranny. because the 5th gear sensor might be alocated (moved to a different spot).. but if you disconnect all 4.. that should do the work. MAKE SURE YOU DONT disconnent the speed sensor from the tranny. (you check engine light will not go on. at least not on S13's)




Credit
taken from Club240.com

[SloS13]

saweet. Hopefully I'll have time to rig that up before I hit the track. thanks x1000

[virus77]

I think you can also snip the speed sensor wire at the ecu and your speedo will still work but your ecu wont have the signal(ecu doesnt use this signal much any, dont worry)

Also I think you can disconnect the 5th gear sensor (maybe 4th and 5th) from the transmission and it removes the limiter aswell while still maintaining a speedo.

[nissanfanatic]

Yea. Clip that speed sensor wire running to the ECU and then unplug 4th and 5th gear sensors from the tranny. I did this and still had RPM/speedometer but no more gay speed limiter.

[SloS13]

^^ wish I woulda read that before I started cuttin stuff. ANywho, I cut the wire and ran wires to it from my headlight popup switch. Works great!

[Florida240sx]

I just unscrewed my kick plate by the ECU. Sniped I *beleive* ECU pin 32.I'll check in 15minutes oniz's diagram. And my speedometer works great.

[Florida240sx]

Yes it is ecu pin 32. Yellow wire with a green stripe. This is for s13 DOHC

[SHIFT_Lock]

Or just get a auto ka24de ecu. Plug it in. And you get more MPG.

[S13FX]

Just a quick note it's the same wire for the SOHC too

[side waz]

Yes it is ecu pin 32. Yellow wire with a green stripe. This is for s13 DOHC

Ok just to clerify this, clip the wire AND disconect the 4th & 5th sensor's or, clip ONLY the ecu wire? I'm also guessing just clip and tape each end so they never touch right?

As well, your speedo, odometer and tach still work just fine?

Lastly, you've gotten rid of the gov but what about the rev limiter that "supposedly" kicks in when the speed limiter is removed?

I'm sorry for all the questions but I REALLY want to get rid of this stuff and still have everything else working ok. Now that I'm boosting I'm still getting passed big time on the highway due to the gov and it's PISSIN ME OFF to no end.

Well please let me know about this when you can and thanks VERY much for your help.

Take care.

Easy

[ILikeMy240sx]

Even with the speed signal wire is cut on the ECU if you do not remove 4th and 5th gear sensor, your engine RPM limiter will kick in hence limiting your speed so you have to unplug those two sensors from the tranny.

Also, Virus is right. Speed sensor wire goes to the speedometer first then from speedo it goes to the ECU so, if you cut that wire from speedo to ECU, your speedo will still work but your ECU won't see it.

[side waz]

Hey cool thanks a lot man.

Just one more question.

For the tranny sensor's, which EXACTLY are the 4th and 5th ones? Lets say I'm under the car, from the passenger side, looking at the tranny. Do I count from the backside of the car forward towards the motor or from the motor back towards the driveshaft? I just want to make sure I get the right ones.

Also the SPEEDO, ODOMETER AND TACH all work properly?

[nissanfanatic]

click here

Unplug those.

[side waz]

Alright I know which ones to disconnect now, thanks.

The only thing I'm not clear on is DOES THE SPEEDO, ODOMETER AND TACH WORK PROPERLY after cutting the speed wire to the ecu and diconnecting the the tranny sensors? It would'nt be a good thing if I did'nt know how high I was reving, especially being turboed now.

I appoligise if I'm being a pain on this but I just want clerification before doing all this.

Thanks a lot.

[midnightclubbaa]

Or just get a auto ka24de ecu. Plug it in. And you get more MPG.

i'm with him ^^^^

[virus77]

After cutting the wire to the ECU and disconnecting the sensors everything will function normally(speedo, tach, trip and odometer .

[Kenrik]

At what MPH does the gov kick in? I have a 89 manual and I brought her upto 112mph yesterday but I did not try to go any faster because I was on a busy road and I did not feel like jail time! (I know i'm bad LAMO)

[virus77]

You were almost there, its around 118

[Florida240sx]

117mph.Sometimes mine kicked in late.Did 125 once or twice. All I have done is cut the wire. No unplugging or messing with tranny sensors. ALthough in my one vid somethign happened and it could be another speed limit? But way past 117mph.

[side waz]

Ok cutting the speedo wire to the ecu worked great. I now can go past 190km's p/hr and surprised my buddy with his SR on the highway.

Now as for the tranny sensors, when I was under the car today I noticed there were 4 of them. There was 2 connectors that were kinda squareish and 2 that were round. It seemed the order was one square, one round, one square and one round.

So my questions is do I unplug the squareish ones or the round ones? I did unplug the round ones and my tach was working fine but I can't figure out if I have the right ones or not to remove the rev limiter.

[Florida240sx]

I just cut my ecu wire and everyhtign was good.Didn't bother messing with tranny sensors.

[K240]

Ok, I am in the middle of wiring the setup that Biggamehit posted, the "Hard way" but I have a question. Out of the two wires coming from the speed sensor, i spliced into the green one, and then i am wiring the two wires to the little switch, that is normally for fog lights etc...Now there are three prongs, if you will on the switch. My question is of the double wire, which of the three prongs on the switch do I hook the wire to?

[K240]

Credit
taken from Club240.com

See, I bought a on/off switch like the one pictured, but mine has three prongs, which wire of the double wire goes to which prong?

[K240]

Bump!

[Mustangs_Suck]

I just cut my ecu wire and everyhtign was good.Didn't bother messing with tranny sensors.

so you're telling me you just clipped the Pin #32 wire, and you had all your speedo, tach, trip,odo meters - but the speed govenor was gone - and you could take it past 5000 rpm's in 5th gear? And this was a DOHC manual ECU?

[side waz]

Florida is lucky then. I snipped my speed wire at the ecu and I can go to somewhere between 200-210km's but as soon as I hit 5000 rpm's, BOOM, the rev limiter kicks in like a son of a bit_h!

That's why I know I have disconnect the tranny sensor's and I'm still waiting to know which ones to remove. There is two that are square ish and two that are round ish. A little help please.

[K240]

Florida is lucky then. I snipped my speed wire at the ecu and I can go to somewhere between 200-210km's but as soon as I hit 5000 rpm's, BOOM, the rev limiter kicks in like a son of a bit_h!

That's why I know I have disconnect the tranny sensor's and I'm still waiting to know which ones to remove. There is two that are square ish and two that are round ish. A little help please.

You want to disconnect the 2nd and 3rd ones shown in the pic above^^^

[Florida240sx]

Let me find my vid.I hit 5650 I beleive.However I hit a cutoff twice but it's def past 5500rpms in 5th think 5600-5700 range.

[Florida240sx]

Well here it cutoff at 5200rpms. http://videos.streetfire.net/P...A8B70 But I have had it past it. When I get my car back I'll take a new vid.

[babowc]

Or just get a auto ka24de ecu. Plug it in. And you get more MPG.

can anyone verify?
is there any harness alteration required?

[dft24ds]

when I did my auto to 5spd swap I swapped the auto ECU for the manual ECU and it plugged right up no problem.

[K240]

Yep, there is no difference in the harness, its a direct replacement!!!

[babowc]

i see..
hmm, but i always thought automatic cars used more gas than manual?

i dont see how it can be any different >_<, but im gonna go pick up an ecu from the junkyard or something.. see how it works out
i barely get 250 to a tank..

[K240]

the way the tranny is set up, and gearing, 5speeds get better gas mileage, but the actual ECU's fuel map, gets better gas mileage...correct me if im wrong

[babowc]

oooh
okie i guess ill be changing to the auto..
never knew 240sxs got this kind of.. not-so-great gas mileage

[mr2lickit]

So does the auto ecu make better gas milage (I heard it makes the car run rich)? I also did a 5 speed swap but I'm currently using the auto ecu and auto wiring harness. I heard that you need the manual wiring harness b/c it has an extra plug that goes somewhere?!?! I was going to purchase both harness and ecu for the manual, but if not needed I wont. Also will that effect later tuning the car if its an auto ecu. Sooooo off topic but Needed info hehe.

[Florida240sx]

No need for the M/T harness and ecu to drive fine. However that is a question, I have longed to ask about tuning later on.Whether it is affected.

[phuphyter]

Quick (maybe dumb) question. Does the auto ecu adversely affect engine performance in any way since it gets better mileage?

[Mustangs_Suck]

I'm currently running the auto ECU on my 5spd swapped KA-T.

I have no speed governor, and I can go to redline in each gear.

So maybe instead of just cutting all these wires on the manual ECU, you can just get an auto ECU and have fun

The DOHC speedo goes up to, what 120?? I've had the needle go half way between the 120, and back to 0 again So obviously I have no fuel cut off anymore..

the mechanic I had said he found something that caused the ECU not to communicate well, and he just fixed it..so maybe that was it, but if not - from my experience with it, swapping to the auto ECU will eliminate all rev limiters and speed governors.