Someone told me of a mod that can be done to the inside of the distributor on a cg13 that removes the 6k5 rev limit. I'm a bit reluctant to say here what it is, but has anyone reading this heard of it? I don't understand how the ecu reacts to the changed signal.
CG13 Rev limiter removal by distributor modifications.
- Thread starter chickenwaahoo
- Start date
micra_pete
Ex. Club Member
i wish you you all the luck in the world with that one
squarepants
Ex. Club Member
prefaclifts dont have limters, only the facelifts do. dont know if this is any help?
ollie240585
Ex. Club Member
My pre-facelift has a limiter. So dunno where u've got that from Squarepants
micra_pete
Ex. Club Member
All k11's have rev limiters
squarepants
Ex. Club Member
i was told that prefaclifts cg13's didnt have them, wasnt to sure just thought it may be of some help! made me look silly really
are we talking about the top speed limter here? or the rev limter?
goldstar0011
Ex. Club Member
ollie240585
Ex. Club Member
Ah I'm not sure on that, I know I have a limiter of some kind. I can't tell if it's a rev limiter due to the fact I don't have a rev counter. lol.
Also my cars off the road at the mo due to it being dead :'(
Also my cars off the road at the mo due to it being dead :'(
Antony
Ex. Club Member
there is a rev limiter on all cars (well most, some early 1950's cars used to just run out of power or get valve bounce)
the face-lift micra's have got a speed limiter (like all jap cars after 1998 with the gentlemans agreement in japan.....like the skyline)
the pre-facelift ones dont have a limiter, (they have a rev limit, so the engine doesnt blow up but no speed limter...its just runs out of puff at 120 something..)
the face-lift micra's have got a speed limiter (like all jap cars after 1998 with the gentlemans agreement in japan.....like the skyline)
the pre-facelift ones dont have a limiter, (they have a rev limit, so the engine doesnt blow up but no speed limter...its just runs out of puff at 120 something..)
squarepants
Ex. Club Member
thats the limter iam on about!, the top speed limiter not the the revlimiter lol
the facelift's limiter is at 115mph so i belive, but who need's to go that fast when the max speed you do is 70mph.
if you are looking to remove this i think you would be looking at the ecu side of things, not to sure tho!
So many myths. No wonder everyone gets so confused all the time!
Ok the bottom line on this:
Every K11 has a RPM limiter. Its around 6900. There is no exception to this.
It is possible that the K11 has a speed limiter - pete will confirm on this. However unless you have a turbo you wont hit it - period!
You cannot remove the RPM or Speed limit by playing with the distributor.
The only way you can remove the RPM limit is to reprogram the ECU.
Everyother myth that you have heard in contradiction to this is wrong.
Ok the bottom line on this:
Every K11 has a RPM limiter. Its around 6900. There is no exception to this.
It is possible that the K11 has a speed limiter - pete will confirm on this. However unless you have a turbo you wont hit it - period!
You cannot remove the RPM or Speed limit by playing with the distributor.
The only way you can remove the RPM limit is to reprogram the ECU.
Everyother myth that you have heard in contradiction to this is wrong.
micra_pete
Ex. Club Member
yep, everything ed says there is correct
all k11's have rev limiters, some are different to others, the cg13 tends to be lower than the cg10, the limit cannot be removed but it can be raised.
also all k11's have speed limiters, it justs not all of them "use it" or have one low enough to hit in normal situations
all k11's have rev limiters, some are different to others, the cg13 tends to be lower than the cg10, the limit cannot be removed but it can be raised.
also all k11's have speed limiters, it justs not all of them "use it" or have one low enough to hit in normal situations
bobsp16
Site Supporter
my old mk3 escort xr3i had one on the rotor arm,swopped it for one off a carb modle and wayhay 7500rpm flyer went from about 112mph flatout to around 125,,,,,why carnt things be that easy today and it only cost about £4.00......
and there's no point in raising the limiter until you change your cams anyway
and there's no point in raising the limiter until you change your cams anyway
R
Robin Cooper
Guest
what age is your pre face lift? mine is 97 in the middle of alot of changes i.e got anti roll bars and limiter but it id not the face lift.
Its been around a lot longer than 1998.
Its been around a lot longer than 1998. The speed limiter in japan is a government enforced rule at 180km/hr.
micra_pete
Ex. Club Member
very true bob
Alienfish360
Awesome Dawson
Why would you want to rev that high when max power is at 6k and max torque at 4k?
micra_pete
Ex. Club Member
just so people are aware, i have just been informed very reliably that it is possible to remove the rpm limit within the dizzy.
i have no reason to doubt this is possble
i have no reason to doubt this is possble
could you shed any light on how to do this? not that i will, just curiosity!
Sorry but I think thats nonsense.
The dizzy provides the crank angle and cam position sensor. Both are vital for the engine to run and both are required for the engine to run. The distributor also contains the coil and ignition driver, usually separate but all contained on the K11.
I am open to suggestions but I'd like to see someone demonstrate HOW by altering any of this that 1, the engine would still run and 2, remove the limiter, unless for some unknown reason that the dist has a limiter below that of the ecu alone.
The dizzy provides the crank angle and cam position sensor. Both are vital for the engine to run and both are required for the engine to run. The distributor also contains the coil and ignition driver, usually separate but all contained on the K11.
I am open to suggestions but I'd like to see someone demonstrate HOW by altering any of this that 1, the engine would still run and 2, remove the limiter, unless for some unknown reason that the dist has a limiter below that of the ecu alone.
59 bhp is more than enough
Deactivated Account
mike says that ive got a rev limiter-less dizzy in my garage. i could open it up and take pics if people would like?
micra_pete
Ex. Club Member
ed. im thinking the ecu thinks the engine speed is set at at certain rpm, im not going to go into how its done, as someone charges to do, so im not going to cause problems for them.
ta
ta
This is just what the Tacho reads.. it reads more than what it actually is.. more like 6250 whish is what my old cg13 with 1.6ECU limited on the RR
I have a stock dist sitting on my desk now, I also hope to have a method by which to spin it at around 4000 rpm equil 8000 engine rpm. I then have a feq counter to count pulses and also oscilliscope to watch the outputs.
I hope at some point this evening show if there is a limiter in these things or not..
I hope at some point this evening show if there is a limiter in these things or not..
well its early days yet but this is not like any other CAS ive seen before on an eccs system, there is still a chance i shall be eating my own words yet...
That is an image of the crank position wheel. Now I admit that I always thought that this generation of ECCS had 360 degree slits and not a 4 position toothed wheel and a 5marker point like this. Very odd. Now i have heard that by modifying this it supposidly removes the limiter. It still doesnt make sense, and modification to this wheel especially the tdc marker would ruin an hopes of the ecu knowing where the engine is for sequential injection.. Perhaps with carbs this wouldnt be an issue...
That is an image of the crank position wheel. Now I admit that I always thought that this generation of ECCS had 360 degree slits and not a 4 position toothed wheel and a 5marker point like this. Very odd. Now i have heard that by modifying this it supposidly removes the limiter. It still doesnt make sense, and modification to this wheel especially the tdc marker would ruin an hopes of the ecu knowing where the engine is for sequential injection.. Perhaps with carbs this wouldnt be an issue...
Ok getting more in depth now. Further investigation shows that the CAS on the K11 is a simple single signal output, unlike the Pulsar, March ST, B13 etc N14 series of ecus, which have two signal outputs. This is really quite odd. I wonder how many other Nissans share this. I am now going to power the sensor up and have a look at its outputs and see what it does.
Fordy
Ex. Club Member
ed it controls something like the 300zx (power transistor?) that goes on the left cam cover
cause on consult we sometimes get the fault code "ignition signal primary" from the k11's which is the bit you posted up and its the same fault on the 300zx's when the power transistor goes faulty so maybe they are alike in someway in what they control?
cause on consult we sometimes get the fault code "ignition signal primary" from the k11's which is the bit you posted up and its the same fault on the 300zx's when the power transistor goes faulty so maybe they are alike in someway in what they control?
I have circled the main parts to this module.
The area in blue is soely responsible for the CAS pickup. The bit in red is the ignition coil driver, and the bit circled in red/pink is the actual ignition transistor for the coil. Its quite interesting since you dont often see the transistors without a case on them (usually metal or plastic).
I now have the cas driver working:
It's output is a pull to ground (hence why I have the 10K pull up resistor. Now im going to spin the disk within the cas and see if it cuts out at all. If it doesnt then there is no rpm limiter, and its a trick that fools the ecu in some way....
The area in blue is soely responsible for the CAS pickup. The bit in red is the ignition coil driver, and the bit circled in red/pink is the actual ignition transistor for the coil. Its quite interesting since you dont often see the transistors without a case on them (usually metal or plastic).
I now have the cas driver working:
It's output is a pull to ground (hence why I have the 10K pull up resistor. Now im going to spin the disk within the cas and see if it cuts out at all. If it doesnt then there is no rpm limiter, and its a trick that fools the ecu in some way....
Ok test setup:
I am using a motor which would be used to start model planes etc, its not an extremely fast motor, but it is torquey, and ideal for this. In fact indirectly this test has in fact measured the speed of that motor! In any case you can see it driving the spindle side of the K11 dist.
On the output from the CAS I have this:
You are looking at a frequency counter on the left which counts the pulses out of the CAS (number of pulses per second), and on the right an Oscilloscope which shows the waveform from the CAS.
As you can see from the above image the Freq counter is showing 398 pulses a second. Now for every rotation of the dist spindle there are 5 pulses. So
398/5 = 79.6 Revolutions a second.
x60 for RPM
79.6x60 = 4776 RPM
The Distributor rotates at half the engine speed so now multiply this by 2 to give the equalivent engine RPM
4776x2 = 9552 RPM
So at 9552 RPM you can clearly see that the dist is still functioning as it should do.
So what's been discovered?
My thoughts:
The K11 CAS output waveform consists of a start pulse followed by 4 longer timing pulses. The start pulse is the constant by which all the engine timing is measured, modifying or altering this will render the timing of the engine inaccurate and it may or may not even run at all. I can see how it may be possible to change the markings on this disk to alter the way in which the ecu responds to the rpm limits, however if as I have been informed its done by elongating the start mark then this may only lead to upset the engines timings elsewhere. Since I don't know exacly what is involved by this I cannot really comment, but what I can say however is that the distributor as it is has NO RPM limit built in. (at least to 9600rpm) Therefor conventional rpm removal or lifting (by ecu programming) will work as expected.
Ed
I am using a motor which would be used to start model planes etc, its not an extremely fast motor, but it is torquey, and ideal for this. In fact indirectly this test has in fact measured the speed of that motor! In any case you can see it driving the spindle side of the K11 dist.
On the output from the CAS I have this:
You are looking at a frequency counter on the left which counts the pulses out of the CAS (number of pulses per second), and on the right an Oscilloscope which shows the waveform from the CAS.
As you can see from the above image the Freq counter is showing 398 pulses a second. Now for every rotation of the dist spindle there are 5 pulses. So
398/5 = 79.6 Revolutions a second.
x60 for RPM
79.6x60 = 4776 RPM
The Distributor rotates at half the engine speed so now multiply this by 2 to give the equalivent engine RPM
4776x2 = 9552 RPM
So at 9552 RPM you can clearly see that the dist is still functioning as it should do.
So what's been discovered?
My thoughts:
The K11 CAS output waveform consists of a start pulse followed by 4 longer timing pulses. The start pulse is the constant by which all the engine timing is measured, modifying or altering this will render the timing of the engine inaccurate and it may or may not even run at all. I can see how it may be possible to change the markings on this disk to alter the way in which the ecu responds to the rpm limits, however if as I have been informed its done by elongating the start mark then this may only lead to upset the engines timings elsewhere. Since I don't know exacly what is involved by this I cannot really comment, but what I can say however is that the distributor as it is has NO RPM limit built in. (at least to 9600rpm) Therefor conventional rpm removal or lifting (by ecu programming) will work as expected.
Ed
Paul Smith
Site Supporter
I would just like to add that this modification works with great success, I picked my car up last night after having the modification done and it most certainly DOES work,
Thanks again to Humphris Motorsport for doing that for me.
http://www.humphrisoxford.co.uk/
Thanks again to Humphris Motorsport for doing that for me.
http://www.humphrisoxford.co.uk/
Ed is officially supergeek. lol
*hats off to you*
Anyway so unless there's different dizzys used by the CG's (something like what 59bhp was saying, and I recall something about nissan changing them due to faulty CAS sensors which would overheat and stop working, causing the engine to stall and not restart until they cooled down) what Ed has found is that there is a way to trick the ECU into letting the engine spin faster?
I gather this is another one of these cheapy modifications people do to these cars to get more power from them and the results could often be unpredictable?
*hats off to you*
Anyway so unless there's different dizzys used by the CG's (something like what 59bhp was saying, and I recall something about nissan changing them due to faulty CAS sensors which would overheat and stop working, causing the engine to stall and not restart until they cooled down) what Ed has found is that there is a way to trick the ECU into letting the engine spin faster?
I gather this is another one of these cheapy modifications people do to these cars to get more power from them and the results could often be unpredictable?
I have already contacted Matt, hopefully he will help.
I wanted to establish weather there was a RPM limiter in the dist in the traditional sense. I.e. above x-RPM the unit stops sending signels. This is what I wouldn't accept, and as I imagined it doesn't. However having modifying the sensor wheel is somewhat a different modification. I am surprised it works and this area is what I am hoping may may help with.
I wanted to establish weather there was a RPM limiter in the dist in the traditional sense. I.e. above x-RPM the unit stops sending signels. This is what I wouldn't accept, and as I imagined it doesn't. However having modifying the sensor wheel is somewhat a different modification. I am surprised it works and this area is what I am hoping may may help with.
