CG13 Rev limiter removal by distributor modifications.

[Ed]

I don't know precicesly. I would imagine one of the slits is made wider. The ecu will count the time between the start and stop of a slit, if the time is too short it will know that the RPM is higher than the ECU limit RPM. NOW if you make that slit longer, time will be longer and the ECU will think that the engine is turning SLOWER, Alter it by a fraction, and say you may find youself with a much higher rev limiter, but all the load cells will not really apply correctly, although it would still run. If you then upped thefuel rail pressure to compensate for the fact that all the load tables are a bit out it may even work. And you could retard the ignition slightly to compensate for the ignition tables being out slightly too. In anycase. Thats just a guess...

Ed

 

[NeX]

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!

are you sure?

when i get my car to 120mph there is a flat spot right at the top. you can feel the loss of power, its at about 119 according to the GPS

 

[James]

The 1.6 though NeX? Lol

 

[Ed]

Going off topic

 

[chickenwaahoo]

So where did we end up with this? Is your car still running OK Paul?
We have found on some rallies (Colerne in particular) with long straights where we are flat out in 5th (with 14" slicks this is about 95mph ish) that we could do with say 500rpm more. We will be building an engine soon, on throttle bodies and stand alone, so it won't matter then, but still very interesting.

 

[Paul Smith]

Hi, Yep my car is still fine, its alot nicer drive reving that bit higher. I tend not to rev above 7200rpm but it will do if i want to. What i found is by reving that bit more in 4th gear seems to help 5th. what i found was 5th never really had much power more of a cruising gear but by getting that bit extra in 4th seems to give 5th a bit more pull, which is nice. (hope i explained that alright).

 

[Napster]

i do enjoy reading the "knowledge" that everybody has on MSC

Ed in my opinion what you did and discovered was crazy......BUT awesome for testing something new, due to the fact you where inquisitive over the matter, because you had one idea in your head and didn’t just want to pass the matter off

Ok so I kinda get the end result......but what happens now? i mean regarding changing RPM limit?

People where discussing "timing" and "Ed" said bout:
"The ecu will count the time between the start and stop of a slit, if the time is too short it will know that the RPM is higher than the ECU limit RPM. NOW if you make that slit longer, time will be longer and the ECU will think that the engine is turning SLOWER, Alter it by a fraction, and say you may find yourself with a much higher rev limiter, but all the load cells will not really apply correctly, although it would still run"

I know "Paul Smiths" micra seems to be running ok? do u know exactly what they did?? or was it as discovered above?

but going back to timing and problems occurring.....is this a definite? because does that mean a new dizzy and ecu and engine components have to be uprated to stop engine problems or am i wrong or will it work fine!!!!???

Thanks
Napster

 

[Ed]

Basically there is no rev limiter in the Distributor, but this mod does work (even if its not ideal). My theory on this is that the modification of the dist may remove the ability of the ECU to fire sequentially, I would need to test to be sure) this is no real issue, but since one of the timing slits is now longer, that makes the apparently speed to the ecu appear lower, so it then causes an increase in the apparent rev limiter.

I spoke to Matt Humphris a couple of times about this now, and he has seen no apparent problems with this setup, although admits that obviously its not as good as a remapped ecu.

Ed

 

[Napster]

Basically there is no rev limiter in the Distributor, but this mod does work (even if its not ideal). My theory on this is that the modification of the dist may remove the ability of the ECU to fire sequentially, I would need to test to be sure) this is no real issue, but since one of the timing slits is now longer, that makes the apparently speed to the ecu appear lower, so it then causes an increase in the apparent rev limiter.

I spoke to Matt Humphris a couple of times about this now, and he has seen no apparent problems with this setup, although admits that obviously its not as good as a remapped ecu.

Ed

thanks for clearing that up ed!

another question....(forgive my ignorance)......but regarding the "ECU Remap", instead of adapting the dizzy, with remapping the ecu on a standard 1.3 (cg13) what exactly are you going to change, increase, adapt to get a better power increase etc......or you mean change ECU setup to a a cg13 with a turbo???

if thats confusing (probably is, so my apologies) i can try and explain in another way?

thanks again

 

[evade]

Just FYI,

My dizzy has been modified slightly to work with my standalone ECU - in order to get it working we had to cover up that little hole on the rotor disc.

We also had to offset the placement of it so we could get the base timing needed to match the ecus

It all works though..to think all thats covering that hole is a little piece of some sort of tape..spinning that fast..for that long..im surprised its lasted haha..was supposed to get a new disc machined but never got around to it.

 

[Antony]

so ed, the standard micra ecu?. can it be mapped to alter Rev limit, Injector duty cycle and ignition timing?... if so, whn do i book it in with you?..lol

 

[Craig]

You will need, as I understand it - basically - to clone your ECU onto a new EPROM that is affixed to your ECU. This new EPROM is unlimitedly (ish) flashable so that you can 'reprogram' your ECU, it's not like some cars, Volvos for example, where the original ECU is flashable.




As I understand it, I await Ed to post and say I have tyoed a load of rubbish

Craig

 

[whipit]

Basicly what micra pete does.

 

[MickMannis]

so the limiter is in the ECU only? Not in both like previously stated. So what does modification of the sensor wheel do? Trick the ECU in thinking its at a lower RPM?

The dizzy cant send a RPM signal, Therefore it stops working, And you can rev up to 110k, But i wouldnt go over 100k imo

Adam

 

[Retepetsir]

Wowsers, thread from the dead!

 

[Robb]

Wow 110k rpm

 

[Noddie]

i know its going off subject but this tread is old anyway so i see no harm, just going back to what everde said, is it quite possible that to get the micra cas to work with a standalone you have to cover up the little hole in the dizzy? also, if you do ever read this everde, what do you mean by 'off setting it'. if anyone can help that would be great.

 

[Chrismo]

If you want to put the limiter a bit higher......you do as Matthew says: Cut the little metal between the hole and the ****. This way the electronic limiter goes away, and the fuel-cut comes in at 7500 rpm.

Done it myself and it works 100%. At first I was a bit worried there was no limit anymore, but when I go further, there is one at 7500.

WORKS





gr Chrismo

 

[baguete]

If you want to put the limiter a bit higher......you do as Matthew says: Cut the little metal between the hole and the ****. This way the electronic limiter goes away, and the fuel-cut comes in at 7500 rpm.

Done it myself and it works 100%. At first I was a bit worried there was no limit anymore, but when I go further, there is one at 7500.

WORKS





gr Chrismo

Hi Chrismo, you said that at 7.500rpm the fuel cut comes in. I have that problem. In 1st and 2nd gear, i can push it to 8.000rpm, but in 3rd
and 4th it simply cuts at 7.300-7.500rpm. I have the stock ECU but with NIStune, i can alter all the maps, so how do i remove the fuel cut?

 

[Noddie]

Hi Chrismo, you said that at 7.500rpm the fuel cut comes in. I have that problem. In 1st and 2nd gear, i can push it to 8.000rpm, but in 3rd
and 4th it simply cuts at 7.300-7.500rpm. I have the stock ECU but with NIStune, i can alter all the maps, so how do i remove the fuel cut?

i doubt that the fuel cut is part of the map, it will be a rev limit option in the softwear. the reason you may be getting to 8k in first and second could have somthing todo with the engine's momentum taking it there, if you gradualy rev up in 2nd can you still get to 8k?
does anyone have any answers to my question? Ed? you must know

 

[baguete]

i doubt that the fuel cut is part of the map, it will be a rev limit option in the softwear. the reason you may be getting to 8k in first and second could have somthing todo with the engine's momentum taking it there, if you gradualy rev up in 2nd can you still get to 8k?
does anyone have any answers to my question? Ed? you must know

Not momentum, the revlimiter is set to 8.000rpm in the ECU. It only hits the fuel cut when it goes alot of time in a gear, like in 3rd or 4th...
I already know what to do to take out the fuel cut, just need to raise Max Theoretical Pulsewidth in the ECU and it should be ok till 8.000rpm.

 

[Noddie]

Not momentum, the revlimiter is set to 8.000rpm in the ECU. It only hits the fuel cut when it goes alot of time in a gear, like in 3rd or 4th...
I already know what to do to take out the fuel cut, just need to raise Max Theoretical Pulsewidth in the ECU and it should be ok till 8.000rpm.

how does altering the pulse width raise the rev limit? i didnt think they were linked...

 

[baguete]

how does altering the pulse width raise the rev limit? i didnt think they were linked...

Because even if you have the revlimiter raised, say to 8.000rpm, the fuel cut comes in and you cannot rev past 7.500rpm on higher gears...

---------- Post added at 22:32 ---------- Previous post was at 22:26 ----------

See it here, the fuel cut comes in at 7.300rpm even with revlimiter set to 8.000rpm:

Yellow - HP
Blue - Torque


Video (the altered maps didnt have nothing special yet):

http://www.youtube.com/watch?v=I238GDblp-Y


Stock:
55HP @ 6000rpm
79Nm @ 4000 rpm

Modded:
80,7HP @ 6819rpm
88.8 Nm @ 6012rpm


When i have time, i will scan and upload the printout.

 

[Noddie]

Because even if you have the revlimiter raised, say to 8.000rpm, the fuel cut comes in and you cannot rev past 7.500rpm on higher gears...

---------- Post added at 22:32 ---------- Previous post was at 22:26 ----------

See it here, the fuel cut comes in at 7.300rpm even with revlimiter set to 8.000rpm:

Yellow - HP
Blue - Torque


Video (the altered maps didnt have nothing special yet):

http://www.youtube.com/watch?v=I238GDblp-Y


Stock:
55HP @ 6000rpm
79Nm @ 4000 rpm

Modded:
80,7HP @ 6819rpm
88.8 Nm @ 6012rpm


When i have time, i will scan and upload the printout.

i still dont see what the pulse width has to do with it:S pulse width is just how much fuel goes in per cycle, not when the fuel cut is... well, thats my understanding anyway.

can noone help with my question???

 

[baguete]

i still dont see what the pulse width has to do with it:S pulse width is just how much fuel goes in per cycle, not when the fuel cut is... well, thats my understanding anyway.

What happens is that TP has a max value, which the engine achieves at 7.500rpm. So, the ECU enters on safe mode and cuts all the
fuel even if you have the revlimiter higher than that. Just raise that value so it stops entering safe mode and only cuts on the specified rpm.

Check this:

http://www.nistune.com/docs/NIStune_Mapping_Guide.pdf

and see the "Fuel Cut" part.

 

[Ed]

Its not the TP. Its simply the rev limit. Its very easy to increase when you have access to ecu code, via rom board or what not need to make sure everything else is still ok however.

 

[baguete]

Its not the TP. Its simply the rev limit. Its very easy to increase when you have access to ecu code, via rom board or what not need to make sure everything else is still ok however.

I know Ed, i had set the revlimiter to 8.000rpm on Dyno, but he cuts at 7.300rpm, because the TPMax is
too low. Only happens on high gears, not on 1st or 2nd. I can make a video of running on 1st and 2nd,
and it doesnt cutout until the revlimiter of 8.000rpm... And will raise TPMax value and make a new Dyno.