Hwo got a OEM crank pulley they dont use?

Don't now about other ecu's.

 

There is a "small" problem with the idea of running with a flywheel sensor tho...

Keep in mind that the original problem is that the cas flickers back and forth in front of the sensor, right. And cause it got so many holes in it this represents a problem.
Now imagine doing it from the flywheel, If you want to run fully sequential you will need a cam sync signal. (if not you just need a missing tooth wheel on the crank). The cam signal will in this case come from the cas.
The ecu will start counting teeth from the cam sync signal until it figures its time to fire it up. Now since the cam sync is still in the cas, and the cas STILL flickers the count will start at different crankangles every time.
Im my case i will run a 24 tooth wheel. If the camsync flick should have a negative effekt on MY car it would need to flick more than 15 degrees (360*/24). As this is not likely to happend i will be safe.
But a flywheel with all its teeth will have very high resolution and it might be a problem, setting you right back where you started.
The solution would be to hack of a tooth or two from your flywheel (your starter might not like that) and make a camsync LEVEL trigger. That is a trigger that is open for one crank rev and closed for the next (total of one cam rev).
Your ECU will start to count from the missing teeth on the flywheel, and determin what cylinder to fire up depending on if the cam signal is high or low.
Of course you still will need to find a ecu that supports that many teeth.
Or you could do the same with a smaller missing tooth wheel on the pulley.

 

Apparently Haltech have this problem too....

http://forums.haltech.com/viewtopic.php?f=28&t=9929&sid=4b126a6ec48a1b7b0fafdf64711526b7

So there is THAT myth busted...

 

can anyone confirm the Cam sensor setup

so 36-1 crank trigger wheel but do you need to change the CAS disc?

 

If you are using a crank mounted missing tooth type trigger wheel, you dont need a cam position sensor.
E

 

You do if you want to run sequential fuel and ignition.
I ended up with a racepully from Ati with 24 treet. And an AEM disk in the cas

 

Thanks mate yeah sequential for sure. Pure for idling on big injectors. So aem disk in cas and then crank wheel to suit. Thanks heaps.

 

No you dont m8. Sorry. Your info is flawed. Missing tooth timing wheel will handle full sequential happily unless you are using some dinosaur old ECU in which case you might as well fit a carby.

Furthermore just having consistent synch timing is pointless when your primary triggering events are handled by the cam position sensor. If the timing is scattered there, nothing will correct it.

You either go full crank triggering or just run stock and get over it like most of the rest of the Nissan belt driven world.

E

 

This link should save me alot of typing...

http://www.msextra.com/doc/ms3/trigger-wheel.html

 

So i got back from work, got nothing better to do and have an actual keyboard infront of me (instead of the phones softkeys) so i guess i just as well might fill in a little.

Tass, i`m sure your last reply comes from a missunderstanding or that your brain just stopped working for a moment. So this if for those that dont know how it works.

As our engines are 4 stroke engines it takes two full crank revolutions to do a full "circle". Thats 720 degrees (suck,squeeze,BANG,blow).
Say you got a two cylinder (example just for simplicity) 4 stroke engine...
You got a missing tooth triggerwheel on the crank. 36-1 or whatever.
Engine running and the ecu sees the missing tooth then starts to count degrees and theet until it knows it is time to fire a plug. But wait! What plug to fire?
As there is only the crank trigger wheel it does not know witch revolution the crank is at. Is piston one headed for the bang or is it piston two? As the ecu simply doesnt know cause nothing is telling it it would need to be run in batch fire/wasted spark mode. It has to fire both injectors at the same time and both plugs.

Now if you have an engine that goes a full cycle on just 360 crankdegrees then thats another animal. That would be 2stroke engines and rotarys. Then you will be able to fire just the injector/plug that is next in line.

If you have a SYNK signal going at half crankspeed (camshaft) on the 4stroker the ecu knows that hey there was the cam signal, now i KNOW that cylinder nr one is coming up for the fire. And it also knows that the next time the missing cranktooth is passing the sensor it is cylinder two is up for it.
Next time the cam signal fires again its back to cylinder one... and so on...

So if you know an ECU that is able to determine what cylinder thats about to fire with ONLY a missing tooth wheel mounted on the CRANK then name it. Cause i want it! That ECU must have been made with some very cool alien tecnology or something.

If the missing tooth wheel is mounted on the CAM on the other hand. that would be all you need cause it rotates at half speed. It would fight the purpose in our case though since the cam is so unstable in relations to crankdegrees.

Now it seem Tass that you missunderstood and thought i would use the crankwheel for synk and the aem disk in the cas for timing, but its the other way around of course. If it WAS the case, then i would agree. Would be pointless.

"The rest of the Nissan belt driven world" are seeing timing scatter as well especially on highly modifyed cars. They are also fighting it with crankmounted triggers (aaaand cam sync sensors).
And to be honest so SHOULD everyone running high powered VG`s too IMHO.
Many may be running ridiculous power with the stock CAS, but they would probably be able to run even ridiculouserer power with a stable timingsignal as one wouldnt need to run lower timing that necesairy trying to avoid knock cause of the scatter.

puh.. Wouldnt that have been fun to type on a phone with autocorrection set in another language..

 

Pretty much whole reason I want to do it especially with nitrous.

The aem disk has the 24 slots us the single tdc(I think) slot. That tdc slot is the one the ecu uses to synch correct?

 

Correct.
What ECU do you have?

 

Got any pics of the pulley?

 

Mine? Sure



I did hack of a thooth off it tho. So its now a 24-1 wheel

 

Awesome. One more pic request

Which part did you mount the sensor too? I've seen a couple of setups but no clear detail.

 

Here is a pic. The bracket here is still a work in project. Needs some more bracing. I however drilled and tapped (and helicoiled) into the AC compressor bracket. So taking the ACbracket off will take the sensorbracket with it if that makes sense.
It is said that if you, when you are done, can move the sensor just a little bit with force, then its not good enough

 

Hahaha swear this is exactly where I'm going to put mine! Well done for posting pics. I'm going to start playing around with solid works to make a cnc 36-1 wheel and bracket. I think the timing drift results in lots of engine failures and detonation for the VG30DETT.

Thanks heaps mate

 

yes i am absolutly sure more high hp engines would have survived if people were aware of this problem.

You`re welcome!

 

Just figured i would post before and after pictures. The before picture is the same as posted at page one...





Relevant changes that would affect graph.
My old JWT400+ cams on old log
New JWT500 cams on the new log
And obviously the stock CAS setup vs cranktrigger.
This is obviously just what the ecu sees, but i can assure you the actual timing as pr shoot with a timinglight is dead steady.

 

Can you elaborate please ?