Syvecs Forums

Hi,

I'm in the process of putting a 4G somewhere it shouldn't be, and am wondering what's the best way to deal with the crank trigger?
I see the new S6 firmware has capability for the OE 4G crank and cam sensor, but is my S6 capable of handling this trigger? I recall reading that only the later FPGAs will handle this?

Before the new code was released my plan was to use a 36-1 trigger wheel for the crank, and possibly use the cam sensor too.
Now there's the possibility that the OE setup might work, only it seems the resolution is quite poor.

What should I do, and what are the pros/cons of each?
OE setup (assuming my S6 can cope with it) - low resolution?
Crank trigger disc and OE cam sensor - best scenario?
Crank trigger disc only - wouldn't sense cam belt breakage, but would it actually make much difference to resulting damage over disc alone?

Thanks,
Jezz.

Hi Jezz

Im not sure on the later FPGA situ but Pat will hopefully answer that for you.

In an ideal scenario it would be best to say just use the stock triggering system but depending on the spec of your engine this might not be the best way. What is the basic specs of your engine, is it stock?

But either way i would say to always try and use a Crank and Cam sensor.

Ryan

Thanks Ryan.

It's a stroked/forged 4G.

The thing that concerns me about the stock setup, assuming my S6 is capable, is that there are only 2 pulses per crank rev. Which doesn't sound the best?
http://www.solaris-ecs.co.uk/forum/view ... =4g63#p325

The OE cam sensor appears to be a strange affair too, it has 2 cutouts, but they are assymetric.

Thanks,
Jezz.

Jezz,

If you're building the engine then it is a no-brainer, ditch the original as fast as you can, it's a woefully inadequate affair that comes second only to the RB26 / SR20 way of doing things, at least a 4G63 has a crank sensor, LOL We added the 4G63 pattern support for OEM compatibility only, so that when people moan that they have to replace their trigger wheel with the S6 but not on other ECUs we can at least turn round and say that now replacement is optional but very highly recommended....

It is an option for people that aren't getting an engine built, and also for Group N regulations (a stock ECU must still run the car, however badly, obviously if the trigger was replaced then the stock ECU would be at a bit of a loss as to how to run it!). Other than that, time to get rid.

There are 4 edges per revolution on the stock setup, so an edge every 90 degrees. Quite what happens in those 90 degrees is anyone's guess. The crank could speed up. It could slow down. It is a long time between updates! 36-1 has a tooth every 10 degrees, ie 9 times as much information. Not exactly difficult to see why that's going to result in better accuracy But at least there are 4 per revolution, whereas previously we could only see 2 rising edges or 2 falling edges per revolution, ie 180 degrees between updates, which the FPGA simply says "NO!" to, way too little information.

The cam signal is indeed asymmetric and it is this which keys the symmetric crank signal. It should be possible to get 720 sync off the cam sensor along with a 36-1 crank wheel. However, in previous testing, 36-1 has proven to be too quick for the stock Evo sensor (the voltage slew rate is too slow), ergo an 18-1 is a better option if keeping the stock sensor. If you're replacing the sensor too then 36-1 is about as good as it gets!

As for your FPGA version, remember that it's a flash part and can be reprogrammed, so it can be updated to the latest version, albeit that is a return to base job. When you see the boot messages it will tell you the version. Anything from 2.16 onwards will support double edge triggering needed for the 4G63 pattern.

Hope this helps,

Pat.

Yes, thanks Pat that helps a lot.

I didn't realise the FPGA is flashable, i thought it was hardware. I'm pretty sure my FPGA version is 2.15 as i remember checking a while back after reading the thread i linked before.

I shall use a 36-1 trigger then, any recommendations for a suitable sensor? I have to buy a sensor either way as I don't have a stock one.

So you would you advise using the cam trigger? is there any mileage in modifying the cam trigger 'barrel' to give a single pulse per 720 deg.

Cheers,
Jezz.

Jezz,

If you're retrofitting a 36-1 then it doesn't need to be in the stock location, which opens up the possibility of using a more conventional trigger ring with something like the Cossie VR sensor. They should be inexpensive and easy enough to come by I suppose possible alternatives could be found on any vehicle that runs Bosch Motronic management (a lot of European cars) since they have a preference for larger tooth count tone wheels (60-2 being fairly common). If their sensors will go quarter of a million miles without problems, I imagine it will do a job for you

The FPGA in the S6 is indeed a flash part, if it's 2.15 and you want to try a dual edge triggered pattern then we should be able to reprogram the device with the latest FPGA fuse file. Just let us know and it shall be arranged.

In terms of the cam, no need to change anything, because it is asymmetric. If we have a crank pattern that is capable of 360 sync on its own then we can use the Manual Cam Checklist, which allows arbitrary cam patterns to be used for phase detection. It is similar to the way the VVT is set up, but instead of looking for actual cam tooth angles at defined crank rotation points, we look at how many cam teeth have been seen at defined crank rotation points. So if a tooth happens later in phase 360-720 than in phase 0-360, putting a check point between the two teeth will show it has happened in phase 0-360 but not in 360-720, ergo we know which phase we are in. Hope that makes some sense ?

Cheers,

Pat.

Thanks again Pat, it makes lots of sense.

I had a look at a calibration and the Manual Cam Checklist over the weekend and it did seem to be what I was looking for.
You wouldn't happen to have the relevant numbers handy for the 4G cam trigger, would you?

I'll be using a conventional trigger disc, rather than an OE replacement. I can find only one OE replacement which is only 12 tooth and $110.
I found an Electromotive trigger disc kit for the USDM 4G63 which is quite elegant, so I'm going to use that for inspiration along with a universal 60-2 or 36-1 disc.
http://www.electromotive-inc.com/trigge ... 73002.html

A 1/4 million miles? 1/4 of a thousand would be a nice start.

I've bought a 6.5" 36-1 trigger wheel and spent a bit of time looking at how to mount it to the front pulley/crank and how to mount the sensor yesterday, while scratching our heads about how best to go about it we had thought.
I'm removing the balance shafts from my 4G, meaning there's room to mount a decent sensor where the balance shaft belt idler is mounted, and could then possibly use the balance shaft drive pulley as a trigger wheel. This would be a far more elegant solution as everything is contained behind the lower belt cover.

The pulley has 38 teeth, I'd remove one to give a 38-1.
This gives an pretty odd angle/tooth though, 9.4736842105263157894736842105263 degrees, to be precise . Would this cause any issue?
Also the amplitude of the teeth isn't that great, Is this a concern?

Alternatively, would I be better off getting a 3.5" 36-1 trigger disc and mounting it in place of the balance shaft drive pulley.

Here's a picture of the stock pulley...



Cheers,
Jezz.

Looks like this idea is now defunct, may well be planning on using a Toyota 1ZZ trigger and sensor now and mounting it on the crank in place of the balance shaft drive pulley.