Crank Triggers And Rb Possibilities .

[discopotato03]

Crank triggers get mentioned often with high performance and I gather most motorbike ignition systems so I though its time some info could be added here for those interested .

The reason to consider crank triggers is that any ignition system driven by a distributor or camshaft will have slop or backlash to some degree and the only rock solid reference your ever going to get is from crank position - at the crank/pulley/flywheel .

If you google crank triggers for RBs you generally go straight to Ross kits but at $2000 to buy and something like $1000 to fit they're not a cost effective solution for most of us . There's lots of other engines catered for like American V8s and a few popular Japanese fours but not so much Nissan RBs , shame they never had LHD Nissans with RBs in them ...

In another thread here I posted a link to GTROK where some thinking individual mounted a toothed trigger wheel to the back of an OE RB (26 ?) crank pulley and if thats reasonably straightforward to do I'm stuffed if I know why every power hog isn't doing this . A crank trigger should be piss easy for most aftermarket engine management systems to read and the only other thing you need is a cam reference so you can time sequential fuel injection .

I'll throw up some links that have interesting reading about the possibilities of fitting trigger wheel on pulley systems to Nissan RB engines .

Without looking I know Nissan used a crank trigger for one year only (1981 USDM 280ZX Turbo L28ET) and Mitsubishi had them on some 4G63 turbo engines . I'm told BMW have used something in their flywheels and have a Hall sensor in their bellhousings to sense them .

I chased a link to this site and it has a few interesting links and pics within , its a Datsun 1600/510 site BTW .

http://www.the510rea...p?f=10&p=154506

I think if you can crank trigger a basic Nissan L Series engine you can do anything . The major differences pulley wise is of course the current multi v flat belt systems rather than the 70s era single v belts and pulleys .

This is the GTROK link that shows pics of a trigger wheel mounted on a std RB crank pulley .

http://www.gtr.co.uk/forum/161454-ati-crank-trigger-shells.html

I'm not suggesting that everyone should spare no effort to have a crank triggered RB six but with a bit of thought and effort I don't think it would be a megga expensive thing to do .

If anyone has any additional info on crank triggering an RB for reasonable money can they post it here please .

Cheers Adrian .

Edited January 1, 2013 by discopotato03

[NYTSKY]

Keen to see some results too, a friend of mine has the full ROSS kit and will be fitting it in a few weeks.

I only know of Paul (Piggaz) having the same kit so documented real world results have been limited.

[Risking]

I've fitted 4 Ross trigger kits.

They all worked perfectly. One of them was with a Haltech PS2000 pro plug in ecu. Haltech had to change the ecu software to read the new 24-1 trigger as the pro plug in was locked to the Nissan optical sensor.

One was with a motec M600 and works spot on.

One an m800 again working Great.

The last is a wired in PS2000 on an Sr20 that's nearing completion.

I do agree Ross' pricing can be a tad high considering what you are actually getting but it is nicely finishe gear and does work.

Just check carefully the sensor position. The first ones I did the sensor wasn't in the middle of the chopper wheel. I know Ross has fixed that issue now but I still check them.

[Risking]

It's also very easy to have a trigger gear laser cut and a step machined into it to locate centred on the Oem crank pulley.

Counter sunk M6 bolts drilled and tapped into the back of the balancer will hold it.

A simple bracket to hold a Honeywell Hall effect sensor and away you go.

Cam sensor is a little harder and I really like Ross's setup for that.

[GTRNUR]

Anyone that has good knowledge of how to setup their after market management should be able to do this. I think where the problem comes in is that the engine management installer/tuner isn't often the same guy as who does the engine build, and its not uncommon for these two guys to not talk.

I've done quite a few crank trigger setups, not on RB's but on engines that never had EFI to begin with. I have had a more success using Hall Effect sensors than reluctor, as the triggering event produces a more clean switching signal that isn't dependant on RPM.

On one of my engines at the moment I have mounted the sensor through the flywheel cover plate on the back of the engine, and trigger it from the bolts that hold the flywheels pressure plate in place. This was an easy solution for me as I just replaced 2 flywheel bolts with grade 12 studs, and screwed them through the flywheel so they protruded 3mm higher than the surface of the back of the flywheel. The air gap to the sensor was then set with washers under the tag that holds the sensor in place.

I have heard of this approach being done on RB's from the other side of the flywheel too, with the reference sensor mounted in the bell housing. Far too much of a pain to install in my opinion, but it has been done. If/when I do an RB with this method, the sensor will mount straight on the flywheel cover as well. If flywheel bolt triggers aren't an option, its no big deal to drill and tap in a few small holes for a few long grub screws to be installed to trigger off.

Sync sensors are easy to put in place. With an RB you could use the cam sensor and change the disc. But I would be more inclined to mount a sensor inside the timing belt cover where it can trigger from a cam gear. It doesn't really matter where you have it trigger from, as you can alter your injector and ignition sequencing later to make it run. If I were using adjustable cam gears I'd just replace the 3 of the 4 locking bolts on the adjustment lock with 316 stainless bolts, and trigger off the 4th. I have used this approach as well where a sensor was positioned to sync/trigger directly off the front of a camshaft. Works a treat!

[GTSBoy]

Surely it would be worth investigating putting the angle sensor from the VQ engines onto an RB. They read teeth on (attached to) the flywheel.

[Risking]

It's a part of the dual mass flywheel on the manual VQ's.

They just use a Hall effect sensor same as the common Honeywell sensor everyone uses.

There wouldn't be much point trying to use an VQ gear when you could just index an RB flywheel on a dividing head and instal your own pick up points then mount the sensor.

Most Motorsport applications use the crank pulley/front of the engine.

Manufacturers use a lot of flywheel and internal engine triggers to keep things hidden and compact

It's easier to set up, view problems, keep clean and maintain than a flywheel trigger.

[GTSBoy]

Well, it's part of the driveplate on the autos too. I've seen people use that toothed ring added onto other flywheels when doing VQ->Skyline etc conversions. That's pretty much what I would have done if I'd manned up and put a VQ30 into my car instead of a Neo.

[Risking]

The auto flex plate would be much easier to adapt than the manual flywheel.

From memory the sensor mounting hole is tapped into the sump on a VQ so using that setup in a conversion makes sence.

The 4G63 and most Mitsubishis have neatly done trigger setups with chopper plates behind the timing gear.

Problem with a factory nissan balancer is there is not a lot of space between the pulley and timing case to fit a trigger wheel in.

[rob82]

If your laser cutting a missing tooth crank triggers make sure that the missing tooth cutout is not as deep as the other teeth. It can be an issue on some ecu's using reluctor style sensors as the voltage induced can be slightly higher than other the other teeth which can upset the filtering.

As for hall vs reluctor, most hall sensors are just an reluctor sensor with a Schmitt trigger output that produces a square wave. Most basic ecu's deal with square signals better than sinusoidal signals that increase voltage with increasing revs. But with some high end ecu's you can get better signalling with reluctor sensors as the filtering can be performed through software.

[GTR_JOEY]

Keen to see some results too, a friend of mine has the full ROSS kit and will be fitting it in a few weeks.

I only know of Paul (Piggaz) having the same kit so documented real world results have been limited.

I've got one.. Works great

[Risking]

This is a quick rendering of a trigger wheel I get done to use behind a factory RB26 balancer.

I normally get 4-5 of them done at a time and works out rather cheap.

Obviously uses a Cam referance for TDC having 6 trigger events.

[discopotato03]

Personally I would rather try to use a new factory crank pulley damper and try to mount the toorhed wheel on the back of that . If one could be supplied set up and with a suitable Hall sensor and mounting bracket the install becomes straightforward .

With the missing tooth wheels I think these are intended to be used with ignition only computers or with basic batch fire fuel injection . To run sequential EFI you need a reference signal driven off a camshaft (in the RBs case) because the complete four stroke cycle takes two crank revs and only one camshaft revolution . The computer needs to know slightly ahead of time when the crank (no 1 cylinder) is approaching top dead centre on the beginning of the first revolution of the two rev cycle .

Somewhere there is a pic of the I assume exhaust cams nose with a wing on it for the hall sensor .

If as mentioned above a sensor can be mounted under the belt cover that would be good too .

If you could keep the standard CAS in position you would have a back up system or at least something workable while the crank trigger was being set up and tested . Looks standard though the average leg of ham probably wouldn't notice changes anyway .

Cheers A .

Edited January 1, 2013 by discopotato03

[Risking]

That's what that trigger wheel above is used for. Factory balancer that just needs to have the mounting holes drilled and tapped

[rob82]

Personally I would rather try to use a new factory crank pulley damper and try to mount the toorhed wheel on the back of that . If one could be supplied set up and with a suitable Hall sensor and mounting bracket the install becomes straightforward .

With the missing tooth wheels I think these are intended to be used with ignition only computers or with basic batch fire fuel injection . To run sequential EFI you need a reference signal driven off a camshaft (in the RBs case) because the complete four stroke cycle takes two crank revs and only one camshaft revolution . The computer needs to know slightly ahead of time when the crank (no 1 cylinder) is approaching top dead centre on the beginning of the first revolution of the two rev cycle .

Somewhere there is a pic of the I assume exhaust cams nose with a wing on it for the hall sensor .

If as mentioned above a sensor can be mounted under the belt cover that would be good too .

If you could keep the standard CAS in position you would have a back up system or at least something workable while the crank trigger was being set up and tested . Looks standard though the average leg of ham probably wouldn't notice changes anyway .

Cheers A .

Missing tooth wheels are used on both sequential and batched fired ecu's. I believe the missing tooth wheels came about so that manufactures could still time an engine and keep it running if the sync sensor failed. It can also be used as an early way of determining where the crank is at before the sync is picked up.

[Risking]

Just to add some interest to the thread.

Here is a trigger set up from an GRM built 18 deg chev supercar engine.

Its filthy and has been sitting around but its complete and shows what they use and how simple it can be.

Nothing flash just straight forward sensor mounted to a machine bracket and a 4 trigger wheel.

Also a photo of the dizzy which is all custome made to suit the morrision injection. Using a simple single trigger and sensor.

An important thing to notice is that the trigger event happens pre TDC. approx 50 degrees is the magic number they use. no point giving it a trigger event at TDC as they cant process the event and fire everything that quickly.

[Nur33]

Here's the setup on my Drag RB26 it is a Godzilla Motorsport/Custom setup has not missed a beat. I will be putting a similar setup on my SR20 Time Attack Engine.

[discopotato03]

That type of Hall sensor distributor pickup was a popular Bosch distributor conversion back in the 70s and 80's . Things like Olden red motors and some Australian built Japanese cars with local content parts sometimes got them .

For the record does anyone have pics of std RB25 and 26 puleys and are they all one piece so to speak - belt pulley wise ?

A .

[Risking]

Nicely done NUR33.

Notice you've moved the power steering down under the alternator.

[Nur33]

Yeah needed to make more room for Turbo and Dry Sump Pump, turned out pretty good.