Trigger Wheels And Sensors (What worked what did not.)

Patriq · Post by **Patriq** » Fri Feb 06, 2009 1:09 pm

third image

Dean924s · Post by **Dean924s** » Fri Feb 06, 2009 3:16 pm

alexander wrote:dean, without looking it up, i don't suppose your existing gear was terribly expensive.
so why not just buy another one, put them both on a bolt, and lock them together with a couple of bolts, epoxy glue, tack weld etc.
that will double the thickness and you wont have to change your existing work.

alexander.

I will have to look at that. I am concerned that there is a slight beveled edge to the teeth. This would leave a gap in the teeth in the center of the trigger wheel. I could machine the two faces of the two wheels but for that$$$ I bet I could just purchased what I need. I also found out that the gear manufacturer has a machine shop local to me that will make modifications to gears relatively cheep. I am thinking of going with the 1/2" wide gear and having it lightened up be machining out metal from the outside edge (trying to keep it to a singe step. While I am there I will have the center hole re rilled to match the mounting stub for the rotor so ti will be a bolt on deal. I will then have them rill the hole I need for the locking bolt or I will just have it slotted so ti will allow for some adjustment of the wheel relative to the trigger.

There are two advantages to this. the frost is i becomes a much more plug and play install. The second is that by milling the gear I remove a tremendous amount of metal form the outside of the gear greatly reduce the rotating mass of the trigger. Lastly by going to a bigger gear with the similarly scaled up tooth design I am betting that I will get a much better / cleaner signal. (A case where bigger is better LOL)

Cost of gear is about $50 I would need a 1/2 hour of machine time at $70/hour. I have been wanting to clean up the mount of the sensor anyway so this would be a good incentive to do so.

I will probably try the two gears together (I already have a second one anyway and see if it helps. I will have to re shim the sensor out but that is just adding a bolt and or a washer under the bracket.

alexander · Post by **alexander** » Fri Feb 06, 2009 10:57 pm

keep us posted

Supercharged Nat · Post by **Supercharged Nat** » Wed Feb 11, 2009 10:01 pm

sorry to drag this post back up but a set of feeler gauges are perfect for setting the gap very accurately (you the things you use to set psark plug gaps, valve clearances etc). I just thought id mention it.

DannyP · Post by **DannyP** » Thu Feb 12, 2009 1:17 am

Nat I didn't have .040"(1 mm) as a single gauge, but that's what I used. I put .018 and .022 together, no problem.

Dean924s · Post by **Dean924s** » Sat Feb 21, 2009 5:13 pm

Supercharged Nat wrote:sorry to drag this post back up but a set of feeler gauges are perfect for setting the gap very accurately (you the things you use to set spark plug gaps, valve clearances etc). I just thought id mention it.

In my book I encourage people dragging them back up it keeps all the related questions / Tech on a subject in one place. Having to run through 10 posts on trigger wheels (although interesting) can be a bit tedious. I was hoping that by starting this thread that others would post up there info and as the title says what worked well and what did not.

I space my sensor as close to the wheel as I can. If I can get it closer that .030 of an inch I will. Basically I will set it will a piece of paper between it and the teeth on the side that is closest to the sensor when you rotate the wheel. (they are never perfectly round)

I have got in a 3/8" wide wheel that is almost identical in width to the stock RX7 trigger for there VR sensors. I have also figured out a way to modify the VR sensor from the RX7 so using larger wheels is not a problem. (swap around how the management and the sensor are mounted to the bracket). The only thing I am wondering is that since I swapped the sides that the sensor mounts to the magnet if I in effect have switched the polarity of the sensor meaning I will have to wire it opposite from how I currently have it set up. We will see.

I also have taken my vernier dial calipers to a bunch of trigger related parts and will post up photos and measurements so others can reference them.

Anyway I was hoping that this thrend would / will become a repository for anyone's tech and questions related to trigger wheels and the sensors.

Dean924s · Post by **Dean924s** » Mon Feb 23, 2009 9:56 pm

I also spent a significant amount of time re working the 3/8" trigger wheel I got. The primary reason was to remove weight and to eliminate the ugly mounting bracket that I had for the sensor in my current setup. My new setup uses the modified sensor mounted to the cam cover directly and the trigger wheel will be skimmed using fender washers. I also get the trigger wheel with a much more accurate hole so centering it on the camshaft will be a much more precise affair.

Anyway photos of a bunch of things I measured:

First off Ford VR sensor measurements:

Dean924s · Post by **Dean924s** » Mon Feb 23, 2009 9:58 pm

Next up Ford Trigger Wheel Measurements:

Dean924s · Post by **Dean924s** » Mon Feb 23, 2009 10:04 pm

Rx7 sensor measurements

EDIT: I was going to post photos of my RX & Sensors. Measurements of the sensor its self as well as photos of the standard sensor and the one I modified for clearance when you want to use a larger trigger wheel but I got a big read message that said

"Sorry, but the maximum file size for all Attachments is reached. Please contact the Board Administrator if you have questions."

brent when you get a chance could you resolve this?

Many Thanks!!!

DannyP · Post by **DannyP** » Mon Feb 23, 2009 11:01 pm

Dean, you might have too many files uploaded. Try deleting some of your older or unneeded stuff.

Post by **brentp** » Tue Feb 24, 2009 8:35 am

Nope, it's was something I needed to adjust. It's fixed now..

Dean924s · Post by **Dean924s** » Tue Feb 24, 2009 10:38 pm

Ok Back to the Pix

RX7 sensor measurement of the actual pickup.

Dean924s · Post by **Dean924s** » Tue Feb 24, 2009 10:40 pm

Standard unmodified sensor against the trigger wheel. Note the tight clearance to the magnet. This is about as large as wheel you can use with an unmodified RX7 sensor

Dean924s · Post by **Dean924s** » Tue Feb 24, 2009 10:41 pm

Now the modified sensor Note the additional clearance

Dean924s · Post by **Dean924s** » Tue Feb 24, 2009 10:42 pm

And finally the two together showing the difference in the clearance.