Ben

iTrader: (33)

The crank wheel is really bad ***. I have some more pics of it here
https://www.miataturbo.net/forum/t40676/

The sensor bracket mounts to existing locations on the pass side of the crank. The bracket boss is 1/2" thick and it came with replacement bolts that were each 1/2" longer than the factory bolts that came out of the block. The two allen cap screws allow adjustment of the sensor front to back to get it on the same plane as the wheel, as well as adjustment in and out from the wheel to set the gap.

The wheel itself has a center section that is concentric with the crank pulley, fits around the crank nut, and is secured by bolts around the crank nut. It too came with longer hardware to replace the factory hardware.

I wish I knew the origin of the unit, but as you can see by the rust, I got it used. It came off fmowry's car. It was on the car when he bought it, but maybe he knows more about it, or maybe he can point us towards the previous owner.

ftjandra

iTrader: (6)

I think it was made by Vishnu.

--Ferdi

TrickerZ

iTrader: (6)

Dammit Ben, I want that setup! I'm going to PM fmowry and see if he can point me in the right direction.

Ben

iTrader: (33)

Unfortunately it's been raining today. Have not been able to make forward progress on the car. :(

However, I did get the timing light on it today. I am extremely thrilled to report that timing is dead-nuts on. No scatter that my eye can detect to 4000 rpm. No hardware delay to 4000 rpm. Good stuff.

Tomorrow is supposed to be sunny, so hopefully I can get it buttoned up and take a ride.

AbeFM

iTrader: (3)

No hardware delay, huh? That's interesting. Generally by 4 it'll start showing up, and by seven it's pretty obvious. I guess there IS no delay loop inherent in a VR pick up, whereas I use a fixed delay as part of the noise filtering.

Joe Perez

iTrader: (8)

Ok, I'm feeling like a retard. I pulled up my MSQ to see what my latency setting was (I remember that I did have to dial in some latency with my 36-1 VR setup) and for the life of me, I can't remember where in MT that selection is made.

Bueller?

Ben

iTrader: (33)

Mine is under Basic > More Ignition Settings
about 80% to the bottom

Ben

iTrader: (33)

Some googling confirms that what I have is a Vishnu TEC trigger kit.

TrickerZ

iTrader: (6)

Yep, after PMing the original buyer, I confirmed that as well. So disappointed I can't get one

I need to find another good way of doing it now. Joe, you want to make me a nice hub like you did for yours? Course that still means I need to make a mount for the sensor.

Joe Perez

iTrader: (8)

Yeah, that's MS2. I'm going crazy trying to find it again in MS1...

Well, like I said in the other thread- if you have a hot, single sister in the 25-35 age range who is looking to get hooked up with one of your friends, then we can probably work something out.

Beyond that, I sold my lathe to Abe when I left CA.

TrickerZ

iTrader: (6)

It just so happens I do, but I'm not sure it'll work out. She bats for the same team...then again, you never said she had to be straight.

I wish I had a lathe. It would be so easy to make the part with a decent lathe.

Ben

iTrader: (33)

On the dyno today, one of the bolts that holds the trigger wheel cup to the crank pulley snapped. 2 others loosened up. The resultant banging noise sounded like I lost a rod. 1 bolt remained tight. We snugged the other 2 down. The broken one seems like it's going to back itself out all the way, which is awesome.

When I installed the wheel, I did loctite the bolts with blue. This weekend I'll remove them and hit them with red. Hopefully the broken bolt will fully extract itself and I'll find replacement hardware.

The rattling noise was a huge mystery. Sounded like bad engine damage, but we couldn't find what it was. We even pulled the cam cover and timing covers off, assuming it was the bearings in the tensioner or idler.

Wasted 3 hours of dyno time troubleshooting.

BOOO!!!

JKav

iTrader: (1)

Ben, I'll bet dollars to donuts (whatever the f*ck that means) that there's nothing between your trigger wheel/adapter and the four little allen bolts that hold it to the crank pulley.

What happens is that, over time, engine vibration causes the bolt heads to chew away at the soft aluminum adapter beneath them. The bolts then lose preload, loosen, and then eventually snap off. As you've found.

Loctite won't solve it.

The solution involves opening up the ID of the aluminum adapter on a lathe so that you can drop in the factory washer-ring thingie between the four bolts and your aluminum adapter. BTDT.

Ben

iTrader: (33)

There are little washers behind the allen bolts, but they have a very small OD, not too much larger than the allen heads.

Dammit.

JKav

iTrader: (1)

Yeah there's not space in there for individual washers of adequate size.

Ben

iTrader: (33)

Car is going to Orlando next week. As an interim fix, I'll remove each bolt individually and replace them with loctite red. I can also grind down an edge of a washer such that it has a short side, and put the short side against the inner edge of the aluminum cup. Hopefully that will spread the load out on a large enough surface to hold.

A solid, flat, thin steel disc may also work. Cut it to the ID of the pulley, drill it out for the 5 bolts, and put a thin coat of JB behind it.

Joe Perez

iTrader: (8)

The bolts broke at the head, or along their shaft?

This sort of thing was a great worry of mine initially, but it's all held up rather well. I do have a nice solid chunk of aluminum between my wheel and the flat, inner surface of the crank, but still, those bolts are awful long and subjected to quite a bit of stress.

Worst thing that's happened is that the wheel is cutting a bit of a groove into the face of the sensor. It's obvious that they've come into contact a few times. Can't quite figure it out, but I'm assuming I've got some flex in the sensor mounting bracket, which is quite long. Every now and again, the engine skips on me- almost always at high RPM and under high load. This could be indicative of the sensor coming into contact with the wheel- I assume that'd **** up the signal enough to confuse the software...

JKav

iTrader: (1)

A solid disc will work. The advantage of the factory washer ring thing is that you can also fit hex head bolts in there with it. More surface area than allen bolts and nicer for servicing.

Ben

iTrader: (33)

1 bolt broke at the shaft, just aft of the head. Jay's description of the failure mode sounds accurate. Under 50 street miles on the set up, and a little time on the dyno.

Man it would be nice to have a lathe.

The disc I think is the route to go.

Ben

iTrader: (33)

The 3 remaining socket cap bolts were tight after 20 miles. The original mazda hex bolts have a integrated 6mm washer. I removed each socket cap bolt individually and replaced it with a new 7mm washer and loctite red. I am going to give the loctite 24 hours to set this time, I failed to do that when I previously installed the wheel. Hopefully that will make a difference.

The 4th broken bolt seemed like it would extract itself, but so far has not. What a PITA area to get tools to, if it comes to that.