Converting 202 to ABS Crank Trigger

[Holden202T]

ok bit more progress, starting to make the trigger mount, wondering how sturdy its going to be with the available bolts to mount it, i guess will just have to see and adapt and overcome if the need arises - at least with this setup i can easily rev the motor and watch the mount to see if it vibrates or anything.

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so this is roughly how its going to go, will weld the plates together and add a few gussets and 'suck it and see'

Fireblade, as far as getting it running on the stand you need the 1. pink (with red stripe) wire on the under dash plug powered (not the one that goes to the aldl plug its just straight pink) you also need the 2. red (switched power) and 3. red/black trace (constant power) wires on the black engine plug (near front drive side of motor in a commodore) and also there is a 4. green/white trace one here, i use this just so it works the fuel pump relay properly, but you don't need it if you are happy to run the fuel pump by another source.

3. connected to constant power OR directly to a switch

Relay 1 (5 pin relay with 2 x 87 pins
1. connects to one of the 87 pins (for this one i got a male flat spade lug and ground it in half, slots into the small plug perfectly)
2. connects to the other 87 pin
pin 30 is power from battery
pin 86 is earthed
pin 85 is +12v through a switch

Relay 2 (4 or 5 pin relay)
pin 87 goes to the +ve fuel pump wire.
pin 30 is power from battery (i have this through the same switch as above)
pin 86 is 4. from above.
pin 85 is +12v through a switch

oh and do you have a link for the ebay item ? is it this one http://www.ebay.com.au/itm/holden-turbo ... 231fff6755 if so wont work for me, i need something with the turbo infront of the motor mostly, the old gem bay is pretty small

[v6bucket]

Can you use a std blue motor manifold & a "J" pipe for the turbo setup?
How many notches are machined in the balancer?

[Holden202T]

yeah i have tried the cast iron blue manifold, it would work but its not optimal so i'm going to get laser cut flange and make my own that goes under the efi manfiold and forward to where the battery used to be and mount the turbo there.

so the J pipe would have to go forwards under the engine mount then turn up behind the alternator towards the battery box area.

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turbo will sit roughly in this area where the spanner and relay is.

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the balancer needs 3 slots cut in it, so get the sensor mounted, get the motor on 10 degrees advanced, then from the sensor, mark it and 2 other evenly spaced slots - this basically replaces the 6 pointed star in the electronic dizzy and fires each time these slots pass the balancer sensor.

[Holden202T]

ok bit more progress on this one, got the trigger roughly mounted and wired it into the camira ignition module for a test run .... so far so good.

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[youtube]http://www.youtube.com/watch?v=b69em-imNyU[/youtube]

can someone thats had a bit of experience with this tell me if thats too much choppiness in the rpm trace, to me it looks more rough than the 202 dizzy trace was ?

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anyways happy with the results, its working and my rough angle grinder slots are close enough hehehe about 6-7 degrees on the diag mode timing light..... you will also notice in the top picture i fucked up cause the TDC mark is on 8 degrees and it should be 10, but thats cause i had to swap balancers and marked it with the balancer pushed on a few mm and did it by eye so i could remove it again to do the slot cutting in the vice! very precise workshop i have hahahahah

it also shows though how much the balancer can spin on the inner part, this balancer in the picture has done about 150,000kms on a worked motor that revved to about 6500rpm and it was a powerbond street one which apparently are glued together with the rubber .... hopefully the race one i have on the gemini will be less prone to slip as i don't use its v belt groove at all so no load other than engine acceleration.

my suggestion to anyone wanting to do this mod would be to either buy a brand new balancer and make sure its a good one or make up a chopper wheel to bolt to the front of the balancer that can't slip!

[The1]

nice work, will be good to see the results at the end!

[Fireblade.954]

Thanx, for the wiring help. Also I met a guy with a 202 in a vh commodore he had the turbo right out front just off the fan. Looked real cool and worked a treat. May not work for you but just an idea, oh he used one piece of 4inch pipe with a bung on the fire wall end and turbo on the other. And sorta put dents to accommodate the inlet. Primitive but worked a treat.

[Fireblade.954]

Btw, let me know if u need a price on a turbo. I'd love to see that happen.

[Holden202T]

turbo is in transit as we speak, and the manifold will be a custom one that brings the outlet up infront of the motor on the passenger side! it will happen!

[Holden202T]

so finally got the good balancer on the gemini motor slotted and alot more accurately too i might add! and put the sensor on the gemini for a test run, seems to work fine, will remove the bracket and gusset it a bit to make it more solid before paint and final install but shes good to go really. Check this log of the rpm trace compared to the one a few posts back up! this is the difference between rough slots and precise ones!

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and heres a few quick snaps of the setup - i wanted to get it on the gemini before the weekend so i can test this out at gunnedah drags! and if it misses or plays up i can just plug the dizzy pickup back in (its still all in place) and then keep racing!

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[Circlotron]

Wow! Talk about deja vu! I made up a crank trigger for my 202 HQ back in 1991. Still have the disc and the sensor bracket out in the shed somewhere. I'll find it and take a pic. I used a white disc and a photo-reflective sensor normally used to detect the presence of a sheet of paper in a photocopier. Fed into a home made analogue advance curve box that you could set advance at 1000 rpm increments with pots. Worked quite well and was =absolutely= steady on a timing light.

I think taking the pulses off the outer ring of the balancer is a bad idea. Whenever the ring mass + rubber elasticity hits resonance (hopefully at crank torsional resonance) it is going to vibrate back and forth some degrees like mad to keep the crank from doing same. This will make your timing accuracy go down the toilet.