pictures of modified gt dizzy for 12-1 in megasquirt

**compnut21** · 4-22-08, 16:13

i get asked about what tooth to grind a lot so im posting pics.

that one, 3 right of that g wheel, then the one 180 opposite of it.

just make sure they are flat and you don't screw up the teeth beside them (note: one of mine is slightly pointed now)

if it helped.

**compnut21** · 4-22-08, 16:16

edit: reserved space for changes?

**fredio54** · 4-22-08, 16:52

is it just me or did you destroy the tooth on the right of the gap in the last picture there?

**Zach** · 4-22-08, 17:16

yeah...he speared it pretty good

So you grind two teeth off? That one, and the one directly opposite?

**eraezer** · 4-22-08, 17:30

Isnt that a 24-2 wheel now?
Since you cut 2 tooths off and they are 180degrees apart and when counting in your pictures there is 11 on each side which makes it 11+11+2 = 24.

**SiFlyBy** · 4-22-08, 17:35

sweet. thanks for the pics...one less thing I have to worry about

**compnut21** · 4-22-08, 18:23

Quote:

Originally Posted by fredio54

is it just me or did you destroy the tooth on the right of the gap in the last picture there?

...kinda

i took off the front of it on accident, so now it has more of a wedge shape. works fine though

Quote:

Originally Posted by Zach

yeah...he speared it pretty good

So you grind two teeth off? That one, and the one directly opposite?

yeah

Quote:

Originally Posted by eraezer

Isnt that a 24-2 wheel now?
Since you cut 2 tooths off and they are 180degrees apart and when counting in your pictures there is 11 on each side which makes it 11+11+2 = 24.

megasquirt uses it as a crank signal. for each crank movement it moves half a turn. therefor its a 12-1 crank wheel basically. technically it is a 24-2 cam sensor.

Quote:

Originally Posted by SiFlyBy

sweet. thanks for the pics...one less thing I have to worry about

**fredio54** · 4-23-08, 3:14

ROFL, better you than me! Have you scoped it? I'd be interested to see how it looks. There's a reason it works, but i bet that pulse is off centred compared to the other giving you (if you used a decoder that cared, ie ms2) rpm wobble. My scope of my 36-1 is wonky as because it's not straight on the pulley... however the tooth spacing is right, so the centres are good. so long as it works i guess :-)

**whitestalker89** · 7-10-08, 12:38

what is the diffrence between the gt dissy or a lx/gl when using mega squirt?

**compnut21** · 7-10-08, 15:23

lx one needs to be welded shut, gt needs to have 2 teeth removed. you end up with the same thing, just a different way of doing it.

**n2o_matt** · 7-10-08, 17:54

So are people doing this rather than using two VR conditioners with the 24 tooth Ne signal and then the g1 signal which is a one tooth wheel in the gt disty?

This seems like a good option for people running v3 since it only has one conditioner. I bought a 2.2 with a daughter card that has two VR conditioners. Its built but i haven't added the daughter card yet... we'll see what happens.

**compnut21** · 7-10-08, 22:00

Quote:

Originally Posted by n2o_matt

So are people doing this rather than using two VR conditioners with the 24 tooth Ne signal and then the g1 signal which is a one tooth wheel in the gt disty?

This seems like a good option for people running v3 since it only has one conditioner. I bought a 2.2 with a daughter card that has two VR conditioners. Its built but i haven't added the daughter card yet... we'll see what happens.

pretty much. i didnt feel like adding more electronics so i removed some teeth. imo it was easier to do than adding another vr to the v3 board or finding a welding a lx dizzy.

**Matt Cramer** · 7-11-08, 8:55

Quote:

Originally Posted by whitestalker89

what is the diffrence between the gt dissy or a lx/gl when using mega squirt?

A lot.

GTs used a Nippondenso 24/1 distributor much like a Toyota ESA. These have computer controlled advance.

The GL used a 4 tooth wheel, a VR sensor, and a mechanical advance. Taking control of the spark means locking out the advance mechanism - or you can just run fuel only if you're not going to be tuning your spark curve.

And the LX V6 is a Ford TFI that can be used with no mods to the distributor and more or less the same Megasquirt setup as a 5.0 Mustang.

**Zach** · 7-11-08, 12:23

Quote:

Originally Posted by Matt Cramer

A lot.

GTs used a Nippondenso 24/1 distributor much like a Toyota ESA. These have computer controlled advance.

The GL used a 4 tooth wheel, a VR sensor, and a mechanical advance. Taking control of the spark means locking out the advance mechanism - or you can just run fuel only if you're not going to be tuning your spark curve.

And the LX V6 is a Ford TFI that can be used with no mods to the distributor and more or less the same Megasquirt setup as a 5.0 Mustang.

+7

....

**n2o_matt** · 7-11-08, 17:49

Quote:

GTs used a Nippondenso 24/1 distributor much like a Toyota ESA.

they're technically 24-2 err 24-1-1.

There are three wheels, two of them have 1 tooth OR maybe there is two wheels, one with 24 the other with 1 tooth but there might be two pick ups. I'm not really sure how it is physically setup, but i do know that there are 24-2 signals per cam rotation.

Not to hijack - can some one PM me if they are running the gt disty with two VR sensors in MS? I need to clear up a few things...