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Building: Built Formula 27 narrow chassis Fiat TC
posted on 1/4/13 at 09:16 PM
toothed wheel positioning
Hi all I'm rabidly trying to get my engine back together and Microsquirt installed ready for Stoneleigh but it's now looking doubtful
without some serious midnight oil burning , but I'm trying .
could you please look at these pics and confirm I'm on the right track with positioning my toothed wheel on the crank pulley
cheers
[Edited on 1/4/13 by Valtra]
"If it looks like it works and it feels like it works, then it works"
I do hope you're right because the logic you followed is exactly what I did last week, but I'm a while away from testing it. However, do
check that the Microsquirt ECU is expecting the VR sensor to be in the middle of the missing tooth gap. On my DTA ECU the position is based on the
trailing edge of the first tooth past the missing tooth.
Can't you just adjust the number 1 tooth offset in the software with a timing light to make sure that the engine is and the position that the
ECU expects it to be?
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Building: Built Formula 27 narrow chassis Fiat TC
posted on 1/4/13 at 09:57 PM
quote:Originally posted by dave_424
Can't you just adjust the number 1 tooth offset in the software with a timing light to make sure that the engine is and the position that the
ECU expects it to be?
This is how it is done on megasquirt anyway
Is that aimed at the original post or the reply ?
"If it looks like it works and it feels like it works, then it works"
Urm it's relevant for both, I didn't think that you had to have the missing tooth in a specific orientation to TDC, I know that because
whilst cranking engine speed changes due to compression strokes so best to not have the missing tooth at TDC because the sync of the ECU might get
lost.
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Building: Built Formula 27 narrow chassis Fiat TC
posted on 1/4/13 at 10:15 PM
Ok Thanks, I think. The instructions I remember reading said that for a 4 cylinder engine the missing tooth should be 9 teeth advanced from tdc , i.e
90 degrees . then the ecu should sort out the correct timing for the revs and load
"If it looks like it works and it feels like it works, then it works"
he goes through setting the tooth offset which is something that you adjust the ignition timing that the ECU thinks that it is versus what is the
actual timing.
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Building: Built Formula 27 narrow chassis Fiat TC
posted on 1/4/13 at 11:48 PM
quote:Originally posted by coozer
This for a V8 but gives you a good idea of where it should be..
yes so for a v8 it's the 5th tooth before TDC and then you'd fine tune it with a strobe to fire at 10degree BTDC and correlate that with
the screen reading .
"If it looks like it works and it feels like it works, then it works"
Your set-up looks correct to me. However make sure your timing marks are visible and you can strobe them once the engine is running. If you are using
Tuner Studio to tune you can temporarily fix the timing at a convenient figure and then adjust the trigger angle offset to get the timing to exactly
match the marks. There is a lot of adjustment available so you could be several teeth out and still be able to correct it - might make it tough to get
the engine to start in the the first place though!
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Building: Built Formula 27 narrow chassis Fiat TC
posted on 2/4/13 at 11:33 PM
quote:Originally posted by old_timbo
Your set-up looks correct to me. However make sure your timing marks are visible and you can strobe them once the engine is running. If you are using
Tuner Studio to tune you can temporarily fix the timing at a convenient figure and then adjust the trigger angle offset to get the timing to exactly
match the marks. There is a lot of adjustment available so you could be several teeth out and still be able to correct it - might make it tough to get
the engine to start in the the first place though!
Thanks
"If it looks like it works and it feels like it works, then it works"
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posted on 2/4/13 at 11:44 PM
as long as that engine is set to TDC in that photo, then it all looks good to me!
regarding the mention of correcting it in the software, if you find that for some reason, your missing tooth isn't exactly in the right place,
the software (megajolt does anyway, i expect the megasquirt software will be the same if not better) allowed you to set a correction of +/- 5 degrees.
so if the ignition is expecting the edge of a tooth, and you've set to the middle or the other way around, then you can correct by up to 5
degrees either way
tuner studio might have more adjustment, i don't know. but you can be slightly out without worrying too much
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posted on 3/4/13 at 06:51 AM
quote:Originally posted by blakep82
as long as that engine is set to TDC in that photo, then it all looks good to me!
regarding the mention of correcting it in the software, if you find that for some reason, your missing tooth isn't exactly in the right place,
the software (megajolt does anyway, i expect the megasquirt software will be the same if not better) allowed you to set a correction of +/- 5 degrees.
so if the ignition is expecting the edge of a tooth, and you've set to the middle or the other way around, then you can correct by up to 5
degrees either way
tuner studio might have more adjustment, i don't know. but you can be slightly out without worrying too much
Yes set at TDC . and thanks that sounds sensible , as expected. so long as it starts then the timing should be easy enough to set up.
"If it looks like it works and it feels like it works, then it works"
And thanks from me - it seemed the logical way to do it but I've had a few brain fade moments lately on my 4AGE Midget project that I'm
starting to doubt myself.
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posted on 3/4/13 at 12:05 PM
quote:Originally posted by whitestu
M sure you can adjust the bracket, then if you get the trigger wheel slightly wrong you can correct it by moving the pick up.
Stu
Yes the Sensor is in a slotted hole . Thanks
"If it looks like it works and it feels like it works, then it works"
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posted on 3/4/13 at 07:46 PM
quote:Originally posted by Jed
And thanks from me - it seemed the logical way to do it but I've had a few brain fade moments lately on my 4AGE Midget project that I'm
starting to doubt myself.
Here here
"If it looks like it works and it feels like it works, then it works"
posted on 3/4/13 at 07:16 AM
