TPI timing
Thread Starter
Instructor
Joined: Jun 2005
Posts: 193
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From: woodinville washington
TPI timing
i just scanned my '91 TPI due to a SES light, and noticed she's running 14 degrees timing at idle, this seems extremely high from what i know about motors. does this seem right? the car runs great, and there was no knock retard
Pro
Joined: May 2003
Posts: 671
Likes: 1
From: WATERFORD CT
Back it of to about 6 or 8 deg I know some here run it higher like 10 and 14 but 6 is the stock setting.So 6 or 8 deg is a good starting point.By the way maybe tomorrow if I have time I am going to drop mine to 0 to 2 deg.Yep sounds totally backwards but I read in Corvette Fever a while back that is is some sort of a secret performance setting for the TPI cars .But I doubt it
Last edited by montie98; Sep 30, 2005 at 03:53 AM. Reason: Forgot something
Thread Starter
Instructor
Joined: Jun 2005
Posts: 193
Likes: 0
From: woodinville washington
thanks, it seemed a little high, but i've never had a problem with knocking or pinging, ill set it to 8 and see what happens, please let me know what happens when you set it to 0 or 2, im interested to find out how that would increase performance.
Melting Slicks
Joined: Jan 2002
Posts: 2,238
Likes: 4
From: Milan
Yellowdragon you said you scanned the car and you have 14 deg of timing?
If this is a total timing in NOT high at all !! It's too little!
You should put your initial setting at 6 deg with a timing gun light with the est connector DISCONNECTED.
You must put it to 6 deg (not 8 not 4,...).
In your chip you have (if stock) an initial timing setting of 6 deg in a constant called "spark adv initial (distr. setting)".
Your total timing (the one you see in the scanner), is: the 6 deg (the constant in the chip) + the timing added by the ecm.
If you are at 3 at the distributor (instead of 6) and then the ecm add (via est) 15 deg , the scanner will show 21 (but in reality you are at 18 ( 15 + 3)). If you put your distributor at 0 the scanner will shows 21 (again) but in reality you are at 15.
Advancing only the distributor (turning it counterclockwise) without changing the constant in the chip is a simple way to advance ALL the spark curve in all the rpm and in all load condition. It's a trick, but personally I don't like it.
-Beppe-
If this is a total timing in NOT high at all !! It's too little!
You should put your initial setting at 6 deg with a timing gun light with the est connector DISCONNECTED.
You must put it to 6 deg (not 8 not 4,...).
In your chip you have (if stock) an initial timing setting of 6 deg in a constant called "spark adv initial (distr. setting)".
Your total timing (the one you see in the scanner), is: the 6 deg (the constant in the chip) + the timing added by the ecm.
If you are at 3 at the distributor (instead of 6) and then the ecm add (via est) 15 deg , the scanner will show 21 (but in reality you are at 18 ( 15 + 3)). If you put your distributor at 0 the scanner will shows 21 (again) but in reality you are at 15.
Advancing only the distributor (turning it counterclockwise) without changing the constant in the chip is a simple way to advance ALL the spark curve in all the rpm and in all load condition. It's a trick, but personally I don't like it.
-Beppe-
Drifting
Joined: Jan 2002
Posts: 1,261
Likes: 4
From: Middle River MD
Originally Posted by montie98
Back it of to about 6 or 8 deg I know some here run it higher like 10 and 14 but 6 is the stock setting.So 6 or 8 deg is a good starting point.By the way maybe tomorrow if I have time I am going to drop mine to 0 to 2 deg.Yep sounds totally backwards but I read in Corvette Fever a while back that is is some sort of a secret performance setting for the TPI cars .But I doubt it
Heh, mines at 2 deg. now but I didn't do it for performance, but to get rid of a persistent pinging problem. FWIW it runs like an escaped convict as it sits. I suspect I need a better tune but haven't done that yet. The band-aid fix will do for now
Melting Slicks
Joined: Jun 2004
Posts: 3,032
Likes: 4
Originally Posted by conv90
Yes, 6 deg BTDC on the mark on the balancer with the est connector DISCONNECTED.
-Beppe-
-Beppe-
you disconnected that wire first, right?oh- and I had mine set at 0* for a while as a band aid until I could figure out why it was pinging.
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Race Director
Joined: Sep 2000
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From: The Top of Utah
Originally Posted by montie98
Back it of to about 6 or 8 deg I know some here run it higher like 10 and 14 but 6 is the stock setting.So 6 or 8 deg is a good starting point.
Your scanner is reading what the ECM is adding to the base timing. The scanner has no way to know, or read, the base timing, so it cannot display the base OR the total. The spec for your base timing is 6° BTDC. With that added to the 14° from the ECM, equals 22° at idle. That sounds about right. You should check your base timing, just to be sure.
RACE ON!!!
Le Mans Master
Joined: Feb 2000
Posts: 9,715
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From: Kempner Texas
Originally Posted by CFI-EFI
NO! NO! NO!
Your scanner is reading what the ECM is adding to the base timing. The scanner has no way to know, or read, the base timing, so it cannot display the base OR the total. The spec for your base timing is 6° BTDC. With that added to the 14° from the ECM, equals 22° at idle. That sounds about right. You should check your base timing, just to be sure.
RACE ON!!!
Your scanner is reading what the ECM is adding to the base timing. The scanner has no way to know, or read, the base timing, so it cannot display the base OR the total. The spec for your base timing is 6° BTDC. With that added to the 14° from the ECM, equals 22° at idle. That sounds about right. You should check your base timing, just to be sure.
RACE ON!!!
Jake
Race Director
Joined: Sep 2000
Posts: 17,298
Likes: 33
From: The Top of Utah
Originally Posted by JAKE
Do we have a math error here?
Jake
Jake
RACE ON!!!
