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| Forum name | Performance/Engine |
| Topic subject | 12.5:1 pistons & timing retard |
| Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i5&topic_id=21635 |
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21635, 12.5:1 pistons & timing retard Posted by Exe, Apr-28-02 06:44 AM ive been told if i were to get the 12.5 pistons with the howell rebuild kit i would need a timing retard device. im wondering as to what exactly does a timing retard do? what timing is it retarding =P? if i were to get the pistons is it as easy as setting the retard to the right level and thats it? is there no setback to doing this? tia. | |
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21636, RE: 12.5:1 pistons & timing retard Posted by HadesOmega, Apr-28-02 10:53 AM retarding your timing makes your ignition system fire the spark earlier than TDC or when it suppose to. If you compression is mega high the mixture might ignitite due to the extreme compression and you get detonation and misfiring. Pretty bad stuff for you engine and your HP. So by firing the spark before it detonated you prevent this. YOu probably might have to run octane booster also. | |
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21637, RE: 12.5:1 pistons & timing retard Posted by Breezio, Apr-28-02 01:29 PM Hades.. you got it backwards.. Retarding the timing (ignition timing) makes the spark happen later, so that way you don't have the shockwave from the explosion hitting your piston on it's way up (causing a PING like noise, and possibly damaging components) on a stock motor the spark happens quite a way before TDC (top dead center) depending on RPM, this is normal.. but the higher compression you go (be it from higher comp pistons or Forced induction) you will need to pull (retard) timing in the ignition so it doesn't spark as earlier, because when you have higher compression it makes the mixture burn faster (more powerful) and so there is a higher change the shockwave from the explosion will hit the top of the piston before it gets to/past TDC. | |
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21638, RE: 12.5:1 pistons & timing retard Posted by Exe, Apr-30-02 06:11 AM so would i just set the retard to the right amount and be done with it? how do i know what to set it to? | |
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21639, RE: 12.5:1 pistons & timing retard Posted by Fast420A, Apr-30-02 07:11 AM You would have to tune the engine until it is in a safe range of retard and no detonation. | |
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21640, RE: 12.5:1 pistons & timing retard Posted by Michael_97RS, May-01-02 03:26 AM I'm not sure you would need timing retard on a stock ECU. The Neon guyys with the AFX run 8 degree retard, approximmnately. The AFX uses 30 degrees timign advance. Our stock ECU only geta around 20 degreeas advance, from those who have datalogged. There have been some Neon guys runnign 12.5:1 on stock ECu and they get about 25 degrees advance. So I think it could be done. | |
