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| Timing question | Login/Join |
DRR Pro |
Has anyone had this happen to them Dragster runs mid 4.40’s with a MSD distributor NO crank trigger with 34* of timing. Now I install a crank trigger, set timing at 34* then phase it Go to the track and it only runs back to back 4.58’s. Baffled so I disconnect the crank trigger and plugged the MSD distributor back in and set timing to 34* and it runs 4.46. What in the world would cause this. IDK guess I have a killer MSD distributor worth .012 lol. Thanks in advance Brian Mollison 2013 American Dragster 2020 Sumerduck Dragway VA Top ET Champion 2017 Sumerduck Top ET & SSS Track Champion 2017 MAC Top ET Track Champion 2009 Sumerduck Dragway Va Top ET & IHRA SSS Track Champion 2008 IHRA Division 1 Top ET Bracket Final Runner-up 2007 Colonial Beach Dragway Top ET Track Champion | ||
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| DRR S/Pro |
As with any newly installed crank trigger, check the two wire going to it, green and purple, make sure they are reversed. Next would be to get the crank trigger wires as far away from the coil wires. Does the motor run clean??? Simple test, try a new crank trigger pick up. | |||
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| DRR Pro |
The phasing of the crank trigger will depend on the type of ignition you have analog or digital. With analog ignition you want the trigger to produce the least amount of timing when phased. With digital, you want the trigger to produce the maximum amount of timing. By phasing is meant , when the wires from the crank trigger are inter-changed going to the ignition box. | |||
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| DRR S/Pro |
That should be taken care of at the ignition box by the +/- labels on it. Purple/Violet (+) and Green (-). If he has an MSD crank trigger sensor it has the same color layout, other may or may not but it should have a plus minus label shown in the paper work. When all else fails switch the wires | |||
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| DRR Pro |
The ignition box is a 7al3 box. The wires from the MSD and the distributor are the same color and the crank trigger wires are also the same color and the connector can only be hooked up one way. IDK Brian Mollison 2013 American Dragster 2020 Sumerduck Dragway VA Top ET Champion 2017 Sumerduck Top ET & SSS Track Champion 2017 MAC Top ET Track Champion 2009 Sumerduck Dragway Va Top ET & IHRA SSS Track Champion 2008 IHRA Division 1 Top ET Bracket Final Runner-up 2007 Colonial Beach Dragway Top ET Track Champion | |||
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| DRR Sportsman |
The easiest way to check the crank trigger polarity is with a timing light. When it's correct the magnet is directly under the pickup. When they are reversed they won't be lined up. Denis LeBlanc | |||
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| DRR Pro |
You have analog ignition so you would want the most retarded timing when switching polarity. To switch polarity of the trigger just reverse the M+ and M- wires on the 7al3 terminal strip. When switched if the timing is now more retarded then this way is correct. If the timing becomes more advanced then this way is incorrect. What Action said about shinning the timing light at the pick up also works as he said. The magnet should be almost directly over the pickup. | |||
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DRR Top Comp |
But if both the timing was 34* with distributor and 34* with crank trigger why performance difference? The net timing was still 34*? That is a pretty significant difference in performance from 4.40's to 4.58. https://postimg.cc/gallery/np3zpruo/ "Dunning-Kruger Effect" -a type of Cognitive bias where people with little expertise or ability assume they have superior expertise or ability. This overestimation occurs as a result of the fact that they do not have enough knowledge to know they don't have enough knowledge. Before you argue with someone ask yourself, "Is this person mentally mature enough to grasp the concept of a different perspective?" If not there is no point to argue. 4X NE2 CHAMPION. 2020 TDRA NE2 Champion | |||
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| DRR Trophy |
The 7AL-3 will retard your actual timing setting by 4 degrees in operation. If you phased in your timing at 34 your actual timing will be 30 when checked with a light on a crank trigger ignition. So you need to phase in your initial timing at 38 to get 34 in actual operation used with a crank trigger. I use my MSD billet distributor totally locked out. I lost over .06 in et eighth mile when using the distributor only and bringing in full timing well under low side launch rpm. | |||
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| DRR Sportsman |
Just went thru this with a 7AL-3.. Changed motors and put crank trigger back on, set timing to 34 degrees, went to track and car sounded terrible and would hardly run under power. Brought it home, checked everything, timing was still on 34, but it was at idle, I just happened to reach up and give it a little gas and timing took off to 40 something degrees. Switched wires and timing rock solid. | |||
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| DRR Pro |
Here’s a patch cable that I made that will quickly reverse the wire polarity of the pickup when installed between the pickup and cable. The pin extractor in the pic is a Blue Point GA 500A. Use this if needed to permanently change the polarity of the pickup plug in.  | |||
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DRR Sportsman |
if the wires are reversed then your going to lose a he11 of lot more then .12.LOL I willing to bet you run a timing chain combined with the twisting of the camshaft @RPM. your timing is retarded a little at race RPM. Easy way to tell, set crank trigger @32 and see if it picks up,if it does take a little more until you get back your ET. Joe Without data, you’re just another guy with an opinion. | |||
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| DRR Pro |
It has a belt drive not a chain. I will do some checking Brian Mollison 2013 American Dragster 2020 Sumerduck Dragway VA Top ET Champion 2017 Sumerduck Top ET & SSS Track Champion 2017 MAC Top ET Track Champion 2009 Sumerduck Dragway Va Top ET & IHRA SSS Track Champion 2008 IHRA Division 1 Top ET Bracket Final Runner-up 2007 Colonial Beach Dragway Top ET Track Champion | |||
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| DRR Pro |
Oh I agree 100%. Didn’t make since at the track. Have to find time and check it out again. Thx everyone’s suggestions Brian Mollison 2013 American Dragster 2020 Sumerduck Dragway VA Top ET Champion 2017 Sumerduck Top ET & SSS Track Champion 2017 MAC Top ET Track Champion 2009 Sumerduck Dragway Va Top ET & IHRA SSS Track Champion 2008 IHRA Division 1 Top ET Bracket Final Runner-up 2007 Colonial Beach Dragway Top ET Track Champion | |||
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| DRR Sportsman |
My first thought would be is the distributor you are using with the crank trigger a mechanical advance and is it completely locked out. Just wondering whether the distributor could be advancing and going out of phase with the crank trigger. B.J. Masiello | |||
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| DRR Trophy |
be sure the wheel is on correctly. It is directional and can be put on backwards... | |||
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| DRR S/Pro |
Your transducer is junk, most likely. It's why you will never see an msd wheel or transducer on any of my engines. strangemagicperformance.com oldsperformanceproducts.com WD dealer for just about all your performance needs. | |||
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| DRR Top Comp |
Good call. OP check the polarity on the crank trigger wheel, too. | |||
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| DRR Pro |
What brand is better iyo? Or do you just use a distributor trigger? | |||
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| DRR S/Pro |
I use Moroso. Never had a failure yet. I've experienced over 20 bad msds, most of the time it's the transducer. 2 of the times it was the wheel. strangemagicperformance.com oldsperformanceproducts.com WD dealer for just about all your performance needs. | |||
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