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Need a shift light and is my tach really laggin this bad?

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Old 07-29-2012, 11:23 PM
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Default Need a shift light and is my tach really laggin this bad?

Did a test today in my car. Shifted at 6000rpms while watching speedo too as best I could. Speedometer claimed 70mph at 6000rpm. When I use this-http://www.f-body.org/gears/
I find that I shoulda been hitting about 75. I've checked at various other RPM's on videos i've made and I have found that its off by as much as 400rpm's. I know that this is a common issue, but do aftermarket shift lights run directly to the PCM so I can shift at a true RPM. If I shouldn't be shifting at 6000rpm's by all means tell me. I am researching running nitrous and would imagine that its beneficial to get this problem resolved beforehand.
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Old 07-30-2012, 02:07 AM
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Shift light will be wired into the signal wire to the existing tach. Whatever the pcm is putting out, the shift light will see.

Stock tachs are notoriously inaccurate at higher rpms.
Old 07-30-2012, 11:26 AM
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So the signal wire from PCM will be accurate, but the tach just lags. I am looking at the Harlan. Thinking red is a good choice. Another thing I am worrying about is when I run nitrous and set my windows switch to say 3000rpm-6000rpm that my 3000rpm will actually be for instance 2750rpm and from what i've read its bad to spray at low RPM's. However I do not want some big tach cluttering up my car. Any suggs?
Old 07-30-2012, 06:12 PM
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I had the same "lag" in my tach also. the shift light is much more accurate. here my adjustable one from summit. its blue and very bright (too bright). I would either go red or yellow IMHO

http://m1147.photobucket.com/albumvi....html?newest=1


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Old 07-30-2012, 06:38 PM
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I've got the autometer 2 1/16 digital shift light and it looks killer in my 6le vent gauges
Old 07-31-2012, 03:41 AM
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I've had a Raptor Performance shift light in my AC duct above the radio for quite awhile, it works great!
http://www.ws6project.com/user_stor/.../shift-lights/

Last edited by 99Bluz28; 07-31-2012 at 03:51 AM.
Old 07-31-2012, 04:03 AM
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All you need is a single LED bulb mounted in your line of vision but that is hardly noticable, you will find that when it comes on your eyes will most certainly see it.
My car is different than you guys, I occassionally road race, Club fun Drags etc. I have it mounted directly in my line of vision above my speedo.

A big ugly multi bulb ricer shift light is not needed.



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