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FE Power Forums => FE Technical Forum => Topic started by: JamesonRacing on September 29, 2015, 07:32:46 PM

Title: In car video of weekend run. Is second gear shot?
Post by: JamesonRacing on September 29, 2015, 07:32:46 PM
Car made three good passes on Saturday at Byron, best of 10.29 @ 130, but the last run the car slowed 5mph and was went 10.54.  Not sure, but the in-car video looks like second gear went by very quickly.  Launch is on a transbrake, 2-stepped at 4100rpm, stall should be around 5000, shift light at 6900.  Thoughts?

The good news is it looks like my jetting is solid, with the A/F meter reading right around 0.85.

https://www.youtube.com/watch?v=Q5600Elv0dc
Title: Re: In car video of weekend run. Is second gear shot?
Post by: Nightmist66 on September 29, 2015, 07:58:09 PM
Too bad we didn't get an outside video. The car sounded much better than inside and not to mention the air under the tires on the second or third pass. :D
Title: Re: In car video of weekend run. Is second gear shot?
Post by: JamesonRacing on September 29, 2015, 08:44:56 PM
Yeah, will have to get the external mount attached next time out.  Here's an earlier run for comparison:

https://youtu.be/zwdHDCTcYbM
Title: Re: In car video of weekend run. Is second gear shot?
Post by: thatdarncat on September 30, 2015, 11:42:32 AM
A lot of things can make an ET change of a few tenths that don't necessarily mean something failing on the car, but a loss of 5 mph without an obvious reason ( like a sudden strong headwind ) would have me wondering too. Have you checked the band adjustment? Band adjuster lock nut come loose? Drained some trans fluid and inspected? How many runs on the trans and converter?  Other than transmission related the obvious next areas would be fuel or ignition. Low on fuel or plugged filter? Loose plug wire or failing coil? Were you working on anything on the car just before the pass that may have been knocked loose? ( I did that one recently myself )
Title: Re: In car video of weekend run. Is second gear shot?
Post by: Drew Pojedinec on September 30, 2015, 02:32:13 PM
Servo seals getting hard can make this an issue.
Mine would freewheel in second and slam right into third.


(guess I should mention that I am offshore and can't view the videos, but just relating a second gear loss and how it feels)
Title: Re: In car video of weekend run. Is second gear shot?
Post by: plovett on September 30, 2015, 04:34:01 PM
I don't think it's your tranny, judging by the video.

It seems to that the rpm when you shift into 3rd would be lower if 2nd gear were slipping.  You'd go through 2nd in less time and shift to 3rd at a lower mph, so the rpm would be lower at the start of 3rd gear.  I don't see that in the two videos.  Maybe your high stall convertor might cover that up to an extent though?

I think something else caused the higher ET.  Wind?, air quality?, heat soaked engine?, ?????

JMO,

paulie