Trans/converter issue?
Thread Starter
10 Second Club
Joined: Oct 2015
Posts: 238
Likes: 5
From: Hillsdale, MI
Trans/converter issue? I never noticed this until I put the go pro on my gauges. The 2-3 limiter bump I think will be taken care of once I get the speedometer calibrated for the 3.73 I have from the 3.42. The thing I'm slightly concerned with is the rpm's that I'm crossing the finish line in. I'm seeing 6100-ish. After calculating converter slip (or efficiency) with the 96% efficiency of the ss4000 (I found this in a couple spots on the internet), it says I should be at 5700-5800 rpm crossing the line with 3.73 and 26.4" (83" rollout/circumference) tire, but I'm showing 11% "slip".
Is this actually the converter or is 3rd slipping a little? Or is it something else? If a trans issue, would the transgo hd2 kit "fix" it for a little while?
Trans is a 3 year old stock rebuild with 5k miles on it.
**I also posted this in Drag Tech. Apologies if that was incorrent.
Is this actually the converter or is 3rd slipping a little? Or is it something else? If a trans issue, would the transgo hd2 kit "fix" it for a little while?
Trans is a 3 year old stock rebuild with 5k miles on it.
**I also posted this in Drag Tech. Apologies if that was incorrent.
Last edited by Hardtop Brian; Oct 23, 2016 at 11:37 AM.
If third was slipping my opinion tells me it would look like a cut-loose. The rpm would go up and mph would go down.
The only thing I see wrong is a lean reading on the wideband.
I really don't think you can calculate converter slip if you have it tuned for 3.42's and you're running 3.73's. It has to be tuned for the gear thats in it, otherwise you're guessing at mph and your shift points are wrong, etc
I'm used to just running a car, once you get into electronics and calculating efficiency, etc, you're no longer enjoying the sport. It just creates more questions and looking for problems that don't exist. JMO
The only thing I see wrong is a lean reading on the wideband.
I really don't think you can calculate converter slip if you have it tuned for 3.42's and you're running 3.73's. It has to be tuned for the gear thats in it, otherwise you're guessing at mph and your shift points are wrong, etc
I'm used to just running a car, once you get into electronics and calculating efficiency, etc, you're no longer enjoying the sport. It just creates more questions and looking for problems that don't exist. JMO
Thread Starter
10 Second Club
Joined: Oct 2015
Posts: 238
Likes: 5
From: Hillsdale, MI
If third was slipping my opinion tells me it would look like a cut-loose. The rpm would go up and mph would go down.
The only thing I see wrong is a lean reading on the wideband.
I really don't think you can calculate converter slip if you have it tuned for 3.42's and you're running 3.73's. It has to be tuned for the gear thats in it, otherwise you're guessing at mph and your shift points are wrong, etc
I'm used to just running a car, once you get into electronics and calculating efficiency, etc, you're no longer enjoying the sport. It just creates more questions and looking for problems that don't exist. JMO
The only thing I see wrong is a lean reading on the wideband.
I really don't think you can calculate converter slip if you have it tuned for 3.42's and you're running 3.73's. It has to be tuned for the gear thats in it, otherwise you're guessing at mph and your shift points are wrong, etc
I'm used to just running a car, once you get into electronics and calculating efficiency, etc, you're no longer enjoying the sport. It just creates more questions and looking for problems that don't exist. JMO
rpm's are rpm's regardless of rear end. I'm comparing the tach to when I cross the finish line and the trap speed, not what is showing on the speedometer (120+). I guess there is some error in there since trap speed is the average mph over the last 60'. But like you said, maybe I'm looking into it too hard and making something of nothing
