Do I have a trans/converter issue?
Thread Starter
10 Second Club
Joined: Oct 2015
Posts: 238
Likes: 5
From: Hillsdale, MI
Do I have a 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.
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 don't have an answer for your title but do have a couple questions for you.
Are you commanding that afr at wot and if so what amount of timing are you running at wot with that afr? Also, why size tire are you running. If you would rather pm that information that is fine as well.
Are you commanding that afr at wot and if so what amount of timing are you running at wot with that afr? Also, why size tire are you running. If you would rather pm that information that is fine as well.
Thread Starter
10 Second Club
Joined: Oct 2015
Posts: 238
Likes: 5
From: Hillsdale, MI
I also don't have an answer for your title but do have a couple questions for you.
Are you commanding that afr at wot and if so what amount of timing are you running at wot with that afr? Also, why size tire are you running. If you would rather pm that information that is fine as well.
Are you commanding that afr at wot and if so what amount of timing are you running at wot with that afr? Also, why size tire are you running. If you would rather pm that information that is fine as well.
I'm running the 3052R MT 26x8.5x15 pro drag radial. 26.4" dia.
I am not commanding that afr. It's a Frost bolt on tune and I just installed the gauges a couple days before and wanted to see where everything was. You can't see it well, but the fuel pressure drops to 50.2 at launch and climbs to 53 by the end of the pass. I have a racetronix pump and hotwire to install and hopefully that will fix that issue.
I'm running the 3052R MT 26x8.5x15 pro drag radial. 26.4" dia.
I'm running the 3052R MT 26x8.5x15 pro drag radial. 26.4" dia.
Couple things , did you ever figure out the problem? Mine is having almost the exact same problem very similar car mine is bolt on 00 SS with a vig 3600 rebuilt trans about 5k ago with a frost Tune ...
Also did you notice a difference going from 3.42 to 3.73 ?
Also did you notice a difference going from 3.42 to 3.73 ?
Thread Starter
10 Second Club
Joined: Oct 2015
Posts: 238
Likes: 5
From: Hillsdale, MI
I think the problem ended up being not calibrated for the 3.73s. Once pcm was retuned by Frost, I didn't have the issue since. Here is a pass after retune, but also installed the transgo hd2 kit with PBA spec holes for the separator plate:
After that day of racing, I bought hp tuners. Found out the car was shifting at 6100 so I played around and got it to shift at 6500 and picked up 1 mph in the 1/8:
As for converter efficiency, I assume I was coming up with high slip % because 1- going off factory tach and video 2- using trap speed which is an average. With hp tuners, the % calculates much better using logs.
3rd gear also holds fine on 100 and 150 shots:
3.42 to 3.73 tightened up the take off feel making for a better around town experience. I can't say that I notice a difference at the track.
After that day of racing, I bought hp tuners. Found out the car was shifting at 6100 so I played around and got it to shift at 6500 and picked up 1 mph in the 1/8:
As for converter efficiency, I assume I was coming up with high slip % because 1- going off factory tach and video 2- using trap speed which is an average. With hp tuners, the % calculates much better using logs.
3rd gear also holds fine on 100 and 150 shots:
3.42 to 3.73 tightened up the take off feel making for a better around town experience. I can't say that I notice a difference at the track.
