vacuum modulator trans control
Thread Starter
Drifting
Joined: Dec 1999
Posts: 1,330
Likes: 36
From: Waynesboro, PA
Co-winner 2020 C4 of the Year - Modified
vacuum modulator trans control
Who has heard of these? Some companies are using it on the 4L60-E. It has something to do with the fact that on a supercharged car, the boost can come on too fast and the stock computer gets confused or something, causing the line pressure to go to maximum pressure too early, blowing apart some trans internals. It basically removes the computer control of line pressure and replaces it with a vacuum/boost reference control. :confused:
Drifting
Joined: Jun 2001
Posts: 1,997
Likes: 1
From: Lake Ozark MO
Re: vacuum modulator trans control (POLOVETTE 94)
I had this conversion done when I lost the 3rd & 4th clutch packs on a fresh tranny rebuild.
My tranny guys hooked up to the failed unit and found out that the PCM wasn't commanding the correct line pressure in 3rd and 4th. It's a problem they've seen before on F-bodies with reprogrammed PCMs.
They recommended the vacuum modulation conversion. I think the kit is about $200. After the install I couldn't be happier. Transmission has survived some harsh treatment as well as several dyno runs on nitrous.
I was very accepting of the advice to go "retro" since I couldn't trust the PCM to perform it's duties properly.
My tranny guys hooked up to the failed unit and found out that the PCM wasn't commanding the correct line pressure in 3rd and 4th. It's a problem they've seen before on F-bodies with reprogrammed PCMs.
They recommended the vacuum modulation conversion. I think the kit is about $200. After the install I couldn't be happier. Transmission has survived some harsh treatment as well as several dyno runs on nitrous.
I was very accepting of the advice to go "retro" since I couldn't trust the PCM to perform it's duties properly.
Thread Starter
Drifting
Joined: Dec 1999
Posts: 1,330
Likes: 36
From: Waynesboro, PA
Co-winner 2020 C4 of the Year - Modified
Re: vacuum modulator trans control (Dan Parker '96)
Good. I thought I was the only person who heard of this. Apparently two people heard about it. :D
