700R4 pressure question
Thread Starter
Instructor
Joined: Sep 2007
Posts: 218
Likes: 7
From: Tonbridge, Kent
700R4 pressure question
Hi Guys,
My 74 BB has bee off the barely used over the last couple of years. I noticed last week when I took her out I found she wasn’t shifting correctly. I noticed that the TV cable connection to the carb had come off as the plastic end had split. I messed around for a while however wasn’t happy with the way the TV cable felt. I decided to test the pressure and hook it up to a gauge.
I have a Max pressure of 160psi with TV cable pulled fully out and around 70psi at idle, is this too low behind a 450hp/400lb/ft BB?
What is the best way to increase the pressure to ensure no long term damage?
Cheers
Peter
My 74 BB has bee off the barely used over the last couple of years. I noticed last week when I took her out I found she wasn’t shifting correctly. I noticed that the TV cable connection to the carb had come off as the plastic end had split. I messed around for a while however wasn’t happy with the way the TV cable felt. I decided to test the pressure and hook it up to a gauge.
I have a Max pressure of 160psi with TV cable pulled fully out and around 70psi at idle, is this too low behind a 450hp/400lb/ft BB?
What is the best way to increase the pressure to ensure no long term damage?
Cheers
Peter
Thread Starter
Instructor
Joined: Sep 2007
Posts: 218
Likes: 7
From: Tonbridge, Kent
Yes pressure was taken at idle, never tried it In reverse. I was just getting static readings.
I previously fitted a 2004R about 18 years ago, from BT Overdrives and that was a strong build, which had line pressure of 300psi. Not that sure with pressures on the 700R4, as I never fitted this trans.
I saw this thread the other day and was wondering if these pressures are normal for a 700 or should they be as high as my old 2004R?
https://nastyz28.com/threads/700r4-t...ssures.333308/
PS. Jim Jabroni not sure if you got my email reply?
I previously fitted a 2004R about 18 years ago, from BT Overdrives and that was a strong build, which had line pressure of 300psi. Not that sure with pressures on the 700R4, as I never fitted this trans.
I saw this thread the other day and was wondering if these pressures are normal for a 700 or should they be as high as my old 2004R?
https://nastyz28.com/threads/700r4-t...ssures.333308/
PS. Jim Jabroni not sure if you got my email reply?
Drifting
Joined: Aug 2019
Posts: 1,515
Likes: 499
retry the test at 1000 rpm and then at 2000 rpm and see what you have at minimum TV and at max TV , not sure what rpm your idle is at but down low below 1000 rpm is not always a good indication of what you have compared to 2000 rpm unless a pump or pressure regulator problem,
Thread Starter
Instructor
Joined: Sep 2007
Posts: 218
Likes: 7
From: Tonbridge, Kent
I’m on holiday at the moment, and quickly had a look at the car before I left. Just run a pressure test with it in reverse and also drive. Didn’t take it out for a drive as I didn’t have time. Pressure at idle in Park I set at 90psi. If I slacken the TV Cable minimum pressure is 65psi, which I heard is a little too low? In Reverse at idle pressure @ 650rpm is around 170psi increasing to about 190psi holding the brake and increasing to 1500rpm. In Drive the pressure was slightly lower at 160psi and 180psi respectively. I quickly did this test over literally a couple of minutes to give you guys a rough idea of pressure. I know I need to give it a proper test drive, and see pressures at WOT and in each gear.
I did buy a new TV cable to fit as I wasn’t sure the one fitted was working properly, however after having a look at it’s operation at the moment I think it is working ok.
Peter
I did buy a new TV cable to fit as I wasn’t sure the one fitted was working properly, however after having a look at it’s operation at the moment I think it is working ok.
Peter
