Manual VB 727 line pressure
#253887
03/14/09 10:28 PM
03/14/09 10:28 PM
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Posts: 761 Southington Ct.
turbobitt
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Is there a prefered line pressure for a full manual non-transbrake VB ? I would like to set the pressure a little more accurate than the measurment method described in the kit. Just looking for a ballpark figure. The TV linkage is set for max pressure full time. Thanks, Allan G.
1970 Challenger w/572 Hemi street car and my pride and joy.
1986 T-Type with 272 Stage 2 Buick V6 engine - True 8 second street car. Just updated the engine and put down 928 HP @ 35# boost to the ground on chasis dyno.
1976 Cee Bee Avenger Jet Boat - 460 Ford powered.
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Re: Manual VB 727 line pressure
[Re: 440Jim]
#253890
03/15/09 09:16 AM
03/15/09 09:16 AM
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Posts: 761 Southington Ct.
turbobitt
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Thanks for the replies. This transmission is going behind a roller cam, 572" Hemi. I will check it today and if it is around 150 than maybe I'll leave it alone.
Allan G.
1970 Challenger w/572 Hemi street car and my pride and joy.
1986 T-Type with 272 Stage 2 Buick V6 engine - True 8 second street car. Just updated the engine and put down 928 HP @ 35# boost to the ground on chasis dyno.
1976 Cee Bee Avenger Jet Boat - 460 Ford powered.
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Re: Manual VB 727 line pressure
[Re: turbobitt]
#253891
03/15/09 11:05 AM
03/15/09 11:05 AM
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Joined: Jul 2008
Posts: 30,486 Florida STAYcation
dOc …
The village idiot's idiot
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I have never actually experimented with this ... but with the car I am working on now I will. I say it depends on what your race-car-combo is. Some might need to run 165 psi ... but with a car that does not weigh much, has better aero than a big-car and does not have a ton of horsepower ..... I think you can run A LOT less. PLUS ... running not-more-than-you-need line-pressure is EZier on the metal and rubber seals AND it would take less power to run way higher than necessary PSI. My combo will be a front-motored dragster ... that all I hope it will do is be a mid-9 second "fun car" .....zero maintenence .... "change the oil once a year". I am going to set my trans at 80 psi or so.
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Re: Manual VB 727 line pressure
[Re: dOc …]
#253892
03/15/09 12:48 PM
03/15/09 12:48 PM
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Joined: Aug 2005
Posts: 761 Southington Ct.
turbobitt
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I check the line pressure this morning and it was around 95 PSI. I dropped the pan and removed the VB and shimmed the spring with about .200" worth of washers. The was some adjustment left but not much. The spring looks flimsy so I didn't expect much results. After reinstalling the pressure only cam up to 110 psi. I should also add that it didn't matter how much RPM, or frst, second, or third gear, pressure stayed steady. Car weight is at 4000 pounds. Engine should be good for 700HP. Allan G.
1970 Challenger w/572 Hemi street car and my pride and joy.
1986 T-Type with 272 Stage 2 Buick V6 engine - True 8 second street car. Just updated the engine and put down 928 HP @ 35# boost to the ground on chasis dyno.
1976 Cee Bee Avenger Jet Boat - 460 Ford powered.
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Post deleted by Defbob
[Re: turbobitt]
#253893
03/15/09 01:04 PM
03/15/09 01:04 PM
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Anonymous
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Re: Manual VB 727 line pressure
#253894
03/15/09 02:11 PM
03/15/09 02:11 PM
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Joined: Aug 2005
Posts: 761 Southington Ct.
turbobitt
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I've been looking for pressure regulator springs and can't find any. May need to call around tomarrow.
1970 Challenger w/572 Hemi street car and my pride and joy.
1986 T-Type with 272 Stage 2 Buick V6 engine - True 8 second street car. Just updated the engine and put down 928 HP @ 35# boost to the ground on chasis dyno.
1976 Cee Bee Avenger Jet Boat - 460 Ford powered.
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Re: Manual VB 727 line pressure
[Re: turbobitt]
#253897
03/15/09 05:24 PM
03/15/09 05:24 PM
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Joined: Jul 2008
Posts: 30,486 Florida STAYcation
dOc …
The village idiot's idiot
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The village idiot's idiot
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Florida STAYcation
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Quote:
Car weight is at 4000 pounds. Engine should be good for 700HP. Allan G.
If yours is OK with 700 hp and pulling 4,000 lbs ....I should be good-to-go with 50-60 psi.
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Re: Manual VB 727 line pressure
[Re: turbobitt]
#253898
03/15/09 08:05 PM
03/15/09 08:05 PM
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Joined: Jan 2003
Posts: 16,932 NC
440Jim
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Quote:
Thanks for the replies. This transmission is going behind a roller cam, 572" Hemi.
There is more to it than just line pressure, the entire trans build and valve body comes into play. For that big motor and heavy vehicle, I would want a valve body designed for at least 120 psi, and prefer 5 clutches in the front drum. Just my opinion. I don't know what valve body you have, but it sounds like a modified stock one. Call John at CRT and order one of his valve bodies.
If you really want to experiment, he might sell you one of his regulator springs.
http://coperacingtrans.com/
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Re: Manual VB 727 line pressure
[Re: 440Jim]
#253899
03/15/09 08:39 PM
03/15/09 08:39 PM
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Joined: Feb 2003
Posts: 12,675 Columbia, CT
moper
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turbo, are you sure the pump is good and the bushings/sealing rings are working properly? Seems like a ton of preload to get it to work.
Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.
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Re: Manual VB 727 line pressure
[Re: CRIKEY]
#253902
03/16/09 12:06 PM
03/16/09 12:06 PM
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Posts: 12,675 Columbia, CT
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I'm getting out of my league admittedly at this point. But it seems like if you can't get past 110 psi, steady or not, with 3/4" of air behind the preload plate, plus .220 of shim, it seems you have leakage somewhere in the system. Maybe John Kunkel or Cope can chime in on that.
Well, art is art, isn't it? Still, on the other hand, water is water! And east is east and west is west and if you take cranberries and stew them like applesauce they taste much more like prunes than rhubarb does. Now, uh... Now you tell me what you know.
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