dual feed ?
- Thread starter Lee Thompson
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I can't find it but I just bought one a few months ago .. Give him a call 
Billet one's are really nice but pricey.. We are goin to Bruce's (PTS's) one when we do a spare trans.. Just got some other billet parts from Bruce and they look KILLER :biggrin: .. Hopefully it will push Melissa into the 9s with her street beater GN 
Billet one's are really nice but pricey.. We are goin to Bruce's (PTS's) one when we do a spare trans.. Just got some other billet parts from Bruce and they look KILLER :biggrin: .. Hopefully it will push Melissa into the 9s with her street beater GN IMO the last thing you want to do is lessen apply pressure to the direct clutch by increasing direct clutch return spring pressure. The available friction area of the direct clutch is borderline as it is. If anything, you should be increasing apply pressure, and lessening apply time. If you think you have a problem, that would usually be evidenced by the direct cluch pack AND the band showing disress, you should be playing with the band side, not the direct side. Work on getting the band off faster, not slowing the direct clutch apply time and pressure. As long as you're using a wide band, and you should be using a wide band, you have more room to work the band side rather than the clutch side. The direct is what has the most problem taking hold. Why tempt fate? Maybe some new tech has developed. Please correct me if my thinking is wrong here.
my dual feed system works properly at accomplishing band knock off at a faster rate than the orignal calibration.with the same orifice sizes in the plate the dual feed area is larger and requires more time to fill the cavity increasing direct clutch apply time.this is factul but not a huge concern,measured in mili seconds.here is what i did find early on in relation to the bind up.if i left the orifices in the plate all stock there would be a noticable bind up on the lift during a 2/3 ratio change.this showed itself as the wheels slowing down during the ratio change.opening the 3rd acc hole that knocks off the band reduced and eventually eliminated this on the lift BUT produced soft 2/3 ratio changes below 3/8 throttle.this was actually a bind .at heavy throttle however third gear would chirp the tires.band ,clutch and servo clearances and types had very little noticable effect on these things when they were functioning as they should.after thorougly studying the circuit it became apparent that the third accumulator check ball in the case (the one next to the hole in the plate we were opening not the capsule)was a flow restriction to knocking off the band although gm designed it in to control the exhaust of the third clutch on a downshift.then i realized that depending on throttle position and the 3/2 controls valve position there were other flow restrictions in the circuit.now remember these were placed in the circuit during it design to control clutch exhaust,BUT THEY ALSO CONTROLLED BAND KNOCK OFF OIL.third acc oil takes a whole different path depending on the 3/2 control valves position.the thrid acc orifice and check ball both needed to be omitted from the circuit,but how?what would the effects be?would we exhaust too slow?too quick?we already knew we needed the band knock off oil and flow to be sped up.we also knew the ball impeded the knock off oil path at the case pocket as the 2 holes under pressure forced the check ball to restrict the flow.after testing we found that the circuit would function well without the 2 holes in the plate OR the checkball and that the 3/2 control valve being forced into its "HIGH SPEED UPSHIFTED POSITION"WOULDNT CAUSE any kickdown problems at lo throttle angles when the band was normally closed especially if you added a .060" bleed hole to the direct drums outer area.also note that we tried leaving the ball out and not touching the holes and the wheels would lock on a 2/3 ratio change on the ground.this showed that too fast a knock off with a small feed to the direct clutch was a move in the wrong direction and began to show what the circuit needed to be happy and functional.the proper hole size i found now is .130" with a smaaler hole feeding the shift valve its oil supply and a slightly larger hole being at the recieving end of the open side of the shift valve.eliminating the 2 holes in the plate along with the valve pinning created the need to cross drill the feed hole into an area further down in the circuit that bypassed all the obstacles to flow and proper operation.this also reduced the cubic volume of the circuit resulting in faster flow and now reintroduced the bind up back into the circuit again although very slight and not with poor shift feel at any throttle angle.after going back in to enlarge th PRNOD orifice and the 2/3 feed it was gone.now came the really slow 3/2 at high speeds(MUCH LIKE THE DELAYED 4/3 BACKSHIFT ON AA VALVEBODIES CAST WITH A 4/3 CONTROL VALVE ,ANYONE SEE THEM ITS THE ONLY V BODY WITH THAT VALVETRAIN) .this necessitated speeding up the rate that third clutch oil in the circuit LOCATED AHEAD OF THIRD ACC CHECKBALL AND CAPSULE PRESSED INTO THE CASE that exits at the closed shift valve.this hole can be used to apply the direct clutch on the bench with the shifter in od or 3rd position for those of you who care.abnyhow the improved exhaust was obtained by removing another checkball from the case that has absolutely no use during the upshift but is a flow restricer when the circuit "blows down".it fortunateely has a smaller hole next to it .make no mistake this, is not the third acc ball and hole.this is another one.removing the ball blocking the large hole and resizing the hole KICKED THAT IN THE BALLS.now for those who dont want to drill the valve body we now have a plate and reengineered clutch pack that puts a new shine on the old circuit that i had already perfected.LESSONS LEARNED: KNOCK OFF OIL RATE NEEDED TO BE INCREASED BUT TOO MUCH WAS NO GOOD.FLOW IMPEDERS IN THE CIRCUIT HAD TO BE REMOVED BEFORE THE CIRCUIT RESPONDED HAPPILY ALL AROUND WITH THE NEW ORIFICES .DUAL FEED ,WHEN DONE PROPERLY,IS THE PROPER WAY TO REDUCE CLUTCH FAILURE IN THIRD IN THE 2004R AROUND .SMOKING CIGARETTES CAUSES LUNG CANCER.
