RacinDuallie
Black Sheep Racing
For reference we are locing up first gear......
This might possibly help eliminate some confusion.
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New CRT 48RE Competition Only Trans Brake
- Thread starter CRT
- Start date
kole32
New member
RacinDuallie
Black Sheep Racing
this is irrelevant, as it is relating to a stock valve body not a modified one......
This might possibly help eliminate some confusion.
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kole32
New member
Oh so sorry my bad ?.... I’ll let John continue to explain it. I just can’t figure out what you’re having a hard time understanding. I’m sure John will have more data this week once we do some more testing.
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RacinDuallie
Black Sheep Racing
I personally burnt up multiple single disc and triple disc converters back in the day, paramount in our battles was lock up pressure.
Plugged filters, transmission torn down and inspected everytime, internally everything looked as good as the day installed, cut the converters open that's where the material that plugged filters came from.
I know the trans world has advanced, but to say 50 psi lock up is fine, yes this has me confused. No bong water changes needed.
kole32
New member
Well so far, with johns valvebody in my truck, the converter does not slip when in lockup, (1157hp 1987ft lb tq at the crank) I understand that everyone wants an adequate amount of testing before they install a product in their truck, and I know John wants everything perfect before he is selling anything to anyone. But so far no issues have arose. Ethan from Wilson Patterson diesel has one In his truck, has 3,000 miles with no issues, so far everything is working as it should. Now correct me if I’m wrong, but the converter clutch is disengaged with pressure applied and when there is no pressure on the lockup piston, the converter clutch is engaged ? Like I said if I’m wrong correct me.
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DieselheaD
New member
it’s only 50 psi because no one has monitored pressure the way cope is, on the VB test bench that muldoon and firepunk have it nets different numbers because the hydraulic circuit being tested is deadheaded after being fed line pressure (obviously higher than 50) the circuit is not supposed to leak down so on the bench it will always read whatever the line pressure is.
cope is getting real time numbers on an actual transmission not just a VB bench...
kole32
New member
T-MAN
misunderstood
This isn't correct, there is no spring to apply lockup so pressure is needed.
T-MAN
misunderstood
I agree here , but I feel the test port is kinda useless if its not showing any pressure change to the lockup circuit with a base line pressure of 110, 175,200 and 250psi I feel there has to be a change to apply pressure simply because a converter wont hold very much horsepower at 110psi line pressure. this is just my 2 cents though
Big Blue24
Comp Diesel Sponsor
Don't take this the wrong way, but that is not entirely correct.
When the converter is unlocked, line pressure fluid flows through the inside of the input shaft to the underside of the lockup clutch assembly and floats the lockup clutches and apply piston away from the billet cover. This release oil, after flowing around the clutches and apply piston fills the bowl/turbine side of the converter. It then flows out of the converter hub on the outside of the input shaft through the trans pump, through the case, through the valve body and lockup switch valve assembly, and out to the cooler circuit.
When the converter is locked, main line pressure flows through the shuttled switch valve in the VB, through the case, through the pump, and into the converter hub. This oil raises pressure in the bowl/turbine side of the converter and applies the lockup piston. Oil trapped beneath the lockup piston and inside the input shaft is routed to a vent in the valve body that dumps directly to the pan. This vent is only opened up when the lockup switch valve is shuttled.
Just a quick terminology lesson, oil flowing through the input shaft to the underside of the piston is commonly termed converter release oil. Oil on the opposite side of the lockup apply piston is commonly termed converter apply oil.
I'm guessing/theorizing Cope is only seeing 50 psi apply because his converter apply tap/hardline is plumbed to the wrong port on the transmission pump and we are receiving bad information from the test gauge. His release oil tap appears to be the correct port because it closely follows line pressure until lockup is commanded on the Muldoon VB which utilizes a factory switch valve. The only other explanation I can come up with is Cope has a burned up converter on the test tranny and he's seeing a ton of leakage past the lockup clutch assembly and therefore shockingly low apply pressure.
FYI, we (PDD) have logged numerous tests on a real truck with a real transmission with added ports for the specific purpose of comparing converter release and apply pressures at various line pressure settings. What we learned has tremendously increased converter life in our high line pressure race transmissions.
FYI, we also have a hotrod/modified VBT4000 test stand equipped with a variable speed pump drive that we mapped to the flow output of an OEM 48RE pump so we can simulate engine RPM and that too has led to new technologies/discoveries. Don't take this wrong, but there are tons of "hungry" companies constantly competing to get a leg up on their competitors behind the scenes and eventually you the customer will reap the benefits from the R&D as everyone is forced to innovate or die. Don't be so close minded to think Cope or Firepunk or Muldoon are the only shops/builders out there testing with a real bench. Goerend has both a transmission dyno and a VB test stand. ATS, BD, Revmax, Suncoast, Redline, Ulitmate Trans, all have VB test stands. Goerend is working on some torque converter regulation valve body setups to prevent ballooning whilst allowing greater than 200 psi line pressure for race applications. I'm serious, there is a lot going on behind the scenes!!!
I agree, something is not right with the test data for the apply pressure number. Either the port is not tied into the correct circuit in the pump, or the converter clutch is hurt and it can only hold 50 psi because the rest bleeds past the burned lockup clutch(es).
Once again, Cope, I don't have an axe to grind, I love the innovation and I'd like to see your custom VB work well. We (PDD) don't offer a reverse pattern manual VB and occasionally we lose a complete transmission sale because we don't have one. So hurry up and sort this thing out, or move the port, or fix the converter, whatever so we can see the real numbers. My tidbit of advice, you aren't holding 1000+ HP long term with just 50 psi apply, so if it does hold with the current VB, something is throwing off the numbers in your test transmission.
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RacinDuallie
Black Sheep Racing
RacinDuallie
Black Sheep Racing
CRT
New member
BINGO
CRT
New member
Have him send me his valve body. Let me test it and see what he has.
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RacinDuallie
Black Sheep Racing
CRT
New member
When my trans needs to be updated it's going to somebody who's been posting in this thread.
Someone who understands the lock up priorities for diesel drag racing
* Hint! ( It's not you John )
op:
Take your hints back into your bong and smoke it. Prove me wrong. So me data not a text.
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CRT
New member
You want 200 psi in lock up ? Here ya Go. My vb on firepunk answer matic 230 psi in lock up. CRT-X55ODLU-PRO-FIREPUNK - YouTube