TH400 Charge flow pressure

[turbobitt]

by unshimmed i mean stock shim,stock seat and stock spring.some came with 2 shims but that is not the norm,

I ran the blue spring, seat and two shims and/or a shim and thick washer or whatever combination allowed me to get the spring seat as far up the valve without falling into the undercut. The best pressure I was able to get was 155 psi with both pumps. I even tried the new Sonnax no leak boost and PR valves with the teflon seals with no change. The TCI spring gives me 200 psi with no shims. My pump pressure was always steady with the exception at idle with some small fluctuations but maintaining full pressure.
Allan G.

 

[Otto J]

I ran the blue spring, seat and two shims and/or a shim and thick washer or whatever combination allowed me to get the spring seat as far up the valve without falling into the undercut. The best pressure I was able to get was 155 psi with both pumps. I even tried the new Sonnax no leak boost and PR valves with the teflon seals with no change. The TCI spring gives me 200 psi with no shims. My pump pressure was always steady with the exception at idle with some small fluctuations but maintaining full pressure.
Allan G.

Is it possible your cooler isnt flowing enough causing a restriction making pressure rise?

 

[turbobitt]

Is it possible your cooler isnt flowing enough causing a restriction making pressure rise?

Otto,

I verified my cooler is free of any restriction. The lines running to the cooler and the cooler itself are fairly large. It is easy enough to remove since I don't use a conventional radiator hook-up and include in our test.
Allan G.

 

[turbobitt]

Here's another question, How much pressure do you think the converter contributes as its natural tendincy to move fluid ? In other words, will the converter boost the pressure by pumping it out ?
If so, I can see how some converters with different stator designs and efficientcies would effect charge flow pressure.
Maybe another good thing to chalk up on the list of test, PTC vs. old Precision industries.

Allan G.

 

[Alky V6]

There are a few factors related to the fluid inside the TC such as circulating flow force, internal flow restriction and centrifugal force that contribute to balloning of the torque converter. Internal flow restriction is what the converter manufacturer is responsible for.
Another factor is the fluid feed volume and resulting pressure of the fluid in the TC. This factor is what we can control, and has the most affect on the forward push of the TC.

The amount of forward push is directly related to the measured pressure of the fluid exiting the TC.

The area of the inside of the TC hub x the pressure is the amount of forward push or force the TC has.

 

[turbobitt]

There are a few factors related to the fluid inside the TC such as circulating flow force, internal flow restriction and centrifugal force that contribute to balloning of the torque converter. Internal flow restriction is what the converter manufacturer is responsible for.
Another factor is the fluid feed volume and resulting pressure of the fluid in the TC. This factor is what we can control, and has the most affect on the forward push of the TC.

The amount of forward push is directly related to the measured pressure of the fluid exiting the TC.

The area of the inside of the TC hub x the pressure is the amount of forward push or force the TC has.

I understand that but my question is, how much does the torque converters internal fluid flow add to charge pressure. I have to believe it is a factor. If the charge flow/TC oiul feed was completly blocked, would it pump itself dry or would it recirculate oil ? Not sure if anyone could answer this but throwing this out there.
This line of questioning is circulating around the fact that I have a .113 feed orfice with 100 PSI charge flow. I'm drumming up some theories as to why this may not be the norm. Maybe the torque converter is boosting the pressure ? Could fin angle influence this pressure ? All just questions that are floating around.
My biggest concern at this point would be to reduce the orfice to a point that the pressure is correct but then the cooler in ineffective because of lack of flow.
Allan G.

 

[Alky V6]

There was a case where I restricted feed to the point that I had 0 measured pressure on the cooler line and still had 1 quart in 20 seconds. This was on a transmission dyno. It was a C4 transmission.

 

[turbobitt]

Almost done

This will be the final configuration. The soft tubing will be easier to manuver around the moing parts. Havn't had a chance to mount the pump in the case but confident it will work.
Chris, Maybe after X-mas we can run the test ?
Allan G.

 

[chris718]

Sounds good.

 

[turbobitt]

For those who are interested, Brian (Bison) and I took a trip yesterday to see Chris at CK performance to do some TH400 charge flow testing and evaluation. We spent a solid 12 hour day and accumulated some interesting data. We will be meeting again in a few weeks to hopefully complete our testing so Chris can compile the data into a nice Bulletin. I think once we are done, people will need to re-think about charge flow pressure and how it relates to crank thrust failures and cooler design/selection.
Thanks Chris for allowing us to be involved with this research.
Allan G.

 

[Alky V6]

For those who are interested, Brian (Bison) and I took a trip yesterday to see Chris at CK performance to do some TH400 charge flow testing and evaluation. We spent a solid 12 hour day and accumulated some interesting data. We will be meeting again in a few weeks to hopefully complete our testing so Chris can compile the data into a nice Bulletin. I think once we are done, people will need to re-think about charge flow pressure and how it relates to crank thrust failures and cooler design/selection.
Thanks Chris for allowing us to be involved with this research.
Allan G.

More data is always a good thing. Keep us posted.

 

[chris718]

I am looking forward to the next round of testing,and must add that you are responsible for alot of good data we found.Without plumbing in the cooler on the dyno we would have never got as far as we did.I would bet we are probably one of a handful of people on the planet who have ever measured line,converter hub charge,cooler out and cooler in at the same time.To me in the trans arena it is like being the first crew of shuttlers to orbit the earth or walk on the moon.That is how rewarding it has been for me.We know what we need for the next round and I will start gathering what we need to make our data the most accurate and thorough anyone has compiled on the subject.Hats off to Brian and Allen(no Wendys next time brrrrrrrrp)

 

[quickt]

Is an after market input being used?

 

[turbobitt]

All of our baseline data was taken with a stock input and stator support. One of our test transmissions that we started collecting data on has an aftermarket input and stator tube with known hole diameters. We also have expanded our testing on a few converters but only scratched the surface. We also have a few other tricks up our sleeves for removing the effects of different variables. We have another days worth of testing for sure.

What we really need is a transmission from a car with known thrust issues to test. Based on what I've seen, My car should have toasted the bearings out instantly but 3500+ miles later it still lives with .007" clearance........Stayed tuned.......

Allan G.

 

[chris718]

ALLEN ,got a hollow converter today .

 

[bison]

Is an after market input being used?

We will be testing various inputs and taking the converter variable out of the picture. There is a a lot more to it than the converter pressure that is eating up thrust bearings. Im under the assumption that some of these instances had ballooned converters based on the lack of thrust failure in Allan's S2 where the charge pressure and cooler restriction was huge but no thrust failure or the engines had a clearance issue in the thrust area on assembly. He ran a Precision converter for years with no failure and most recently a 9.5" PTC with no failure but looking at the actual pressures he shouldnt have gotten out of the driveway without thrust failure. The amount of cooler flow based on pump clearances was huge also.

 

[turbobitt]

This is where "not all converters are created equal" statement comes from. Some converters can sustain line pressures without balloning while others are not so lucky.
Allan G.

 

[Alky V6]

We will be testing various inputs and taking the converter variable out of the picture. There is a a lot more to it than the converter pressure that is eating up thrust bearings. Im under the assumption that some of these instances had ballooned converters based on the lack of thrust failure in Allan's S2 where the charge pressure and cooler restriction was huge but no thrust failure or the engines had a clearance issue in the thrust area on assembly. He ran a Precision converter for years with no failure and most recently a 9.5" PTC with no failure but looking at the actual pressures he shouldnt have gotten out of the driveway without thrust failure. The amount of cooler flow based on pump clearances was huge also.

That's true. Not all crank thrust failures can be attributed to excessive TC charge volume. And, excessive TC charge volume doesn't always guarantee a crank thrust failure.

 

[quickt]

We will be testing various inputs and taking the converter variable out of the picture. There is a a lot more to it than the converter pressure that is eating up thrust bearings. Im under the assumption that some of these instances had ballooned converters based on the lack of thrust failure in Allan's S2 where the charge pressure and cooler restriction was huge but no thrust failure or the engines had a clearance issue in the thrust area on assembly. He ran a Precision converter for years with no failure and most recently a 9.5" PTC with no failure but looking at the actual pressures he shouldnt have gotten out of the driveway without thrust failure. The amount of cooler flow based on pump clearances was huge also.

Sounds like a cool test. We done some testing a couple years ago. Not nearly as extensive as you guys are doing. We did find some problems with different inputs, hole sizing, and the converter stator hub.

 

[chris718]

Regardless of the source of spiked pressures ,less than 80 psi in the cooler return has been effective at controlling thrust problems for me up until now.I would now reevaluate that and come to a lower # that doesnt restrict cooler volume ,but corrects for overpressured converter because of possible converter,input shaft and cooler restrictions .The stator assembly appears to be the first thing in the way