Your main line pressure will effect the cooler line out pressure even with the mod. Ex: 235 psi main line will have a different (higher) reading than 175 psi main line pressure with or without the modification. Just something to be aware of.
What size is the orifice you're using?Interesting. I found even with the restriction, the main line PSI did effect my cooler out PSI.
What size is the orifice you're using?
I've used both 7/64 and 3/32. What I've found is the return or exhaust out the converter has a role in the feed presure as well.
The part in bold should be, exiting the torque converter and going to the cooler. Ooops.This next tip has nothing to do with T/C over charging.
Another source of a cross leak that is widely ignored is the rear bushing in the pump cover. This bushing has the job of supporting the rear of the input shaft and also separating torque converter feed oil going to the torque converter (post orifice) and lube oil returning from the cooler. If this bushing has anything more that .001 to .002" clearance, T/C feed oil will bypass to the lube circuit of the transmission, and flow through the T/C and cooler will be affected. The common symptom observed from this is higher than usual trans temps since oil flow through the cooler is slowed down by this cross leak.
Lazaris. If cooler pressure is varying significantly with line pressure changes after adding the orifice, you should check for crossleaking or just replace the pump assembly.
One way that oil pressure can bypass the pressure regulator assembly all together and affect T/C charge pressure is running too much pump gearset face clearance. .001" to .003" is the acceptable range. I always shoot for .001" to .0015".
Something else to check. After doing the mod, always run a mill file across the surface of the pump cover to knock down any raised metal that always occurs because of the drilling and tapping of the feed hole. This raised metal, if left alone, will prevent the two halves of the pump coming together completely to seal hydraulic passages in that area of the feed hole. Cross leaking will happen because of this.
This next tip has nothing to do with T/C over charging.
Another source of a cross leak that is widely ignored is the rear bushing in the pump cover. This bushing has the job of supporting the rear of the input shaft and also separating torque converter feed oil going to the torque converter (post orifice) and lube oil returning from the cooler. If this bushing has anything more that .001 to .002" clearance, T/C feed oil will bypass to the lube circuit of the transmission, and flow through the T/C and cooler will be affected. The common symptom observed from this is higher than usual trans temps since oil flow through the cooler is slowed down by this cross leak.
Don I'm running the pump I bought from you. So I know you did all that stuff already. I was just making a point that the feed pressure is only one area to look at. The fluid being able to return or exhaust will effect the feed pressure no matter how small you make the orifice. I actually removed my pump bushing because the converter I use has one. This reduces the back pressure (return). I also incorporate another device in case of a spike in pressure.
Have you ever seen some of the real fast cars leave during dusk or night off of the trans brake? You will actually see sparks come out from the middle of the car. Do you know what that is? It actually pretty amazing. I have see it alot on some really high HP cars that need the line presure to make the tranny live. I have a video of Dan Millen's car doing it. Its occuring right after trans brake release when the feed pressure spikes.........
Have you ever seen some of the real fast cars leave during dusk or night off of the trans brake? You will actually see sparks come out from the middle of the car. Do you know what that is? It actually pretty amazing. I have see it alot on some really high HP cars that need the line presure to make the tranny live. I have a video of Dan Millen's car doing it. Its occuring right after trans brake release when the feed pressure spikes.........
OR -the converter is getting pushed out of the trans. , bending the flex plate
which in turn ends up hitting the starter pinion. This the the same action that takes out your thrust bearing!!! Mike
I see these sparks pretty regularly at the local heads up races during the night runs.
I saw what the effects were a few passes later. The converter had pushed hard enough on the flexplate to bend it. It pushed so much so that the heads of the bolts holding the converter to the flexplate had gotten into the oil galley plugs of a small block. It easily cut .100 off the height of some of the plugs. This means the converter had to try and move off the pump at least 1/8 of an inch.
Same situation with a Buick V6. The converter pushed far enough forward to make the flexplate chew into the starter.