Head is spinning after reading line pressure sticky
#1
Head is spinning after reading line pressure sticky
OMG,
Read every post & there's no safe conclusion. Some say shift kit, others say edit PCM, raise pressure, don't raise pressure, used a built transmission & a cooler; transmission broke anyway, transmission shop technician set my pressure too high & I thought he knew what was best. Seems to me that there are no fool safe solutions, only delaying of the inevitable.
Am gonna try an Auto Performance & Transmission Center 4L60E wake up kit.
Consists of an intermediate billet servo, overdrive billet servo, & an oversize pressure boost valve. Supposed to provide smooth firm shifts. Shift firmness increases with speed. Will post short term & then long term results.
Read every post & there's no safe conclusion. Some say shift kit, others say edit PCM, raise pressure, don't raise pressure, used a built transmission & a cooler; transmission broke anyway, transmission shop technician set my pressure too high & I thought he knew what was best. Seems to me that there are no fool safe solutions, only delaying of the inevitable.
Am gonna try an Auto Performance & Transmission Center 4L60E wake up kit.
Consists of an intermediate billet servo, overdrive billet servo, & an oversize pressure boost valve. Supposed to provide smooth firm shifts. Shift firmness increases with speed. Will post short term & then long term results.
Last edited by LS1-450; 10-11-2005 at 09:23 AM. Reason: edit for experimental solution & parts change
#5
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I have tuned for line pressure and seen the trans later ****. I have personally used a Transgo 3 washer shift kit and it just **** very prematurely in a sponsor built A4 = Costly and not something I expected but more like was scared of! I have seen the TG 2 washer trans ****. My solution, TH350 Will be enroute within 24hrs No line pressure to mess with, and with a trans brake and reverse manual valve body, wont really care. Yes, there are ppl running this or that built A4 and will pound their chest, but until there are several ppl running the same build and really abusing the **** out of it, I cant support it anymore. I used to cheerlead for the vendor that built mine, but now, I realize what other seasoned A4ers said, Its only a matter power vs. time.!
Charlie
Charlie
#6
Originally Posted by CAT3
I have tuned for line pressure and seen the trans later ****. I have personally used a Transgo 3 washer shift kit and it just **** very prematurely in a sponsor built A4 = Costly and not something I expected but more like was scared of! I have seen the TG 2 washer trans ****. My solution, TH350 Will be enroute within 24hrs No line pressure to mess with, and with a trans brake and reverse manual valve body, wont really care. Yes, there are ppl running this or that built A4 and will pound their chest, but until there are several ppl running the same build and really abusing the **** out of it, I cant support it anymore. I used to cheerlead for the vendor that built mine, but now, I realize what other seasoned A4ers said, Its only a matter power vs. time.!
Charlie
Charlie
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I'm not convinced that line pressure alone, within the
limits GM originally designed, is going to kill trannies.
Yeah, you might be applying the higher end of it more
often but if it's there at WOT anyway, who cares if
it's also full line at half throttle?
Thing is, the people who are pushing line up are also
running more power, often more torque and torque
multiplication and needing line to make up holding
power. 4L60E, the 6 is 600 lb-ft input shaft torque
rated. Do the math on a 2.5 STR converter, 400lb-ft
motor (with torque being likely full-on at the point of
peak torque multiplication, not like stock) and then
guess at how much design and manufacturing-bad-luck
margin was left on the table by the folks who made up
the shaft torque rating. Soothing, isn't it?
You can improve the guts and take out prime failure
modes 1, 2, 3, ... but if you keep on challenging the
capacity, sooner or later you will find N+1.
Personally I'm fairly impressed with the capacity, GM
back in the day didn't put the TH350 behind anything
stouter than a smallblock, maybe 400lb-ft with a low
multiplication, low stall speed converter. A stock TH350
would probably get beat up too, behind a decent LS1
motor. But the TH350 has the benefit of only 35+ years
of aftermarket upgrade learning and price erosion.
Too bad about the 1:1 final drive....
limits GM originally designed, is going to kill trannies.
Yeah, you might be applying the higher end of it more
often but if it's there at WOT anyway, who cares if
it's also full line at half throttle?
Thing is, the people who are pushing line up are also
running more power, often more torque and torque
multiplication and needing line to make up holding
power. 4L60E, the 6 is 600 lb-ft input shaft torque
rated. Do the math on a 2.5 STR converter, 400lb-ft
motor (with torque being likely full-on at the point of
peak torque multiplication, not like stock) and then
guess at how much design and manufacturing-bad-luck
margin was left on the table by the folks who made up
the shaft torque rating. Soothing, isn't it?
You can improve the guts and take out prime failure
modes 1, 2, 3, ... but if you keep on challenging the
capacity, sooner or later you will find N+1.
Personally I'm fairly impressed with the capacity, GM
back in the day didn't put the TH350 behind anything
stouter than a smallblock, maybe 400lb-ft with a low
multiplication, low stall speed converter. A stock TH350
would probably get beat up too, behind a decent LS1
motor. But the TH350 has the benefit of only 35+ years
of aftermarket upgrade learning and price erosion.
Too bad about the 1:1 final drive....
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Originally Posted by DeViOuSwOn
So are you saying shift kits hurt the trans no matter what, ie the 4l60's?
#9
Seems like the 4L80E swap w/ a cooler is a good solution once the 4L60E breaks down. Can anyone comment or have experience with how well the 4L80E holds up after a swap?
BTW, CAT3 - 11.791 w/a 113 MPH trap speed is some awesome driving. Well done!
BTW, CAT3 - 11.791 w/a 113 MPH trap speed is some awesome driving. Well done!
Last edited by LS1-450; 10-11-2005 at 02:18 PM.