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Discussion Starter #1 (Edited)
Ended up breaking a U joint and it broke the back of my stock case glide. I was in a time jam and went with a 1500 HP ATI super glide aftermarket case 1.80 gear set. Old trans was a basic stock case / tci input shaft, 7 clutch ATI direct drum, kevlar band, TCI brake, and 1.76 TCI helical gear set. Also went with new molley drive line and larger 135O billet yokes. Added about 8 lbs. 60' is off Mph is down a solid 1-1.5 in 1/8, and 1.5-2 in the 1/4. Similar Da and no other changes. New trans doesn't feel like it's slipping but shift is a good bit softer than old trans, and there is a lot more growl at idle. Kinda sounds like a old pete jackson gear drive. Also notice flex plate flexing forward a little when you rev car up in Park. Converter has about 1/8" of clearance. I was expecting same time or a little quicker from the straight cut planets. Could the hd parts be soaking up that much power?
 

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Check the line pressure. Stock pump? Them 1.80's can be tight, weight hurts. I assume you have compensted for weather/corrected altitude.
 

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Discussion Starter #3
New trans has a high flow pump, old trans stock pump. Da was really close.
 

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Discussion Starter #5
Define "hi flow" pump? Uses different gears that are bigger than stock?


Hutch
Hutch I don't know I bought trans as a complete unit from ATI. Just Says "High flow pump". A buddy of mine is ATI dealer and I was stranded out of state with a race coming up. They do recommend their synthetic type F fluid and Im running hygard. With old setup hygard picked it up almost 2 mph.
 

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Long ago I built two 'identical' PG's for a foot brake guy. One was quicker by half a tenth. Shit can drive you nuts. One thing for sure, too much pressure will slow you down.
 

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Discussion Starter #7
Just checked crank endplay and it's .030". Was .005 before this trans went in. You can watch it flex the flex plate when you rev engine in park. Pushed flex plate 1/4" forward and can see where ring gear has been rubbing starter housing.
 

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Stock48 - Can you do a cooling line pressure test? I've got a similar problem and just did one on my glide. My average pressure was 50 psi, with a range of 40-65 psi.
 

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Discussion Starter #11
Sounds like you found your problem.


Hutch
Yes I think so. Now the question is wtf do I do now. Is there a chance my big 10.5" conveter and hygard could have been the problem? They do recommend their synthetic type F fluid for the transmission. I did tell the guy on the phone when I ordered it I would be running hygard and asked if it would be a problem and he said it should be fine. Could this thing have been on the limit with the thinner fluid and I pushed it over with the hygard and my big converter?
 

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Discussion Starter #12
Stock48 - Can you do a cooling line pressure test? I've got a similar problem and just did one on my glide. My average pressure was 50 psi, with a range of 40-65 psi.
I will test both line psi and cooler psi when I get home. Then I will drain fluid and put in the recommended fluid and test again so we can see.
 

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Great - more data to compare is a good thing. I'm running the ATI synthetic, BTW. I also found 180 psi line pressure at idle; my thrust was at .020" after about 300 miles and 9 passes.
 

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Discussion Starter #14 (Edited)
This thing had less than .006" after all summer of beating on it with old trans and ??? Psi lol. Im going to fix old trans and put it back in and see what cooler psi is. If I haden't broke U joint old trans would have never gave me a prob. Was almost nothing in pan even after explosion. This ATI trans did get me thru the race, got me the win and the limited street record tho.
 

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Congrats on the win! I'm looking forward to seeing what you get for pressure. This is like the 5th time I'm posting it, but what the hell; perhaps it'll be useful to you - here's video of my gauges during my test today:

http://youtu.be/9z-vVLlYr2k

Here's a question for you - did you use the same TCI input shaft, or did you use ATI's? Apparently, different shaft designs can lead to drastically different pressures (I'm not even close to an expert here, but perhaps some of the pros can delve deeper into this line of thought...)
 

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Discussion Starter #16
Congrats on the win! I'm looking forward to seeing what you get for pressure. This is like the 5th time I'm posting it, but what the hell; perhaps it'll be useful to you - here's video of my gauges during my test today:

http://youtu.be/9z-vVLlYr2k

Here's a question for you - did you use the same TCI input shaft, or did you use ATI's? Apparently, different shaft designs can lead to drastically different pressures (I'm not even close to an expert here, but perhaps some of the pros can delve deeper into this line of thought...)
Old trans had TCI input with bushing in between ATI trans is complete from ATI with vasco input and no bushing. Input just flops around in there. What we need to know prob lies inside my old trans.
 

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Oil leaves converter @ input shaft, bushing can restrict out flow. A S/G racer w/468 rat motor ate like a half a dozen crank thrusts once, finally figured out problem was a restricted cooler, that would be 'restricted out flow'.
 

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Can you elaborate more on this subject?
Transmissions were oem case stock configuration units for a foot brake application. Line pressure was same on dyno, transmissions were set up to be identical including torque readings on the force required to rotate the out put and input shafts while applying air to the low servo. Regarding line pressure, higher readings will require more hp @ the trans pump. That reality is why most 'class' racers run 3 qts. of oil in the engine and as little line pressure in the trans as they can get by with.
 

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Discussion Starter #19
Oil leaves converter @ input shaft, bushing can restrict out flow. A S/G racer w/468 rat motor ate like a half a dozen crank thrusts once, finally figured out problem was a restricted cooler, that would be 'restricted out flow'.
My other trans has a input shaft bushing and this one doesn't seem to have a bushing and if it does it's a loose one. Could the thick hygard oil be causing the psi to go too high?
 
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