I would suggest starting off totally stock. See how it goes.
Then consider loading some or all of the trans tune that Scotty loves so much. It is more amazing the more power you put down.
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11-17-2015
I would suggest starting off totally stock. See how it goes.
Then consider loading some or all of the trans tune that Scotty loves so much. It is more amazing the more power you put down.
11-17-2015
+2 on that. The kit is meant to compensate for the sloppy stock tolerances, which you no longer have. I'm sure the shifts would be firm without the kit at all
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11-17-2015
Same thing happens to me too!Originally Posted by JamesIvey24
11-18-2015
Ha! You guys make me laugh. Wait till I help my brother in law with his. He'll be doing the work, so my hands will be free to take even more pictures. Probably be representative of more common build as well. Basically stock with VB and CP upgrades, a shift kit and tighter clutch pack clearances.
I think the trans settings I have right now came from Scotty. The only thing I changed was to lessen the shift times. I'm definitely putting those back to stock. Everything else though.... Eh, I dunno. I really like the shift points. Mostly when and how it downshifts.
Right now in the tune, I have performance mode set up with all the custom tweaks, and the non-performance table is what stock performance mode used to be. (If that makes sense?) Anyhow, the other day I was driving and just for grins I turned performance mode off. First time I accelerated out of a corner I thought something was wrong. Took forever for it to downshift. I can't see any advantage in reverting back to that. But if you have a solid reason why, I'll listen.
Clearance... I'm not a grammar Nazi, but the machinist in me can't let that slide.
But yes, I totally agree. The trans I built for my father in laws car was stock with VB and CP upgrades, a shift kit and tighter 2nd clutch pack clearance. On a stock tune, the shifts on that thing are great.
11-19-2015
Only thing you should ever mess with in the shift times tables are the mutli's, other then that, leave the base shift times alone. Was told by a GM ecu programmer that the most common misconception that people have about shift times is that it makes their car shift faster, when in fact the clunk that you feel from lowering that table is merely a shift "error" and a reduction in line pressure. Those shift times are merely set the limit to how long it should take for the transmission to shift before going into shift error, if you reduce those times to an un-achievable value you will error all the time. My shift time tables are totally stock and my average shift times with the transgo shift kit are .1-.2, no more no less, rest of the adjustments I have made were merely dialing in the firmness of shift pressures and TCC duty cycles. Now it shifts fast and smooth as butter, without that harsh neck snapping feel.
11-21-2015
Can you elaborate? I just cruised through all the trans tables in HP tuners and I didn't see anything that fits that description.
There may be something to that. I actually took some time to think about this before I replied.
One of the first things I did when I got my tuner was shave the shift times down to (what I now know is) an achievable amount. I wanted to replicate the way my old carb'd S-10 with a fresh/tight 700r4 shifted. It had a very distinct "push" when it hit the next gear. After tuning the car, you could definitely feel the shift. However, I wouldn't call it a "push" as much as maybe....... a bump? I guess I would compare it to a clutch dump? Anyhow, I didn't like it. So I started moving the shift times up until I got a good solid shift without the bump. Here's where I'm at now. Keep in mind, this is my current stock transmission. I will be going back to stock shift times when I install the built trans.
Stock performance shift times
Tuned performance shift times
The difference
As you can see, nothing crazy.
Would you be willing to share your tune? I'd be interested to see those changes.
11-21-2015
On a 4T65e, shift times can be set "sorta" quick, though I wouldnt set it much faster than the .175 factory time on the 2-3 shift. 1-2 can go down some and leave the 3-4 stock is fine. Adding line pressure is good way aswell, like 5-10% because anything more will just start to clunk into gear and not be as smooth.
But in something like a 4L60e or similar, it's alot different. Going past .275 isnt such a good idea, but .300 is great. Seeing how stock times are near .500 and .600, then adding slight amounts of line pressure again to achive the rest.
Then get into something like the 6L80e in my truck, talk about crazy amounts of tables and stuff that can completely fubar the whole shifting if you do it wrong. It's a clutch to clutch trans and everything is electronically controlled.
11-22-2015
You got it pretty much, theres a big difference between fast shifts and hard shifts. You can have it slam the gear so hard it feels like it will rip it out of the mount, but that doesnt mean that its doing it "quick". And its hard to perceive clutch engagement just by the seat of your pants, there is alot that you can review in datalogs in HPT for transmission that tell you just how fast your car is shifting. But you have to look at those tables in relation to the shift pressure tables as they will scale accordingly. Now I don't have a performance shift mode on my GP GXP because of its year, but this is what my stock shift time table looks like.
HPT's wording of the tables can sometimes be misleading but you can see that my stock tables are scaled for more allowed shift time at lower torque levels, but it is also directly proportional to shift pressure as well. And there in lies the error that is typically made. People will take that table and lower it across the board. Sure you might be able to achieve .175 on your tune if the trans pressure setting is for 96psi, but at 36ft lbs of input torque, the trans pressure might be somewhere like 15-20psi, and thus it will never be able to achieve the value you set for it, so the trans thinks something is wrong, and thus you get that BANG on the shift because it is an internal limp mode as it was explained to me. The trans does what it can to prevent damage because of that un-achievable value. And remember there are alot of aspects about the TCM that we arent allowed to edit or have no access to from GM, and that is just another part of it. The tables have to work in layers with each other for them to work right, so you have to be really delicate about how you mod them.
None the less youve done a fantastic job with the hard parts of the trans, so I wouldnt be quick to jump into software changes without experiencing what the hardware changes have done for you yet. THe sonnax line pressure booster kit and the valve body upgrades along with the shift kit are going to make a world of difference as they are mechanically modifying the trans within the bounds of the known stock software values. See how it is, go from there, id be happy to send you my tune file, just PM me your email, but I gotta warn you in advance, my settings will probably be drastically different, I wasnt as aggressive with building my trans as you were so my software values will likely be more heavily modified to reflect that fact.
12-07-2015
Swung by the transmission place (the rebuild shop, not the parts house) this afternoon and got this:
Took a little while. They had to figure out how to write it up. I guess not a lot of people walk in off the street to buy a torque converter...
12-07-2015
my transmission shift time is set to .125. I think that is the fastest the transmission can shift. I like it a lot.
ok, I went and double checked and it is set to .200. at some point it was set to .125, but not anymore.
one more edit: performance shift is set to .125 and normal is set to .200
Last edited by SgtMarshal; 12-07-2015 at 10:06 PM.
12-08-2015
It can't even shift that fast lol.
Not with stock valve body and clutches anyway.
12-08-2015
Im throwing my precision converter from TEP in the trash and getting a circle d sometime in the spring. Can't stand how sloppy the thing is.
12-08-2015
why not just have it restalled instead of buying another?
12-08-2015
we shredded the sprags in two of those std precision converters at only 500whp. they are their basic rebuild line.
youll know it cause youll loose all forward/reverse...except just after starting it up and puting it straight into drive from N...then it'll drive at low throttle/load for 10-20ft till the turbine no longer holds.
their only performance converter line is sold by their other company, precision industries....a damn good converter
12-08-2015
I understand what you're saying, but you have to remember, I am using it for a SC 3800. It sounds like the issues you speak of are more related to the miss use of the 4t65e in a V8 car. Plus, I can't justify the cost of a custom converter. The new in box PNH converter was well under $200 after tax.
"at only 500whp" LOL! Shouldn't be a problem for me.
12-08-2015
Has anyone used patc converters?
12-08-2015
its not stock, its a built dynotech
12-08-2015
A co-worker just had a converter failure in his V8 GXP. Same symptoms, exactly as described. Stock engine. I believe it was a PNH in it. PI makes a decent converter. Wish PTC would make one for us.
12-08-2015
precision of new hampton, not PI, they wont restall their reman converters. I've used them before in other cars with great success but its just sloppy in the GXP.
Well circled was only 450 for a custom 4t65e converter, unlike the 850 i was quoted for a PI converter through TEP, so its reasonable enough in price that its worth the swap. But realistically the SC 3800 can make more power then the LS4 can with the right mods, especially in the torque department with the blower. You will run into the same issue the GXP guys have stock once you start putting power through it.
lol TEP claimed never had a return on the PNH converters too, i knew that was bull**** from day 1. But that was all expected even before I bought it, $150 dollar converter, cant expect miracles even if its re-manufactured to OEM standards. It's only as good as its designed from the factory. Custom is the way to go.
12-09-2015
Right. To be clear, Precision Industries (PI) and Precision of New Hampton (PNH) are 2 different and independent torque converter manufacturers.
$450 isn't bad. I'm just fairy certain the the PNH converter will do what I need it to. I don't anticipate ever being over 350whp. Shoot, I'd be happy to hit the low 300's.
I don't doubt that there have been defective PNH converters found before, but from all the research I did, I couldn't find even one. That says a lot... Think about it, what's the first thing you do when you get a defective anything? I tell EVERYONE that will listen. I found multiple instances of other converter failures. All things considered, I don't think you can get a better sub $200 converter. In fact, when I bought my first PNH converter, I spent a lot of time talking with the trans shop manager.* He said, when they were deciding on which unit to stock and use they actually went to the PNH factory for a tour. During that tour, they pulled a random converter off the shelf and cut it open. I don't know a ton about converters, but he said, it was the best (mass) built unit that he had seen. That sealed his decision.
Also, if we're being completely honest, the issues you have with your PNH converter are not manufacturing defects. It meets all the manufacturing standards. It just doesn't meet your standards, and there's nothing wrong with that. You know what you want, and you know where to get it.
* This particular shop has multiple locations in Tucson and builds/installs thousands of transmissions every year. They use ONLY PNH converters for every trans they build.
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