Limits ? not towing, thanks

 

I suppose the standard answer is 90hp over stock....but it depends on what you use to get there....something that disables tq mgmt will lower that number and your trans life....as well, depends on how you drive....the stock tq converter is slop and cant take much for too long....

I put 13k on my stock trans and smarty level 3....but i drove relatively mildly....if you want to thrash and race everyone, it's not goona last too long.

 

I heard the same too. Max hp for stock 48e 90 hp, some people say 60. I kinda alternated between 60-90 hp in the months I had my stock trans up until I had my trans upgrade When I turned up the Smarty to 130 hp, boy what a difference.
There is a lot of advice that says to make a trans upgrade one of your first modifications. I think that's good advice. You're going to have to do it eventually anyway.
I've heard a TC/VB will get you a lot of life out of your transmission up to around 500 hp. Of course some people can tear up a trans with a 60 hp increase, I guess because they think they're 'safe'.
Then on the other hand, Luvnacummins had his stock trans last a long time with twins, etc. and from what I understand he wasn't that easy on his trans!
If you slip your clutches in your TC or main transmission, it makes it easier to slip them next time. If you look, you will see a number of people who have slipped their trans first time on a high hp setting in the Smarty, esp. the beta software with lowered torque management. If you slipped clutches in TC, and you replace anyway, you got lucky. If not you have to do more work when you upgrade your trans if you have slipped the trans badly. I may be wrong, but I don't think that you are any more likely to only slip the tc, in other words I wouldn't count on just having to replace that if it needs work.
If you know what turbo (either stock or aftermarket improved) you're going ot end up with, that can make a difference in what converter you pick. Les at Goerands said that I would want a slightly 'looser' TC since I wanting to replace the turbo. If you plan to stay stock, you can stick with the tighter, slightly better gas mileage TC (also you can opt for the 100,000 warranty instead of lifetime and save $200 from Goreand Bros for the TC)
I liked Goerand parts myself, but there are other good trans parts out there too. I think Goerand is a good combo of price, quality and service. You won't hear anything bad about him!

 

60 HP slipped my TC and prompted me to do the TC and VB. But if you are just towing (like me) and not racing you could get away with 90 or maybe more by keeping the revs up and watching the tach for slipping. It's that low RPM, high torque pull that gets the tranny and also raises the EGT. So rev it to 2200 or so and keep an eye on it. Then do the tranny anyway when you can.

John

 

Im at around 500 right now and the limits are very noticeable but I cant say that it is done yet maybe 550.

 

What year of truck? The 06 and 07 TC seem to be a little tighter.

 

04.5 QC

 

I ran an XZT (65hp) on my stock auto for a year or so, no problems, I never worried it would give problems really because it wasnt a huge low end torque boost, seemed more top end hp. It is a good improvement on a stock auto, made the truck quite a bit faster, esp on the freeway.

I then unhooked it and put on a Smarty on the stock auto. I ran it on #3 mild, which is supposedly only 60hp, but it is alot more torque on the bottom than the XZT. I only did this for a week or so, but the trans seemed fine. I ran it a few times on #7(130hp) and it seemed fine too, but I felt like it was a bad idea still. I installed a Goerend VB and tried it out on #9(170hp) thinking I could get away with it for a few runs. At half throttle with the TC locked up it skipped real bad and made the truck buck real bad. I did that twice and from then on my TC slipped while locked up with the Smarty on any level with very little throttle. This weekend I took the truck to the track and ran 104mph with the TC unlocked the whole time it felt like with the Smarty on #9, so evidently my TC was only messed up during lockup.

After we left the track, I put the Smarty on stock power, and the TC now locks without slipping or shimmying. The stock trans is stouter than I imagined. I am sure a few more runs at the track on #9 will put an end to my trans though.

Sorry for the long winded post. I had the same question a few weeks ago. My experience is you can run ALOT more power unlocked than with the TC locked if you just upgrade the VB. I asked Dave Goerend about upgrading the clutches in the trans and he says he likes the stock clutches once there is more pressure via an upgraded valvebody. My two 104mph passes seem to confirm he is right, not that he needs my confirmation, but you know what I mean.

 

On my 04.5 100hp would slip the stock TC. After I did the TC and VB, I thought I was pretty safe on the internals with no high boosted launches. I ran it at 500-550hp for around 30k miles, but when it was pulled apart the third gear pack had definitely been too hot.