Chances of it blowing are about 50/50 either it will or it won't.

Definitely no safe rule of thumb for that one. I have done one or two at 10-15psi.

I have also seen guys blowing them up trying it for the very first time also, so keep that in mind.

 

Hmm thats exactly what i figured. Ive done about 4 or so at 10 psi and seemed to do fine, buthave only 38k on my truck so im sure my days are numbered. I would love to put a built suncoast in it just not tommaro. Can deffinatly tell my tranny holds me back on putting my power to the ground.

 

You will bust the Sprag if you continue. I would not do boosted launches with the stocker unless your ready to buy a built unit.:thumbsup:

 

This is what not to do with a stock trans.!!!
This was testing some prototype clutches that did not hold up. You can see it give up when i shifted from 5th to 6th.

 

That was NICE!! From what I understand a boosted launch of ANY kind on a stock trans and torque convertor is a death wish for the trans but they can be done for a short time

...btw, I like the cooking thermometer in the AC vent (did I see that correctly)

 

Hey rjp can u get me a number on a fully built unit drop in ready to go to hold 800hp or so.

 

The same setup Michael Dalton is running would be a good fit for you. I would have to call in order to get an exact price; Ill Pm you a rough number if you'd like?

 

12-15psi.

Sent from AutoGuide.com Free App

 

The other day when I hammered on mine from about 25 mph it done fine but when shifting from 5th to 6th it went into 6th for just a second then seemed like it kicked its self out and back into 5th. Of course I let out of it then and figured that was the end of it but hasnt done it since then.

 

Im sure it did the same thing as mine did in the video; If so it was your overdrives slipping.

 

I have done this maybe twice since I bought the truck. When I do it I never let it go into 5th and 6th gear. I let off when it is in 4th.

It seems like upper gears don't like it. A couple people I know with allison transmissions don't let there truck go past 4th either. You're asking for it if you do.

 

I agree with RJP that a stock trans is only going to take so much. But I think the 4th gen trans is doing 10 times better than the 3rd gen one. And even then, I hit my stocker with 500 for 2 full seasons. 10-15 passes a month before it finally went. And it wasn't the sprag that went. I welded the od/ud clutch packs together. All of them.

I rebuilt it. And raced on it for the rest of that season all with the lower sprag still the factory model. Never touched it other than to pull it out and clean it. The whole trans had lots of clutch material in it.

I'm not linked with a transmission company, so my experience is limited to my customers. But I just wanted to throw that out there.

 

I agree with RJP that a stock trans is only going to take so much. But I think the 4th gen trans is doing 10 times better than the 3rd gen one. And even then, I hit my stocker with 500 for 2 full seasons. 10-15 passes a month before it finally went. And it wasn't the sprag that went. I welded the od/ud clutch packs together. All of them.

I rebuilt it. And raced on it for the rest of that season all with the lower sprag still the factory model. Never touched it other than to pull it out and clean it. The whole trans had lots of clutch material in it.

I'm not linked with a transmission company, so my experience is limited to my customers. But I just wanted to throw that out there.

Good to meet you Dave...

 

Off topic but I believe the 4th gen clutch is even holds better than the 3rd gens as well!

 

Off topic ,but I've noticed this as well it may be due to defueling though. Pulling my gorilla 56 in the next few weeks to go to a 68rfe was curious so been running through the threads

 

Hey dave how much boost did you launch at with yours?

 

Before the revmax, sweet spot was 10-12. She popped at texas diesel nationals with 18lbs. Now i have a revmax, caltracs, she's lowered, nitto 555rs, and 18 is netting me a 1.74 60', 20 spins them and my 60' goes to 1.8. My problem is stock turbo, it just has nothing left. Good thing is its fixing to.be a shop decoration..

 

Lol well hopfully it will become a decoration when you want it to and not a need to.

 

Ive launched mine lots from anywheres from 12-18psi with stock turbo and about 10-12psi with new turbo. Trannys holding up good so far. Got about 55000kms. Also i always launch in manual mode and shift manually when i race. So far so good, knock on wood.

 

Eventually its gonna go. No question about it. But I really think this 4th gen trans is actually a good transmission. I have guys in the 600-650 who have been hitting it hard monthly, and its holding up good. Hit the 3rd gen trans with 600 once and I think its done.

I guess that 10psi of line pressure really did the trick...:confused013:[/QUOTE]

Oh i know it wont last forever. Lol. Im babying it a little bit now that summers pretty well over lol. Gonna save up for a new one. Hoping to get one next year some time.

 

Really guys are putting 600+hp to the ground on a stock trans. That's crazy. I thought they would slip before then.

 

Rjp if you wouldnt mind I would like to have a number so I know what to expect. Thanks

 

PM Sent....

 

I've only seen it on trucks with a clutch slipping slightly seems like the worse it begins to slip the more it defuels. However it naturally hard to tell when they begin to slip it unloads the power train therefore it uses different table and well of course it seems to defuel. On the swap, I am tired of trying to go fast with manuals. Yes they are fairly reliable ,but they're never going to shift as quickly as an auto. A gorilla-56 is very similar to a auto if not tune right it wont live. So I figure why not go with a auto in the first place. It also gives me the opportunity to get a certain aftermarket companies products off my truck.

 

Uh ohhh... Someones not happy with their tranny lol ^^

 

Tranny works flawlessly other issues here

 

Oh thats good. Well not good about the other issues. Lol.

 

I want to say Im anywhere from 10-15 on mine but I usually tend to stick around 10ish. Im cutting 1.95 60fts with my dually on 34's chock full of oilfield tools and an aux tank (about 9k density alt) I've been really happy my team purple. It is flat out amazing what the full lockup control can do to your 60fts and overall time. I forgot to turn it on for one pass and I was something like 15.5 in the 1/4. Next round I tuned it up to the second level on the next round and knocked over 1 second off the E/T and 60ft went from 2.3 to 1.95! Needless to say, totally shocked. Right now I am looking at pulling the motor and swapping in a set of Carillos with coated pistons. Adding dual fuelers, 100% overs and a good lift pump. Should be able to get it into the 12's with a little massaging from Dave. Figured instead of pulling a Ronne and adding scenic windows to the block and dumping 15k into another motor, we'll get it right before we turn it up

lol back on topic.