broke driveline on Dyno
 

So we were dyno tuning my truck, they checked and corrected the pinion angle for me. We did a stock pull on it (full boltons no tune) and it dynoed 242 rwhp and 310 rwtq. Then they tune it for me and drive line gave out at 5007 rpms @ 291.5 rwhp and 333 rwtq the graph looked like the truck was still pulling really hard when the driveline gave out, we'll see today what it puts out with the new, stronger driveline. I have nothing to compare it to I know it's not done but what do you guys think about the numbers it's putting out so far?

Driveline as in drive shaft? I hope that was the jist of it.

yeah drive shaft, I guess we'll find out today if that's all that took a :turd:

let me guess....aluminum?

no video :(

It's in my camera but i have no clue how to post it.

Awesome! I don't know how to post videos either. Put it on youtube, I guess.

my videos are on a high def video camera. I don't know how to convert them into a file that i can upload to you tube.

hmmm. me neither

what gear were you in?

i believe it was in 3rd gear. the mph were around 114 so i'm sure it was 3rd

i couldv'e sworn i heard on here to dyno our trucks in second for this very reason.

what can I say "ooops" lol
we're putting in a stronger one we'll see how that one holds up...

Damn maybe I should upgrade soon... I did a top end run a few weeks ago and the speedo was long past being pegged out at 120. Guess I got lucky

Sounds like the drive shaft might be a weak point in the NNBS trucks... I get a vibration so strong at 100mph that I'm afraid to go any faster. I assumed it was the wheels, but it could be the drive shaft... Hopefully not!

If your truck is lowered I can almost guarantee you it's the drive shaft. Check the pinion angle and have it corrected and even then the stock drive shaft is not made to go over 100mph... It looks real pretty when it brakes though... lol

That's the weird part, it was vibrating before I put the drop shackles on.
Lets hope I never have to find out how pretty it looks...

Na...your cool....its not a NNBS thing...these guys have the aluminum d-shaft...they have been twisting off on dynos since 1999 GMT800

um......mine didn't break....

was also researched for bout 45 minutes straight over 100 mph on open roads on a vette run when the vettes were out of commission....(yes the 95 mph governor is gone)..........according to the laptop while tuning it has seen 130-140 but that I haven't seen firsthand........but since the guys from the shop have been stopped in my old vette at 120 mph while tuning when it wouldn't act up on the dyno.......I believe them..

of course I have seen this happen with a 99 pickup on a dyno and it was close to stock as well.

Wtf , a nnbs thing ?
and someone mentioned it happens when lowering , am i missing something or what

I know some shops that wont even dyno trucks with aluminum d-shafts. They have had too many twist and break at high speeds and it just got too dangerous.

Sucks to hear about it crapping out.

There's got to be more to it than that. The Nissan Titan has an aluminum d-shaft and they're torque monsters and I've never heard of one failing.
Maybe it's due to the truck being lowered, or lifted...(?)

JB1- Nice looking truck.

Awesome number man....oh and mine didnt break on the dyno :D

http://www.youtube.com/watch?v=WteiwojcGlw

son las nnbs . . weak @ss driveshafts. .. . it's prob the ls6 head's . they put on them . . ;)

Its not an NNBS thing.
Concensus was always to Dyno in 2nd. I've seen like 4 or 5 posts since I joined here of people doing a dyno run in 3rd and the drive shaft lets go. Sometimes taking out the trans with it. Usually aluminum or a steel 1 piece.
There have been a few that did it on the highway. Just because you HAVE gone that fast, doesn't mean your driveshaft was enjoying the ride. crawl under it after a run like that and see if there are marks on the driveshaft or bottom of the truck.
That too has been done.

2piece steel ftw!

I'll see if i can find a couple of the threads later.

see my El Camino in my sig it has a inland aluminum driveshaft 5500 stall convertor, T400, with trans brake 16 inch wide slicks 1200 hp on NOS and runs 8's in the quarter....maybe you need a better aluminum driveshaft.....
http://i208.photobucket.com/albums/b...N/P2230011.jpg

Whats the weight on that elcamino?
Edit: I guess I should ask, Was that full weight? cuz if so, DAMN!

3190#empty....#3400 ...uh #3410 with driver:
sigh:

wow I didnt know the 1 piece steels were having problems too.

Did everyone miss out on the 50HP gain so far?

Good luck with it Luis, I bet Xessive puts you at 300hp before your outta there.

Gm balances the drive shaft to match the tire rating and governed speed of the vehicle.
if you end up on a dyno in 3rd gear you will end up well beyond what it is balanced for.
A high speed balance before going to dyno can sometimes prevent failure, not always. the longer the shaft the worse it will shake, but it's kinda of hit and miss, some have a problem, some don't.
My 07 gmt900 2wd xcab had a 96" alum one piece shaft and it probably looked like a skipping rope the one time I tried to dyno the truck, shook so bad i shut it down.

lol, yeah I think everyone missed that part... We'll see today if it gets put together with the stronger shaft see what it puts out...

How much is a high speed balance?

I forget, maybe 100 bucks, if you take it out of the truck yourself?

thrown driveshaft
 

My 07 nnbs rcsb truck with 5.3,3.42's,handheld tune,AEM cai,Borla catback at 120 mph out came the driveshaft. Tore up my exhaust,and the gas tank. It's a one piece steel shaft. Now I scared to run over 75 LOL!!!

what motor is this? 50 hp from the tune? what are the new numbers

this is a 5.3 I still don't have the final number cause when the driveline broke, some how a wheel cylinder broke also and the wheel cylinder was on back order. I just got it today and I should put everything back together today and off to the dyno again.

You guys. This isn't a torque power issue. Like some have mentioned it is pretty much a factory balance issue. GM isn't going to spend more money to guy high speed balanced shafts that go above the fuel shutoff speed. Typically, this has been happening on the standard cab/longbed and ext car/short bed trucks with the long 72" AL driveshafts. They just aren't balanced well enough for these high speeds and say adios when the speed gets high enough. The speed at which they start to resonate is mush lower than say a shorter 1 piece steel or AL shaft. In fact, the 1 piece AL shaft in the reg cab short beds is actually better for high speeds than steel due to the weight savings and larger diameter. Strength is in the steel though. I think a lot of the failures with the shorter ones would be due to the u joints, not vibration. It's good to dyno these in 2nd gear though as a lot of people have pointed out.

i just broke a one piece steel at the drag strip at about 90 mph

That sux!! Yeah I guess I need to look into a custom made high speed blanced driveshaft.