: Safe launch PSI?
ratlover 04-29-2004, 12:30 PM I’m wondering with just a 125hp juice/attitude with low boost fueling at 5 how many #’s of boost are safe to launch with? I have 265’s and my t bars cranked about .75” over stock. I will be running tie rod sleeves but everything else stock. So what is considered safe on the street. Also what is safe at the track with the bars dropped all the way? Thanks. I’ve done a couple launches with 2 or so PSI(about 1200 rpm or so I believe) but have been chicken to try anything else since I don’t want to break anything. So whats considered safe?
And outa curiosity. What are you big boys launching at with the big tunes?
I would like to not find out things the hard and expensive way. I would prefer to use your guys experience then scatter things and say “next time I will back her off”
Next is trans timehttp://www.dieselplace.com/forum/smileys/Wink.gif Havent limped or sliped her yet and don’t plan on it.
White Duramax 04-29-2004, 12:32 PM I would say around 8-10psi for a 4wd launch with the bars lowered.
Kennedy 04-29-2004, 12:45 PM With the bars up anything over 3psi sends my truck off on a tangent, and I hear a howl for quite a ways. Haven't played much to determine if it is tire howl or not. Just don't want to tear up my truck...
Micheal Tomac 04-29-2004, 01:34 PM your stock C1's won't last forever doing boosted launches
ratlover 04-29-2004, 01:59 PM Mike Thanks for the warning. This is just with a stock trany I assume? Or do even the built tranys have problems holding the truck while building boost? If you dont mind me asking. What do you leave the line at with your tunes? You spray right off the line? You just run sleeves and droped bars right? Or have you done something to your drag link? I thought at one time you straped it but now dont?
John, this happens with the lower juice tunes? At 2 psi(about the lowes I could get the attitude to show before 0) she just took offhttp://www.dieselplace.com/forum/smileys/Cool.gif
With a regular juice 8-10 pounds is safe from grenading things(generaly, I know there are no 100% safes) with droped bars, fairly small tires and sleeved tireods.
Tough decision on whos trany upgrade....
To quote the Tacobell dog "I think I need a bigger box"http://www.dieselplace.com/forum/smileys/Evil Smile.gif
ghettosled 04-29-2004, 02:55 PM ATS and a few others make a C1 clutch pack for high boost launches. Those were pretty trick, the other stuff is just raybestos clutches with an extra added in and the pressure plates are machined to allow for them.
ratlover 04-29-2004, 03:02 PM so the suncoast kit is just more of the regular clutches? man are those trany upgrades expensivehttp://www.dieselplace.com/forum/smileys/Cry.gif
The good old converter transgo package is all stock internals and clutches with just a different VB right? I assume it still holds better than stock though....another thread I suppose.....
Maybe the front end isnt the limiting factor of launch PSI.....whats the stock allision good for in 1rst gear holding it back at the line. Semi long term......I'm sure it would hold back the converter at stall for a fewhttp://www.dieselplace.com/forum/smileys/Dead.gif
Micheal Tomac 04-30-2004, 12:43 AM stock tranny will take boosted launches for awhile but if you're going to make racing a habit, you need single sided C1's
making a #2 only pass I launch at 10psi
I spray out of the hole
beefed up tierods, dropped tbars, no strap
Super Diesel 04-30-2004, 02:33 AM Hey John K. it's your tires toeing in on take off. The track bar can't hold in one place, so it lets the tires toe in from the force of the drive from the wheels. I've done that for the entire 1/4 mile. Talk about rolling resistance! Now it's just strait hard core acceleration! I love it! Super Diesel
ratlover 04-30-2004, 09:20 AM racing wont be a habbit. I will run her a few times at the track but mostly embarassing stangs and such on the street.http://www.dieselplace.com/forum/smileys/Evil Smile.gif So that will limit my launch rpm.
ATS the only ones with the single sided c1's you are talking about? kinda leaning twards them since I am unsure of the transgo/converter will be enough.
hdmax 04-30-2004, 12:48 PM I say 0 is the boost level for a lanch. If you plan on making the truck last, I think doing a 0 psi race will make things hold togather a lot longer.
I never boost up (power brake) when racing, regardless of the situation. If my truck isn`t fast enough doing it that way, I will lose the race. But my truck will still be in one piecehttp://www.dieselplace.com/forum/smileys/Cool.gif
I`ll save the power braking to the nuts and the ones that have the money to break and repair. Because that will happen sooner then later.
ratlover 04-30-2004, 01:09 PM Your just no funhttp://www.dieselplace.com/forum/smileys/Tongue.gif
I understand that launching with boost aint good on things long term but no performance mod or even getting on it stock is good on things long term.
Just trying to figure out what is generaly considered reasonably safe and wont hurt the long term reliablity a ton or scatter things. I'm a nut but I would prefer to spend my $$$ on going faster as apposed to fixing stuff I've trashed. A fine line we all walk I know....
hdmax 04-30-2004, 01:36 PM Your just no funhttp://www.dieselplace.com/forum/smileys/Tongue.gif
I understand that launching with boost aint good on things long term but no performance mod or even getting on it stock is good on things long term.
Just trying to figure out what is generaly considered reasonably safe and wont hurt the long term reliablity a ton or scatter things. I'm a nut but I would prefer to spend my $$$ on going faster as apposed to fixing stuff I've trashed. A fine line we all walk I know....
All it takes is one time to make your day badhttp://www.dieselplace.com/forum/smileys/Big Smile.gif
You could drop the drive shaft (front or back, then again maybe both) bend or break the tie rod, distroy the engine, transfer case, or transmission. break the differential. (Once again, the front or back, or both)
But it is your truck (engine, tranny, transfer case, differentials, and so on, and on, and onhttp://www.dieselplace.com/forum/smileys/Approve.gif) So do what you want as long as you do not hurt others.http://www.dieselplace.com/forum/smileys/Big Smile.gif
Kennedy 04-30-2004, 01:49 PM Hey John K. it's your tires toeing in on take off. The track bar can't hold in one place, so it lets the tires toe in from the force of the drive from the wheels. I've done that for the entire 1/4 mile. Talk about rolling resistance! Now it's just strait hard core acceleration! I love it! Super Diesel
Any pics?
Been thinking about going 2wd. Have traction bars in testing on a 2wd truck w/slicks. Worst case scenario is that the 2wd truck cannot be made to hook. Even if it doesn't, the 4x4 guys should get good use for controlling wrap up and pinion angle...
ratlover 04-30-2004, 02:13 PM Break stuff? I thought thats what warantee was for?http://www.dieselplace.com/forum/smileys/Evil Smile.gif
Same bars the 4x4 guys running big tires and lifts should work at controlling wrap I would assume? A 4 link could be made to ride well and be daily driven, might not be cheap though.... Sounds like you got a project on your hands
ghettosled 04-30-2004, 02:53 PM i'm interested in some traction bars for the 2wd. Please let me know what sort of feedback you are getting. Was thinking about making some similar to the Caltracs.
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