Competition Hopping down the track...

[wildmanben]

Looking at your signature you look to be at or lower than the 500hp mark for sledpulling. You basically answered your own question. You dont have enough power to run 4th. Stick to 3rd low or 2nd gear hi range.

Last time I dynoed was 578hp. So I dunno if that helps the equation. What would be a good 2. 8 turbo to run?

 

[jwilliams3]

For a non bushed 2. 8 I would definitely say something along the lines of the Aurora 5000 from ATS or suggest a II K31 Hybrid that PDI sells.

With the ATS you can get the T3 housings with the II Hybrid I think they are T4 housings but you also have a choice of A/R's to your liking.

 

[RAMICATOR]

wow i was going to start this thread myself. we cant run traction bars at many pulls here so i just made some spring clamps and that didnt let her squat much at all, i have may tires at 60#'s, tried 4th lo, didnt come out very hard, ( it was my first hook, the nerves were a bit restless) started with little bounce and got worst, so i got out of it. second hook i ran 2nd hi ( nerves much better now) came out on the wood, and about half track bounce bounce snap. dont ask me why i didnt get out of it, because i know better. anyway i twisted the axle shaft right off the mounting flange:{. oh well poop happens.



this was just a test and tune, black dirt track, loose as a goose, and a sled that starts like trying to pull a 4 bottom plow.

 

[wildmanben]

Heres a video of the pull:

Video of Teapot Days pull



I was the first truck.

 

[bgilbert]

Have someone get on your rear bumper and bounce up and down on it with your tires set to half the rated pressure. Then air them up to rated pressure or above it 80+, and watch how the tires bounce/flex up and down. You'll get alot with very little pressure, and hardly any with rock hard tires.



Then again Michael, you're just a silly gasser puller!

 

[MMiller]

Have someone get on your rear bumper and bounce up and down on it with your tires set to half the rated pressure. Then air them up to rated pressure or above it 80+, and watch how the tires bounce/flex up and down. You'll get alot with very little pressure, and hardly any with rock hard tires.



Then again Michael, you're just a silly gasser puller!

This coming from a guy that has never hooked to a sled:-laf. Bill why you trying to drag me back in here on this one? You know if I had it to do over again, my puller would smoke too. Just found the TDR too late, and already had the gasser built..... oh wait, you wanted me to look at the 440 truck down the road from here, for you to pull didn't ya.



Here's another way to look at it Bill... ... ... Take a basketball, pump it up hard, and bounce it, then take alot of the air out of it, then bounce it. What happens? Heck take a tire off your truck. Pump it up to 80 psi, and drop it off the back of your truck. Then drop the pressure to 35, and try it again. Which is going to bounce higher and longer? My guess is a tire at 80 psi.



BTW for everybody else, I have another truck, not in my sig that I pull. It does not have swampers on it. Swampers belong in the mud. My puller currently has BFG MT's that have worked fine so far. I'd buy some Truxxus AT's but my puller is a low budget one right now... .....



Gosh, I stepped right back in

 

[Jim Fulmer]

I'm no puller but I am a little bit of a suspension and a motor guy. What do you run for shocks?



There is a reason I run Rancho 9000's, you can make them hard so the rear end doesn't hop or shake the rearend.



If you ran a lower gear you can keep the R's up and out of the T/Q band... ... . wonder why I spin mine to near 4K or so before I shift.



I know your looking for wheel speed but the power is not quite there... ... . don't we all want more. Wish I could join you'll but my 4x4 is going to be a driver.



Jim

 

[wildmanben]

it just has some plain shocks on it. Should replace them I suppose. I appreciate all the help guys!

 

[jp8819]

Not a expert on the matter just my take on it. By increaseing the pressure in the rear tires you are trying to elimating the sidewall flex or keeping it to a min so that it never starts bouncing where in offroading people want it to flex for added trackion over rocks and such and are not going fast enough for it to start bouncing. This all in theory that rear springs and shocks are not creating the bouncing issue and fairly solid.

 

[dan shss]

Like stated above try clamping your springs. .

 

[PSU-CE]

How much lift do you have? What kind of springs/set up in the rear? Even if the hitch is low, what kind of hitch is it? It could be flexing. By watching the video it looks like it's in the rear of the truck and may have to do with axle wrap. Even though you said you have traction bars it may still have to do with some funky movement in the rear end/suspension. At 45 pounds it's not the air pressure that's causing it, 45 is a decent pressure for the rear. Shocks won't do much to stop what's happening, you first need to find the cause and fix it. Try spring clamps to make the springs more rigid (to keep them from flexing) and keep the air pressure up in the rear.

 

[wildmanben]

I have 2" leveling coils in the front and the rest is stock. OEM reciever hitch and a 2" drop hitch that is upside down that I welded a bunch of bracing to.

 

[wildmanben]

OK pulled again last night. Left the hitch the same and aired the tires up to 65psi. No bouncing at all. Very smooth the whole way. The track was really soft and wet so I pulled in 3rd. Got 1st out of 11 with 249. 6 ft. I didnt see anyone go very far. Even the Super Farm tractors werent making their 300+ pulls this time. Oh well it was fun. Thanks for all the help!