Pulled yesterday with ITPA and finished 7th out of 8. Dissapointing to say the least. This time I tried running my 33's and they seem to be hooking up too well. Last pull on the 31's I was hitting the rev limiter at 7K this time I could only hit 6100. I was first hook, and the track was wet, and I was in a rocking chair the whole way down the track even after trying to get out of the throttle and get back into it so I dropped that hook, and came back last after dropping 5 psi out of the front. The track had dried out quite a bit on top, so I took a line in the drier part and the truck bounced a little coming out of the hole, then settled in and went down the track, but I just couldn't build the rpm's I was looking for.

I was planning to change my gearing this winter to pick up another 4 mph, but with what I'm seeing in the motor, I'm not sure about it. I'm going to look at jetting again to see if the motor is loading up or what! I'm thinking the 5.5 power valve is coming in too soon and not letting the motor build rpm fast enough, so I picked up a vacuum gage to get a reading below the carb. Boy it's frustrating trying to get this dialed in!
I'll post video's in the next few days for you guy's to critique.

Take that power valve out of there and go up 4 jet sizes from what's in there now ... That should get you close ....

I'm 97 Sq. on my 1250 Domi... and she purrs really nice ....

Well,,,, Earlier, I had the pv's out, and started with 92's and it was rich, so I dropped back to 88's and it still was rich, but we later determined that the rich condition could be caused by the head gaskets leaking off into the water system. I pulled the heads and dumped the copper gaskets and put a set of cometics on, and that seems to have cured the leaking problem. Then I talked to a Holley tech, and a few others, and they recommended I put the powervalves back in, and go back to the original 84 jets, which is where it is now.
I'm going to try ripping across the yard at WOT to see if I can get an accurate plug read. If not, I've got a pull on Thursday and I will cut the ignition at the end of the run and get a tow off the track so that I can get a plug reading.

The other thing I'm considering is the air pressure on the rear tires. Right now I'm at the max recommended air pressure of 65lbs, and I think I'll bump it up to 70 and lower the front from 40 to 30 to lessen the bite on the rears and help control bounce on the fronts. What do ya think?

Truck Pulling 101

For a long time I've told pullers how to set up the tires pressures so it hooks and doesn't bounce ..
You must not of seen the posts... But OK here it is again.

You only need 28 too 35 Psi in the rear tires .. any more then that and you get a rounded foot print, your trying to get a flat foot print any less the 28 and your loosing hitch height when you leave the line.
And the fronts I'm running mine right now at 8 Psi ... this way when the truck unloads it has room to pick the front up .. By lowering the air pressure in the front tires from 32 psi to 8 psi you'll drop the front end 3".. for every inch the sled has to raise the front of the truck to make it level it's like adding 100 extra pounds to the weight bar. So 3" plus 1" in the suspension = 400 Extra pounds.
And the added plus to this deal is a flat soft tire doesn't bounce..


ShaZam

With that low of tire pressure, do you need bead locks?

NO you don't need bead locks .. they stay put pretty good ..
you may want to mark the tires to keep track of how much they move if any ......


ShaZam