Need help unhooking...

[Ahamay17]

Recently purchased the truck and have had it to one test and tune as it was set up by the previous owner who was not concerned with how fast it ran, but rather wanted it to be consistant and pull the front wheels on every pass... I on the other hand want to squeeze every last tenth I can out of it... Right now it is seriously dead hooking, even without a burnout...

The front suspension has trick springs with CE 3 way adjustable rebound only shocks, currently on the softest setting for easy lift. The ladder bars are in the lowest hole, the rear shocks and springs are non adjustable, rates are unknown, the rear ride heights can be changed by moving the lower shock mounts up or down on the rear end brackets, currently the right rear ride height is 3/4" lower, preloading the left rear... As is the truck leaves straight, the nose goes right to full extension, and remains fully extended for the entire 1/8th...

Time slip as is

1.52 - - - 60
4.35 - - - 330
6.70 - - - 1/8
104.3 mph

I was told it went 6.40's in cool air, before changing to the current setup to pull the wheels... The only thing I know that was changed for the current setup is the ladder bars were lowered one hole to the bottom...

As always anyone who takes the time to respond is appreciated!

Ray

[SIlverBulletS10]

I had pretty much same set up on front end but chained down front end and went from 1.40s to 1.26s mine had way to much front end travel. I was running leafs with cal tracks though

[soopertrucker]

If you want to take some bite out I would start by raising the ladder bar back up to the next hole. I'll bet when the previous owner lowered it they probably didn't reset the pinion angle. Excessive pinion angle and not enough power and/or launch rpm will make one dead hook. One and a half to two degrees should be plenty of pinion angle for your power to weight with a ladder bar. Also staggered shock heights or settings is not the proper way to preload. It should be done with the adjuster on the ladder bar. You can also put travel limiters on the front suspension to take some weight transfer out. Make one change at a time so you'll know if it helped or hurt.

[Diabolical]

You are loosing some reaction time with that much movement on the front end..
Like SIlverBulletS10 (http://www.s10racer.com/board/member.php?u=1078) stated.. Strap the front end down and check all the variables as soopertrucker (http://www.s10racer.com/board/member.php?u=224) suggested..

[Ahamay17]

As for doing the preload the correct way, should I raise the right side ride height or lower the left to make the shock mounting match?

Once that has been corrected I'll raise the bars one hole and make sure the pinion angle is 1.5 to 2 degrees... I assume now is the time to set the preload correctly with the ladder bars, how exactly is that done?

I won't make any other adjustments until I've made a pass...

If I still need it looser will stiffening the extension on the front shocks help at all, or does the travel have to be limited not just slowed?

Thanks!

Ray

[soopertrucker]

The answer to your first question depends on if you want it to set higher or lower. The second depends on what ladder bar you have. A pic would help alot. If it's double adjustable it will be simple depending on if the adjuster is on the top or the bottom. To properly set preload you really should set initial preload while it's on scales. Preload should be set with the driver in the drivers seat. I wish you were closer I would take care of this for you. You can set your preload without scales but it will take longer. If it's a dbl adj bar just set it on a level surface, loosen the jam nuts on the adjuster on the passenger bar,turn the adjuster left or right till it's loose enough to turn a half a turn by hand. This should have it nuetraled out. To add preload turn the adjuster in the direction that makes the passenger tire start to put more pressure on the ground. It shouldn't take much. Then the rest will have to be done at the track. If it leaves and pulls right put more preload, if it goes left take some out. Depending on how bad only make quarter turns.

[434 smallblock]

good post

[Ahamay17]

Ok, I lowered the left rear lower coil over mounting location to match the right, raised the ladder bars one hole up from the bottom, and took this pic of what I think is the adjuster you are referring to, on the bottom right directly above the "S"..?

Also found the rear end was offset to the right, centered it up...

I didn't get to check the pinion angle, i don't have my angle finder here, need o go pick it up tommorrow, but it looks like the angle was correct with the bars in the lowest hole, and now it appears to be pointing up a degree...

Again thanks for your time!

Ray

http://i230.photobucket.com/albums/ee226/ahamay17/IMAG0204.jpg

[soopertrucker]

Cool dbl adjustable that makes everything easier to adjust. You will want to set your pinion angle first after you neutral everything out. Just in case you don't know, pinion angle is checked in relation to the angle of the driveshaft, meaning if you lay your angle finder on the drive shaft and zero it out then put it up against the flat part of the yolk or pinion support and dial it in. But remember as you change pinion angle drive shaft angle changes too. To set pinion angle clean the adjusters and the ladderbars where you can draw a line straight through the adjuster and the ladder bar where you can keep up with your turns. Then turn both adjusters evenly until you get your desired pinion angle. After that's done then you use the passenger side only to put in some preload. On your bars you will do this by making the adjuster longer. Make sure after you set your pinion angle you still have plenty of thread engagement on your heims. If you want to talk pm your number and a good call time and I'll be happy to talk with you about it.

[Ahamay17]

Actually your instructions are very easy to understand, and I know exactly what I need to... However there are a few other things I'd like to discuss if that's cool with you... PM sent

[Ahamay17]

*Update*

The "stuck" set up had wedge in the left rear by raising the bottom left rear coilover up one hole (3/4") on the bottom mounting bracket, then preload was added to the right rear with the ladder bar...

I removed the wedge, centered and squared the rear end, put the front of the ladder bars back in the bottom hole, neutraled out the ladder bars, checked the pinion angle, its at 2*, Put preload into the righr rear using the jack and socket method as I don't have scales...

Now it hasn't left the garage so the verdict is still out, however it feels completely different when I push down on the suspension... Before when I pushed down on the rear it would sink slightly on the right rear almost none on the left rear, and the front would come up... When I pushed down on the front it felt very springy and quick to rebound, like it had no shocks...

Now when I push down on the rear, it goes down evenly and the front doesn't move, when I push down on the front it comes right back up and stops...I can't imagine this not being a step in the direction I am wanting to head in...

The plan now is to hit the track this saturday and see just where its at... Whatever happens I'll be back to share, and probably be seeking more advice :)

Thanks again!

Ray

[Ahamay17]

I had pretty much same set up on front end but chained down front end and went from 1.40s to 1.26s mine had way to much front end travel. I was running leafs with cal tracks though

I collected the materials to fab myself a set of limiters, could you ballpark your travel before and what you have it limited to? I'd like to get them made and installed before hitting the track in case I need them...

Thanks!

Ray

[soopertrucker]

Hey Ray, How did it go Saturday? Inquiring minds want to know.

[Ahamay17]

Never made it to the track, just before leaving we noticed a wheel bearing on the trailer making a noise, popped the cover off and found it was bone dry and totally junk... Made me sick to my effing stomach...

The track is closed next week and the week after the weather will likely be much better then it was for our first tnt (104*ambient) so now I'm afraid we've lost the opportunity to compare apples to apples...

Ray

[Ahamay17]

*Update*

Tonights race 9-17-11 was cancelled due to rain... and as i expected even if the races were held the ambient temperatures would have been 30 to 35 degrees cooler... So a true comparison is likely lost forever...oh well thats racing...

Because I have another week now, and my brakes won't hold much of a stall as well as the pedal is way to high, I decided to take a look at the pedal/push rod and see what the leverage ratio was... turns out to be 2.5 to 1, according to Willwood for my set up it needs to be at least 6 to 1... Also I'm not a fan of how the push rod was lengthend... Eff me and call me anal, but I tend not to use 3/8'' galvanized water pipe on my race cars... I'm pretty certain this is not the work of the chassis builder... Regardless it will be corrected before I hit the track again!



http://i230.photobucket.com/albums/ee226/ahamay17/IMAG0207.jpg

[soopertrucker]

Oh now that's purty. You would be surprised at how common stuff like that is even on a very presentable race car or truck. I stay busier straightening out messes like that more than doing stuff straight up.

[Ahamay17]

*update*

Finally made it to the track again...

Truck went perfectly straight right off the trailer, thanks for the help here Tim... It didn't feel much different then the first time... and ended up with very similar time slips

Time slip with 11 psi in slicks

1.53 - 60
4.35 - 330
6.73 - 1/8
104.24 - mph

Tempertures were in the low 80's... When we lowered air pressure to 10, or raised it to 12 our et dropped tp 6.82ish, on the previous tnt at 104* the same thing happened but the best times were on 10 psi...

It still dead hooks, and I think 30" of tire patch, and 5.33 gears are going to be tough to loosen up with my horsepower... I also think the front ride height is to high... I have one more tnt next month to give it a shot, so let me hear the suggestions!

FWIW in the off season I'm hoping to go with narrower slicks, a gear, and converter if needed, that will work with a 250 to 300 shot in the 1/8, which also means adding a charging system, vacuum pump, and a second fuel system... So any suggestions along these lines are also welcomed :)

Ray

[farond21]

Ray where did you test at? I was at Tulsa Friday night and Sallisaw Saturday night? Ill look for your truck next time Im out and come over and say hey. :smile5:

[Ahamay17]

I tested in Salisaw, actually I think I pitted almost right across from you as our tailgates faced... I thought I recognized your truck, but wasn't sure...

What do you think of Tulsa? Did you test 1/8 mile or 1/4?

Ray

[farond21]

Dang. Yep that was me. Your truck looks good. Tulsa was OK I found that sallisaw was fairly slick last night and my truck was 2-3 tenths slower than it should have been.