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60' still stinks

Posted By: weedlayer

60' still stinks - 03/14/15 06:51 PM

http://youtu.be/pKFVjucUHHY

changed to double adjustable shocks, original anti-squat was 84.3%, now at 181.2%. 60' just does not get any better. 1.48 - 1.51. Should be low 1.4 easy.

incrementals are all in line for 10.2's at 134 except the 60'



Posted By: MR_P_BODY

Re: 60' still stinks - 03/14/15 07:05 PM

I couldnt load the vid.. but is it spinning.. what
is the front of the car doing.. and is the back lifting
up or staying pretty even with the slick
Posted By: davenc

Re: 60' still stinks - 03/14/15 07:25 PM

I'm no expert, but it doesn't sound like the motor comes cleanly off the two-step. Possible carb issue?
Posted By: Harley

Re: 60' still stinks - 03/14/15 07:35 PM

The front of the car looks very stiff.
Posted By: Craig

Re: 60' still stinks - 03/14/15 08:11 PM

What rear shocks and what setting? In the vid, looks like no rise in back which you should have with that 4-link setting. Looks like rear shocks need the extension loosened.
Posted By: Quicktree

Re: 60' still stinks - 03/14/15 08:24 PM

what converter?
Posted By: weedlayer

Re: 60' still stinks - 03/14/15 11:50 PM

This is the first time I saw a video also. I was too low rpm off the 2 step. Everything looks stiff. No rise front or rear.
Converter was good for a 1.405 with Caltracs and leafs, normally 1.450. 8" PTC built from dyno sheets.

Front is Bob's profab with single adjustable QA1 set all the way to minus.

Rear is QA1 double adjustable with "R" (rebound) set all the way to minus.

If minus is not loose, I guess I'm bassackwards on the shocks.
Posted By: Quicktree

Re: 60' still stinks - 03/14/15 11:55 PM

you may not have enough power to work the new chassis. I ran into that with my challenger. it had very little movement no matter what I tried. you are going to need around 5600 on the converter. I was around 1.48s 60'also converter was way to tight for the power I was making.
Posted By: gregsdart

Re: 60' still stinks - 03/15/15 12:19 AM

What is the most travel you can get out of the front end? Rear? I would start full lose, max travel on both ends, with a video looking at the rear from an angle, hopefully including the front tires as well. It looks like the rear hit, stuck for an instant, then spun, so it might be too aggressive at this point, with the front too stiff as well.
Any idea of how much stall the converter has , and where is your torque peak?.
Posted By: MR_P_BODY

Re: 60' still stinks - 03/15/15 12:38 AM

What rpm are you leaving at.. might want to try a LOT
more to plant the tire.. I have the same issue if I
dont leave hard
Posted By: sshemi

Re: 60' still stinks - 03/15/15 12:46 AM

Looks like front susp tops out too fast.
Posted By: abodiesonly1

Re: 60' still stinks - 03/15/15 12:54 AM

Sounded like a slight bog coming off the 2 step as well as no flash....

Vert sounds tight
Posted By: Quicktree

Re: 60' still stinks - 03/15/15 01:07 AM

here's a video of mine reacting the same way. my wife took the video so bear with me.I won that pedal fest on the top end by the way

http://s579.photobucket.com/user/Quicktree09/media/Challenger/SDC11213.mp4.html?sort=3&o=1
Posted By: B3422W5

Re: 60' still stinks - 03/15/15 01:25 AM

Those huge rear tires eat up a lot of steam. Bet it would 60 foot better with way less under it.
Posted By: Cab_Burge

Re: 60' still stinks - 03/15/15 01:29 AM

It looks like and sounds like it porpoised on the starting line, front and back started to rise and then the back slips back down, try stiffening up the compression, not the extension, on the rear shocks only. Take one of each (front and rear)shocks off and experiment with the settings on a bench so you know which adjustments does what to your shocks One other thing when you jack the car up to remove the shocks, check to make sure you have enough travel on both ends with the suspension fully extended down that the shocks have more travel left in them, not held up tight enough to hold the suspension up
Posted By: Quicktree

Re: 60' still stinks - 03/15/15 02:03 AM

Quote:

Those huge rear tires eat up a lot of steam. Bet it would 60 foot better with way less under it.

yes they do, but it doesn't spin
Posted By: Quicktree

Re: 60' still stinks - 03/15/15 02:06 AM

Quote:

It looks like and sounds like it porpoised on the starting line, front and back started to rise and then the back slips back down, try stiffening up the compression, not the extension, on the rear shocks only. Take one of each (front and rear)shocks off and experiment with the settings on a bench so you know which adjustments does what to your shocks One other thing when you jack the car up to remove the shocks, check to make sure you have enough travel on both ends with the suspension fully extended down that the shocks have more travel left in them, not held up tight enough to hold the suspension up

I didn't see or hear that at all sounded more like a tight converter to me.
Posted By: Sport440

Re: 60' still stinks - 03/15/15 03:54 AM

Oh, it definitely spins from what I saw, even with those big heavy meats.

The front moves very little as does the back. the front also appears limited in its travel. It may just be it drops when he loses traction.

I think his rear axel isn't hitting hard enough or evenly enough. Not sure about the front, since hes losing traction.
Posted By: abodiesonly1

Re: 60' still stinks - 03/15/15 04:04 AM

Its dead hooking and bogging ever so slightly, but you can hear it.

Converter doesn't flash in the slightest.
Posted By: Sport440

Re: 60' still stinks - 03/15/15 04:55 AM

Quote:

Its dead hooking and bogging ever so slightly, but you can hear it.

Converter doesn't flash in the slightest.





I disagree, from the Vid, its not dead hooking. Sure, its not the greatest vid.

Its hard to tell by looking at the slick alone, but if you focus on the rim, it spins about a revolution and a half or so. Im assuming the slick is too, hard to see it.
Posted By: skrews

Re: 60' still stinks - 03/15/15 05:08 AM

Quote:

Looks like front susp tops out too fast.



X2 Not enough travel IMO.
Posted By: weedlayer

Re: 60' still stinks - 03/15/15 03:32 PM

If the converter is tight, which it appears, then the car lost a lot more weight after all the modifications than 2 different scales years apart show. The scales say it lost about 220, but the time slips say it lost closer to 400. I guess that would make the converter tighter. I did not change anything in the driveline, so the .3 to .4 decrease in et and 5 to 6 increase in mph is all weight loss. I do know I need to increase my launch rpm, which should help the converter situation.

So, assuming I have the front shocks as loose as they will go, what's the secret to loosening the front end? It is a Bob's profab with coilovers. QA1 single adjustable.
Posted By: Quicktree

Re: 60' still stinks - 03/15/15 03:43 PM

Quote:

If the converter is tight, which it appears, then the car lost a lot more weight after all the modifications than 2 different scales years apart show. The scales say it lost about 220, but the time slips say it lost closer to 400. I guess that would make the converter tighter. I did not change anything in the driveline, so the .3 to .4 decrease in et and 5 to 6 increase in mph is all weight loss. I do know I need to increase my launch rpm, which should help the converter situation.

So, assuming I have the front shocks as loose as they will go, what's the secret to loosening the front end? It is a Bob's profab with coilovers. QA1 single adjustable.

need to talk to Bob on that deal.
Posted By: weedlayer

Re: 60' still stinks - 03/15/15 04:20 PM

Tony, did you get yours to react better or are you living with it? I built what I wanted it to be even though I knew it would be underpowered and overtired as they put it.

Just needs some more work
Posted By: MR_P_BODY

Re: 60' still stinks - 03/15/15 04:34 PM

Are you working with the E-body in your sig pic
Posted By: Quicktree

Re: 60' still stinks - 03/15/15 04:40 PM

it was hooking so not a big concern of mine. if you are going to bracket race make it hook consistent and don't worry about 60' mine was a little slow on 60' but mine was a stock stroke 360 with indy heads. but it was real strong on the big end mph wise. very deceptive for competitors. won a few rounds with people lifting. so it just depends on what you are looking for. I could have adjusted the converter and made it better but didn't want to spend the money.
Posted By: dizuster

Re: 60' still stinks - 03/15/15 06:04 PM

I don't know about the particular valving of that shock... but... it is VERY VERY VERY (did I say VERY?) unlikely that 180% anti-squat will want the rebound on full loose. Especially with that big of a tire.

At 180%+ anti-squat, it's trying to hit the tire VERY hard and separate the body. If you have the shock on full loose, it will slam the tire into the ground and use up all of it's travel very quickly in the run. In extreme cases it will actually hit the tire so hard, the tire will bounce back off the ground and unload the tire (which is what's probably happening here).

If you watch the video, the rear is out of travel before the motor ever even makes it up to the flash RPM, within the first 5 feet of the run or so.

The only other thing that would make it act like this is if the shock didn't have enough travel for the separation that the body is trying to achieve at 180%+ anti-squat.

I'm not sure what you have the compression settings at, but if you're going to run the anti-squat that high, I would run them near full tight on compression, and put them somewhere in the middle on rebound to start with.

Full loose on the fronts is fine for now. If you get in a situation where it starts to pitch rotate, and suddenly spins a few feet out, that is a symptom of the front shocks topping out and unloading the rear tire. I don't think that's what you're dealing with here at all though.


Here is a thread I posted last fall... sort of talks about/shows the tire hit that I'm referring to with the shocks too loose.

Mine is a cal-track car, but not so different then your 4-link with the Anti-Squat up that high.

https://board.moparts.org/ubbthreads/show...amp;Search=true

Good luck!
Scott
Posted By: Monte_Smith

Re: 60' still stinks - 03/15/15 06:19 PM

It's not spinning the tires............It's got a BIG tire, not a lot of power, probably not a lot of gear and some other things. Basically it just doesn't have the "nuts" to work the chassis with that big tire on it.

Monte
Posted By: dizuster

Re: 60' still stinks - 03/15/15 09:19 PM

Month it went 1.40's with the same tire and caltracs before. Something is going on with the new suspension.
Posted By: Quicktree

Re: 60' still stinks - 03/15/15 11:02 PM

Quote:

Month it went 1.40's with the same tire and caltracs before. Something is going on with the new suspension.

depending on what the conditions were we he ran that vs now. and the 4 link needs a little power to work it. like Monte said big tire low power thats what you get. been there done that.
Posted By: MR_P_BODY

Re: 60' still stinks - 03/15/15 11:14 PM

For one thing.. I think he is putting too much emphasis
on the anti squat.. that goes in line with the IC..
if the IC isnt right its picking up from the wrong
point of the car... if it isnt hitting the tire hard
enough move the IC back and up... but when the IC
is up it doesnt hold the hit as if its lower
Posted By: Cab_Burge

Re: 60' still stinks - 03/16/15 12:07 AM

Try setting the 4 lingk I.C at 50 to 51.0 out and 5.0 to 6.0 off the ground I've heard those settings are pretty good for your average door car at or close to 3200 bls with driver that will run in the high tens to high nines Maybe sommeone a lot more knowlegable on setting a four link car up will chime in with a better, more knowlegable(SP?) setting
Posted By: weedlayer

Re: 60' still stinks - 03/16/15 03:55 AM

The closet I can get to that according to my program would be the following


That also means I went the wrong way again.

I don't really care about chasing et, just want to optimize the set up for consistency.
Posted By: MR_P_BODY

Re: 60' still stinks - 03/16/15 04:22 AM

Quote:

The closet I can get to that according to my program would be the following


That also means I went the wrong way again.

I don't really care about chasing et, just want to optimize the set up for consistency.



Well.. hows it working now... you have to change
so why not try what someone suggest.. its no big
deal to put it back to what doesnt work
Posted By: Quicktree

Re: 60' still stinks - 03/16/15 07:22 AM

I can tell you I moved mine a few times and it did absolutely nothing.
Posted By: MR_P_BODY

Re: 60' still stinks - 03/16/15 07:30 AM

Quote:

I can tell you I moved mine a few times and it did absolutely nothing.



What did you move Tony.. IC length or height.. once
you find the right place there is only 4-6 changes that
work for your car... yeah the 4 link has a pile of
adjustment points but that helps you find the RIGHT
points to play in... once you find the right place
you only get a few minor moves
Posted By: Cab_Burge

Re: 60' still stinks - 03/16/15 07:42 AM

Quote:

I can tell you I moved mine a few times and it did absolutely nothing.

I've moved the front adjustments on three different ladder bar cars trying to improve the 60 ft times, those three cars weren't spinning the tires so nothing made it better. The OP is spinning now so he needs to fix that problem, doing nothing changes nothing I did end up changing the front shocks on my ladder bar Duster at first and finally ended up with a set that helped the 60 ft. times some, not a bunch, but some I later changed the rear single adjustables to double adjustables and experimented on setting and that help some more I learned like Mike is saying once you get it close minor changes can help you some more, not a bunch though OP, try what you want to
Posted By: Quicktree

Re: 60' still stinks - 03/16/15 07:59 AM

he's not spinning, I don't think
Posted By: Quicktree

Re: 60' still stinks - 03/16/15 08:00 AM

Quote:

Quote:

I can tell you I moved mine a few times and it did absolutely nothing.



What did you move Tony.. IC length or height.. once
you find the right place there is only 4-6 changes that
work for your car... yeah the 4 link has a pile of
adjustment points but that helps you find the RIGHT
points to play in... once you find the right place
you only get a few minor moves


both, made no difference on the way the car reacted, just not enough power.
Posted By: weedlayer

Re: 60' still stinks - 03/16/15 01:08 PM

I did not beat up Cab's suggested setting. I laughed at me for going the opposite way. I thought I needed more anti-squat from the way my 4-link program reads when I maybe needed less. It looks like several posters think I went to high on the anti-squat.
Posted By: Leigh

Re: 60' still stinks - 03/17/15 12:07 AM

It's that oil pan
Posted By: weedlayer

Re: 60' still stinks - 03/17/15 12:40 PM

Quote:

It's that oil pan



Me and that pan are still in training
Posted By: tboomer

Re: 60' still stinks - 03/17/15 12:49 PM

No help to ya Ray but that old pack mule looks pretty good! I am sure you will get it figured out!
Posted By: gregsdart

Re: 60' still stinks - 03/17/15 02:09 PM

Quote:

The closet I can get to that according to my program would be the following


That also means I went the wrong way again.

I don't really care about chasing et, just want to optimize the set up for consistency.


Once you get the right setup, you will get both. I would go a tad shorter, say 36 to 38 inch out, and about 7 to 8 inch high for starters. That is close to a ladder bar setup, but just a tad softer due to the length. My thinking is be just above 100 percent anti squat. Too much anti squat try's to raise the back of the car too violently, and the force applied momentarily pushes the nose down due to the opposite and equal reaction around the Cg. That momentary force only lasts for a very short instant, but it puts energy into the front end in the wrong direction. I believe a 10.30 car is too fast for that to work. Another thing is spring rates. Too much is a killer. Too little needs a lot of shock to control. What do you have on both ends?
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