Bracket Talk
I/C adjustment on 4 links

This topic can be found at:
https://drr.infopop.cc/eve/forums/a/tpc/f/80760912/m/1627073696

June 10, 2021, 12:23 PM
ts393c
I/C adjustment on 4 links
If you have a car that wants to wheel stand a lot do you move the I/C up higher in the car and make it shorter or move the I/C lower to stop wheel stands. I don't have the numbers with me now but I know it's pretty far forward in the car now. It's been so long since I set it up I can't remember the numbers. I'm thinking about moving the instant center up and back and see if that will help keep the frontend down some.

Side not is I can control some of it with the front shocks but I almost have to go full tight to do it. (afco double adjustable) but if the air gets good it still wants to come up.
June 10, 2021, 12:30 PM
ski_dwn_it
Higher will calm the wheelies.

In and out will make the hit longer (time wise) vs shorter

A little weight on the nose will do wonders also.



Configuration: 3350#, 582 C.I.,

60 - 1.24
1/8 - 5.53@ 126MPH
1/4 - 8.73@ 159MPH



3700#+210lb driver, FULL interior, through mufflers, 10.5 tire.
60'-1.333 (IN 4000ft DA! Joisy Math excluded; 1.25sec using JOISY MATH.) Wink
1/4 - 9.60@144MPH

June 10, 2021, 01:19 PM
bry-war
quote:
Originally posted by ts393c:
I almost have to go full tight to do it. (afco double adjustable) but if the air gets good it still wants to come up.


Alternative would be to put a stiffer spring on the front. Especially if you have to run the spring adjusters way up to make ride height.
June 10, 2021, 02:43 PM
Curly1
Yes, I would move it up and back some until it does as you wish then fine tune with shocks and weight if needed. Note as you move it up and back your rear shocks will work harder you may need to tighten up extension on them some.


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June 11, 2021, 07:43 AM
ts393c
quote:
Originally posted by bry-war:
quote:
Originally posted by ts393c:
I almost have to go full tight to do it. (afco double adjustable) but if the air gets good it still wants to come up.


Alternative would be to put a stiffer spring on the front. Especially if you have to run the spring adjusters way up to make ride height.


I have done went up to 450 on the springs. It helped a little but not much.
June 11, 2021, 07:56 AM
ts393c
Thanks all for the comments.
It is a short wheelbase car (97) and it has 51% weight on the front and 49% on the rear. Total weight is right at 3400 pounds. I went to a little bigger motor this year that has a little more torque and now it wants get up to high. Done bent a set of wheelie bars because of it. So I am trying to just tame it down some.


I did check it last night. I was out 75 and 9 off the ground. I shortened it up to 46 and 12 off the ground now. This should be above the anti squat line now. Hopefully this will slow the front down but still let rear hook up.
June 11, 2021, 11:22 AM
Jonesz
quote:
Originally posted by ts393c:
Thanks all for the comments.
It is a short wheelbase car (97) and it has 51% weight on the front and 49% on the rear. Total weight is right at 3400 pounds. I went to a little bigger motor this year that has a little more torque and now it wants get up to high. Done bent a set of wheelie bars because of it. So I am trying to just tame it down some.


I did check it last night. I was out 75 and 9 off the ground. I shortened it up to 46 and 12 off the ground now. This should be above the anti squat line now. Hopefully this will slow the front down but still let rear hook up.


Get the bottom bar pointed down in the front some. it has to be running "up hill" now, with a 12" height, which causes separation and ill handling
June 11, 2021, 11:42 AM
ts393c
quote:
Originally posted by Jonesz:
quote:
Originally posted by ts393c:
Thanks all for the comments.
It is a short wheelbase car (97) and it has 51% weight on the front and 49% on the rear. Total weight is right at 3400 pounds. I went to a little bigger motor this year that has a little more torque and now it wants get up to high. Done bent a set of wheelie bars because of it. So I am trying to just tame it down some.


It was pointed down. It is pointed up some now but there is now way to raise the I/C with out the bar pointing up some.

I did check it last night. I was out 75 and 9 off the ground. I shortened it up to 46 and 12 off the ground now. This should be above the anti squat line now. Hopefully this will slow the front down but still let rear hook up.


Get the bottom bar pointed down in the front some. it has to be running "up hill" now, with a 12" height, which causes separation and ill handling

June 11, 2021, 11:46 AM
ts393c
quote:
Originally posted by Jonesz:
quote:
Originally posted by ts393c:
Thanks all for the comments.
It is a short wheelbase car (97) and it has 51% weight on the front and 49% on the rear. Total weight is right at 3400 pounds. I went to a little bigger motor this year that has a little more torque and now it wants get up to high. Done bent a set of wheelie bars because of it. So I am trying to just tame it down some.


I did check it last night. I was out 75 and 9 off the ground. I shortened it up to 46 and 12 off the ground now. This should be above the anti squat line now. Hopefully this will slow the front down but still let rear hook up.


Get the bottom bar pointed down in the front some. it has to be running "up hill" now, with a 12" height, which causes separation and ill handling


It was pointed down. It is pointed up some now but there is now way to raise the I/C with out the bar pointing up some.
June 11, 2021, 01:38 PM
green1
quote:
Originally posted by ts393c:
quote:
Originally posted by Jonesz:
quote:
Originally posted by ts393c:
Thanks all for the comments.
It is a short wheelbase car (97) and it has 51% weight on the front and 49% on the rear. Total weight is right at 3400 pounds. I went to a little bigger motor this year that has a little more torque and now it wants get up to high. Done bent a set of wheelie bars because of it. So I am trying to just tame it down some.


I did check it last night. I was out 75 and 9 off the ground. I shortened it up to 46 and 12 off the ground now. This should be above the anti squat line now. Hopefully this will slow the front down but still let rear hook up.


Get the bottom bar pointed down in the front some. it has to be running "up hill" now, with a 12" height, which causes separation and ill handling


It was pointed down. It is pointed up some now but there is now way to raise the I/C with out the bar pointing up some.

You can raise the rear on the shocks a little to get the front of lower bar to raise a little. I have recently did this to get rid of a subtle rear bounce off the line. I don’t know if it’s the proper thing to do but did it last time out trying not to do anything drastic because I was only getting one time run and the car was consistent as it was.
June 13, 2021, 08:02 AM
Bad News
[Q[/QUOTE]

Alternative would be to put a stiffer spring on the front. Especially if you have to run the spring adjusters way up to make ride height.[/QUOTE]

I have done went up to 450 on the springs. It helped a little but not much.[/QUOTE]

Too much spring in front will hold the front end too high at speed. You want the front end to be just about down on the back half of the track. Too much air under the car, and maybe tripping the beams with the tires instead of the nose.
June 15, 2021, 06:34 AM
ski_dwn_it
quote:
Originally posted by ts393c:
Thanks all for the comments.
It is a short wheelbase car (97) and it has 51% weight on the front and 49% on the rear. Total weight is right at 3400 pounds. I went to a little bigger motor this year that has a little more torque and now it wants get up to high. Done bent a set of wheelie bars because of it. So I am trying to just tame it down some.


I did check it last night. I was out 75 and 9 off the ground. I shortened it up to 46 and 12 off the ground now. This should be above the anti squat line now. Hopefully this will slow the front down but still let rear hook up.


Try it there. That is where I have mine with same wheel base. And similar weight. Doesn't wheelie hardly anymore. Before it was it of control and used grid to tame it down.



Configuration: 3350#, 582 C.I.,

60 - 1.24
1/8 - 5.53@ 126MPH
1/4 - 8.73@ 159MPH



3700#+210lb driver, FULL interior, through mufflers, 10.5 tire.
60'-1.333 (IN 4000ft DA! Joisy Math excluded; 1.25sec using JOISY MATH.) Wink
1/4 - 9.60@144MPH

June 15, 2021, 09:36 AM
ts393c
quote:
Originally posted by ski_dwn_it:
quote:
Originally posted by ts393c:
Thanks all for the comments.
It is a short wheelbase car (97) and it has 51% weight on the front and 49% on the rear. Total weight is right at 3400 pounds. I went to a little bigger motor this year that has a little more torque and now it wants get up to high. Done bent a set of wheelie bars because of it. So I am trying to just tame it down some.


I did check it last night. I was out 75 and 9 off the ground. I shortened it up to 46 and 12 off the ground now. This should be above the anti squat line now. Hopefully this will slow the front down but still let rear hook up.


Try it there. That is where I have mine with same wheel base. And similar weight. Doesn't wheelie hardly anymore. Before it was it of control and used grid to tame it down.


I did try it last weekend. It still pulls the wheels but not as bad. More of a slow rise now where it was yanking them up out of the lights before. Had my shocks set pretty soft but I think I can tighten them up some to calm it down some more. I was at a really bad track and it still hooked every pass so I believe I'm going in the right direction. I'll be at a good track this weekend so I should be able to see how it's going to react.

Thanks all for your comments.
June 15, 2021, 10:29 AM
ski_dwn_it
Try adding some weight to the nose of the car. That will work wonders. People are afraid of that because it counters out thinking of going fast...but its bracket racing and sometimes weight will make the car more efficient.
June 21, 2021, 09:50 AM
moparacer
Do the shocks. If you get to full tight on the rebound up front then have them re-valved.

I had my shocks re-valved over the winter and went from carrying the fronts to the 60 ft timers on full tight, and putting it on the bumper once in killer air, to barely daylighting the drivers side front.

Not as much fun but the car works a heck of a lot better now.
June 24, 2021, 03:32 PM
The Bozman
quote:
Originally posted by Jonesz:
quote:
Originally posted by ts393c:
Thanks all for the comments.
It is a short wheelbase car (97) and it has 51% weight on the front and 49% on the rear. Total weight is right at 3400 pounds. I went to a little bigger motor this year that has a little more torque and now it wants get up to high. Done bent a set of wheelie bars because of it. So I am trying to just tame it down some.


I did check it last night. I was out 75 and 9 off the ground. I shortened it up to 46 and 12 off the ground now. This should be above the anti squat line now. Hopefully this will slow the front down but still let rear hook up.


Get the bottom bar pointed down in the front some. it has to be running "up hill" now, with a 12" height, which causes separation and ill handling


Should be in the 56 out and 4 up if you are making any kind of power


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