Question Scales 4 corners

Posted By: SCATPACK 1

Question Scales 4 corners - 09/04/12 03:40 PM

If you scale a 3200 lb B body with a big block and auto and 4 link in it. I know this is open to a lot of conjecture. But I need a starting point to shoot for. Assuming the weight bias is 55-45 front to rear. With the fat driver in the car, what would you shoot for at each corner.

Posted By: Cab_Burge

Re: Question Scales 4 corners - 09/04/12 07:07 PM

30 to 50 lbs more on the right rear compared to the left rear

I install both batterys and offset the fuel cell to the right side to get there

Posted By: MR_P_BODY

Re: Question Scales 4 corners - 09/04/12 07:29 PM

I would start at 20-25 pounds extra on the RR tire
and if it still goes right on the launch at more

Posted By: rickseeman

Re: Question Scales 4 corners - 09/04/12 07:45 PM

There will be people telling you to screw on this and preload that to get the weights on each tire equal but I have never understood that. I would say put it together neutral and tune from there.

Posted By: SCATPACK 1

Re: Question Scales 4 corners - 09/05/12 04:43 PM

Quote:

There will be people telling you to screw on this and preload that to get the weights on each tire equal but I have never understood that. I would say put it together neutral and tune from there.

OK Another question, New to 4 links and want to be sure its right or close. Do you set the weight with the springs or do you preload the 4 link to get the weight you want on each wheel.
For example, if the back right is less than the back eft, would you tighten up the left front spring or the right rear spring or both? IF you tighten up the right rear spring, does that shift more of the weight to the front wheels or does it just affect the right rear wheel. Or do you set all 4 of the springs the same and adjust the weight by putting pre-load into the 4 link bars?
thanks again for your help.

Posted By: Cab_Burge

Re: Question Scales 4 corners - 09/05/12 04:51 PM

I think the hieght and length of the intersecting point( IE 7 inches up and 54 inches out) is far more important to start with than the weight bias. I don't have much experience with a four link but I listen to guys that have them and have ask them what they do and what they set them at. It is the combination of each car, weight, weight bias, HP and tire size that makes the end results work. I would put the car on the scales with your body weight in the seat and the car set up like it will be run, IE batterys, gas in the fuel cell and so on and find out what amount of preload on the left front spring takes to load the right rear the way you want it

Same thing on the rear adjustments, most of the guys I've listen to don't do more than one flat on the right bar(not sure if it is the upper or lower bar, sorry) to set preload

Posted By: dartman366

Re: Question Scales 4 corners - 09/05/12 04:52 PM

Quote:

Quote:

There will be people telling you to screw on this and preload that to get the weights on each tire equal but I have never understood that. I would say put it together neutral and tune from there.

OK Another question, New to 4 links and want to be sure its right or close. Do you set the weight with the springs or do you preload the 4 link to get the weight you want on each wheel.
For example, if the back right is less than the back eft, would you tighten up the left front spring or the right rear spring or both? IF you tighten up the right rear spring, does that shift more of the weight to the front wheels or does it just affect the right rear wheel. Or do you set all 4 of the springs the same and adjust the weight by putting pre-load into the 4 link bars?
thanks again for your help.

I cannot answer anything as to 4 links but remember to have the car at race weight as if it's sitting on the starting line with you or someone or thing of your equal weight in the driver seat, I run a ladder bar car so I am watching this so to learn more about 4 links.

Posted By: SCATPACK 1

Re: Question Scales 4 corners - 09/05/12 10:32 PM

Any other thoughts on setting the springs to even out the balance or using the bars tire load with???
thanks

Posted By: MR_P_BODY

Re: Question Scales 4 corners - 09/06/12 12:37 AM

Quote:

Quote:

There will be people telling you to screw on this and preload that to get the weights on each tire equal but I have never understood that. I would say put it together neutral and tune from there.

OK Another question, New to 4 links and want to be sure its right or close. Do you set the weight with the springs or do you preload the 4 link to get the weight you want on each wheel.
For example, if the back right is less than the back eft, would you tighten up the left front spring or the right rear spring or both? IF you tighten up the right rear spring, does that shift more of the weight to the front wheels or does it just affect the right rear wheel. Or do you set all 4 of the springs the same and adjust the weight by putting pre-load into the 4 link bars?
thanks again for your help.

You leave the pre-loag ZERO till you get the weight
set... if you mess with the left front it will move
weight to the opposite corner(LF to RR).. once you
get the car in shape and at ride height then you put
in a small bit of pre load... different weight cars
and the way they're built will require different pre
loads.. mine uses 15# pre load

Posted By: 10secGTX

Re: Question Scales 4 corners - 09/06/12 04:02 AM

This is crazy .... i just finished doing this to my GTX I was hoping you could see the picture, it reads

wgt 3832 w/ me 190lbs
frt 50.5%
rear 49.5%

lft frt 1000 rgt frt 934
lft rear 974 rgt rear 924

my friend said dont touch a thing

Attached picture 7366815-scaled9-5-12.jpg

Posted By: MR_P_BODY

Re: Question Scales 4 corners - 09/06/12 04:21 AM

Quote:

This is crazy .... i just finished doing this to my GTX I was hoping you could see the picture, it reads

wgt 3832 w/ me 190lbs
frt 50.5%
rear 49.5%

lft frt 1000 rgt frt 934
lft rear 974 rgt rear 924

my friend said dont touch a thing

Have you run it on the track yet
EDIT
The numbers dont have to be equal(nice if they are)
but he may have added in weight already on the RR

Posted By: Viper469

Re: Question Scales 4 corners - 09/06/12 04:26 AM

Right or wrong here's what we did. After making some initial passes(the car went hard right). We added some preload about 2 flats. Car still went right(not as bad). We scaled the car, approx #40 heavier on the LR. We then added #30 the the RR corner. Tried to lose as much #'s as we could find off the lt side, probbally #10-20. ended up at 1/2 turn of preload. Car went straight.

Then we added nitrous. And right it went.

Adjusted the RR spring perch up 1 1/2 turns, also adjusted the RF spring perch down 1 turn(mostly did this to get the car to sit somewhat level again). Then we just kept adjusting preload till it went straight. Ended up at 1 full turn.

Food for thought. Adding weight buy adjusting LF spring isn't going to have much effect on the RR if the front wheels are in the air.

Here' a pic after we got it sorted out. Pulls the wheels nice and even and goes nice and straight down the track.

MY advise try and get more weight on the RR then the LT. Then adjust preload till it goes straight.

Posted By: 10secGTX

Re: Question Scales 4 corners - 09/06/12 05:08 AM

Quote:

Quote:

This is crazy .... i just finished doing this to my GTX I was hoping you could see the picture, it reads

wgt 3832 w/ me 190lbs
frt 50.5%
rear 49.5%

lft frt 1000 rgt frt 934
lft rear 974 rgt rear 924

my friend said dont touch a thing

Have you run it on the track yet
EDIT
The numbers dont have to be equal(nice if they are)
but he may have added in weight already on the RR

This is how I've had for a year...it went 1.47 60' I'm lucky it hasn't gone left or right in any violent manner ....of course my wheelies are 2-4 inches off the ground.if that

Posted By: SB412DUSTER

Re: Question Scales 4 corners - 09/06/12 05:14 AM

Quote:

This is crazy .... i just finished doing this to my GTX I was hoping you could see the picture, it reads

wgt 3832 w/ me 190lbs
frt 50.5%
rear 49.5%

lft frt 1000 rgt frt 934
lft rear 974 rgt rear 924

my friend said dont touch a thing

Are you sure you dont have the rear numbers mixed up??

Posted By: MR_P_BODY

Re: Question Scales 4 corners - 09/06/12 05:19 AM

Quote:

Quote:

This is crazy .... i just finished doing this to my GTX I was hoping you could see the picture, it reads

wgt 3832 w/ me 190lbs
frt 50.5%
rear 49.5%

lft frt 1000 rgt frt 934
lft rear 974 rgt rear 924

my friend said dont touch a thing

Are you sure you dont have the rear numbers mixed up??

That would be my guess

Posted By: SB412DUSTER

Re: Question Scales 4 corners - 09/06/12 05:28 AM

Quote:

Quote:

Quote:

This is crazy .... i just finished doing this to my GTX I was hoping you could see the picture, it reads

wgt 3832 w/ me 190lbs
frt 50.5%
rear 49.5%

lft frt 1000 rgt frt 934
lft rear 974 rgt rear 924

my friend said dont touch a thing

Are you sure you dont have the rear numbers mixed up??

That would be my guess

That or his friend had the rear wires pluged in the wrong scale.

Posted By: 10secGTX

Re: Question Scales 4 corners - 09/06/12 05:29 AM

all the scales were marked as to were they go ....out side of that, I climbed in the car with my helmet and fire jacket on and he set the scale. w/o me car weighs 3637 has a 50.3% frt 49.7 % rear ....hell if i know but i am sure i put the rgt frt and rgt rear in its proper places

Posted By: dartman366

Re: Question Scales 4 corners - 09/06/12 08:06 AM

have to get my notes to give numbers but we had mine within a couple of pound's of being equal in the rear and after a couple of passes I had to add 30# to the right rear.

Posted By: quickd100

Re: Question Scales 4 corners - 09/06/12 11:03 AM

I wish my weights were that close. I scaled mine last weekend:
DF 1144 PF 1056
DR 800 PR 732
Set up Billy Shope's traction dyno. One full turn of the right rear upper bar and I could get the passenger front tire coming off the ground first. Set it so both front wheels came up at the same time. Dave

Posted By: cudaman1969

Re: Question Scales 4 corners - 09/06/12 03:18 PM

Can't remember exact numbers but my 4-link a-arm tube car but they where equal lr rr rf and lf 60# more. I put 250# in drivers seat for me. I added 40# lead under bat box on rr and cranked up spring on lf till equal (not much)four link bars neutral. Then i got in the seat and while watching the digital scales turned the top right bar(had a panel i could remove) to take the slack out but not changing the numbers.It would hook on snot and go straight,2517# with me in it, 5.60 125 in the eight mile just clean the tires and go to line, bam gone.If you try to scale a ladder car you have to take out one bottom bolt on rear. Ladder will hold it in a bind if you don't,crank the springs in front then put the bolt back,done.Either way you want more weight on right rear tire(at launch it rotates lf to rr) its in the old Chrysler manuals.

Posted By: rickseeman

Re: Question Scales 4 corners - 09/06/12 04:31 PM

With a B-body and a big block and an auto I don't see any need to do any tuning yet. Just put it together neutral (don't worry about corner weights either) with no preload and run it. I guess you can start with a 55" long and 5" high IC. People that talk about all this 4 link tuning are working on cars with a much higher power to weight ratio than you have. Cars that when you let go of the button all hell breaks loose. I doubt that you are planning on leaving on the rear bumper or 1.00 60 foot times.

Posted By: @#$%&*!

Re: Question Scales 4 corners - 09/06/12 05:01 PM

The left/right difference is less than the driver weight. The left side has a 190 driver and it weighs 116# more than the right.

Quote:

Quote:

Quote:

Quote:

This is crazy .... i just finished doing this to my GTX I was hoping you could see the picture, it reads

wgt 3832 w/ me 190lbs
frt 50.5%
rear 49.5%

lft frt 1000 rgt frt 934
lft rear 974 rgt rear 924

my friend said dont touch a thing

Are you sure you dont have the rear numbers mixed up??

That would be my guess

That or his friend had the rear wires pluged in the wrong scale.

Posted By: SCATPACK 1

Re: Question Scales 4 corners - 09/06/12 05:05 PM

Quote:

With a B-body and a big block and an auto I don't see any need to do any tuning yet. Just put it together neutral (don't worry about corner weights either) with no preload and run it. I guess you can start with a 55" long and 5" high IC. People that talk about all this 4 link tuning are working on cars with a much higher power to weight ratio than you have. Cars that when you let go of the button all hell breaks loose. I doubt that you are planning on leaving on the rear bumper or 1.00 60 foot times.

60 ft times last year with the old motor was 1.35. But it seemed to always be spinning the tires thru first and second gears. You could actually see 2 stripes from the car where it just ran down the track. It Never yanked the front end off the ground no matter where the bars were set. I thought there was some room for improvement and wanted to be sure we started from the very beginning and got it right this time. thanks to everyone for their insight on using the scales.
Jerry

Posted By: SCATPACK 1

Re: Question Scales 4 corners - 09/06/12 05:08 PM

Quote:

The left/right difference is less than the driver weight. The left side has a 190 driver and it weighs 116# more than the right.
Quote:

This is what I did not understand too. Wouldn't you try to set the weight on the rear evenly on both tires with the driver in the car.

Posted By: 10secGTX

Re: Question Scales 4 corners - 09/07/12 04:44 AM

Quote:

This is crazy .... i just finished doing this to my GTX I was hoping you could see the picture, it reads

wgt 3832 w/ me 190lbs
frt 50.5%
rear 49.5%

lft frt 1000 rgt frt 934
lft rear 974 rgt rear 924

my friend said dont touch a thing

Im trying to understand if there is an error in my scaling ....this is the data before and I weighed 195 with gear sorry

lft frt 930 rgt frt 898
lft rear 893 rgt rear 916

for a total of 3637 so give or take 2 lbs

does this help the 190/ 195 does not just sit on the driverside it would be spread through out the car via suspension?

I'm just asking

Posted By: Cab_Burge

Re: Question Scales 4 corners - 09/07/12 05:26 PM

Quote:

Im trying to understand if there is an error in my scaling ....this is the data before and I weighed 195 with gear sorry

lft frt 930 rgt frt 898
lft rear 893 rgt rear 916

for a total of 3637 so give or take 2 lbs

does this help the 190/ 195 does not just sit on the driverside it would be spread through out the car via suspension?

I'm just asking

Have you raun your car this way and if so how did it go? If not I would go run it now this way, looks good to me

Let us know either way

BTW, I can move 20 to 40 lbs on the right rear of my car by leaning over towards the trans. tunnel instead of sitting straight in the drivers seat, that wieght does not distribute evenly in my car, ladder bars and coil overs