Instant center AS and IC ht. numbers
10-19-2009, 07:57 PM
#62
ic , cog, all fine and dandy. also take into consideration how a small change in rotation of end of torque arm will change the rotation of the front end. So .... if tq arm rotates up on an arc of 1 inch, how much will the nose of the car rotate up on an arc? Well, I would say it depends on where the chassis side of the torque arm is attached to the chassis (from front to back). What you've got is levers acting upon levers. I would say the shorter the torque arm, the more lift you can get on the front end (change in nose travel is inversly related to the change in torque arm length). But you won't get any lift with a short arm unless center of gravity will allow (so you will need to move that back as well).
So... How do I get my 60' down. Isn't that the real question? Seems to me you want 2 things... Have enough traction (no 1 objective). Rob less of the motors power into the suspension (no 2 objective); in other words get the weight to the wheels, get the power to the wheels as quickly as possible and use it to get the car going forward instead of binding the suspension, putting the nose vertical, or raking the car up in the back.
Makes sense to me.
So... How do I get my 60' down. Isn't that the real question? Seems to me you want 2 things... Have enough traction (no 1 objective). Rob less of the motors power into the suspension (no 2 objective); in other words get the weight to the wheels, get the power to the wheels as quickly as possible and use it to get the car going forward instead of binding the suspension, putting the nose vertical, or raking the car up in the back.
Makes sense to me.
Last edited by tee-boy; 10-20-2009 at 06:32 AM.
10-20-2009, 11:10 AM
#65
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The adjustment holes in our arm isnt just a selling tool. We have been building this arm since early 95( we have made upgrades and revisions as we learned). I have found after 1000s of passes on t/a equipped cars that this suspension isnt like a 3/4 link or a ladder bar. 90% of the info about this suspension is for road racing cars so you throw that out the window.
If you move the front of the t/a up in the car then it will hit the tire quickly but it will unload the tire faster. Lowering the arm will pick up more weight and keep the tire planted longer. I dont get into all the math formulas for this style suspension because the theory isnt right.
If you move the front of the t/a up in the car then it will hit the tire quickly but it will unload the tire faster. Lowering the arm will pick up more weight and keep the tire planted longer. I dont get into all the math formulas for this style suspension because the theory isnt right.
i like having lots of adjustment but to me its no good unless i know what the effects will be.... i've been looking at your TA for a while but as it is right now i have no idea as the effects of the TA and LCA angles... like i said i'd buy one if i knew i could make changes to the IC and know where it puts it.
10-25-2009, 11:22 PM
#67
is there anything you can tell us on setting up your TA... right now i have a BMR Xtreme but it plants the tire hard on the starting line and *usually spins about 5-10' out....
i like having lots of adjustment but to me its no good unless i know what the effects will be.... i've been looking at your TA for a while but as it is right now i have no idea as the effects of the TA and LCA angles... like i said i'd buy one if i knew i could make changes to the IC and know where it puts it.
i like having lots of adjustment but to me its no good unless i know what the effects will be.... i've been looking at your TA for a while but as it is right now i have no idea as the effects of the TA and LCA angles... like i said i'd buy one if i knew i could make changes to the IC and know where it puts it.
10-26-2009, 09:48 AM
#68
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a big block and small block car will 60' totally different.... ours is a big block on dope... and its a little heavy up front so i'm not looking for anything too crazy on these 275 radials... just an average of about 1.35
10-26-2009, 11:11 AM
#69
Ls3 How you think a stroked LS3 build would do for you?
10-26-2009, 12:59 PM
#70
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what do you mean? BBC and sbc cars torque curve is rediculously different and bbc are much heavier... plays a big part in 60'... thats why you see all these rediculous 60' times out of small block cars and not big healthy BBC cars..... play a big role especially on a mediocre to **** hole track...
10-26-2009, 07:32 PM
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what do you mean? BBC and sbc cars torque curve is rediculously different and bbc are much heavier... plays a big part in 60'... thats why you see all these rediculous 60' times out of small block cars and not big healthy BBC cars..... play a big role especially on a mediocre to **** hole track...
10-27-2009, 04:45 AM
#74
what do you mean? BBC and sbc cars torque curve is rediculously different and bbc are much heavier... plays a big part in 60'... thats why you see all these rediculous 60' times out of small block cars and not big healthy BBC cars..... play a big role especially on a mediocre to **** hole track...
10-27-2009, 09:10 AM
#76
10-27-2009, 09:38 AM
#77
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I'll let you school me if you want? LOL... 
If what you're saying is true, then why do several manufactures offer torque arms with adjustable vertical settings for the front? If what you're saying is true, then adjusting the front of the torque arm up, or down, wouldn't have any effect at all. Correct? Here's an example of what I'm talking about. BTW, I have no idea what to believe at this point and I'm just trying to learn like anyone else.
My car is lowered almost 2" and it has a Spohn tunnel mounted torque arm. I fabricated some new rotator plates for the front so that I could move the front of my t/a upward toward the tunnel. My thought process was that since the car is lowered, the front of the t/a needs to be raised back up. I did this because after reviewing my videos in slow motion, the tires were being hit really hard at first (driving them downward), then unloading almost immediately. After raising the t/a up about 1.5", and after reviewing more video, the tires weren't being hit nearly as hard and the launches were more controllable. Since then, I've installed Strange drag shocks in the front and now I've moved the t/a back down one hole (about .75"), and set the rear (comp engineering) shocks on full firm on compression (70/30). I'm hoping to get the tires to plant hard again (but not AS hard as previous) and that the added front drag shocks, and stiffer compression on the rear shocks will help keep the tires planted longer.
BTW, this is a 6sp car and I'm currently launching around 5k rpm and still spinning my way to 1.66 - 1.70 60' times. Would love to hit mid 1.5's.
Mike
If what you're saying is true, then why do several manufactures offer torque arms with adjustable vertical settings for the front? If what you're saying is true, then adjusting the front of the torque arm up, or down, wouldn't have any effect at all. Correct? Here's an example of what I'm talking about. BTW, I have no idea what to believe at this point and I'm just trying to learn like anyone else.
My car is lowered almost 2" and it has a Spohn tunnel mounted torque arm. I fabricated some new rotator plates for the front so that I could move the front of my t/a upward toward the tunnel. My thought process was that since the car is lowered, the front of the t/a needs to be raised back up. I did this because after reviewing my videos in slow motion, the tires were being hit really hard at first (driving them downward), then unloading almost immediately. After raising the t/a up about 1.5", and after reviewing more video, the tires weren't being hit nearly as hard and the launches were more controllable. Since then, I've installed Strange drag shocks in the front and now I've moved the t/a back down one hole (about .75"), and set the rear (comp engineering) shocks on full firm on compression (70/30). I'm hoping to get the tires to plant hard again (but not AS hard as previous) and that the added front drag shocks, and stiffer compression on the rear shocks will help keep the tires planted longer.
BTW, this is a 6sp car and I'm currently launching around 5k rpm and still spinning my way to 1.66 - 1.70 60' times. Would love to hit mid 1.5's.
Mike
