fine tuning suspension and AutoX
07-15-2012, 08:49 AM
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fine tuning suspension and AutoX I've pretty much have a full koni/strano set up. I've done about 6 or 7 auto X days this year and needed some quick help.
The front of my TA seems to want to bounce a lot after a hard brake and turn. Spectatos describe it as if I have blown shocks. Do I need stiffen up my konis or loosen them?
Also, same scenario, coming into a hard turn with a lot of speed and hard on the brakes, my rear end really seems to want to bounce, skip, shift, etc. in the turn. I was told from other racers that it is common in panhard bar set up cars. Any tips to help keep this from happenning. I think I can really bring my times down if I can fine tune these 2 things. I've got UMI lca with brackets, torque arm, and sbc.
thanks in advance guys.
The front of my TA seems to want to bounce a lot after a hard brake and turn. Spectatos describe it as if I have blown shocks. Do I need stiffen up my konis or loosen them?
Also, same scenario, coming into a hard turn with a lot of speed and hard on the brakes, my rear end really seems to want to bounce, skip, shift, etc. in the turn. I was told from other racers that it is common in panhard bar set up cars. Any tips to help keep this from happenning. I think I can really bring my times down if I can fine tune these 2 things. I've got UMI lca with brackets, torque arm, and sbc.
thanks in advance guys.
07-15-2012, 09:45 AM
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What kind of torque arm? Short arm? Long? What hole do you have the LCA's in?
Trying to clarify what's taking place with your rear end. Is it brake hop? What do you have the konis set to?
Trying to clarify what's taking place with your rear end. Is it brake hop? What do you have the konis set to?
07-15-2012, 11:52 AM
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I believe my fronts are 5 turns from full soft and rears are 1/2 turn from full soft. Its a chassis mount torque arm and lca are in middle hole. Strano rear sway bar. I think I may may be still on the brake when I start into the turn. Next event I'm going to work on braking harder or earlier to see if that helps.
07-17-2012, 08:51 AM
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So when you say chassis mounted torque arm, is it the short one? Aka attached to either the tunnel brace or 3 point SFCs? Or is it attached to the transmission tailshaft, or the relocation kit which some people add? Sorry for all the questions.. it's important though.
Short torque arm will help you gain traction when giving it gas or leaving a corner. At the same time it will have an adverse effect on braking and cause brake hop a lot easier.
Short torque arm will help you gain traction when giving it gas or leaving a corner. At the same time it will have an adverse effect on braking and cause brake hop a lot easier.
07-17-2012, 09:13 AM
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In general you want to brake mostly before the turn and as you begin the turn slowly come off. Sometimes a little braking can help the back end come out a little but you dont want to do that too much.
Yeah.. I'm not sure if you are willing to do this or not, but the short arm is not what you want for autox. Unless there's something you can do to tune out the wierd stuff that happens to the rear under braking. If you brake really hard, you will likely get brake hop and that's BAD.
Also what do you have for a PHB? Stock one?
Do you have an account on frrax?
Yeah.. I'm not sure if you are willing to do this or not, but the short arm is not what you want for autox. Unless there's something you can do to tune out the wierd stuff that happens to the rear under braking. If you brake really hard, you will likely get brake hop and that's BAD.
Also what do you have for a PHB? Stock one?
Do you have an account on frrax?
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07-17-2012, 09:37 AM
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No account on frrax. Never heard of it. I'd be willing to do whatever. Umi phb.
Just got into auto x this year and don't think I'll ever make it back to the drag strip. My car is set up all wrong to begin with but still a blast in our local club. Its a iron block 408 trans am.
Im trying to learn how everything seems to effect something else. Such as my torque arm increasing my brake hop. Thanks for all the info. These are the little things I need to consistently better my times
Just got into auto x this year and don't think I'll ever make it back to the drag strip. My car is set up all wrong to begin with but still a blast in our local club. Its a iron block 408 trans am.
Im trying to learn how everything seems to effect something else. Such as my torque arm increasing my brake hop. Thanks for all the info. These are the little things I need to consistently better my times
07-17-2012, 04:07 PM
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I've pretty much have a full koni/strano set up. I've done about 6 or 7 auto X days this year and needed some quick help.
The front of my TA seems to want to bounce a lot after a hard brake and turn. Spectatos describe it as if I have blown shocks. Do I need stiffen up my konis or loosen them?
Also, same scenario, coming into a hard turn with a lot of speed and hard on the brakes, my rear end really seems to want to bounce, skip, shift, etc. in the turn. I was told from other racers that it is common in panhard bar set up cars. Any tips to help keep this from happenning. I think I can really bring my times down if I can fine tune these 2 things. I've got UMI lca with brackets, torque arm, and sbc.
thanks in advance guys.
The front of my TA seems to want to bounce a lot after a hard brake and turn. Spectatos describe it as if I have blown shocks. Do I need stiffen up my konis or loosen them?
Also, same scenario, coming into a hard turn with a lot of speed and hard on the brakes, my rear end really seems to want to bounce, skip, shift, etc. in the turn. I was told from other racers that it is common in panhard bar set up cars. Any tips to help keep this from happenning. I think I can really bring my times down if I can fine tune these 2 things. I've got UMI lca with brackets, torque arm, and sbc.
thanks in advance guys.
You did use the upper (stock) perch for the front konis correct? Are you SURE about the setting (can you go out and check)?
As for the rear, like z28bryan said a short torque arm can cause some braking issues, look into a stock length one.
07-17-2012, 08:54 PM
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I have strano springs and koni 4/4. Fronts ARE set to 5 turns from soft and rears are half turn from soft. I have stranos sway bars front and rear. I have umi lca with brackets in middle hole. Umi phb. Umi short torque arm. Umi sfc. New tie rods. I wanna say the only thing still stock are the a arms, bushings, k member etc.
I believe that's all my sus mods
I believe that's all my sus mods
07-18-2012, 09:10 AM
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This is brake hop bro and don't let it get out of hand or it will break things in your rear end. Been there done that. Take a look at this video at the 55 second mark.
That is a very minor example of brake hop.
You need to get on Frrax for sure. LS1Tech is great but Frrax lives autox.
http://www.frrax.com/rrforum/
Check out this post on brake hop and the fix for it:
http://www.frrax.com/rrforum/index.p...1&#entry168471
This is the valve that will fix it:
http://www.speedwaymotors.com/speedw...lve,23498.html
The guys above are right the stock longer torque arm would be better for autoX
What pads are you running?
You need to get on Frrax for sure. LS1Tech is great but Frrax lives autox.
http://www.frrax.com/rrforum/
Check out this post on brake hop and the fix for it:
http://www.frrax.com/rrforum/index.p...1&#entry168471
This is the valve that will fix it:
http://www.speedwaymotors.com/speedw...lve,23498.html
The guys above are right the stock longer torque arm would be better for autoX
What pads are you running?
Last edited by charchri4; 07-19-2012 at 12:05 AM.
07-18-2012, 04:33 PM
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Waiting for trackbird to validate me on frrax.
Using hawk hps pads with braided lines and ate blue fluid.
Yeah it didn't feel too bad but one of the corner workers said it was terrifying to watch.
Using hawk hps pads with braided lines and ate blue fluid.
Yeah it didn't feel too bad but one of the corner workers said it was terrifying to watch.
07-18-2012, 05:25 PM
#13
We talked, we know the issue... it's not a car issue. 
See, that's how I work, I ask questions. The brake hop is pretty much driver induced, and so is the nose flying up. See Dan is new to autox, and as much as some think it's easy, it most certainly is not
Starting with the nose unloading. It is, because he's slamming on the brakes in a straight line, then jumping off them hard (causing the nose to unload abruptly). He has to learn to trail brake (as in trail off the brakes, not brake hard to the apex that's not trail braking that's idiocy) and roll off the brakes as he starts to add steering.
Brake hop. That's being not helped by the TA he has and we will change that. But it's also a matter of the sticky tires, the landing on the brake pedal and how the ABS works (and that solid axle cars even without ABS can and do brake hop). Brake too hard/late, the rear wheels try and lock, which is much worse in an LS1 than an LT1 car since the bias is electronic it's always trying to use as much rear as it can. The ABS frequency and the axle's up and down frequency are very similar. When they "match up" it's bang-bang/brake hop city. He has to, and I'm sure will, learn to squeeze the brake pedal down and he as to not just depend on the ABS to do it all. ABS is not a cure-all, it's nice if you miss a little, but you shouldn't be in it all the time, hard.
See, that's how I work, I ask questions. The brake hop is pretty much driver induced, and so is the nose flying up. See Dan is new to autox, and as much as some think it's easy, it most certainly is not
Starting with the nose unloading. It is, because he's slamming on the brakes in a straight line, then jumping off them hard (causing the nose to unload abruptly). He has to learn to trail brake (as in trail off the brakes, not brake hard to the apex that's not trail braking that's idiocy) and roll off the brakes as he starts to add steering.
Brake hop. That's being not helped by the TA he has and we will change that. But it's also a matter of the sticky tires, the landing on the brake pedal and how the ABS works (and that solid axle cars even without ABS can and do brake hop). Brake too hard/late, the rear wheels try and lock, which is much worse in an LS1 than an LT1 car since the bias is electronic it's always trying to use as much rear as it can. The ABS frequency and the axle's up and down frequency are very similar. When they "match up" it's bang-bang/brake hop city. He has to, and I'm sure will, learn to squeeze the brake pedal down and he as to not just depend on the ABS to do it all. ABS is not a cure-all, it's nice if you miss a little, but you shouldn't be in it all the time, hard.
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07-18-2012, 06:10 PM
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Starting with the nose unloading. It is, because he's slamming on the brakes in a straight line, then jumping off them hard (causing the nose to unload abruptly). He has to learn to trail brake (as in trail off the brakes, not brake hard to the apex that's not trail braking that's idiocy) and roll off the brakes as he starts to add steering.
Brake hop. That's being not helped by the TA he has and we will change that. But it's also a matter of the sticky tires, the landing on the brake pedal and how the ABS works (and that solid axle cars even without ABS can and do brake hop). Brake too hard/late, the rear wheels try and lock, which is much worse in an LS1 than an LT1 car since the bias is electronic it's always trying to use as much rear as it can.
Brake hop. That's being not helped by the TA he has and we will change that. But it's also a matter of the sticky tires, the landing on the brake pedal and how the ABS works (and that solid axle cars even without ABS can and do brake hop). Brake too hard/late, the rear wheels try and lock, which is much worse in an LS1 than an LT1 car since the bias is electronic it's always trying to use as much rear as it can.
I currently have stock LS1 brakes, but someone I know has offered to upgrade me to C5 front brakes (just the brakes, not the calipers...maybe later on those). Would that put me in a different autoX class? Currently the only mods I have are intake and exhaust. Also, would that affect the bias at all, since I would have larger front brakes? I'm assuming that would make it more balanced overall?
07-18-2012, 06:56 PM
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Im glad I caught you Sam. I appreciate all the advice and plan to work on the little things we talked about. Everyone else who help point me in the right direction.
Looks like I have a lot of driver error to correct
Looks like I have a lot of driver error to correct
07-18-2012, 09:45 PM
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Not that I'm really involved in the convo but thanks for the advice since I'm about to start autox'ing myself. I've got two questions if you don't mind....
I currently have stock LS1 brakes, but someone I know has offered to upgrade me to C5 front brakes (just the brakes, not the calipers...maybe later on those). Would that put me in a different autoX class? Currently the only mods I have are intake and exhaust. Also, would that affect the bias at all, since I would have larger front brakes? I'm assuming that would make it more balanced overall?
I currently have stock LS1 brakes, but someone I know has offered to upgrade me to C5 front brakes (just the brakes, not the calipers...maybe later on those). Would that put me in a different autoX class? Currently the only mods I have are intake and exhaust. Also, would that affect the bias at all, since I would have larger front brakes? I'm assuming that would make it more balanced overall?
07-19-2012, 12:19 AM
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I agree with Sam. My car wheel hopped like crazy when my son drives but not with me. I'm a left foot braker so my inputs between gas and brake are seamless but he stabs the brakes. I edited my above post with a video if you want to see a minor example of wheel hop. It's at 54 seconds.
Now it is possible for it to be a car problem and in my case it was. I put a pair of pads on the front that were suppose to be temporary but I never got around to changing them before it trashed my rear end. So if you run grabbier pads on the back then the front like I did it makes a big mess.
Good luck!
Now it is possible for it to be a car problem and in my case it was. I put a pair of pads on the front that were suppose to be temporary but I never got around to changing them before it trashed my rear end. So if you run grabbier pads on the back then the front like I did it makes a big mess.
Good luck!
07-19-2012, 02:01 PM
#18
Not that I'm really involved in the convo but thanks for the advice since I'm about to start autox'ing myself. I've got two questions if you don't mind....
I currently have stock LS1 brakes, but someone I know has offered to upgrade me to C5 front brakes (just the brakes, not the calipers...maybe later on those). Would that put me in a different autoX class? Currently the only mods I have are intake and exhaust. Also, would that affect the bias at all, since I would have larger front brakes? I'm assuming that would make it more balanced overall?
I currently have stock LS1 brakes, but someone I know has offered to upgrade me to C5 front brakes (just the brakes, not the calipers...maybe later on those). Would that put me in a different autoX class? Currently the only mods I have are intake and exhaust. Also, would that affect the bias at all, since I would have larger front brakes? I'm assuming that would make it more balanced overall?
So C5 rotors and stock calipers? Don't waste your time or money.
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Check out our KONI prices, our Master Cylinder Brace, and new Xtracker Hub/wheel bearing upgrade kits!
07-19-2012, 11:18 PM
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Yup, being smooth without sudden sharp movements make for a cleaner and hopefully a faster run. Also, the condition of the course itself can make for some violent hops or bangs on any car. After the first run, you can identify where the imperfections are located and drive accordingly....it's all part of the fun of autocross!
