Boss Springs and Koni Sports
1/4/13, 10:35 AM
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Boss Springs and Koni Sports
I was wondering if anyone has tried this combo on a GT. I have looked at the price of Boss springs and Koni sports versus koni sports, steeda hd mounts, steeda sport springs, steeda lca relocation brackets, and steeda bump steer kit.
I like the look of the boss's wheel gap and think this would be a better solution to having to correct all things I put out of whack by lowering the whole car. I am also concerned that just grabbing items out of column a and adding them to column b does not always work out. I am hoping someone here has tried this or has some input that will help me decide.
I like the look of the boss's wheel gap and think this would be a better solution to having to correct all things I put out of whack by lowering the whole car. I am also concerned that just grabbing items out of column a and adding them to column b does not always work out. I am hoping someone here has tried this or has some input that will help me decide.
1/5/13, 10:04 AM
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Thank you for sharing that. Your comment is exactly what I am afraid of. Has anyone tried either the Laguna Seca springs or the regular boss springs with Koni sports? Or has anyone tried a different adjustable shock and strut combo that works well, maybe d-specs. I'm hoping there is a good solution to be found. The price of the boss shocks and struts is way out of my price range.
1/5/13, 12:02 PM
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Yeah, I don't know. Sadly, I don't know enough about suspension to even guess. I know my brembo gt is bouncy on uneven roads and bugs me. I took a ride in a friends boss and the ride was actually exactly what I wanted. It was firm but comfortable. The wheel gap was a little less than my car and looked pretty good.
I scrape a little in my drive way at home and work now. I figured a bigger drop would make this worse. I'm hoping someone that knows more or has tried these set ups can enlighten me. I'm pretty set on the boss or ls springs. I just need a damper that I can afford to work with it. I can't afford to spend more than 800 on shocks and struts.
I scrape a little in my drive way at home and work now. I figured a bigger drop would make this worse. I'm hoping someone that knows more or has tried these set ups can enlighten me. I'm pretty set on the boss or ls springs. I just need a damper that I can afford to work with it. I can't afford to spend more than 800 on shocks and struts.
1/5/13, 12:54 PM
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Do you by chance remember the name of those threads? I'm hoping someone in another thread has worked out a good combo. Have you read about a shock/strut combo that works with the boss springs?
Last edited by Mr. V; 1/5/13 at 12:55 PM.
1/5/13, 01:11 PM
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No - sorry. These weren't Boss specific threads. I'm going from memory on the 08/09 GT's and Bullitt's from a few years back. The settings were either too stiff - losing traction on rough roads and/or a punishing ride, or too mushy - allowing too much roll.
I've stayed away from Sports because of that, and I've never read any update to that issue.
I've stayed away from Sports because of that, and I've never read any update to that issue.
1/6/13, 01:54 AM
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I would consider trying a boss front/ 55d rear, to cut down on the reargap and keep a stockish ride height and quality. Just not sure what dampers would be best, maybe takeoff Boss LS.
I'm goint to install P-spring front and 55d rear w/ yellows in a few weeks.
1/6/13, 05:36 AM
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Ross
I am curious, if you put the p springs in front, a 1 inch drop from stock, and the 55d in the rear, a 1/2 inch drop from stock, aren't you creating more rake from front to back? Since the back is at least 1/2 higher than the front already, if you drop the front 1 inch it will be even lower.
Like I said , just curious as to what advantage this might be in handling or is just for looks?
I am curious, if you put the p springs in front, a 1 inch drop from stock, and the 55d in the rear, a 1/2 inch drop from stock, aren't you creating more rake from front to back? Since the back is at least 1/2 higher than the front already, if you drop the front 1 inch it will be even lower.
Like I said , just curious as to what advantage this might be in handling or is just for looks?
1/6/13, 07:35 AM
#11
You just may like the Hotchkis springs. There is really no difference of a drop in the front compared to the boss springs and has a 1.5 inch drop in the rear which evens out the car perfectly. There is a member who has a SBY Boss with hotchkis springs and has amazing pics with them on his car. I have them on my 13 Boss, the linear springs don't have much more in spring rate than 55d and the ride quality is awesome. Pair those with the yellow and you'll be impressed with the performance and ride quality.
1/6/13, 10:17 AM
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Strano mentioned this combo(boss front and brembo rear) in a suspension thread.
I would consider trying a boss front/ 55d rear, to cut down on the rear gap and keep a stockish ride height and quality. Just not sure what dampers would be best, maybe takeoff Boss LS.
I'm goint to install P-spring front and 55d rear w/ yellows in a few weeks.
I would consider trying a boss front/ 55d rear, to cut down on the rear gap and keep a stockish ride height and quality. Just not sure what dampers would be best, maybe takeoff Boss LS.
I'm goint to install P-spring front and 55d rear w/ yellows in a few weeks.
1/6/13, 02:59 PM
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Ross
I am curious, if you put the p springs in front, a 1 inch drop from stock, and the 55d in the rear, a 1/2 inch drop from stock, aren't you creating more rake from front to back? Since the back is at least 1/2 higher than the front already, if you drop the front 1 inch it will be even lower.
Like I said , just curious as to what advantage this might be in handling or is just for looks?
I am curious, if you put the p springs in front, a 1 inch drop from stock, and the 55d in the rear, a 1/2 inch drop from stock, aren't you creating more rake from front to back? Since the back is at least 1/2 higher than the front already, if you drop the front 1 inch it will be even lower.
Like I said , just curious as to what advantage this might be in handling or is just for looks?
1/6/13, 06:25 PM
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I would have to agree. Tried it with my 2012 vert. Also the slight lowering had me scraping every driveway/parking lot entrance with my Boss splitter. Had to back to stock springs with my Koni sports to get the ride height back.
1/20/13, 06:25 PM
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Im curious on what you guys did since I have some 55d in the box ready to put on. I am considering putting on some koni yellows but I'm not sure what to the fronts since I don't want it lowered that much.
5/4/13, 07:44 AM
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So here's the duffmod for springs...Boss front springs and top coil removed from rear springs on Brembo GT. Best compomise and cost.
I swapped the front springs on my '12 brembo gt with those from the regular boss (not LS!) and it lowered the front exactly 1/2" and increased neg camber slightly (along with about +12% rate). For the rear, I calculated the spring rate of the brembo gt spring if one coil were removed and if you assume the top coil is of the average mean diameter (which it is not), the rate comes out the same (within 4lbs/in) as the regular boss rear spring (not LS!) . However, the cut brembo spring actually ends up a little softer in rate than the boss rear spring (because the top coil has different mean diameter)and also lowers the rear a little more than the boss springs would but still keeps a very slight forward rake on the car. These are probably the stiffest springs you could get away with without replacing the stock dampers. Also, I did not need an alignment correction or adj phb with my mod.
The comments in other threads about staggered tire size and balance are more applicable to cars lowered 1" or more due to change in front roll center height and camber (gain front traction) as well as change in antisquat of the rear (lose rear traction). And syiffer frony rayes work better when defeating the stability control. Oh, remember that the boss mustangs increased rear stabar size with the increase in rear tire width (I retained my rear stabar). In this case, with just 1/2" drop in front and 3/4" rear, the main reason for not using the boss rear springs was just slightly better match to the dampers. Btw if/when I eventually add anti-squat brackets I will probably put the boss rear springs in.
I would recommend my mod to anyone who doesn't want to lower their car much or spend s lot of money to do it. This based on street evaluation since I haven't taken it on the roadcourse or autox in this form as of yet. The FRPP and Steeda springs are great but require new dampers unless you have a boss to start with...and likely an adj phb and alignment. So do my mod for now and then save up for new dampers if you still want to go further with suspension mods.
Just wanted to share my experience and opinion regarding this, even though it does not consider the koni sports. Hope it helps someone.
I swapped the front springs on my '12 brembo gt with those from the regular boss (not LS!) and it lowered the front exactly 1/2" and increased neg camber slightly (along with about +12% rate). For the rear, I calculated the spring rate of the brembo gt spring if one coil were removed and if you assume the top coil is of the average mean diameter (which it is not), the rate comes out the same (within 4lbs/in) as the regular boss rear spring (not LS!) . However, the cut brembo spring actually ends up a little softer in rate than the boss rear spring (because the top coil has different mean diameter)and also lowers the rear a little more than the boss springs would but still keeps a very slight forward rake on the car. These are probably the stiffest springs you could get away with without replacing the stock dampers. Also, I did not need an alignment correction or adj phb with my mod.
The comments in other threads about staggered tire size and balance are more applicable to cars lowered 1" or more due to change in front roll center height and camber (gain front traction) as well as change in antisquat of the rear (lose rear traction). And syiffer frony rayes work better when defeating the stability control. Oh, remember that the boss mustangs increased rear stabar size with the increase in rear tire width (I retained my rear stabar). In this case, with just 1/2" drop in front and 3/4" rear, the main reason for not using the boss rear springs was just slightly better match to the dampers. Btw if/when I eventually add anti-squat brackets I will probably put the boss rear springs in.
I would recommend my mod to anyone who doesn't want to lower their car much or spend s lot of money to do it. This based on street evaluation since I haven't taken it on the roadcourse or autox in this form as of yet. The FRPP and Steeda springs are great but require new dampers unless you have a boss to start with...and likely an adj phb and alignment. So do my mod for now and then save up for new dampers if you still want to go further with suspension mods.
Just wanted to share my experience and opinion regarding this, even though it does not consider the koni sports. Hope it helps someone.
10/14/13, 10:03 AM
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So here's the duffmod for springs...Boss front springs and top coil removed from rear springs on Brembo GT. Best compomise and cost.
I swapped the front springs on my '12 brembo gt with those from the regular boss (not LS!) and it lowered the front exactly 1/2" and increased neg camber slightly (along with about +12% rate). For the rear, I calculated the spring rate of the brembo gt spring if one coil were removed and if you assume the top coil is of the average mean diameter (which it is not), the rate comes out the same (within 4lbs/in) as the regular boss rear spring (not LS!) . However, the cut brembo spring actually ends up a little softer in rate than the boss rear spring (because the top coil has different mean diameter)and also lowers the rear a little more than the boss springs would but still keeps a very slight forward rake on the car. These are probably the stiffest springs you could get away with without replacing the stock dampers. Also, I did not need an alignment correction or adj phb with my mod.
The comments in other threads about staggered tire size and balance are more applicable to cars lowered 1" or more due to change in front roll center height and camber (gain front traction) as well as change in antisquat of the rear (lose rear traction). And syiffer frony rayes work better when defeating the stability control. Oh, remember that the boss mustangs increased rear stabar size with the increase in rear tire width (I retained my rear stabar). In this case, with just 1/2" drop in front and 3/4" rear, the main reason for not using the boss rear springs was just slightly better match to the dampers. Btw if/when I eventually add anti-squat brackets I will probably put the boss rear springs in.
I would recommend my mod to anyone who doesn't want to lower their car much or spend s lot of money to do it. This based on street evaluation since I haven't taken it on the roadcourse or autox in this form as of yet. The FRPP and Steeda springs are great but require new dampers unless you have a boss to start with...and likely an adj phb and alignment. So do my mod for now and then save up for new dampers if you still want to go further with suspension mods.
Just wanted to share my experience and opinion regarding this, even though it does not consider the koni sports. Hope it helps someone.
I swapped the front springs on my '12 brembo gt with those from the regular boss (not LS!) and it lowered the front exactly 1/2" and increased neg camber slightly (along with about +12% rate). For the rear, I calculated the spring rate of the brembo gt spring if one coil were removed and if you assume the top coil is of the average mean diameter (which it is not), the rate comes out the same (within 4lbs/in) as the regular boss rear spring (not LS!) . However, the cut brembo spring actually ends up a little softer in rate than the boss rear spring (because the top coil has different mean diameter)and also lowers the rear a little more than the boss springs would but still keeps a very slight forward rake on the car. These are probably the stiffest springs you could get away with without replacing the stock dampers. Also, I did not need an alignment correction or adj phb with my mod.
The comments in other threads about staggered tire size and balance are more applicable to cars lowered 1" or more due to change in front roll center height and camber (gain front traction) as well as change in antisquat of the rear (lose rear traction). And syiffer frony rayes work better when defeating the stability control. Oh, remember that the boss mustangs increased rear stabar size with the increase in rear tire width (I retained my rear stabar). In this case, with just 1/2" drop in front and 3/4" rear, the main reason for not using the boss rear springs was just slightly better match to the dampers. Btw if/when I eventually add anti-squat brackets I will probably put the boss rear springs in.
I would recommend my mod to anyone who doesn't want to lower their car much or spend s lot of money to do it. This based on street evaluation since I haven't taken it on the roadcourse or autox in this form as of yet. The FRPP and Steeda springs are great but require new dampers unless you have a boss to start with...and likely an adj phb and alignment. So do my mod for now and then save up for new dampers if you still want to go further with suspension mods.
Just wanted to share my experience and opinion regarding this, even though it does not consider the koni sports. Hope it helps someone.
Per using the Boss rear springs, the stock Boss uses a shorter tire on the rear so if you use the stock Boss springs and same size tire front to rear then the rear height would actually be higher on a GT than a Boss.
4/8/14, 07:16 PM
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wow, I missed this post a long time ago. Sorry.
I did not have any issues with the fit to the upper spring perch. This is why I cut the top coil and not the bottom coil. It sits on the axle perch as intended, then just jack it up reattach the strut. Anyway, I've been driving on these for a while now and it has worked out great. I wouldn't mind a little firmer damping but it is not necessary.
I don't think I would ever put the boss rear springs in now. The rake is so perfect the way it is. My goal was stiffer, but only 1/2 to 3/4 drop. Interesting, I didn't think the OD of the boss tires were different front to rear, just the width. Regardless, I am running the same size tire on all corners, but they are about 0.2" smaller in radius from oem size. Here is a pic showing rake and fender gap.
I did not have any issues with the fit to the upper spring perch. This is why I cut the top coil and not the bottom coil. It sits on the axle perch as intended, then just jack it up reattach the strut. Anyway, I've been driving on these for a while now and it has worked out great. I wouldn't mind a little firmer damping but it is not necessary.
I don't think I would ever put the boss rear springs in now. The rake is so perfect the way it is. My goal was stiffer, but only 1/2 to 3/4 drop. Interesting, I didn't think the OD of the boss tires were different front to rear, just the width. Regardless, I am running the same size tire on all corners, but they are about 0.2" smaller in radius from oem size. Here is a pic showing rake and fender gap.
Last edited by duff; 4/9/14 at 06:21 AM. Reason: add pic
7/27/14, 12:36 AM
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DO NOT CUT COILS! spend $149 bucks and get the correct 1/2" lower 55D Springs from Route 66 Speed Shop. No guess work or mis calculations. Visit www.Brembo50.com for more info