Recommended suspension upgrade path
#16
I'm using Swift Sport Machs which on their own were fantastic for dd. They softened up daily driving over small bumps due to their progressive nature. On hard corners they were stiffer than stock. Just keep in mind that with any progressive spring, there will be a bit of an initial roll no matter how slow or fast you take a corner. I now have a 27mm whiteline rear sway installed and it definitely made the car flatter in the corners, but it also made the ride in the rear harsher over single side bumps (read: most bumps). I feel it less in the front, but it's definitely noticeable for passengers in the back.
#17
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#18
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In general, I agree with most of what you said, except for this (which you actually said twice):
The problem with the above is that the chassis of an Evo X is incredibly strong. The front and rear don't roll separately; they roll together. What you ought to be saying is that a stiffer rear bar will cause weight-transfer to affect the rear tires more than the fronts. The move from under- to oversteer that a stiffer rear bar causes is due to over-cooking the outside rear, because that's the tire that now bears the brunt of weight-transfer.
The problem with the above is that the chassis of an Evo X is incredibly strong. The front and rear don't roll separately; they roll together. What you ought to be saying is that a stiffer rear bar will cause weight-transfer to affect the rear tires more than the fronts. The move from under- to oversteer that a stiffer rear bar causes is due to over-cooking the outside rear, because that's the tire that now bears the brunt of weight-transfer.
There are books on suspension set up and geometry and I'm no expert. Jack at EFI Logics for example, I'm convinced, has forgotten more than I'll ever learn on the subject. Whatever I offer, well said or not, are just the basics.
Last edited by Johnr352; Mar 6, 2012 at 04:15 AM.
#19
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When you lower your car, you might consider picking up the rear camber kit and maybe the adjustable front camber bolt..
Whiteline Rear Camber Kit (~200$)
Any front adjustable camber bolt (~30$)
My car is lowered on Tein springs. This seems to be a hit or miss for different cars. I went to get an alignment done and was told my rear camber bolt is worn out of place due to the extra pressure from lowered springs. It's starting to bend the frame and alignment is impossible. A few month later, my front bolt started to wear out also.. The front bolt is fairly cheap compare to rear camber kit..
you can save money by having cheaper brands like Megan.. but Whiteline is the best imo... Plus these are necessary later on if you decide to drop the car lower with coilovers
Side question for the experts:
I've read conversations saying that the Evo suspension is fairly top notch. Randomly switching out parts may actually worsen the suspension. Do I need to worry about this if I install simple parts like rear sways, endlinks, etc.
Whiteline Rear Camber Kit (~200$)
Any front adjustable camber bolt (~30$)
My car is lowered on Tein springs. This seems to be a hit or miss for different cars. I went to get an alignment done and was told my rear camber bolt is worn out of place due to the extra pressure from lowered springs. It's starting to bend the frame and alignment is impossible. A few month later, my front bolt started to wear out also.. The front bolt is fairly cheap compare to rear camber kit..
you can save money by having cheaper brands like Megan.. but Whiteline is the best imo... Plus these are necessary later on if you decide to drop the car lower with coilovers
Side question for the experts:
I've read conversations saying that the Evo suspension is fairly top notch. Randomly switching out parts may actually worsen the suspension. Do I need to worry about this if I install simple parts like rear sways, endlinks, etc.
I strongly suggest, taking all of this advice and find your products and upgrade path and then finding the right shop for the install. Find people who know how to set up high performance and race car suspensions and not just guys who can handle the spring install and set your toe and camber to oem. Find the right shop and talk to them about how you drive, what you want to do and they can help make sure the products you buy are installed and set up in a way that make sense. Camber plates would not be a particularly good modification over stock if the camber and caster settings are all out of whack...
#21
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Well it depends, if you buy springs with aggressive drop for eg: megan, eibach, teins etc. there is strong chance that the shocks will eventually blow or bottom out. But, most people here have ran GTworx and swift springs for long periods without any issues. Also, those two springs will always perform better than cheap coilovers!
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I had a customer who is an instructor at the track with the BMW club who also owns a X. His suspension is stock save for front and rear sway bars. According to him, the front and rear sway bars work in tandem and they have worked wonders for getting around a corner faster without being twitchy.
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Great info. And not to hijack the thread but exactly what bushings are you referring to so I know what to order? I have a stock 2012 and my first upgrade is going to be the gtworx springs and the whiteline rear sway. I was thinking of the roll kit for the front as well, since I am doing all that it might make sense to have them do the bushings at the same time since they will be down there. I love the way the car handles, I would just like a little less sway. I have a basic understanding of the setup, how to create over and under steer (from playing Gran Turismo and iRacing) LOL amazingly enough the games do teach you some stuff.
Thanks again for the info
Thanks again for the info
No.
Sway bars don't make the car stiff they keep it from leaning when under corner forces. Essentially they take that body lean and push it pack down through the tires. That's not a perfect physics description but it will do.
So a bigger (thicker) rear sway will reduce the body lean (roll) in the rear. The Evo X has a tendency to push in the corner, meaning it will understeer. Adding a rear sway helps balance this out some by reducing the roll in the rear and taking some of that energy and pushing it to the tires (rear) and so the car's rear tires will slide a little sooner (as opposed to the fronts) reducing your understeer and improving car rotation.
Too stiff a spring will do the same thing essentially, in that it pushes back the g forces to the ground through the tires (which have a constant grip factor. So that if you put a stiffer spring in the rear than in the front you can "lighten up" the car's rear so that it will slide sooner increasing oversteer. Oversteer isn't better, mind you, just a different problem (snap oversteer, for example is very bad and will scare the peaches out of you on the track).
Stiffer in the front will "lighten up" the handling in the front increasing understeer. If you have a tail happy Porsche, you might want this but the Evo already pushes a bit in the front (meaning the front tires tend to break traction before the rear causing the car to push across the turn instead of rotating, thus the term understeer). So, a sway bar in the front is not particularly helpful. I do think the Evo benefits from a slightly stiffer spring and damping front and rear but that is in combination with other changes to manage the understeer. And, of course, a stiffer spring will change your ride characteristics some.
Lowering the car helps to lower the center of gravity and reduces body roll and sharpens turn in and helps rotate the car. So shorter springs will help a bit with that.
A rear sway will help reduce rear roll, lighten up the tail and help the car rotate. Do that too, when you are ready. (I would now)
Endlinks will help sharpen the steering response and weight transition from one side to the next. Do these for the rear when you do the sway.
Bushings will tighten the whole car up, improve steering responsiveness, turn in, transitions , etc. I suggest them as they are relatively inexpensive, won't change the ride quality, and will improve all the good things about the car's handling. You will feel a bit more of the road though. Drive over bricks, well, you will notice you are driving over bricks.
If it were me, looking back over my own the suspension improvement process for a street car (the race car is a little different). I would do the sway and endlinks and bushings and save up for coilovers. I know, you don't want to get those (but I suspect you will someday). Your car will look stock, ride nicely, and handle better, all the time. Then you find a nice set of used coilovers and camber plates and you are in business.
Sway bars don't make the car stiff they keep it from leaning when under corner forces. Essentially they take that body lean and push it pack down through the tires. That's not a perfect physics description but it will do.
So a bigger (thicker) rear sway will reduce the body lean (roll) in the rear. The Evo X has a tendency to push in the corner, meaning it will understeer. Adding a rear sway helps balance this out some by reducing the roll in the rear and taking some of that energy and pushing it to the tires (rear) and so the car's rear tires will slide a little sooner (as opposed to the fronts) reducing your understeer and improving car rotation.
Too stiff a spring will do the same thing essentially, in that it pushes back the g forces to the ground through the tires (which have a constant grip factor. So that if you put a stiffer spring in the rear than in the front you can "lighten up" the car's rear so that it will slide sooner increasing oversteer. Oversteer isn't better, mind you, just a different problem (snap oversteer, for example is very bad and will scare the peaches out of you on the track).
Stiffer in the front will "lighten up" the handling in the front increasing understeer. If you have a tail happy Porsche, you might want this but the Evo already pushes a bit in the front (meaning the front tires tend to break traction before the rear causing the car to push across the turn instead of rotating, thus the term understeer). So, a sway bar in the front is not particularly helpful. I do think the Evo benefits from a slightly stiffer spring and damping front and rear but that is in combination with other changes to manage the understeer. And, of course, a stiffer spring will change your ride characteristics some.
Lowering the car helps to lower the center of gravity and reduces body roll and sharpens turn in and helps rotate the car. So shorter springs will help a bit with that.
A rear sway will help reduce rear roll, lighten up the tail and help the car rotate. Do that too, when you are ready. (I would now)
Endlinks will help sharpen the steering response and weight transition from one side to the next. Do these for the rear when you do the sway.
Bushings will tighten the whole car up, improve steering responsiveness, turn in, transitions , etc. I suggest them as they are relatively inexpensive, won't change the ride quality, and will improve all the good things about the car's handling. You will feel a bit more of the road though. Drive over bricks, well, you will notice you are driving over bricks.
If it were me, looking back over my own the suspension improvement process for a street car (the race car is a little different). I would do the sway and endlinks and bushings and save up for coilovers. I know, you don't want to get those (but I suspect you will someday). Your car will look stock, ride nicely, and handle better, all the time. Then you find a nice set of used coilovers and camber plates and you are in business.
Last edited by Uscbryan; Mar 6, 2012 at 12:39 PM.
#24
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This is from a complete NOOB but one thing you have to watch out for when people say it will make the suspension "worse" is their definition of worse. Example: My ex bought a Porsche Carerra 4 and ended up trading it on a Lexus GS a few months later because she thought it handled "bad". Her definition of bad was it rode rough. LOL So keep in mind what you think is a better or worse suspension when you are reading what others are telling you.
When you lower your car, you might consider picking up the rear camber kit and maybe the adjustable front camber bolt..
Whiteline Rear Camber Kit (~200$)
Any front adjustable camber bolt (~30$)
My car is lowered on Tein springs. This seems to be a hit or miss for different cars. I went to get an alignment done and was told my rear camber bolt is worn out of place due to the extra pressure from lowered springs. It's starting to bend the frame and alignment is impossible. A few month later, my front bolt started to wear out also.. The front bolt is fairly cheap compare to rear camber kit..
you can save money by having cheaper brands like Megan.. but Whiteline is the best imo... Plus these are necessary later on if you decide to drop the car lower with coilovers
Side question for the experts:
I've read conversations saying that the Evo suspension is fairly top notch. Randomly switching out parts may actually worsen the suspension. Do I need to worry about this if I install simple parts like rear sways, endlinks, etc.
Whiteline Rear Camber Kit (~200$)
Any front adjustable camber bolt (~30$)
My car is lowered on Tein springs. This seems to be a hit or miss for different cars. I went to get an alignment done and was told my rear camber bolt is worn out of place due to the extra pressure from lowered springs. It's starting to bend the frame and alignment is impossible. A few month later, my front bolt started to wear out also.. The front bolt is fairly cheap compare to rear camber kit..
you can save money by having cheaper brands like Megan.. but Whiteline is the best imo... Plus these are necessary later on if you decide to drop the car lower with coilovers
Side question for the experts:
I've read conversations saying that the Evo suspension is fairly top notch. Randomly switching out parts may actually worsen the suspension. Do I need to worry about this if I install simple parts like rear sways, endlinks, etc.
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I've read in many other threads that it helps to pair a lowering kit or coilovers with a roll-center adjustment kit. I have yet to lower my X, but the theory behind the roll-center kit sounds like it would be a valuable upgrade.
http://www.whiteline.com.au/product_..._number=KCA395
http://www.whiteline.com.au/product_..._number=KCA395
#26
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Great info. And not to hijack the thread but exactly what bushings are you referring to so I know what to order? I have a stock 2012 and my first upgrade is going to be the gtworx springs and the whiteline rear sway. I was thinking of the roll kit for the front as well, since I am doing all that it might make sense to have them do the bushings at the same time since they will be down there. I love the way the car handles, I would just like a little less sway. I have a basic understanding of the setup, how to create over and under steer (from playing Gran Turismo and iRacing) LOL amazingly enough the games do teach you some stuff.
Thanks again for the info
Thanks again for the info
Yes. The games are a good start. Turn 2 through Turn 5 at NJMP Lightning would help too...
#27
This is from a complete NOOB but one thing you have to watch out for when people say it will make the suspension "worse" is their definition of worse. Example: My ex bought a Porsche Carerra 4 and ended up trading it on a Lexus GS a few months later because she thought it handled "bad". Her definition of bad was it rode rough. LOL So keep in mind what you think is a better or worse suspension when you are reading what others are telling you.
again, I don't think easy bolt-ons like sways or springs would have that type of effect.. but you never know! I don't want to blindly buy parts just to replace OEM..
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by worse I meant comparison with stock car performance. I understand your example. I am no car mod expert.. In my mind, the suspension is set up balanced. (mathematically, everything) Swapping out random parts might toss off certain calculations. Thus, worsen your suspension...
again, I don't think easy bolt-ons like sways or springs would have that type of effect.. but you never know! I don't want to blindly buy parts just to replace OEM..
again, I don't think easy bolt-ons like sways or springs would have that type of effect.. but you never know! I don't want to blindly buy parts just to replace OEM..
I think when the manufacturor produces a car they tend to set it up to appeal to the masses, which might favor comfort and quite at the expense of better handling. So putting aftermarket parts on may make it worse in that aspect (comfort, noise, etc) but better in pure handling. Such is life that it seems you can't have them both, a car that rides like a Lexus and handles like a F1 car. You have to pick what you can accept and research based on that. Personally I will give up a lot of DD comfort for performance. But I may be odd in that aspect.
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Well it depends, if you buy springs with aggressive drop for eg: megan, eibach, teins etc. there is strong chance that the shocks will eventually blow or bottom out. But, most people here have ran GTworx and swift springs for long periods without any issues. Also, those two springs will always perform better than cheap coilovers!
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