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Old 05-12-2016, 11:56 PM   #1
HachiRo
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How bad is body roll?

Recently upgraded my suspension (kinda) with RSR Superdown springs on brand new 2014 struts. Wheel is RPF1 17x9 +35 with 245/40/17 RS3s.
I feel like my car has the same, if not a bit more body roll.
My tire pressure is at 38 front and 34 rear warm. I've asked a couple of people and they say that some body roll is needed for good handling. From mt understanding of what everyone on here says, body roll should be kept minimal for handling. My front camber is -1.5 and rear at -2.0.

Is the body roll I'm getting from the low tire pressure? Possibly the springs being too low for the stock struts? And should I worry about the body roll?
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Old 05-13-2016, 12:16 AM   #2
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Quote:
Originally Posted by HachiRo View Post
Recently upgraded my suspension (kinda) with RSR Superdown springs on brand new 2014 struts. Wheel is RPF1 17x9 +35 with 245/40/17 RS3s.
I feel like my car has the same, if not a bit more body roll.
My tire pressure is at 38 front and 34 rear warm. I've asked a couple of people and they say that some body roll is needed for good handling. From mt understanding of what everyone on here says, body roll should be kept minimal for handling. My front camber is -1.5 and rear at -2.0.

Is the body roll I'm getting from the low tire pressure? Possibly the springs being too low for the stock struts? And should I worry about the body roll?
What low pressure? Ignore how the car feels re: roll and pay attention to other things. I suspect you've got a fair bit of understeer from the alignment. You may feel like there's more roll because you're on different springs... But roll itself isn't a specific evil. Heck, Miatas have gobs of body roll and do quite well.
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Old 05-13-2016, 01:25 AM   #3
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The body roll is from the wide and grippy wheel/tire setup. I had exactly the same wheels and Dunlop ZII SS in the same size. First on stock suspension for a few months, and then on RCE Tarmac Zero coilovers later. Switching to coilovers brought back the flat handling.

I suspect your suspension setup is outside of it's comfort zone when cornering hard with these wheels/tires since the RSR springs aren't that much stiffer than stock.
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Old 05-13-2016, 02:05 AM   #4
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Also suspension geometry can be compromised by roll center change from being too low.
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Old 05-13-2016, 03:13 AM   #5
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Most likely from soft springs rate and soft damping couple with sticky tires.

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Old 05-13-2016, 05:36 AM   #6
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As already mentioned, roll isn't evil. Some prefer reducing it not so much to "enhance" suspension/grip, but simply because they will feel more subjective confidence to push car more with less roll, not because car will become much more capable with less roll.
And yes, sticky & wide tires will benefit from firmer spring rates, to ride less on bumpstops and lessen roll (of extent with sticky tires, that it may impact handling/grip above just subjective worsening), suspension should match tire selection. IIRC one of main questions that our suspension gurus like RCE/CSG ask before giving out advices, is - what tires you intend to run.
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Old 05-13-2016, 09:01 PM   #7
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Ah, I see. Thanks all. I plan on upgrading to coils eventually, just seeing what's good for the price after reviews and all still. So the body roll I'm getting isn't necessarily bad, but it will affect my handling right? But not to a huge degree?
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Old 05-13-2016, 10:27 PM   #8
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If I wanted to reduce body roll due to my soft spring rates, would it be wiser getting front camber? Or rear sway bars?
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Old 05-13-2016, 10:59 PM   #9
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Quote:
Originally Posted by HachiRo View Post
If I wanted to reduce body roll due to my soft spring rates, would it be wiser getting front camber? Or rear sway bars?
stickier tires, spring rate, and change in roll center all contribute to roll. If you want to change your springs at a later time, it might be best to get roll angle adjusters. This will help reduce roll back to OEM levels, and will still be super useful down the line if you upgrade other components.

Roll can be somewhat good for traction as it helps the suspension adjust alignment favorably. It is more important for double a/multilink (the rear), and may hurt macphearsons (fronts) if you go past the point on the camber curve where it starts to go positive. Roll angle adjusters will help your fronts not be too stupid.

Roll is bad for transitions because it takes a little bit of time for the car to settle and then go the opposite way and settle again. It doesn't matter much for steady state or things like track/road course driving, but it matters for autocross and feel.

front camber if anything will give you more traction which makes more roll. It will kind of help the positive macphearson camber gain, but it doesn't really help the whole feel of it. So while overall cornering traction is improved, you still have the issue where you will have better grip as you start than when you settle.

anti-roll bars will help reduce roll, but they may not be very necessary if you end up getting proper spring rates in the future.

Do they make rear roll center adjusters for the twins though? Changing the difference in the front and rear roll centers can significantly change the feel of the car. This is out of my pay-grade and you might want to ask the real suspension gurus out there. You may also want to see if anyone out there has the front roll center adjsuters
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Old 05-14-2016, 01:59 PM   #10
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BTW, today had 3hours rainy track time and then had a go in track's own mx5 for a while. Yes, it rolled more .. but at no point i felt it limiting me, and imho more pronounced mass transfer during turns made car control even easier.
offtopic P.S.
And as it was track car, it was driven with electronic TC/SC on .. while it killed some fun when i by habbit expected more drift .. i found mx5 nannies working way better then what we have. Less abruptly interrupting, allowing more fun with them on. Not an issue for me, due driving myself with pedal dance, but still, toyobaru could have made VSC better and imho they should improve it in MY2017.
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Old 05-16-2016, 03:52 PM   #11
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Like everyone else said...it's a combo of everything you modified. You lowered your car with springs that lower your car more than an inch (this alters suspension geometry). The springs are not that much stiffer than stock. Wider wheels and tires also play into this. More so the offset of the wheel. I know a lot of people run 17X9 +35 offset, but the lower offset does play into the feeling of more body roll. This is because the lower offset increases the leverage on the suspension giving that feeling of body roll. What I would do is either get a set of good coilovers, or replace your springs with RCE yellows, since it only lowers .8 and has higher spring rates.
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Old 05-18-2016, 02:39 AM   #12
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If you aren't tracking the car, you won't even find 4/10ths of the cars stock limit on the street, let alone with it modified so this entire thread is pointless. So, let's answer that question first.
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Old 05-20-2016, 01:07 AM   #13
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Thanks for asking the question! I am not very familiar with this subject. I have stock suspension except trd lowering springs. However I just purchased trd swaybars front n rear.

Also thanks for the responses!!
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