Road racing setup help

Discussion in 'Mazdaspeed 3 General Discussion' started by gotovato, Jun 4, 2018.

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  1. gotovato

    gotovato Greenie Member

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    hey thanks for the input. i do need an upgraded passenger motor mount and transmission motor mount i just wasnt sure if its needed for road racing the way it would be for drag racing. i have read and it seems the damond mounts are most popular so i guess ill pickup a set of those are some point soon.
    --- Double Post Merged, Jun 5, 2018 ---
    for coil overs, i was really just going to go with a bilstein set and have custom spring rates added and get them revalved or even go with kw v3 and have custom springs and a revalve done. ill have to look into options and affordability. currently i still want to get my corksport camber plates installed, and have a fresh alignment done to see how that helps
     
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  2. phate

    phate Motorhead

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    Step 1: Buy an MS6.

    Corner exit grip is everything, and you need to focus on how to make that better. The more time spent on throttle, the faster you'll be. I was having corner exit issues the same as you, but in my MS6. It was blowing the inside front off if I got on it hard coming out. This year, I can plant my right foot before the apex and the car sticks with only a hint of inside front spin. Things you need to focus on:

    Do everything in your power to keep the front tires on the ground. The key here is sway bar stiffness relative to spring stiffness. The MS3 gets a TON of roll stiffness from bars and tries to lift the inside tires. At the same time, it is very soft in squat and dive, so as you accelerate out the front end lifts and the rear squats. Both things can prematurely lift a tire off the ground.

    Keep that ratio of stiffness in mind - springs vs bars. The MS3 needs more spring, first. With that, keep your spring ratios and frequencies in mind (I subscribe to flat ride philosophy). After that, get enough stiffness from bars to make the car not capsize and dial in over/understeer behavior (get enough roll stiffness as necessary). At that point, you should be really, really close to ideal. You can trim over/understeer behavior using bump stops and spring rubbers.

    If you are inclined to do the math, take a few minutes and read my thread about suspension by the numbers.

    [Notice I didn't mention using dampers to effect handling characteristics, here.]


    You've touched on something extremely important that shouldn't be an after thought. Bump steer behavior is a function of the suspension geometry and has 'good' and 'bad' ranges depending on suspension height (think mid-corner). Measure it. Try to keep the car from functioning in this area, or move it to a range where you don't function.

    But that brings up car height - let the suspension work. If you lower it on those soft coilovers, you're relying on bump stops more than you are the springs. That is likely the source of your nasty oversteer behavior. You can set the car up to utilize them, but they act like a progressive spring and throw off car balance when you overuse them.



    I'm in the no adjuster camp. More knobs to fuck with just gives people an excuse as to why they are driving slow. A good custom setup, non-adjustable, will be sufficient for 95% of situations. The spring, bar, bump stop,and bushings should build the overall attitude of the car.



    KW's essentially can't be revalved. Don't bother.

    Bilsteins are the best base shock you can buy. Tons of shops can work on them, and the sky is the limit.

    Buy the best dampers you can afford. Dampers keep the tires happy, and if they suck your car is going to suck.
     
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  3. Maisonvi

    Maisonvi Silver Member

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    Off the topic of suspension and on the topic of oil coolers and radiators. I was having crazy heat issues at the track.

    Switched to a custom oil plate that removed the stock "oil cooler" and ran it though a 19 row bar/plate cooler. and then put in a koyo rad. At the track a few weeks ago, things were so much better than they were at the end of last year. Stayed way cooler (till things got way hotter lol)

    I actually saved the custom oil plate if you want to do something like that. I can show you what my set up was.
     
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  4. Mauro_Penguin

    Mauro_Penguin Punk in Drublic Gold Member

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    I concur, but for some God awful reason, most MS3 owners get cold feet at the idea of doing any kind of in depth suspension work besides just bolting on coilovers.

    Unfortunately there are not as many bumpsteer solutions for our platforms as there could be. The only off the shelf parts are steering rack spacers, and most MS3 owners won't drop a front subframe.

    But if the OP is mindful of suspension height, he can still keep a decent roll center height and minimize potential bumpsteer.
     
    Mauro_Penguin, via a mobile device, Jun 6, 2018
    #24
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  5. AYOUSTIN

    AYOUSTIN Silver Member

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    For anyone who wants to learn about suspension geometries, here's a pretty good read about roll centers etc. http://www.motoiq.com/MagazineArtic...in-the-Geometry-Part-One-The-Roll-Center.aspx

    A good suspension will either make or break a car. It's what I've focused on the most in the past year and will still be investing some significant money into it in the coming year (drop correction knuckles FTW). Without a doubt in my mind I'd rather drive a 300whp car with an awesome suspension than a 600whp car with garbage OTS suspension.
     
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  6. gotovato

    gotovato Greenie Member

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    image.jpeg
    At this point I'll have to look into bilstein options as I can clearly notice the OTS coil overs are just too soft. Under power car squats and just lights up the front inside tire even under what I'd consider light throttle. Under braking? The car is loose and the rear end has no issue coming out and getting squirrelly. I currently have a white line rear bar on the stiffer setting and am planning to move that to the softer setting for now to test. I will definitely take a look at your thread. Interms of car height I regularly catch shit for my other car buddies (parking lot experts) for not being low enough. I don't think height is a huge issue here as I know suspension travel is a real thing that's very important.

    That's how the car is setup height wise
    --- Double Post Merged, Jun 7, 2018 ---
    So the only bump steer solution I've found is by white line. I have the parts. Me and my shop were just debating on if it's worth the install? Will it help at all?
    --- Double Post Merged, Jun 7, 2018 ---
    I think I'm done power modding as I'm quickly understanding this. If I can't stay on the power I wont beable to do much out there. I have some prime local examples of power vs driver mod/suspension setup so it's pretty easy to see suspension is the next mod for the car.


    One thing I've noticed is even in a straight line under heavy braking coming down from the fast straight, the car loves to dance around under hard braking. Scared the hell out of me the first time it did that.
     
    Last edited: Jun 7, 2018
    gotovato, via an iPhone, Jun 7, 2018
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  7. Code Monkey

    Code Monkey Gold Member

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    Check your alignment, you may have too much toe out in front, I usually run 1/16" of toe out in front, you could do that, or run 0 toe, or even 1/16" toe in, depending on what you like and how the car behaves.
     
  8. gotovato

    gotovato Greenie Member

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    Once my corksport camber plates go in, and rear camber arms the car will get a full alignment and corner balance. Hoping that fixes that issue. I figured it was due to weight transfer and loading up the front end allowing the rear to dance around.
     
    gotovato, via an iPhone, Jun 7, 2018
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  9. AYOUSTIN

    AYOUSTIN Silver Member

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    The whiteline kit will definitely help. Bumpsteer sucks because not only will it slow you down but you'll lose confidence in the car as well which further slows you down. See where you're at with caster as well, for mac strut cars the magic number is usually between 6-9°
     
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  10. gotovato

    gotovato Greenie Member

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    thanks for the tip! i guess ill have to install that bump steer correction kit
     
  11. phate

    phate Motorhead

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    As far as I know, no one has actually measured bump steer on a 3, nor has anyone measured it with the kit. Don't assume anything about the aftermarket, lots and lots of parts don't do what you expect.
     
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  12. gotovato

    gotovato Greenie Member

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    well this is good to know. it is a pain to install and its difficult to tell if its worth it or not. Maybe if I get some free time at some point ill install it but as of now it wont be happening. If no one has tried it with any success then theres no major incentive for me to try it.
     
  13. Mauro_Penguin

    Mauro_Penguin Punk in Drublic Gold Member

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    I tried to a couple of weeks ago, but ran out of time. Definitely takes a bit of time to set up.

    I'm lowered maybe half an inch or so, and have whiteline steering rack spacers. I still had bumpsteer up the ying yang.

    It's been a while for me, but IIRC even with full OEM suspension there is bumpsteer on the 3.
    --- Double Post Merged, Jun 12, 2018 ---
    White line spacers help, but they are not a 100% fix.

    Eliminating bumpsteer adds ridiculous stability to this car.
     
    Mauro_Penguin, via a mobile device, Jun 12, 2018
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  14. phate

    phate Motorhead

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    What are you guys calling "bump steer" that you are actually experiencing? Most of what you feel driving on the road is tramlining - where the wheels want to follow grooves in the road.


    Also, how are you measuring?
     
  15. gotovato

    gotovato Greenie Member

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    im use to the tramlining, its something I noticed when I first started driving on 255 wide tires and I knew that was probably something unavoidable but interms of bump steer, Im assuming that means when the car hits a bump in the road it has a tendency to shimmy either left or right and become unsettled ?
     
  16. phate

    phate Motorhead

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    I'd take a look at bushings. In particular the trailing arm bushing in the rear. In my experience, if the bushings are severely worn, you'll get some nasty behavior like what you're talking about. If they're past their prime they'll have deep cracks in the visible surface, and some can even separate completely through. Get a pry bar and try to deflect them.
     
  17. gotovato

    gotovato Greenie Member

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    I will inspect those before my next track day. I have to give the car a full look over as well as solve another issue now before the next track day. This time when I go out I plan to pay closer attention to the cars behavior on track
     
  18. Mauro_Penguin

    Mauro_Penguin Punk in Drublic Gold Member

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    Tramlining can be reduced with proper alignment, but that jerks the wheel and fights you until the road stabilizes.

    Bumpsteer is a jerking of the steering wheel back and fourth while going over uneven road.

    Tramlining you grip and maintain, bumpsteer you grip and have to fight a back and fourth only on bumps which is more difficult necause of how fast it moves back and fourth.

    That's just me, feel free to correct me if I'm wrong.

    As far as measuring, I marked the center of my bearing hub and marked the chassis with 4 lines. I used a laser to align everything while the car was lifted , had sway bar disconnected, and had the spring removed . Measured at 1" and 2" of compression and rebound. I used a laser pen secured to the rotor (rotor was bolted to hub) to mark toe on graph paper taped to the floor at the static height (using my chassis markings), then at the 1" and 2" of deflection.

    Crude, but it was my first time so I was ironing out bugs. I ran out of time because it took me so long to get the coilover out and remove the spring.

    In the end I just eyeballed the tie rod height with relation to the ground and called it a day. I will go back and try it again in a couple of weeks. So far with just a rough eyeball spacing of the tie rod, the car is ridiculously more stable over bumps, no back and fourth jerking. If the road is uneven, it LIGHTLY jerks but stays there and much easier to handle from the steering wheel. Tramlining due to uneven road is almost non existent. For the record toe setting is -0.02* toe out.
     
    Mauro_Penguin, via a mobile device, Jun 12, 2018
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  19. AYOUSTIN

    AYOUSTIN Silver Member

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    @Mauro_Penguin how are you spacing your tie rods? Does anyone make longer shank balljoints or do any from another car fit? That's usually the easiest/cheapest way to get some roll center correction as well as reduce bump steer a bit.
     
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  20. phate

    phate Motorhead

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    Sent from my SM-G960U using Tapatalk
     
    phate, via a mobile device, Jun 12, 2018
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