Mazda/Mazdaspeed 6 Autocross Thread

[Blendercloud]

Let's discuss some folks' experiences with autocrossing these cars. I'm sure I'm not the only one interested in getting out on a course and flogging the piss out of this car from time to time. Keep the thread clean. Don't turn it into a pissing match with other users. The goal should be to help others with the same interest be competitive and represent our community well against the other makes and models out there.

With that said, I'll go first!

7/19/2009 - 85 degrees F, clear, sunny weather, 40% humidity

I took it easy my first three times through the course. Just trying to get a feel for what autocross was all about. I was getting pointers from some of the veterans who rode along a few times. On my fourth run I picked up the speed a bit and started to really enjoy myself.

My fifth run I was at full speed. Feeling the monsterous amount of torque this car has and just letting it sing throughout the course at 4500-5000 revs was amazing. However, the amount of understeer my car has is atrocious. There was never any shortage of power.

In fact, I'm pretty sure the power-adders I've done have caused me to outgrow my suspension setup. If I was in the throttle more than 25% while trying to turn I was sliding ride off the course. The massive understeer was very predictable though. Unfortunately it was predictably bad.

Braking was a little bit soft, but there was no fade on the Rotora pads and stock rotors. If I found myself coming too hot into a hairpin, the MS6's brakes would typically bail me out.

I rode with a club autocross veteran and his Mazda 6i through the course. The difference was night and day. That car was on rails throughout. Once put into the bracket, his car proved hard to beat for most everyone else. So I picked his brain to see where I could improve.

It looks as though to get this damned car to turn under power I'm looking at the following:
SPC ball joints
Whiteline 24mm rear sway bar
AWR rear sway bar endlinks

I'm riding on General Exclaim UHP tires without much option to change. For the above runs, however, they had less than 500 miles on them. I will be lowering tire pressure to 42psi at the next run versus 51psi at the above run.
Size: 215/45ZR18
Serv. Desc: 93W Load Index 93 = 1433lbs (650kg) per tire
Speed Rating “W” = 168mph (270kph) Load Range XL
UTQG: Treadwear: 380
Traction: AA
Temperature: A380 AA A

 

[tunersteve]

Pics or it didn't happen. (headbang)

 

[Blendercloud]

Pics or it didn't happen. (headbang)

As much as I would love to post pics, you have to be authorized Boeing personnel to have a camera on their property.

 

[cpspeed6]

I'm riding on General Exclaim UHP tires without much option to change. For the above runs, however, they had less than 500 miles on them. I will be lowering tire pressure to 42psi at the next run versus 51psi at the above run.
Size: 215/45ZR18

I have the same tires on stock rims, what psi do you have them at for everyday driving? I thought that 40psi was the limit on these?

 

[dquarasr]

I took it easy my first three times through the course. Just trying to get a feel for what autocross was all about.
.
.
.
It looks as though to get this damned car to turn under power I'm looking at the following:
SPC ball joints
Whiteline 24mm rear sway bar
AWR rear sway bar endlinks

I'm riding on General Exclaim UHP tires without much option to change. For the above runs, however, they had less than 500 miles on them. I will be lowering tire pressure to 42psi at the next run versus 51psi at the above run.
Size: 215/45ZR18
Serv. Desc: 93W Load Index 93 = 1433lbs (650kg) per tire
Speed Rating W = 168mph (270kph) Load Range XL
UTQG: Treadwear: 380
Traction: AA
Temperature: A380 AA A

This may be hard to read, but if you are new to autocrossing, don't start changing the car until you are as good as it. You'd be surprised how much perceived handling characteristics are influenced by technique. You can do the small tweaks, like tire pressures, but resist the temptation to start changing the car.

That said, it's quite possible the tires are the main culprit. Arguably, tires can make the single largest change of any of the mods you can make on the car.

But I can't emphasize enough, that if you're new to autocrossing, work on the nut that holds the steering wheel. It can take a dozen events before you're really taking advantage of what the car has to offer.

 

[tunersteve]

In response to the adjustments on the car, let me add a bit to this.

Our cars, although awd, have a bad tendency to understeer. There are several things one can do to correct this, such as the RSB. I wouldn't jump into everything at once, that way you can tailor the car to your liking. If the RSB doesn't do it, then I'd consider the adj. endlinks, to add even more stiffness to the rear. Next, a rear brace, and finally, the front adj. ball joints.

Also, the alignment can play a big factor. Adding a little negative camber all around (with the ABJ installed) can improve cornering speeds, so you may want to look into that as well.

I recommend anyone interested in these parts head to the suspension section, myself and several others have installs and reviews on them in more detail.

 

[Blendercloud]

I have the same tires on stock rims, what psi do you have them at for everyday driving? I thought that 40psi was the limit on these?

Mine say 51psi max on them. I've actually dropped them to 45psi now that I'm past the first 500 miles. It's a lot more comfortable, too.

This may be hard to read, but if you are new to autocrossing, don't start changing the car until you are as good as it. You'd be surprised how much perceived handling characteristics are influenced by technique. You can do the small tweaks, like tire pressures, but resist the temptation to start changing the car.

That said, it's quite possible the tires are the main culprit. Arguably, tires can make the single largest change of any of the mods you can make on the car.

But I can't emphasize enough, that if you're new to autocrossing, work on the nut that holds the steering wheel. It can take a dozen events before you're really taking advantage of what the car has to offer.

I appreciate you busting my balls gently. (No sarcasm there.) Everyone needs to hear something like that now and then. Being from dirt track racing, pro-street drag, and a little bit of road racing, I can also appreciate that it is much easier to adapt the driver to the car than it is the car to the driver. With that said, the understeer on my car is unmanageable at speed.

I don't intend to spend all that money at one time to try to 'cure' the problem. It will be over the course of the next few months. My first effort will be in the adjustable ball joints. It's a much easier install than the rear stabilizer bar. I can also do a quick and dirty how-to for our "How-To" section. After that install, I can play with different camber for 4-5 runs and see how it works for me.

Depending on how the different camber sets up the car in the corners, I may or may not continue on to other possible solutions.

In response to the adjustments on the car, let me add a bit to this.

Our cars, although awd, have a bad tendency to understeer. There are several things one can do to correct this, such as the RSB. I wouldn't jump into everything at once, that way you can tailor the car to your liking. If the RSB doesn't do it, then I'd consider the adj. endlinks, to add even more stiffness to the rear. Next, a rear brace, and finally, the front adj. ball joints.

Also, the alignment can play a big factor. Adding a little negative camber all around (with the ABJ installed) can improve cornering speeds, so you may want to look into that as well.

I recommend anyone interested in these parts head to the suspension section, myself and several others have installs and reviews on them in more detail.

I think I'm going to go the opposite direction and do the ball joints first. Once I've got it up on the rack I'll get to play with the alignment all-around. As I said above, I plan to do a how-to on that install. It seems easy to me. But I know there are people who don't go after mods if there aren't detailed instructions out there in advance.

 

[tunersteve]

I'm going to try and adjust the rear and add some oversteer first, then eventually do the ball joints and have a more aggressive alignment done with new wheels and tires in the near future.

Blender, I have a how-to for the ball joints saved on my laptop at home, I can send it to you later. It's straight from RPM.

 

[Super Shredder]

Our cars, although awd, have a bad tendency to understeer..

can you elaborate on times that you have experienced understeer, because i consider the car to fight understeer a whole lot more than i could have wished for, and coming from RWD backrounds i feel that the ass is very able to get out there.

I live in the mountains so its a touge match back and forth to civilization between all the subies and lifted super trucks up here. as soon as the awd system feels countersteer it puts power to the back. and if you drop a gear say 4th to 3rd during a 50 mph understeer, and countersteer a full turn theres no way you aren't ripping your way out of it. what i mean to say, is this car can be really violent if you let it. and that violence can really save your ass during random wheel slip.

 

[Blendercloud]

I think Steve was speaking about understeer on dry pavement under hard cornering conditions such as autocross. I've not driven this car in inclimate weather so I can't really comment on that much.

 

[tunersteve]

I think Steve was speaking about understeer on dry pavement under hard cornering conditions such as autocross. I've not driven this car in inclimate weather so I can't really comment on that much.

Yes, I was speaking of a typical or spirited drive on dry pavement.In snowy/icy conditions, I find that the car will rotate and oversteer slightly, yet not slide past the point where a bit of opposite lock will reel it back in.

Take a 90* turn at anything over 45 and you'll plow like a toboggan with understeer.

 

[dquarasr]

I don't know what your intentions are, if you're going out there just ot have fun or if you're trying to be competitive with your car. Reason I'm asking is that certain mods (like RSB) may put you in a different prepration class, where you'll be even further from being competitive, since if you're not doing EVERYTHING the rules allow, you won't have a chance to run with the Big Dogs.

But if you're just out there enjoying the car, times be damned, then, by all means, make selective mods.

Where are you experiencing understeer? Mostly on corner exit, or on entry, too? One way to reduce understeer is to enter turns much hotter than you otherwise would and trailbrake like mad. That won't necessarily help if you're getting understeer on exit, though. Another way is to modify your line so that you're exaggerating late apex, so that you're unwinding the steering wheel as you feed throttle. Some cars tolerate lots of throttle on exit; others don't, the weight transfer taking too much weight off the front tires.

Another thing, since we can't change front camber with a stock setup, don't discount a significant amount of toe-out at the front (and zero and maybe even a touch of toe out at the rear). Front toe out helps turn-in, and rear toe at zero or even toe out promotes oversteer. Of course, this is good for autocross but destabilizes the car at higher speeds, especially high-speed braking, so do this at your discretion, or change it at the track and then change it back before you drive home.

Blendercloud, I wasn't aware of your performance driving experience, hence my comments about technique. But even so, autocross is a different enough animal as to deserve its own techniques.

Thanks for listening.

 

[dquarasr]

Postings out of order

I dunno what happened, but I posted #12 chronologically after 13 and 14, but it showed up between 11 and 13. Weird.

 

[Super Shredder]

if i was to do that i would flick the wheel out then into the turn so centrifical force would move back to the rear suspension (you sometimes see family vans do this and wonder why the hell its too avoid top heavy understeer and the ole 3 wheelie). i understand what your saying though, since i got the strut tower however, the front wheels have been pretty solid in where the car goes.

 

[Blendercloud]

I don't know what your intentions are, if you're going out there just ot have fun or if you're trying to be competitive with your car. Reason I'm asking is that certain mods (like RSB) may put you in a different prepration class, where you'll be even further from being competitive, since if you're not doing EVERYTHING the rules allow, you won't have a chance to run with the Big Dogs.

But if you're just out there enjoying the car, times be damned, then, by all means, make selective mods.

Where are you experiencing understeer? Mostly on corner exit, or on entry, too? One way to reduce understeer is to enter turns much hotter than you otherwise would and trailbrake like mad. That won't necessarily help if you're getting understeer on exit, though. Another way is to modify your line so that you're exaggerating late apex, so that you're unwinding the steering wheel as you feed throttle. Some cars tolerate lots of throttle on exit; others don't, the weight transfer taking too much weight off the front tires.

Another thing, since we can't change front camber with a stock setup, don't discount a significant amount of toe-out at the front (and zero and maybe even a touch of toe out at the rear). Front toe out helps turn-in, and rear toe at zero or even toe out promotes oversteer. Of course, this is good for autocross but destabilizes the car at higher speeds, especially high-speed braking, so do this at your discretion, or change it at the track and then change it back before you drive home.

Blendercloud, I wasn't aware of your performance driving experience, hence my comments about technique. But even so, autocross is a different enough animal as to deserve its own techniques.

Thanks for listening.

I honestly could care less about class competition at this point. I need to learn the sport and the car before I get concerned about that. I want my car to corner well for me and just having fun with driving hard and not getting tickets. The damned sea of cones really gets me now and then. With my power mods I'm sporting, I can't stay in anything close to a stock class anyway.

I'm going to be playing with the alignment once the ball joints are installed. I'll probably go with just a hair of toe out with negative camber in the front and probably neutral toe and just a hair of negative camber on the rear. Between that and dropping tire pressure I think it's going to corner much better.

As for where in the corner it understeers... It didn't matter where I entered the corner, how I entered the corner, or if I swung the ass-end around with some steering or braking, the damned car wouldn't make it through the corner under even partial throttle. Exiting was just as bad. Leaving the apex, if I was at all in the throttle I'd just merrily slide sideways.

I had one of the club veterans (who's been doing autocross for more than a decade) drive it and he crushed 8 or 9 cones in the second turn. When the round was over he got out of the car and said "please don't take offense, but that was the absolute worst understeer I've ever experienced." It leads me to believe that it's not just me who can't get the car to turn.

I think if the car was close to stock (power-wise) it might not be as much of an issue. I could always turn the DSC on next time and see how that fares. It probably wouldn't be something I'd want to use as a solution in the long-term though.

 

[tunersteve]

I think the key here is to get a solid alignment before attacking these other options. It seems that an alignment may be a good starting point in which to make your adjustments.

As for the tight turn and understeer, you can flick the wheel out and deviate, which will allow you to bring the rear around slightly more, but at a reduced speed.

After installing that RSB, the car will get around that same turn at a higher speed, and with much more confidence. It doesn't feel like the weight is trying to battle it out of the turn anymore.

 

[MX5RACER]

I have autocrossed my Speed6 and I did not experience that much understeer. On a few corners I was even getting slight oversteer. I have autocrossed alot of cars, and I would say that my Mazdaspeed 6 is not the worst understeering car I have ever driven. The biggest thing you can do to create understeer is enter a corner really hot, turn-in and then get right back on throttle. If you are not really good about getting back on throttle, you will cause the weight to transfer off the front and never let the front end bite.

 

[Blendercloud]

If anything, I'm glad this thread got folks talking about it. I think it's something we're all at least a little bit interested in. Otherwise we probably wouldn't own the MS6.

 

[tunersteve]

I did just get my Corksport rear frame brace installed last night, I'll be posting a review this afternoon once I get some things done.

 

[Neofolis]

I just spent today at the track. I didn't push things too hard with the car being my daily driver, but my main observation was the lightness of the back end under heavy braking. Obviously weight will transfer to the front under braking, but I was surprised how easily the back end would start squirming.

I found the car more prone to understeer than oversteer, but part of different peoples observations could be down to driving style. I found that no matter how hard I pushed it out of the corners the back end was composed, but I had to moderate turn in at speed to some extent to keep the front where I wanted it. Part of my high speed turn in issues is likely to be the heavy wheels I have, tighter, lower speed cornering was fine.