Mazda/Mazdaspeed 6 Autocross Thread

Forzda, if you could, take a look at my post in the autoX thread. I made a few comments about the AWD system as a whole being a limiting factor in the dynamics of the car. I think at this point we may have a 'next step' in progress of tuning this car.
 
Is that the ocean in the background of your first pic? That's a hell of a place to autocross if so!
 
You had all the electronic nannies off right?

And yes that link is my favorite and I re-read it regularly to get the crap people spew on forums out of my head... ew.

So first things first:
-nannies off
-start with matched tire pressure, chalk or grease marker your tires on your runs and add more to fight rollover on sidewall- I found matched worked pretty well but I was on stock tires so it was futile, though a s***-ton of fun
-EMPTY the car, all mats and such, spare tire etc
-Always do the shortest distance line and edit your throttle input to stay on that, it may feel slow but you'll be surprised
-pick a run in the middle of your runs and make yourself a little uncomfortable, you may learn something- my car was narrow enough to go balls to the wall through a section and the brakes good enough for me to jab em and turn at a right left right lane change style obstacle and
-get CLOSE to the cones, while working the course after my heat the guy who was behind me at my station applauded me for using every inch of the track, he has a mini cooper S that ran a second behind the event-winning Z06
-slalom: remember when changing directions in a slalom, if you went around the left of a cone 50% of the right turn is just un-turning from the previous one- so turn earlier than you thought

Pits: when your run is over, use the brakes as little as possible, windows down, heat on high, engine running, and pop the hood, then turn the engine off after a minute or so but turn key back to on position to keep fans going until heat in heater core is dissipated (cools oil, cools coolant faster)
-while car is cooling, check tires for sidewall rollover and increase pressure and remark tires!

Get a nice 4 wheel alignment from a shop that's performance based and they'll ask you what you do with the car and guide you to some settings that'll loosen up the rear without a sway bar. I definitely got the rear out a bit with some high speed jabs to the brakes while turning- abs helps you from crapping pants in those situations.
 
tunersteve said:
Forzda, if you could, take a look at my post in the autoX thread. I made a few comments about the AWD system as a whole being a limiting factor in the dynamics of the car. I think at this point we may have a 'next step' in progress of tuning this car.
Click to expand...

Yeah, but there's not much you can do with the AWD design, other than apply the full duty cycle(full time VDC) to the pilot clutch solenoid in the rear coupling. Easily done with a simple switch, but you would have to measure the OEM signal with an O'scope to determine the actual DC voltage applied. The AWD module pulses the VDC (duty cycle) of the solenoid to prevent overheating of the solenoid and to allow variable control of the rear torque application. The duty cycle goes up with the speed/steering/rpm, etc.
 
Yes, the DSC was off for all my runs. To prevent coking on the turbo, I advise MS6 users to leave their car running for 5 or so minutes after a run.

In my case, runs were only about 8 minutes apart so I just left the car on. I didn't notice any powerloss due to heatsoak of the intercooler. I had plenty of extra power through all runs.
 
I would be leary about putting more than 50% power to the rear differential. The difference of pulling weight and pushing weight are drastically different. Not to mention, the rear driveline components are designed with the mindset that the front portion of driveline is going to begin the motion forward. I don't think the MS6 rear drivetrain can handle the forces initiating that motion in the long-run.
 
Blendercloud said:
I would be leary about putting more than 50% power to the rear differential. The difference of pulling weight and pushing weight are drastically different. Not to mention, the rear driveline components are designed with the mindset that the front portion of driveline is going to begin the motion forward. I don't think the MS6 rear drivetrain can handle the forces initiating that motion in the long-run.
Click to expand...

Well, theoretically you can only apply 50% of the power to the rear even if it is locked 100% to the driveshaft. The front wheels are driven the same as a FWD car and can't be "disconnected". The car will ALWAYS be FWD with assist from the rear. We could make the F/R split from variable into FULL-TIME 50/50 on our command with a switch. Under "spirited" driving conditions, it essentially is already though, so I don't anticipate any significant difference in handling. It is POSSIBLE though. Who's gonna try it first? I'll draw up the schematic if you or Tunersteve want to try it....
 
It might be handy in the snow and slush, but I dont think for my situation full-time AWD would be suitable. I am interested in exactly how it would be done though.
 
I definitely don't want full time AWD, the mileage would suffer. I would, however, like the options to make the factory setup a bit more aggressive. I think some minor tweaks to the timing of the pulses and such would be a suitable setup for our cars.

What would really be a clever setup would be selectable modes by the user (not the ECU) for traction. I know the car has a snow setting, but via the AP or some other device, be able to adjust torque splitting at the users request. Maybe the creation of a sport mode with an AP map.

Also, im moving some of these posts to the autocross section, to keep this thread more on topic.
 
brandini said:
Forzda did you come to the VA Beach show at Hall Mazda? Man you missed out.
Click to expand...

Yep, I was there with my Miata over by the MiataNuts tents. It was the maroon (Garnet Red) Miata with the Jackson Racing supercharger. Next time I'll bring out the Speed6
 
brandini said:
O YEA!!! I love your Miata! But the green one next to you edged you out. See if you can spread the word about the Dragon trip to the Miata Nuts!: http://www.mazdas247.com/forum/showpost.php?p=4713129&postcount=2
Click to expand...

Yeah, we (the 'Nuts) went to the Dragon the past few years, but not this year. The last weekend in July is "Miatas at the Gap" so we're well aware. I've driven the dragon (about 8 miles worth) at about 9/10s in my Miata. Such a wild run that I was sweaty and a bit nauseated when I got out of the car down at the store!
 
FORZDA 1 said:
Well, theoretically you can only apply 50% of the power to the rear even if it is locked 100% to the driveshaft. The front wheels are driven the same as a FWD car and can't be "disconnected". The car will ALWAYS be FWD with assist from the rear. We could make the F/R split from variable into FULL-TIME 50/50 on our command with a switch. Under "spirited" driving conditions, it essentially is already though, so I don't anticipate any significant difference in handling. It is POSSIBLE though. Who's gonna try it first? I'll draw up the schematic if you or Tunersteve want to try it....
Click to expand...

Actually, if you lock the center diff, you will get way more than 50% of the torque on the rear wheels. It becomes pure physics at that point and the physics dictate that the weight will transfer to the rear tires under hard acceleration.
 
Blendercloud, have you tried pulling the DSC fuse? Apparently that's the only possible way to completely disable traction control.
 
Rix6 said:
Actually, if you lock the center diff, you will get way more than 50% of the torque on the rear wheels. It becomes pure physics at that point and the physics dictate that the weight will transfer to the rear tires under hard acceleration.
Click to expand...


Wow, I've been in a serious debate about this in another forum, but suffice to say that unless there is front wheel spin, the torque applied F/R is essentially equal.

Oh, and note the Speed6 doesn't have a center differential, only a mechanical slipper-clutch very similar to a wet motorcycle clutch.
 
Here's a link to what I was proposing the other day:

http://www.hpamotorsports.com/haldex.htm

Similar design but for our cars. Not cheap, but it might offer a solution for us.

I posted in the Cobb forum, and, as I thought, the AWD system is controlled by another portion of the vehicle, which the AP cannot control.
 
MShreve said:
Blendercloud, have you tried pulling the DSC fuse? Apparently that's the only possible way to completely disable traction control.
Click to expand...


Not sure what you mean by "disable". The traction control works through reducing engine power by closing the FBW throttle plate. By definition, the TC is disabled when DSC is OFF. The AWD control module is the only "controller" for the rear coupling unit and it functions the same way regardless of DSC on or off. You can "disable" the rear drive simply by grounding the E-Brake switch wire... This will turn on the E-Brake light though. Note I have a written a how-to on another forum to add in a switch to disable the rear drive on demand without turning on the E-Brake light. Don't ask me to explain why anyone would want to, but they do...
 
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