In-Car at Willow Springs + Off-track dirt action...Thanks Ice Mode...
 

So here's the short version of the story behind this video. It's nearly 8 months old and I never intended to do anything with it, but the other day I decided I wanted to start teaching myself the basics of video editing so I pulled this footage up and the end result is this video.

This is video from the last time I will ever track my 370Z...at least until I can get another daily driver and turn the Z into a dedicated track car. Why? This was the single most frustrating day I have ever had at a race track. After battling with the lovely ice mode issues most of us are plagued with, I went to this event with the primary goal of testing the last few ideas I had to combat the issue. None of them even remotely worked which left me with zero confidence in the brakes. Determined to salvage the day I just tried to push on and log seat time even though I was losing seconds a lap braking super early with less pedal pressure than I use during normal street driving. Late in the day I decided to start trying to carry a tad more speed and that's when the ABS bit me in the *** and tried to straighten the car out while the track was turning. The ABS and I had a small fight and the ABS ended up winning and the left side tires got in the dirt between turns 8 and 9 and there was no saving it from there. Fortunately it ended up being an uneventful off-track excursion as it could have been MUCH worse at this area of the track.

Although I wasn't happy with the car or the lap time, I still ended up getting 2nd in TT-S so I guess I can't be that bummed.

Nice job. I like the fist shaking at the end. Did you try editing the video with the cockpit view in the lower right corner? I kept wanting to "look ahead" at the track but couldn't. I'm not even sure that would work.

What program did you use for the editing?

No I was just happy enough to figure out how to do the PIP thing I didn't mess around with it haha. Using a free trial of Adobe Premiere Pro CS6.

I really like it. You did a great job figuring it out. I also like the "info screens" or whatever they're called. I'll have to look into Adobe Premiere. Right now I use iMovie and don't have a clue what I'm doing with it. lol

Thanks!

Have you just turned off ABS? I think if you do you might find what is causing your tires to want to lockup in the first place. It might be a suspension or brake setup issue. Many don't have the issue so there has to be a fix.

Cool Video Buddy! I really enjoyed the in cockpit view~

Here is my video of me running 2:01.7 at Button~ Hope you like~

https://vimeo.com/58081295

I haven't personally tried disconnecting ABS as I have been told that because the car has electronic brake distribution when you disable ABS it defaults to 50/50 brake bias mechanically which would be way too much rear brake which means it would be super easy to lock up the rears and spin.

From talking with countless people, professional race teams, etc. I am subscribing to the theory that the ABS computer has parameters set for wheel speed, steering angle, g-forces, brake pressure, etc. If you exceed the parameters through a number of possible situations like too much brake pressure + too much steering angle then the ABS computer triggers ice mode as a safety measure to prevent a spin. I think the settings for the parameters are way too low for driving this car on the track. Plus I think modifying your car only makes it more likely to happen. Adding things like a limited slip differential will change the wheel speed in the rear compared to the stock VLSD. Adding things like suspension and sticky tires will mean you are capable of more lateral and braking gs. In my particular case in the video where I had the off, the mph is high, the car is turning so there is steering angle, and that combined with g-forces above what you would see on the street meant that I was probably already violating the computers parameters so as soon as I even breathed on the brakes the ABS tried to straighten the car out and because I was already at the edge of the track it was enough to put my left side tires in the dirt.

Trust me, I have been battling with the ABS ice mode situation for a long time. I've had the ABS system bled, made sure my fluid was filled all the way, tried multiple brake pad compounds and combinations, etc. As my car and my driving got faster the problem got worse which is why my 370Z is retired from the track until such time as I can make it a dedicated track car and go with an aftermarket dual master setup bypassing the ABS all together.

every car ever gets squirley there.. track falls away slightly.. usually windy and dusty..

plus most of us have a tendency to make the car squirley.. coming in with tons of speed.. real hard to see the edge of the track.. focusing on setting up for exit of 9..

i have yet to drive a car whos back end doesnt dance when braking late going into 9.

thats a lot of steering angle to be braking like that no?

braking needs to be done WAY earlier as you straighten out before turning in...


...in my opinion.. and what do i know.

how does ABS try to 'straighten the car out'?

I wasn't going quick enough to do any serious braking. I just needed a tiny speed adjustment with a slight slight brush on the brakes but as soon as I touched the pedal ABS kicked in.

It engaged the left front brake for a quick second. Nose dove down, rear unloaded, car got loose left side tires went off the track.

Ummm wouldn't ABS provide LESS bite up front than no ABS at all?

ABS pulsates the brakes providing less stopping power and no lock up, no?

ANY braking there will lighten the rear end and cause it to step out. Thus the whole "brake in a straight line" theory.

And it only applied to the left caliper?

It was more braking than I wanted. It was probably both fronts but the left front was loaded so I felt it much more on the left front. Bear in mind we are talking about super super super light pedal pressure here, not even close to threshold, I just needed to slow down a few mph. The amount of pressure applied by the ABS was more than I wanted and more than the car wanted obviously. I hope this doesn't come out sounding like a ****, this wasn't my first track day and certainly not my first time at this track. I am aware of the principles of braking.

trust me, i've seen plenty of guys who have plenty of track days screw up 9.. i've screwed up 9 in one way or another every time i've been there.

so you're saying that you barely touched the pedal and the car just applied tons of brake by itself? is that common?

most people complain about their car's mythical 'ice mode' as being "i broke normally and the abs kicked in thinking the wheels were locking up when they weren't".. thus the term 'ice mode'.. supposedly the car thinks the fronts are easily locking up (like you were on ice) and ABS kicks in, pulsing like crazy preventing you from stopping in a timely fashion... which in theory would help if you were on ice, but since you're not, it just extends your braking distance... ie. less actual braking.

Hey Ryan, I actually had this happen at buttonwillow, I had dead tires and dead pads about 3mm left on front pads, the abs or something would make one caliper brake up front!! Scary shhiet!! With full pads, rotors etc never happens!

you broke and it pulled one way? that sucks.. maybe just one side's pads over heated since there was so little compound left?

did it boost the braking pressure to that one side?

From what I understand about the 370Z ABS/EBD system "ice mode" is a safety feature that monitors the yaw sensor, wheel speed sensors, vehicle speed, brake pressure, steering angle, etc. to determine if the car is in a "safe" situation to apply the brakes. If it thinks it is not in a "safe" situation to apply the brakes, the moment you try to the ABS/EBD takes over and sends brake pressure to whatever corners needed to keep the car under control. With track driving, particularly at that spot on WSIR in a modified 370Z I am guessing that the combination of the mph, g-forces, wheel speed, steering angle, etc. exceeded what the ABS/EBD considered "safe" to apply the brakes which would probably be true if I were in a bone stock 370Z with stock tires. So as soon as the brakes were activated the ABS/EBD took over and sent brake pressure to where it saw fit. Threshold braking is the most common scenario when people experience it for sure but I don't think it HAS to be threshold braking in a straight line, I think its just simply any scenario where the data coming in from all of the sensors exceeds what the ABS computer thinks is a safe situation to apply brakes. Because the car has EBD and can distribute the brake pressure differently to each corner how it reacts depends on the situation its in.

You can try racerender for merging two videos together, I believe the basic version is free.

I think most of us who have pushed these cars hard on track have experienced this issue. It's scary as hell. Especially those of us who threshold brake and trail brake.

Honestly I haven't experienced ice mode since putting large vacuum reservoir on stock braking system. I do think part of issue is vacuum related.

As far as bias when you disconnect abs. While yes bias goes to rear you can tune suspensions and brakes to work without car spinning. And it does take some modification of braking style.

I will be interested in what you do. I know race car up in Nor cal switched to expensive motorsports abs system. What are you thinking? I have heard that there might be ability to tune this out of stock system but no one is willing to take liability of doing this on stock system.

I think it's absolutely criminal that Nissan doesn't warn people about likelihood of this ice mode occurring in motorsports and prohibit track driving of these cars as part of warning to less experienced drivers. You and I and other experienced drivers have managed not to wad up car when this ice mode happens but how about less experienced driver who target fixates and doesn't know how to slow car down without brakes? I'm still convinced the car that magazine testers put into the wall when car was released experienced ice mode and not brake fade.

I'm also curious have you checked rear calipers and are they ok? No leaks etc. I had a stock caliper go bad which I think was contributing to ice mode issue as well.

What you guys experience is absolute nothing new...even the Porsche 997 street cars experienced this in Conti series...as well as mustangs...camaros and even the BMWs so it isn't just a Nissan thing.
Almost all the cars is ST run the Tevus system (allowed to or not) and
every car in GS is now allowed a Bosch Motorsports or Tevis abs system.
When ran the ST 128 BMW after 2 events on the OEM stock pump ...it was toast and only got worse.
Basically I think ice mode burns up the pump and once you start having "ice mode" it will just keep getting worse or more often.
The man to talk to is Kurt Jung..is an electronic guru espc. on ABS systems.
He is also the main dealer Motorsports for the Tevus system.
The Bosch system is pretty advanced 10 preprogrammed maps and 2 specific maps based on inputs for specific car measurements....front and rear track, vehicle weight, wheelbase, and front and rear tire circ.
Both systems are expensive ...but so is crash damage.

They don't quite experience ice mode like we do in 370z. I have been long time Porsche guy and ice mode in Porsches , Mazdas and BMWs isn't nearly as scary as 370z ice mode. Hell my Boxster was raced over and over and never had this issue. My track going MX5 didn't have this issue either? So it's downright inaccurate to say many other street cars have this issue and that the issue is the same. The ice mode in 370 let's off brake pressure far too much at all corners at once and doesnt regain pressure quickly enough. While some other systems may experience minor ice mode issues they aren't the same as what we experience.

And no it's not new it's been issue since our car was released without much done to fix issue other than to put $10k race abs system on car or turn off abs.

Most of cars running grand am run expensive systems due to tuning available. If you are in series to win using stock abs isn't going to cut it typically.

Honestly for me, this is my daily driver right now so I will likely just keep it off the track all together. Down the road if I am able to turn it into a dedicated track car then I would probably go with an aftermarket dual clutch setup with bias adjustment and bypass the ABS all together unless someone comes out with a programming fix.

I had my calipers re-built completely and have checked them periodically and still have the issue so I don't think that's the problem. I think what Downshift said about the pump burning up might be the key to why mine just keeps getting worse.

So wonder why mine was getting worse and worse and then when I put vacuum reservoir on circuit it stopped all together? Haven't had a single instance of ice mode since making that mod? That's only change I made to car as well. Same tracks, same tires, same pads. No ice. We use similar fix in Porsche world with fairly good success, but again ice mode in Porsche world isn't like ice mode we experience. At least with Porsches ice mode doesn't occur until you truly are at threshold and tires would be locked up and their system recovers more quickly than the system on370z. My experience with ice in 370 z prior to vaccum upgrade has been from initial application with car headed straight and I have had enough room to reapply and still nothing at all. Literally forces me to pitch car sideways to slow myself down.

I'm sure a burned out pump in some cars contributes to malfunctioning abs but I'm not sure that's our issue.

Also it's tough to compare a time trial car that takes limited stints on track to professionally driven endurance race cars on race slicks as well. That's a whole different world of stress on braking systems. Hell even racing systems fry in those environments.

Just wonder if spec 350z guys are running off tracks all the time like few stock abs system 370z track cars are. I know 350z had mild ice brake issue so does GTr but nothing like 370z.

Didn't say that was THE issue...I was saying that I belive..continued "ice mode" will burn up the pump...for sure a burnt up pump or failing pump will lead to ice mode more frequently
Which is exactly what I think is the main issue /cause stated waaaaaaay back when. The loss of vacuum or loss of proper built up supply to properly operate modern ABS systems....especially with complex intake / camshaft timing systems.
Again...not saying this is it...just my two cents.

What 'pump' are you guys talking about?

Shamu, can you post photos/info about your vacuum reservoir?

I second this ^ would like more info ok Shamus fix

ABS block/pump
Vacuum assist brakes need vacuum operate the ABS... If there is not an ample amount of vacuum to supply the system to operate... You will not be able to compress the pistons of the brake calipers.. Giving the driver a super hard pedal.
To me... That's why I don't recommend super double throw down brake pads for tracking. Hugher clamping force will trigger ABS to cycle /use more vacuum...big slow hard hits in the pedal. Then there isn't enough time to build up the supply for the next corner... and it starts all over again.
The OEM ABS computer is not programmed for high sampling rates and cannot keep up with the short supply. A Motorsport ABS pump and computer has much faster sampling and cyles...and the pules felt in the pedal are much softer shorter and faster.... More efficient use of the vacuum supply.
The use of a vacuum accumulator or reservoir can help because it allows vacuum to build up giving the ABS a larger supply to feed from.
That's my version.
;)

what size wheels and tires are you using on your z? i'm new to the z world and wanna start doing some track days and also wanna get some nice looking wheel that i can use both on street and track.

18 x 9.5" front with 275/35/18
18 x 10" rear with 285/35/18

There are a lot of great double duty street/track tires out there right now, most are around the 140-220 UTQG (treadwear) rating. The Hankook R-S3 is my personal favorite as its the grippiest on the track and also quite affordable in comparison to other tires in its class.

awesome, i may just put some real good tires on my stock wheels. and just use them for track days then. thank you. btw i love the video.

You might not have experienced it, but the old 350 had it and the C5 and C6 had it. My RX-8 also had it, but never as bad as the 370.

I've heard too many people say "ice mode" kicked in when they screw up.

So that's what we are talking about right? the example of where the ABS kicks in when not needed and basically any real braking goes away is "ice mode"? And mikes example of tapping the brake and it kicks in super hard is something different?

All cars have brake issues and "ice mode" seems to be a BS catch all. I think it needs to be better defined in order to help everyone.

If it can't be precisely defined, there needs to be more discussion about brakes in general than just blaming the car.

"Trail braking" and suspension dynamics can cause the rear to step out... and are the usual culprits.

After that, you can look at the cars. Bias, fade, computers, ABS blocks, vacuum, lines, etc were all designed for the cars on the street, and work arounds and/or driving changes need to be accepted if you're going to track the car.

It's not really Nissans fault if a street car spins on track. It's the drivers.

....in my opinion.

Now that's a good post.

This. Ice mode is just a descriptor for the most common occurrence but it doesn't always feel like ice. The problem is the ABS engaging in general so maybe we call it "safe mode." All cars have certain parameters that have to be met to engage ABS, the 370Zs just seems to be much more intrusive for track driving than other cars.

SO just ask yourself this question. Are you WOT down long straight and going immediately to brakes with no coasting? In other words depleting vacuum all way down straight with WOT and then not building vacuum with long enough deacceleration?

I wish more people would just put big vacuum can on their 370Z brake circuit. With that mod and understanding that our issues are primarily vacuum deprivation you can pretty much get around 99% of ice mode our cars expereince. To date Im close to a year of no Ice mode after being plagued by ice so badly that I disconnected abs for a nearly an entire season while I worked on solutions.

Can you just post a photo of your configuration already? lol I believe you, show me how you handled it so I can copy! hahahah

My 350 wasnt nearly as bad.

The hard pedal and no brake pressure are classic symptom of low vacuum and ice mode.

Its a design flaw by Nissan and I completely reject that "all cars have braking issues" There are many car when you put good fluid and set of track pads will work just fine in track day enviroment. It is Nissans fault for developing a car they say is track ready with braking system that has real issues.

Also I had a rear caliper with less than 8000 miles break on track that did cause me to spin. I controlled car and stayed on track but my expereince with 370Z's brakes has been less than positive.

Heck my old 70's era Porsche/VW 914 had better more reliable brakes than 370Z!

Something like this? You just put it in series with the factory hose from the manifold to the booster?

Summit Racing® Vacuum Reservoirs SUM-G1464 - SummitRacing.com

That is it.