No, for a security convention. We had to visit one of our clients in North Las Vegas while we were here yesterday.

This day job stuff is messing up my racing schedule :)

My buddy Terry is working that show too.

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In "Track Mode" ready to rock for the Tuner Shootout this weekend!

Nice, good luck!

Hey Mike wanna buy back that Kognition wing I bought off you before? I only ask because I'm selling the car :)

Maybe...PM me a price. :)

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The 2012 Modified Tuner Shootout is in the books! I wish I could say everything went as planned, but yet again my day was plagued with incredibly sensitive "Ice Mode." Good news is, after talking with one of the guys from Whiteline, I have a new theory that I have high hopes for being the cause of this level of sensitivity. Now before I get on with this new theory, realize that I am not saying that this is the case of "ice mode" and the level of severity of my particular case the last two track days is what is in question. The past two track days I have hit ice mode in every braking zone every time. It's sensitive to the point where to avoid it, I have to be so light on the brake pedal that the engine is actually slowing the car down more than the brakes. So long story short, I now think it has to do with tire size, overall diameter to be exact. Corvettes apparently have the same problem. Went online and calculated and sure enough my front tires are over 4% smaller overall diameter than stock and my rears a little over 2%. I am going to research it more but from what I have found so far, you want to be within 3% of stock overall diameter to avoid ABS issues. Currently I am on a 275/35/18 on the front for the track. Tire size in a taller sidewall gets a little limited but Hankook does make an RS-3 tire in 265/40/18 which should be well within "spec." I will have to sacarafice a bit of width, but thats way way way better than not being able to use my brakes. So thats going to be the next test, assuming that I can get a set of 265/40/18s in time for my next event in 3 weeks. I am also going to bring stock brake pads to try out in case the tire size thing doesn't fix it.

I admittedly don't know much about how ABS systems or car electronics work so if there's anyone out there that has some insight on this tire size theory, feel free to chime in. As mentioned, my current track setup is 275/35/18 front, 285/35/18 rear.

In other news, my home-made splitter worked really really well. Even though the track Ir an today was small, very small, like didn't even get into 4th gear small, it was very noticeable that the car had a ton more front aero grip, even at those speeds making the car very loose through the higher speed stuff. I can imagine it will be much worse at a larger track. So there are now two ways to go with this. Number one is to add more aero to the rear with a big 'ol wing. That would be best case, but its expensive and I only have 3 weeks to my next event. Next solution is to make a new splitter that is shorter to reduce front aero. Going to try really hard to get a wing as that's the more beneficial situation.

The OS Giken LSD was absolutely phenomenal. Nothing much more to say about it other than that it is a tremendous advantage over the stock viscous LSD.

Fast Intentions exhaust and UpRev tune by Specialty Z worked awesome as well. Everyone loved the sound and the powerband was super smooth and responsive.

suscribed again lol. i unsuscribed after the last two times i thought you were going to get rid of the car lol.

That's a good theory Mike and considering the Vette guys have had the same issue. I assume with your theory the ABS doesn't know how to count for less rotational weight and throws it into ice mode believing it lost traction. Not sure myself. Just throwing that out there. But even so our cars shouldn't have a feature like this.

Glad the splitter worked for you. I'm adding some canards come this weekend.

OS Giken! It's the greatest. So simple.

Mike, if the issue were that tied to the tire circumference, don't you think we would have heard more about it from all the street-oriented folks that are running 20" wheels etc? Also, as you know, I ran those Firebird tracks for a couple years on all manner of tire sizes... I had the most trouble on Firebird "East" with Ice Mode - same for you? the main track was not so bad... I resolved the East track issue by turning ABS off, playing with suspension settings, tire pressures and brake compounds, until I got to a point where braking was optimal... before that with ABS off, the fronts would lock up in almost every braking zone

I don't think its tire size either. I have run several square setups with tires 2" shorter than stock up to slightly larger than stock and have had no issues with it.

Maybe its calibrations of the ABS computer and I'm just lucky mine isn't as sensitive as most?

Travis, so far I have had this hyper-sensitive ice mode issue on both Firebird West and Buttonwillow. How did you disconnect the ABS without disconnecting the VVEL? And what pad compounds did you end up with?

couldn't you just pull the ABS fuse?

Pull ABS fuse or disconnect a wheel rate sensor. Both will do it. (all the usual disclaimers for other people reading this...)

I remember running the West track a little over a year ago now... here it is in my journal http://www.the370z.com/members-370z-...tml#post444490

I did in fact have a couple major ice mode issues there now that I think back to it... coming out of the carousel approaching the turn before start/finish... car locked up a couple times... can't remember which pads I was running probably on page 40-45 somewhere, or maybe a bit later, sorry

I remember thinking this was not a temp issue, but a wheel hop and differential spin rate issue, which is driven by suspension tuning and of course overly conservative abs algorithms

some vid here as well
http://www.the370z.com/track-autocro...tml#post457275

Get hold of a spare fuse module (order from a dealer or online). Pop the cover off the fuse module and snip the fuse for the ABS. Swap modules back and forth as required.

That's what I was thinking to do for my next competition. I really really would like to try to figure this problem out, what triggers it, what helps it, etc. but I probably should wait and do that during a regular track weekend instead of a competition weekend.

Were you running the DTC pads? Which compound in the rear?

The DTC's are a little weird on the torque curve as they come up to temp, I remember having some ABS issues with them until they hit the sweet spot in certain braking zones.

In the beginning I thought tire size might be a factor, but I run the same tire size now as I did back then and have had various other combinations and nothing has really made a difference in that regard. Pad compound however has been #1 in controlling the ABS issue. Low torque, low grab but high temp is what works best.

Mike, I was talking with one of the mechanics for the SFR world challenge team and he said that Nissan was looking into an ABS solution for them and would have it ready before Long Beach.

You may want to check with them and see their approach to the problem.

I'll put money on them installing a race ready ABS system. :)

For the front aero balance issue, what Ive done in the past is put slits in the vertical plane between the horizontal plane and the actual bumper (but low enough that the slits are under the front tray panel). Then to adjust downforce, just tape off sections of the slits.

Worked pretty well for me at Road America.

This time I was on DTC-30 front and HP+ rear. I had to brake so lightly that I have completely ruled out pad compound. Theres another guy I know of running DTC-60 pads without ice mode and he is on stock wheels/tires.

Would be awesome, but I would be surprised if they made it available to the public.

Pretty good idea. Hoping I can get a wing on the car and balance it out with that, but chances are looking slim for that to happen in the coming weeks before my next competition. Might try your method or just make a new splitter that has less surface area.

HP+ is more grabby than DTC-30 at lower temperatures, that is my guess as to what was causing the problem. Get rid of the HP+ in the rear and go with something more compatible and it should be good.

This happened with DTC pads out back too, and I have run HP+ on this car before without any issues whatsoever back in 2009 when I was first tracking the car. It's hard to explain, but I can't stress enough just how little brake pressure it would take to get into Ice Mode. So little pressure was used that I don't think it could possibly be the pad compound anymore.

Now I have been asking everyone and their brother about their thoughts on this and I have a new suggested theory, and that's air in the ABS system. Anyone ever experienced this? Are there any other signs that this would be the cause of the ultra hyper sensitivity?

It certainly could cause this especially if air was in the front lines or a single rear line. It would cause a brake pressure imbalance would could cause one wheel to lock prematurely and activate the ABS.

Do you think that air could have been introduced when you had the calipers off? If the air is in the ABS system itself then you will need someone with the Nissan scan tool to put the controller into bleed mode.

Could have been when I sent the calipers off to get powdercoated. That's one of the only things that could have happened between my last track day back in 2010 where I didn't have this issue and these past two current track days.

that could be it. As for the HP+ pads. I used them on my first outing in the car at Znationals on a small track and ran them down to the backing plates in one 20 minutes session. Didn't have ice mode though.


You might want to take the car to a dealership and have them bleed the ABS pump with the consult.

Video I made of my Fast Intentions exhaust installation with a short sound clip of it at the end!

Nice

I know in working with grand am team engineers they were pretty convinced the issue is related to rears having far too much bias. They left area before I had a chance to go to smaller 350z Brembo rear caliper.

Have you kept notes on how much fuel you have and rear tire condition when you experience ice mode? I can tell you my car locks up rears more often even with 5 gallons less than full. Also suspension settings have had influence - lack of bump in dampers in front allow too much weight transfer allowing rear lockup too.

Our cars are nose heavy. Shift weight off light rears quickly and what do have? ...ice. Add poorly programmed abs ice mode and you have constant ice mode issue when you try aggressive late braking.

But it might be air in ABS system? all of us having same issue? Would like to hear more on this theory.

niceee man! I saw Sebs car from s7 on the back lift. I love your Z man, Its inspiring to see your progress~

Jason

Mike what are your plans for your Z? Such as how far of direaction are you going to take it track wise?

I am suggesting some sort of unique problem like air in the ABS system for my car specificially. I know all Zs get ice mode, but its the hyper-sensitivity of my ABS system specifically that has me guessing. When I first bought this car back in '09 I built it up for the track and got through probably ~12 track weekends without hitting ice mode at all with a few different pad compounds and virtually same mods. Again I want to stress that my problem specifically is not ice mode itself but that my car is much much much more sensitive to ice mode now than it was in the past.

Thanks!

Well first and foremost this Z is my only car so it has to remain a daily driver for the forseeable future. As far as track prep goes, I am focusing on reliability first getting rid of or reducing fuel starvation/ice mode/oil temps/coolant temps/etc. as much as possible. I am not really building the car for anything specific track-wise, just basically something that I can have on hand to use as a tool for seat time and take to some fun events like a time attack or something like that. I can't cage it since its my daily so, although the car is way under-built for the current rulebook, I am trying to keep it within the rules of the Global Time Attack Street Class. Any wheel to wheel racing is going to require a cage, but one day if I can get to a point where this car can be a full track car and I have truck/trailer then I would LOVE to build it to the MotoIQ Pacific Tuner Car Championships Tuner Over class rules and go wheel to wheel sprint racing with it.

Made a short dyno video from my exhaust install!

Just posted up another blog entry on my website about the Modified Tuner Shootout!

Mike Bonanni | Official Website | Living the Dream...

So I took my 370Z to a buddy who is a Nissan master tech at one of the dealerships here in Vegas. I had him investigate all he could as to what could be causing my super sensitive ABS Ice Mode issues and the diagnosis came back almost embarrassingly simple. Wheel speed sensors were good, ABS system did not need to be bled. The codes that were causing my VDC/Slip/E-Brake lights to stay on constantly were due to low brake fluid. This low brake fluid warning would cause the computer to instantly go into safety/ice mode under moderate braking. Topped off the fluid and what do you know, the lights on the dash went away. Fluid level was surprisingly, still above the minimum fill line, but maybe too much sloshing around under track conditions caused the issue. Not 100% sure this will fix my problem, but we'll find out on the 27th when I go back to the track. I don't think it will eliminate ice mode, but I am hoping that it decreases the sensitivity in which it kicks in. I will refrain from posting anything in the ice mode specific threads until I have some feedback.

Ah! I had a similar issue last summer. It seems that in Nissan max really means min on that brake reservoir.

Yep I found the same thing, Max is really Min. All it did to me however was disable VDC and VLSD, ABS was still functional I believe. Hope it helps the ice-mode but I wouldn't get your hopes too high yet.

Went to the track yesterday. Topped off fluid helped with the sensitivity of ice mode, but I have yet another new theory that I feel fairly strongly about.

So I talked a little to one of the World Challenge teams running a 370Z and they are also having major ice mode issues. The one thing that stood out in my conversation with them was that their data showed that ice mode would kick in right around 1g of braking. Which of course sucks if you're a World Challenge car on slicks that are more than capable of 1g of braking. They said at their next race, they were going to try out a new brake kit as well as try disconnecting the yaw sensor to see if the car can run without it hooked up and if it helps the problem at all. They have been trying to talk with Nissan, but they have reportedly not been helpful.

So having this new bit of information in my head when I went to the track yesterday I started seeing if that theory held water. Sure enough, it seems that not only does it seem very plausible that ice mode is triggered when the yaw sensor sees more than 1g braking, but maybe more than 1g period. With the hyper sensitivity issue gone I was back to regular old ice mode. In straight line braking I could gradually ease into the brakes without issue, but then they would hit a certain point and kick in ice mode (probably hitting 1g). Now at another part of the track, a very high speed right hander that decreases in radius, is where I had the most issues with ice mode or ABS kicking in. Through previous knowledge with a race team I used to drive for I know that the Hankook RS-3 tires are capable of producing a sustained 1.4gs pretty easily. Although I don't have data, I am going to safely assume that in this high speed decreasing radius turn, I was above 1g of sustained lateral gs. Because it is a decreasing radius, there is a point in the turn where in my 370Z I have to brush the brakes just slightly to adjust my speed as the turn pinches down. Every single time I did this, with just barely any pedal pressure, ABS would kick in. I wouldn't say it was the same exact thing as ice mode as I wasn't on the brakes hard enough to really tell, but even touching the pedal the ABS would start grabbing at different wheels. It even pulled me off track once (video coming soon) because I am on the very outside edge of the track at this point in the turn and ABS decided it needed to grab hard on the left front and pulled the left side tires of the car off the track. Anyway, so g-forces seem to me to be the common factor in every situation where I was having ABS issues. How we fix this, I have no idea, but hopefully disconnecting the yaw sensor works, but something tells me it wont be that simple.

As for me, pending the results of the World Challenge team's findings with the yaw sensor, I may try that next. If that doesn't work, I am just going to give up and work on a brake pad combo that allows me to run without any ABS. Sick of dealing with it.

Crazy. I'm not sure why myself and my buddy who also tracks can't or haven't had Ice Mode to happen.

So are you just going to pull the ABS fuse? That's all to it? I'd like to learn some skills without ABS.

Do you have data on your car?

Unfortunately its not as simple as just pulling the ABS fuse. First, the ABS fuse is part of a block which is also tied into VVEL. You can cut the ABS fuse prongs off of that block I think to disable just ABS though, or maybe switch from a block to separate fuses? I am not 100% sure. The main problem that I have read is that since the 370Z ABS is electronically bias controlled, when you pull the fuse, the brake bias defaults to 50/50 which results in WAY too much rear brake. Hopefully its something that can be offset by running a really really mid pad, maybe even stock pad, in the rear. I haven't looked too deep into those who have run without ABS and what their setups were etc. I don't actually recall anyone who ran without ABS on the stock Akebonos. I think travisjb did, and I think AE Performance did, but they were both on AP Racing BBKs.