M.Bonanni Project 370Z V3.0 | Clean Slate

ChrisSlicks

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.

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Shamu

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.

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Grant

Mike

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.

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M.Bonanni

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

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SPOHN

Nice

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SPOHN

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

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M.Bonanni

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.

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M.Bonanni

Made a short dyno video from my exhaust install!

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M.Bonanni

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

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

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M.Bonanni

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.

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sig11

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

ChrisSlicks

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.

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M.Bonanni

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.

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SPOHN

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.

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M.Bonanni

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.

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