TravisJB Track Video

travisjb

This thread is to log my track events and any video and commentary. Of course, feel free to jump in and comment and ask questions. Constructive criticism welcomed too! For mods and upgrade discussion, please visit my journal.

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2009 370Z #104
*For Sale*

travisjb

Location/Event: 13-June @ Firebird International Raceway - East Track... NASA AZ event... ~85F... HPDE4 run group
Mods: Stillen (G3 Intake/Headers/HFCs/Cat-back/UD Pulley/Sway Bars), BC Racing ER Series Coilovers, JWT Flywheel and Clutch
Wheels & Tires: Stock/Street
Sponsors: Redline Motorsports, Forged Performance, Doubledown Motorsports

Had 3 very enjoyable track sessions today! FIR East is a short twisty track, with plenty of run-off room, so it is great to run while tuning and getting used to a car. Of which, you may notice a couple missed shifts etc, so let's just keep that to yourself huh ?! Fast lap of the day was 1:06.4, which I am very happy with. A 911 GT3RS ran ~0:59, which was the fastest car at the track today. Fastest car in the race group I will eventually run with (NASA PTA) was 1:02. Overall, I think with weight reduction, sticky tires, and some tweaks to improve braking, I should be competitive at this track. NOTE: my camera is currently in a less than ideal location, so you may be a little disappointed with the video. Will be fixed by next track day. If you want to skip to my fastest lap, go to video 2 and find lap #4. AND TURN YOUR SOUND UP!!!!

In reverse order, here is my 3rd and final session:


2nd session:



1st session:



IMPRESSIONS AND NEXT STEPS:

• Oil cooling... this continues to be a problem, even with the single core Stillen setup... good news is I never went into limp mode... bad news is I routinely hit 280 and peaked near 290 in a later session... really looking forward to my dual core setup, which is coming soon !!
• Suspension... coilovers are performing well... and the car is cornering very flat... I played with the rebound settings a bit but didn't put effort into tuning today... next time out will be corner balanced and perfectly set up and that'll be the time to try and dial in the settings
• Power... for this short track, I had ALL THE POWER I NEEDED... when I timed it right, had no trouble keeping up with newer M3s and various race cars... I'm going to address the power/weight issue through further weight savings and will prob stop investing in +HPs... I think with 200 lbs off, I could have saved 1.0-1.5 seconds
• Brakes... continue to be an issue... I'm confident that with ideal braking I could have dropped 1.0-2.0 seconds
• Tires... remarkably good and controllable for stock tires... these are fun to drive... I'm sure I don't have too much left though ! ... move to sticky tires should buy me 2.0 seconds at this track
• Carbonetic diff... very pleased with this! I'm still new to mech diffs and trying to learn how to use it well, but when I played around with my corner exit speed, I found I was able to pretty much floor it coming out of turns and at worst I had very controllable oversteer, at best it sailed out of the corners!
• JWT clutch/flywheel... this is a no-brainer... if you have the $, do it... makes driving much more smooth!
• Summary... feeling pretty good about the car... I think with just a little more work, I may be able to turn a 1:02 or better at this track

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2009 370Z #104
*For Sale*

RCZ

too long ten min max

nogoodname

import111

Your driving looks very smooth. I can't wait to do the east track. So far at Firebird I have only done main. The corner that you enter at about 24 seconds into every lap, you slow down to around 46mph and leave it in 3rd gear...Did you try dropping to 2nd gear at all to see if you got a better corner exit? In that situation the result can go both ways, just something to consider trying.

Redlinewins

Good runs, call me Monday...we need to talk.

Robert

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www.redlinewins.com

travisjb

NOTE: ADDED FINAL VIDEO AND SOME THOUGHTS ON SETUP ABOVE

You're right I could drop it into 2nd there... I always used to in my Porsche, but this car has a tendency to overheat... I'd be dropping into about 6000rpm at that speed, in 2nd for a very short time and shifting to 3rd at an inopportune moment (up against rumble strips middle of chicane)... that plus I feel pretty good about the power I was getting out of 3rd relative to the grip I had... maybe with sticky tires... appreciate you taking the time to watch and make an observation !

Sure thing Robert.. nice job setting up the car!

__________________
2009 370Z #104
*For Sale*

RCZ

• Quote:

  Oil cooling... this continues to be a problem, even with the single core Stillen setup... good news is I never went into limp mode... bad news is I routinely hit 280 and peaked near 290 in a later session... really looking forward to my dual core setup, which is coming soon !!

I had a similar experience...although I dont remember any 290's. More like 260-270. Lots of WOT at that track though..

• Quote:

  Suspension... coilovers are performing well... and the car is cornering very flat... I played with the rebound settings a bit but didn't put effort into tuning today... next time out will be corner balanced and perfectly set up and that'll be the time to try and dial in the settings

Good to hear the BC's are doing their job well!

• Quote:

  Power... for this short track, I had ALL THE POWER I NEEDED... when I timed it right, had no trouble keeping up with newer M3s and various race cars... I'm going to address the power/weight issue through further weight savings and will prob stop investing in +HPs... I think with 200 lbs off, I could have saved 1.0-1.5 seconds

Same experience here. Most cars couldnt pass me outright on the straights, it was the corners that were the issue haha. I kinda want to start taking some weight off myself... Will focus on that once my suspension is done. How did your alignment settings behave? What were they? What would you do differently?

• Quote:

  Brakes... continue to be an issue... I'm confident that with ideal braking I could have dropped 1.0-2.0 seconds

+1

• Quote:

  Tires... remarkably good and controllable for stock tires... these are fun to drive... I'm sure I don't have too much left though ! ... move to sticky tires should buy me 2.0 seconds at this track

+1 But my car isnt ready for racing compounds yet. Nor are my skills

• Quote:

  Carbonetic diff... very pleased with this! I'm still new to mech diffs and trying to learn how to use it well, but when I played around with my corner exit speed, I found I was able to pretty much floor it coming out of turns and at worst I had very controllable oversteer, at best it sailed out of the corners!

Good to know.. will think about this one in the future.

• Quote:

  JWT clutch/flywheel... this is a no-brainer... if you have the $, do it... makes driving much more smooth!

This is my next mod after suspension

• Quote:

  Summary... feeling pretty good about the car... I think with just a little more work, I may be able to turn a 1:02 or better at this track

+1 on feeling good about the car. Mine gets more solid and confidence inspiring with every mod I do to the suspension.

ChrisSlicks

If you're going to do anything to this car, do the suspension work first as it will be the most rewarding.

I'm fighting with the brakes at every event to try and get them to work correctly. I'm convinced the problem is electronic at this point, their fancy electronic brake force distribution software isn't working for crap. At the next auto-cross event I will be pulling the ABS fuse (a challenge in itself!) to confirm my theory.

travisjb

RCZ, thanks for the comments... does this mean your supercharging ambitions are on hold? Mine are, at least until I figure out which TA and race classes I will run with... don't want to put myself in 'unlimited' categories everywhere and not be competitive (with 650hp vipers, purpose built race cars, etc)

Chris, I'm really interested in what you find out on the brakes... Figure it out and you've got some +reps coming your way !!! Perhaps you could test combination of ducting and ABS bypass both?? I think the lack of air is a serious issue as well

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2009 370Z #104
*For Sale*

ChrisSlicks

What I have learned so far is that the problem manifests itself once heat soak reaches a certain part of the brake/wheel assembly. With appropriate pads you can drive like a maniac, heat the rotors to insane temperatures and everything will work fine. Let the car sit, and the heat soaks into other parts, calipers, wheel hub, sensors etc, then things go wrong.

On Saturday I had the liberty of spreading out some auto-cross runs over a period of time. After the first run on our long 110 second course the brakes worked fine and I let the car sit and cool down for a good 20 minutes on a nice 70 degree day. At the end of that first run oil temperature exceeded 260F, and brake temperature was probably a reasonable 500-600F, calipers were cool to the touch. After that 20 minutes, the brakes rotors had cooled to below 200F (I could touch them but not hold my hand on it) and the calipers now felt quite warm to the touch (approx 120F). On the very next run after that 20 minute cool down the brakes malfunctioned on the second application of the brake pedal which was approximately 30 seconds into the run. It's hard to hear what is going on over the engine, but you can hear the ABS actuator pulsing the front brakes and you feel as though you're driving on loose sand except that there is plenty of lateral grip. You will also feel the pedal push up just slightly but you don't feel much modulation. If this was a panic stop from 70 mph the stopping distance would have been 40-50% longer than normal and you likely would have crashed, fortunately I'm only hitting cones at this point.

Other observations, if you brake gently and straight enough you can avoid the problem 90% of the time. If you suddenly lift off the gas and hit the brake pedal firmly the computer is programmed to boost the brake pressure enough to activate ABS (Brake Assist) and you will experience the problem. To avoid this you have to lift off the gas and then gradually apply the brakes, which costs time and distance.

Which part exactly is being affected by the heat I'm not sure, but I'm fairly confident that it is not the rotors. They are generating the heat which then radiates out to other parts. High friction pads make the problem worse because they are more grabby and make it easier to activate ABS and generate more heat more quickly.

Ducting may help to reduce temperatures but it won't solve the problem.

Next time out I'm going to try and bring an infrared pyrometer and get some more accurate readings. I will also try and get a fuse module that I can hack up so that I can disable ABS without killing the VVEL and the power windows (the module covers 3 slots).

travisjb

Very helpful response, thanks. I've been struggling to describe how my brakes have felt under these conditions but I think you've hit on it exactly when you said it is like "driving on lose sand..." I've also noticed that when it fails in this way, the ABS seems to kick in sooner / with less pressure, so that when you back out of the pedal enough to NOT get ABS involved it is at a lower pressure and thus stopping distance is increased... in other words, you're screwed either way.

Really look forward to your testing results with pyrometer. I think this will shed light on theory that heat is spreading to electronics/sensors as root cause.

I'd like to see some aftermarket mfgrs throw some R&D at this problem too... we're going to need more than just us guys trying to solve it on a shoestring. There need to be more fixes to this problem other than just "here's a big brake kit"... BBKs will be a good option for some - maybe me! - but not most, I suspect.

Travis

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2009 370Z #104
*For Sale*

RCZ

Does anyone have pads/rotors/race fluid yet? I want to know if that fixes all our issues...

travisjb

Not it... here's the list I'm working through:

1. ATE fluid... check
2. pads... partial check... HP+
3. air/ducting... not yet, but soon
4a. rotors... not yet -OR-
4b. BBK... not yet

Did DannyGT or Semtex get rotors? there was some discussion covered on another thread somewhere

__________________
2009 370Z #104
*For Sale*

ChrisSlicks

I think that is what it is going take. Sadly I think BBK's alone aren't even going to fix this, and there are going to be some angry customers who will have spent $4K on one only to find out the brakes still go to crap. My amateur diagnostic skills aren't going to figure this one out unfortunately. What feels really weird is that when it just starts happening it feels like you are driving over patches of sand on the road as it cycles between stopping well and ABS hell. The hotter things get the more it cycles away from the well side.

It could be as simple as we are driving the car outside of the parameters programmed into the ABS computer, but only Nissan Japan knows that answer.

I have pads (HP+ good enough for my temps currently), slotted rotors, and ATE Blue fluid. The problem is still exactly the same.

On the plus side it should solve your rotor gouging issue, but sadly the brakes will still feel like crap.