Track Issues
Thread Starter
Registered User
Joined: Apr 2004
Posts: 137
Likes: 0
From: Norfolk, VA
Track Issues
Track: Reno-Fernley Raceway. Track was fairly high speed (120ish on front and back straights) with 14 turns total. Heavy braking in a few spots (110 to 40 for example). On Saturday, temperatures were in the lower 90's and it was dry as a bone. Sunday wasn't as hot. maybe lower 80's.
Car: 2004 Touring. NISMO exhaust, JWT PopCharger, LMGT4 wheels with Potenza P-03's, NISMO brake pads (installed Friday), MOTUL 600 brake fluid.
Issues: First of all, I had the NISMO pads and MOTUL 600 put in on Friday morning, then drove the 5 hours to Reno on Friday evening.
Got up Saturday AM and drove half an hour to the track. It was a new track for me and it was pretty damn fast. I'd say it took me 2.5 sessions to get comfortable enough where I felt like I could push myself at all. After the first session I noticed a couple of fluid spots on the inside of all four wheels. My first thought was that I was getting a little brake fluid leakage from the bleeder valves. I'm talking maybe teaspoon amount.
After the second session, I only saw fresh fluid inside the right front wheel. About the same amount. I wasn't very concerned because it seemed that the problem had taken care of itself. I talked to a friend and he said that sometimes there is a little seepage after a flush and fill on the brake fluid.
Okay, after the fourth Saturday session I had a TON of fluid inside my right front wheel well. Obviously it had been slung everywhere due to wheel rotation. I also noticed that my brake fluid level had gone down from the MAX line at the beginning of the day to halfway between the MAX and MIN line. Now I was starting to get a little worried.
So, couldn't find the source of the fluid. Brakelines were all dry but there was enough fluid in the wheel well that it was wet to the touch. I noticed that the fluid was concentrated at the louvres in the forward part of the plastic wheel well liner. After getting some more super-friendly advice and assistance from fellow drivers, I got the wheel off and again, couldn't find any leakage from brake components. I still had the large amount of fluid and the drop in brake fluid level.
Finally figured out that the fluid was power steering fluid. After a few runs, the level must've gotten really, really high. It overflowed from the filler cap, ran down the bulkhead on the right side, and got sucked through the louvres in the wheel well liner.
I still had the brake fluid issue though. Saturday night I drove thirty minutes back to the hotel in Reno while trying to work the brakes to see if I couldn't figure out where the fluid was going. Nothing doing. Fluid remained at a constant level and had no leakage that I could find. Got up the next morning and the brake fluid level had dropped by maybe a quarter (between MAX and MIN lines) overnight. No source that I could find. Tested the brakes and drove to the track. Fluid came back to the level of the day before. Okay, so that part was caused by settling/contraction. I still had the issue of the drop from the day before.
Ran the full day - 4 sessions - really hard (at least in my book
) and didn't have any fluid in any of the wheel wells. I did however continue to lose brake fluid. Thanks to daveh I refilled my fluid reservoir and kept running.
As I got ready to leave the track for the drive back to Monterey, I heard some pretty horrible squealing from the right front.
So, I engine braked all the way home. Went very light on the brakes and didn't have any problems. Took the wheels off Monday and got the full story. The inside pads on both front brakes were down to bare metal. I can post pics if anyone wants to see them. Rotors are pretty grooved and pitted. Both rubber piston boots are melted. Bottom line, NISMO pads lasted me exactly two days at the track. I'm 99% sure that the pad wear is what caused my brake fluid level to go down as I couldn't find any other leak source.
Lessons Learned:
1) At the very least, I need dedicated race pads for the track (if not front brake upgrade)
2) I either need to get the NISMO PS Cooler or some higher temp rated steering fluid.
3) People at the track are some of the friendliest and most helpful anywhere
4) I absolutely LOVE this stuff
Sorry for the length but I've found that I get a lot out of people's detailed experiences with their car. I tend to remember things when they come up on mine.
Kyle
Car: 2004 Touring. NISMO exhaust, JWT PopCharger, LMGT4 wheels with Potenza P-03's, NISMO brake pads (installed Friday), MOTUL 600 brake fluid.
Issues: First of all, I had the NISMO pads and MOTUL 600 put in on Friday morning, then drove the 5 hours to Reno on Friday evening.
Got up Saturday AM and drove half an hour to the track. It was a new track for me and it was pretty damn fast. I'd say it took me 2.5 sessions to get comfortable enough where I felt like I could push myself at all. After the first session I noticed a couple of fluid spots on the inside of all four wheels. My first thought was that I was getting a little brake fluid leakage from the bleeder valves. I'm talking maybe teaspoon amount.
After the second session, I only saw fresh fluid inside the right front wheel. About the same amount. I wasn't very concerned because it seemed that the problem had taken care of itself. I talked to a friend and he said that sometimes there is a little seepage after a flush and fill on the brake fluid.
Okay, after the fourth Saturday session I had a TON of fluid inside my right front wheel well. Obviously it had been slung everywhere due to wheel rotation. I also noticed that my brake fluid level had gone down from the MAX line at the beginning of the day to halfway between the MAX and MIN line. Now I was starting to get a little worried.
So, couldn't find the source of the fluid. Brakelines were all dry but there was enough fluid in the wheel well that it was wet to the touch. I noticed that the fluid was concentrated at the louvres in the forward part of the plastic wheel well liner. After getting some more super-friendly advice and assistance from fellow drivers, I got the wheel off and again, couldn't find any leakage from brake components. I still had the large amount of fluid and the drop in brake fluid level.
Finally figured out that the fluid was power steering fluid. After a few runs, the level must've gotten really, really high. It overflowed from the filler cap, ran down the bulkhead on the right side, and got sucked through the louvres in the wheel well liner.
I still had the brake fluid issue though. Saturday night I drove thirty minutes back to the hotel in Reno while trying to work the brakes to see if I couldn't figure out where the fluid was going. Nothing doing. Fluid remained at a constant level and had no leakage that I could find. Got up the next morning and the brake fluid level had dropped by maybe a quarter (between MAX and MIN lines) overnight. No source that I could find. Tested the brakes and drove to the track. Fluid came back to the level of the day before. Okay, so that part was caused by settling/contraction. I still had the issue of the drop from the day before.
Ran the full day - 4 sessions - really hard (at least in my book
) and didn't have any fluid in any of the wheel wells. I did however continue to lose brake fluid. Thanks to daveh I refilled my fluid reservoir and kept running.As I got ready to leave the track for the drive back to Monterey, I heard some pretty horrible squealing from the right front.
So, I engine braked all the way home. Went very light on the brakes and didn't have any problems. Took the wheels off Monday and got the full story. The inside pads on both front brakes were down to bare metal. I can post pics if anyone wants to see them. Rotors are pretty grooved and pitted. Both rubber piston boots are melted. Bottom line, NISMO pads lasted me exactly two days at the track. I'm 99% sure that the pad wear is what caused my brake fluid level to go down as I couldn't find any other leak source.
Lessons Learned:
1) At the very least, I need dedicated race pads for the track (if not front brake upgrade)
2) I either need to get the NISMO PS Cooler or some higher temp rated steering fluid.
3) People at the track are some of the friendliest and most helpful anywhere
4) I absolutely LOVE this stuff
Sorry for the length but I've found that I get a lot out of people's detailed experiences with their car. I tend to remember things when they come up on mine.
Kyle
Joined: May 2002
Posts: 8,621
Likes: 1,392
From: Aurora, Colorado
Did you 'bed-in' the pads before taking to the track? That step can make an enormous amount of difference in how long and well the pads perform. If you really enjoy yourself at the track, do a review of the posts in this section. The brakes and PS issues have been HOT topics (pun intended) here and there is a wealth of information to review. Bottom line: get a BBK for any track use. Get the Nismo PS cooler or some Redline PS fluid (or both) and read up on the other mods that will make your Z more trackable.
You need to get a BBK for sure. It was one of my first upgrades since braking is more important to me than adding more HP 
I took the plunge a few months back and sold my 13" FR for 14" FR and RR. Great set up
Summer is definitely here and a PS cooler will definitely help. Make sure to get a Koyo radiator too
See ya around!
I took the plunge a few months back and sold my 13" FR for 14" FR and RR. Great set up Summer is definitely here and a PS cooler will definitely help. Make sure to get a Koyo radiator too
See ya around!
Nice write up
You should defenitely get dedicated race pads. And since you have to take you're calipers off to change them, you might consider a set of rotors that you use only for lapping with these pads.
That will solve the bed-in issue when swapping pads. Cost wise, it's not that much more expensive (on the long run). You will get the same total wear over a full season. Race pads will last longer at the track and your street pads also.
You should defenitely get dedicated race pads. And since you have to take you're calipers off to change them, you might consider a set of rotors that you use only for lapping with these pads.
That will solve the bed-in issue when swapping pads. Cost wise, it's not that much more expensive (on the long run). You will get the same total wear over a full season. Race pads will last longer at the track and your street pads also.
Trending Topics
Thread Starter
Registered User
Joined: Apr 2004
Posts: 137
Likes: 0
From: Norfolk, VA
Thanks very much for all the advice. I'd like to go with the Stoptech front 14" kit here in the near future. Has anyone installed a kit this themselves? I think I've really been bitten by the DIY bug and would love to get the experience.
Also looking at the PS cooler and Koyo radiator. I've got to decide on priorities here and I guess I think the brakes would give me the most bang for the buck. The Redline fluid is a given though.
Rickdogg--definitely agree on the braking/suspension upgrades vice upping the HP.
dkmura--I've read several things that mention the need to "bed-in" pads but haven't seen anything on how to do it. I'll keep looking. Thanks for the advice.
Can't wait to get some impressions on the new Unitech/Koni's either.
Kyle
Also looking at the PS cooler and Koyo radiator. I've got to decide on priorities here and I guess I think the brakes would give me the most bang for the buck. The Redline fluid is a given though.
Rickdogg--definitely agree on the braking/suspension upgrades vice upping the HP.
dkmura--I've read several things that mention the need to "bed-in" pads but haven't seen anything on how to do it. I'll keep looking. Thanks for the advice.
Can't wait to get some impressions on the new Unitech/Koni's either.
Kyle
Kyle,
I installed the front Stoptech kit myself. I'm not a mechanic, and have limited experience tearing things apart, and putting them back together. If you're good at reading instructions, it should be a 3 hours install for a total newbie. the instructions are pretty good, although I had some difficulty rounting my stainless steel lines. I had to remove and reinstall my front OE brakes for warranty issues, and it took me under 2 hours to take off the wheels, remove the stoptechs, reinstall the OE, bleed the lines, and reinstall the wheels. Just make sure you have a breaker bar to help take those caliper mounting bolts off...they are on TIGHT!!!
I installed the front Stoptech kit myself. I'm not a mechanic, and have limited experience tearing things apart, and putting them back together. If you're good at reading instructions, it should be a 3 hours install for a total newbie. the instructions are pretty good, although I had some difficulty rounting my stainless steel lines. I had to remove and reinstall my front OE brakes for warranty issues, and it took me under 2 hours to take off the wheels, remove the stoptechs, reinstall the OE, bleed the lines, and reinstall the wheels. Just make sure you have a breaker bar to help take those caliper mounting bolts off...they are on TIGHT!!!
Kyle,
At least you learned something about your car without doing a whole bunch of damage. Dave is a great guy. A lot of things to consider here for you as there are many, many options. First, determine how much you want to track.....I suspect you'll be doing this much much more. If this is in fact the case, BBK should be on top of the list. You are NA, so the cooling stuff can wait a couple of months or so. But be ready becuase this summer is going to be a killer if the weather trends keep up. As far as bedding in pads, I'm sure this would have helped with the feel of the pads, but certainly not the longevity of the pads. You definitely need dedicated track pads. Again, daveh is a great person to talk to about this and we have had numerous discussions about the brake issues with our cars.
By the way, did you experience any pad knockback??? It's killing dave as he is a very aggressive driver and I do notice it a bit and it's both annoying and scary at the same time.
Good to hear that you made it to the event and back safely. There is a lot to be said for doing your own work on your car jsut to figure these things out. Personally, I love it. If you do get the BBK, let me know. I think I may do this myself later this year to replace my Brembos.
Regards,
Steven Krohn
At least you learned something about your car without doing a whole bunch of damage. Dave is a great guy. A lot of things to consider here for you as there are many, many options. First, determine how much you want to track.....I suspect you'll be doing this much much more. If this is in fact the case, BBK should be on top of the list. You are NA, so the cooling stuff can wait a couple of months or so. But be ready becuase this summer is going to be a killer if the weather trends keep up. As far as bedding in pads, I'm sure this would have helped with the feel of the pads, but certainly not the longevity of the pads. You definitely need dedicated track pads. Again, daveh is a great person to talk to about this and we have had numerous discussions about the brake issues with our cars.
By the way, did you experience any pad knockback??? It's killing dave as he is a very aggressive driver and I do notice it a bit and it's both annoying and scary at the same time.
Good to hear that you made it to the event and back safely. There is a lot to be said for doing your own work on your car jsut to figure these things out. Personally, I love it. If you do get the BBK, let me know. I think I may do this myself later this year to replace my Brembos.
Regards,
Steven Krohn
Last edited by scubasteve; Jun 2, 2005 at 01:23 PM.
I have done this last year
I started tracking my touring model and quickly found the same problem of consumining pads in one day. I upgraded to the Wilwood kit offered by 350zbrakes . I now have about 8 track days and love the setup. It is 13.6" diameter rotors with 6 pot front and 4 pot rears. I also added the power steering cooler. well worth the nominal cost. I added front A arms this year and rear torsion bars from 350EVO. A great setup also. I went to 17 inch wheels but not sure this was very good due to increased side wall flex. I will have to adjust. I track once a month and have now progressed into the unlimited passing. This level with good drivers is an additional thrill that I really enjoy. I am also friends with Dave. He and I are getting roll bars installed presently and that is another long story. I agree the engine is the last thung to improve. My next area is the LDS conversion to NISMO with heat soak cover.
Have fun. I sure am.
Have fun. I sure am.
Brake pad bedding info from stoptech:
http://www.stoptech.com/whitepapers/bedincontents.htm
Another good resource:
http://www.zeckhausen.com/avoiding_brake_judder.htm
If you don't have the $2k to spend on a big brake kit right away, you might just consider trying some some dedicated track pads. A set of R4 pads from porterfield would cost you around $200 (with your 15% nasa discount). You might be able to get away with that until you go with r-compounds.
I would definatly cut away your dust shields on both the front and rear brakes to allow for more cooling. This is why your inside pad wore faster than your outside. When you go with a bbk down the road you will have to do this anyways. Directions for this can be found on stoptech's 350z big brake kit install instruction manual.
I still have no idea why I haven't had any problems with the power steering fluid. Not that I'm complaining. I do seem to be having knockback more than others though. After commuting this week, I have perfected the left foot brake pump up action so I will be more ready for it next time I'm on track.
http://www.stoptech.com/whitepapers/bedincontents.htm
Another good resource:
http://www.zeckhausen.com/avoiding_brake_judder.htm
If you don't have the $2k to spend on a big brake kit right away, you might just consider trying some some dedicated track pads. A set of R4 pads from porterfield would cost you around $200 (with your 15% nasa discount). You might be able to get away with that until you go with r-compounds.
I would definatly cut away your dust shields on both the front and rear brakes to allow for more cooling. This is why your inside pad wore faster than your outside. When you go with a bbk down the road you will have to do this anyways. Directions for this can be found on stoptech's 350z big brake kit install instruction manual.
I still have no idea why I haven't had any problems with the power steering fluid. Not that I'm complaining. I do seem to be having knockback more than others though. After commuting this week, I have perfected the left foot brake pump up action so I will be more ready for it next time I'm on track.
Is that the answer to our problems.....left foot brake pump? Other than the custom build by 350EVO...... Dave, received your message....been busy. I do have a problem like yours and it won't go away. I am going to buy a pressure bleeder next.
Great suggestion for cutting the dust shields, I almost forgot about that. That would abslutely contribute to the uneven pad wear. I think that some custom cooling ducts are in order here for all of us. I know one of the members from TX has fabricated a set. All we really need is the mounting for the caliper end of the duct. The rest is self-explanatory. Any suggestion for cooling of rear brakes? I have seen those little add-ons that bolt on and are supposed to direct the air flow to your wheels, but I don't think they will work as well as direct venting. Anyone have suggestions?? I'm up to cutting into my NISMO sideskirts if necessary.
-Steve
Great suggestion for cutting the dust shields, I almost forgot about that. That would abslutely contribute to the uneven pad wear. I think that some custom cooling ducts are in order here for all of us. I know one of the members from TX has fabricated a set. All we really need is the mounting for the caliper end of the duct. The rest is self-explanatory. Any suggestion for cooling of rear brakes? I have seen those little add-ons that bolt on and are supposed to direct the air flow to your wheels, but I don't think they will work as well as direct venting. Anyone have suggestions?? I'm up to cutting into my NISMO sideskirts if necessary.
-Steve
Pad knock back is just a fact of life on a track driven street car. Other than changing wheel bearings more often and getting stiffer wheels, any other counter mesure will rapidly become super expensive.
These is not a full race car...
As for rear brakes cooling, I'd be curious how much air goes under the car that we could use ?
These is not a full race car...
As for rear brakes cooling, I'd be curious how much air goes under the car that we could use ?
I have pretty severe pad knockback, but that is due to the fact that I run the 14" Stoptech rotors. Now, Daveh runs the 13" rotors, but also uses stickier tires, so the degree of knockback may be about the same. If I move to R-compounds, I expect to worsen my knockback problems. This is a hub flex problem, and not necessarily have anything to do with wheel flex. Wheel flex, however can cause the spokes to hit your calipers if you barely have enough clearance, and if your calipers are in the lower hemisphere of the horizontal wheel axis. I've never heard of this happening, but I can imagine the results!
To deal with the knockback, I let off the gas a little early to tap my brakes before most turns. This will certainly increase my lap times, and probably drive the guys behind me crazy with the single flash of the brake lights before each braking zone. I probably don't have to tap it at every turn, but it's probably best not to risk it. After reading a few of the posts, I may consider learning to tap with my left foot, so I can leave my right foot on the gas longer. My left foot is just so uncoordinated!
As I learned a few months ago, on this site, pad knockback is an issue with any fixed caliper brake system, even the OE brembos would exhibit this characteristic. The sliding caliper system accommodates the hub flex by sliding the pads and pad brackets along the rails.
I don't spend too much time on the Porsche/Corvette/Viper/S2000 forums, so I don't know if those guys and gals have the same degree of knockback.
To deal with the knockback, I let off the gas a little early to tap my brakes before most turns. This will certainly increase my lap times, and probably drive the guys behind me crazy with the single flash of the brake lights before each braking zone. I probably don't have to tap it at every turn, but it's probably best not to risk it. After reading a few of the posts, I may consider learning to tap with my left foot, so I can leave my right foot on the gas longer. My left foot is just so uncoordinated!
As I learned a few months ago, on this site, pad knockback is an issue with any fixed caliper brake system, even the OE brembos would exhibit this characteristic. The sliding caliper system accommodates the hub flex by sliding the pads and pad brackets along the rails.
I don't spend too much time on the Porsche/Corvette/Viper/S2000 forums, so I don't know if those guys and gals have the same degree of knockback.
BTW, I don't have PS fluid problems either. I've driven in 100 degree weather too. Then again, I don't "wiggle" my steering wheel around much either (drifting through every turn) :-)
Also, I can't remember if our oil guage displays pressure or temperature...but it doesn't seem to move much at all. I assume it means I don't need an oil cooler or large capacity radiator yet.
Also, I can't remember if our oil guage displays pressure or temperature...but it doesn't seem to move much at all. I assume it means I don't need an oil cooler or large capacity radiator yet.
Thread Starter
Registered User
Joined: Apr 2004
Posts: 137
Likes: 0
From: Norfolk, VA
I just wanted to day thanks one more time for all the responses and advice. I'm pretty sure I'm lined up for two to three more events in July and August (June has been sacrificed to the GF). Based on all the feedback, I think I'm going to install either the Wilwood or Stoptech front kit myself before the next track day.
I may do an experiment and run the next event with high temp PS fluid and the one after that with the PS cooler, high temp fluid combo.
dnugyent -- Thanks for the info on the BBK install. I'm definitely giving it a try.
I may do an experiment and run the next event with high temp PS fluid and the one after that with the PS cooler, high temp fluid combo.
dnugyent -- Thanks for the info on the BBK install. I'm definitely giving it a try.
Questions for some of you that have changed to redline PS fluid and installed the Nismo cooler as I'm considering making the change.
Is the Nismo cooler installation easy to do. Do you need to bleed the fluid first, etc. I heard that the system was under high pressure. I'm sure it's not as simple as disconnecting the stock cooler and connecting the Nismo...
Same question if I only change the fluid, what is the process for that, I seached and did not find anything on this.
Thanks
Is the Nismo cooler installation easy to do. Do you need to bleed the fluid first, etc. I heard that the system was under high pressure. I'm sure it's not as simple as disconnecting the stock cooler and connecting the Nismo...
Same question if I only change the fluid, what is the process for that, I seached and did not find anything on this.
Thanks