CMP TRACK DAY NUMBER 3 UH OH TIME TO BUY NEW PARTS :( Options

[MGWLTD]

well i took the GTR to CMP for a weekend track event and the car once again ran flawlessly.

- prior to going this weekend i had my dealer perform the tranny reset to make sure it was fully in spec. this will be the 4th time it was done so yes i am anal but i dont want a blown tranny.

- the car has 4000 miles on it and so far i have had the oil changed once, the tranny fluid changed once and the pos servcie done twice. in addtion to checking the tranny alone 4 times.

- i replaced the stock pads last week with the endless me20 race pads and replaced the fluid with their 650 racing fluid. not sure if i am happy with that as i will explain later.

- car still has the stock potenzas on it and frankly even if they are not toast which they are pretty close i am ready to blow holes in them with a shotgun. they suck!!!!

ok i went out and as usual the car handles, accelerates, brakes amazingly. i was pretty passing everything on the field all day but the car would have been so much faster if the tires were better. it just PLOWED thru every tight corner and scrubbed so much speed . the tires were wailing like a banshee all day and some points even slid so bad that it sounded like when you go over those highway serrations before a stop light on those back country roads. lol

but the real issue was the brakes...they were great and had very little if any fade with the new pads and fluid but i had some issues...

1. obviously the new pads were MUCH better than the stock pads but the downfall of that was now both front rotors have hairline cracks about 1/4 to the left and right of SEVERAL of the drilled holes so yes the stock drilled rotors are NOT up to par for hard track use which is not news i guess to anybody anymore i just figured they would take more than 3 track days to fail. oh well. after each seesion they were smoking for a good 5 minutes!!


2. the brake fluid must have boiled anyway becasue it actually seaped out of the caliper on one side and ate a little of the gold paint off my caliper. i have not checked the tightness of the cap but my tech on thursday spent an hour with nissan downlaoding all the torque specs since they were not complete on the manual and doubel checked EVERYTHING so i was pretty confident he had it tight but i will make sure today.

all in all it was a great day. i have about 5 thousand dollars worth of replacmentsw now which kinda sucks but i guess you pay to play. and it was as blast.

regards
george

any body have suggestions for new tires . i only need to get to the trck and back so it must be a dot tire but is there anything better out there than the dunlop 600's which is what i will be going with if not.

This post has been edited by MGWLTD: Nov 17 2008, 07:52 AM

[zeyd]

could you explain the 5000 please... just for pads and fluid ????

[amfaster]

If your brakes are smoking for 5 minutes after every run it's likely your fault the fluid boiled. Smoking brakes means you didnt cool down enough. Sometimes I take as many as two whole cool down laps with slight throttle to accel to 70-100 mph and using the brakes as little as possible. The brakes need air flow to cool, just sitting isnt good enough. It's mandatory on heavy cars, and really any car, especially at CMP which is hard on the brakes.

Not sure how the GT-R's controls work, but DO NOT put the parking brake on when you get back to pits. That is a sure fire way to boil the fluid.

The cracks are normal, general rule of thumb though is that they are ok until the cracks reach from one whole to another, or to the edge of the rotor, then it's time to replace. Get used to it, it's a fact of life with drilled rotors.

[amfaster]

BTW proper cooling down also lengthens the life of the rotors. Metal can stand heat, but being hot for prolonged periods of time is bad and compromises the structural integrity, and the cracks will grow faster the longer the brakes have to deal with that heat.

The effect is compounded because next time you go out, the brakes, and more importantly fluid, will still be hot, but not as hot with proper cool downs and the fluid is what keeps the brakes cooler, and cooler is better for longevity because hotter metal will flex and bend more under load which is what causes cracks.

B

[Scotts-GTR]

OK i have some sugestions. I have found a lot of what you have said here is true.

1. Understeer - I have found that with a proper setup this can be reduced. Buy the Cobb adjustable suspension setup, and have the car corner balanced. This will take care of the understeer and save your THOUSANDS in tires. Its not the tires, its the suspension. My recommendation is to fix the problem. Here is a link:

http://gt-rr.com/gt-r/r35/cobb_tuning/part...ion_kit/pid/205

2. Brakes - I have found the brakes to be somewhat on the weak side. The rotors in particular are a point were improvements are needed. If you are tracking your car, dont get drill rotors. You get cracks easier, and they cool too fast resulting in warping. I recommend the Alcon solid rotors. You will see much better life out of them. In addition would say since you boiled your fluid that you need to get some Castrol SRF brake fluid. It is the best fluid in the world bar none.

Alcon Rotors:
http://gt-rr.com/gt-r/r35/alcon/part/rotor...nt_pair/pid/198

Castrol SRF
http://www.hrpworld.com/index.cfm?form_pro...;action=product

[Neoseven]

Track tries for now, staying with stock wheels and sizes, Dunlops are probably the best out. Soon, apparently, we will have Toyo R888's available, but from what I have seen with them mounted on stock wheel sizes, they look like they will fit better on a wider wheel. I think it was Chuck who commented, they look like truck tires with all that sidewall when mounted on stock tire widths.

I'm still hoping Bridgestone is going to bring that R compound tire we saw the Nismo GT-R using in that endurance race out and make it available to the US market. I want to stick with 20's for the track in stock size so I am just waiting for tires to be a available, and until then I will just run the Dunlops as replacements for my stock Bridgestones.

This post has been edited by Neoseven: Nov 17 2008, 10:16 AM

[MGWLTD]

the 5000 dollars is basically the cost of 4 new tires ( 2000.00) and new rotors for the front ( 3000.00)



Guys i do appreciate the comments but i do understand the basics of track driving i have been tracking vipers lotuses porsches mustangs etc .for over 15 years. i thought the fluid that GTRR.com sells was good but i will try the castrol thanks for the tip. i appreciate it alot!!!

i ALWAYS let my brakes cool down for a full lap but as you may know when the checkered flag comes on you are able to sneak by one time past the corner workers for an extra lap which i always do and slow it down to about 50-70 miles per hour and basically dont even use the brakes at all so they are getting as much cool down as possible. i did NOT have this issue with the car last month so it is either a product of MUCH better pads making alot more heat or substandard fluid .


i NEVER apply my parking brake EVER!!!

i know the drilled rotors suck i would never get drilled rotors i just figured number 1 that nissan knew better to even offer them but also that they would at least last a bit longer. oh well. i am watinig on GTRR.COM to get the alcon rotors in i already have had them on order for 3 weeks now but may have to end up going with their mines brand since they are not in stock yet.

This post has been edited by MGWLTD: Nov 17 2008, 10:20 AM

[MGWLTD]

Track tries for now, staying with stock wheels and sizes, Dunlops are probably the best out. Soon, apparently, we will have Toyo R888's available, but from what I have seen with them mounted on stock wheel sizes, they look like they will fit better on a wider wheel. I think it was Chuck who commented, they look like truck tires with all that sidewall when mounted on stock tire widths.

I'm still hoping Bridgestone is going to bring that R compound tire we saw the Nismo GT-R using in that endurance race out and make it available to the US market. I want to stick with 20's for the track in stock size so I am just waiting for tires to be a available, and until then I will just run the Dunlops as replacements for my stock Bridgestones.

yes thats my plan too. i want to stick with stock wheel and tire sizes. i hope the dunlops are that much better than the bridgestones like i hear.


george

[MGWLTD]

OK i have some sugestions. I have found a lot of what you have said here is true.

1. Understeer - I have found that with a proper setup this can be reduced. Buy the Cobb adjustable suspension setup, and have the car corner balanced. This will take care of the understeer and save your THOUSANDS in tires. Its not the tires, its the suspension. My recommendation is to fix the problem. Here is a link:

http://gt-rr.com/gt-r/r35/cobb_tuning/part...ion_kit/pid/205

i have not seen this yet i will look into it asap. thanks alot!!!

[tyndago]

The brakes on the GT-R even with 380 mm rotors and 6 pot calipers are marginal at best. No ducting to cool them. Cross drilled rotors suck for hard use.

Heres something I wrote a while ago on the GT-R brakes. http://2009gtr.blogspot.com/2008/08/brembo...n-r35-gt-r.html

Endless says their fluid is as good or better than SRF. I am a firm believer in SRF. In the World Challenge R34 we ran Motul 600 most of the year, then switched to SRF and noticed a dramatic difference in bubbles and fluid color after a single session.

Understeer is safe for a street car. Street cars are all going to understeer. That way most customers go straight into things, not back into things. Coil overs, a bigger rear bar, more front tire, less rear tire. No one wants less rear tire. Its just normally people stuff the biggest rear tire possible under the car, and it does have a tendency to mess with the balance of the car.

[Scotts-GTR]

Ya, all street cars are tuned to push. Like above said its safe. 99% of the owners of the GTR will never push it to that extent. Same goes for drilled rotors. Its a visual effect and 99% of people who dont track the car will never see the problem. Fix the problems at there rout causes, without killing driviability is were you want to live. You know that already though tracking Vipers. Almost all World Challenge cars are running SRF. Its all I will ever run and was the first mod I did to the GTR. Fix that understeer and you will be a happy guy. No more killing tires. DOnt let anyone convince you it is your driving or the cars fault, because its not. It just needs a little tweak.

[amfaster]

the 5000 dollars is basically the cost of 4 new tires ( 2000.00) and new rotors for the front ( 3000.00)



Guys i do appreciate the comments but i do understand the basics of track driving i have been tracking vipers lotuses porsches mustangs etc .for over 15 years. i thought the fluid that GTRR.com sells was good but i will try the castrol thanks for the tip. i appreciate it alot!!!

i ALWAYS let my brakes cool down for a full lap but as you may know when the checkered flag comes on you are able to sneak by one time past the corner workers for an extra lap which i always do and slow it down to about 50-70 miles per hour and basically dont even use the brakes at all so they are getting as much cool down as possible. i did NOT have this issue with the car last month so it is either a product of MUCH better pads making alot more heat or substandard fluid .


i NEVER apply my parking brake EVER!!!

i know the drilled rotors suck i would never get drilled rotors i just figured number 1 that nissan knew better to even offer them but also that they would at least last a bit longer. oh well. i am watinig on GTRR.COM to get the alcon rotors in i already have had them on order for 3 weeks now but may have to end up going with their mines brand since they are not in stock yet.

I gotcha, but if they are smoking, you arent cooling them down enough. 50-70 isnt fast enough to cool them down in 1 lap. At CMP exiting the carousel get up to 100+ then coast until the next turn (forget number) its pretty fast so if you've let off you wont need the brakes, then get back up to 100+ on the back portion coast through the kink to the hairpin, then choke it down and get ready to pit.

If you cant do that effectively (traffic or otherwise), and the brakes are still smoking, go out to the long road outside and drive a couple miles down and back. Thoroughly cooling the brakes is a must and one of the most neglected aspects of tracking, but dilligence pays off with better braking, less mushy pedal, longer lasting rotors, fluid etc.

AP racing 600 is awesome fluid, that or motul. But make sure it's something with a boiling temp around 600+

And yes different pads create more or less heat based on the friction level, they also affect the rotor wear, so while what you have may be better initially, may cost more in the long run by eating the rotors really fast. But usually something other than stock is better.

[thebishman]

Ya, all street cars are tuned to push. Like above said its safe. 99% of the owners of the GTR will never push it to that extent. Same goes for drilled rotors. Its a visual effect and 99% of people who dont track the car will never see the problem. Fix the problems at there rout causes, without killing driviability is were you want to live. You know that already though tracking Vipers. Almost all World Challenge cars are running SRF. Its all I will ever run and was the first mod I did to the GTR. Fix that understeer and you will be a happy guy. No more killing tires. DOnt let anyone convince you it is your driving or the cars fault, because its not. It just needs a little tweak.

Did you replace the brake fluid yourself or did you have the GT-R tech do it for you. If so, was there any mention of the dreaded 'warranty issues'?

TIA,
Bish

[flyfast]

Great reading and interesting stuff! Thankyou everyone!

[Scotts-GTR]

Did you replace the brake fluid yourself or did you have the GT-R tech do it for you. If so, was there any mention of the dreaded 'warranty issues'?

TIA,
Bish

Do it your self. No brake components are covered under warenty anyway as they are all wear items.

[MindlessOath]

i have seen many many many pictures of just the R35 rotors with cracks. everyone that tracks any car for more than one lap

knows these will crack in due time.

those alcone rotors are probably the best, but endless has a set and rdd has a nice set too.

the calipers are not terrible, but they are not for racing. they are great for hard street use or light track duitie. (dont

make me explain please).

Im not sure about the brake fluid you used... endless usa via DOM said its a great fluid, i havent heard anyone test it yet,

but i dont think yours boiled considering its better than the stock brake fluid in more than one way.

If your going to track your car and track it alot, there are ALOT of things you will need to change. brakes, downforce,

suspension, power and weight. The R35 was designed to be an everyday supercar with light track duities in mind. the

nurinburgring doesnt really test brakes well and most of the testing for the R35 really just went around a few laps on other

tracks. nissan wanted to make sure that the brakes would never overheat, hence the drilled rotors... but what they didnt

expect was people racing it or doing multiple laps with hard breaking. hence why the next R35 variant (spec-v) will have

brake ducts for those carbon rotors (tho there is said to be two versions, one with carbon rotors the other without). Using

aftermarket rotors are probably going to be cheaper also, but not only that, but you will reduce some weight, tho it isnt

much, it really add's up at each corner.

the suspension is really bad for racing. its heavy and doesnt offer enought stiffness and has alot of body roll (compaired

to aftermarket). tuners have found that aftermarket springs work better for street and track (again light track). but that

only solves some of the issues. the stock shocks are heavy and can be replaced with lighter aluminum coilovers, they will be

much lighter and stiffer. reducing as much weight as possible in any way before using carbon fiber.

anti roll bars will help for that turn in. as you will notice the bad steer that the r35 has because of its design. "mines" have created a set of anti roll bars that help. i belive "Will" aka underpressure is having some custom made for his R35.

Downforce is actually not that great for the track. you would like to think it is based on nissans marketing annaylisis... but it requires more downforce for the track. i always recomend function over form. the two best downforce additions are the front lip and rear wing. AutoSelect offers a devil spoiler wich is down right agressive and looks very nice. it offers alot of downforce and has been proven by its design on the R34 previous to it. IT also has the first functional air and brake ducts on a front lip. this is so you can cool your slotted rotors by running a duct from the lip to the center of the rotor. its carbon too, its cheaper than the amuse front lip aswell. Amuse offers the next best solution, it offers alot of downforce, the weight is about the same, because im not sure if its full carbon or not, plus its huge, but were talking small number differnces here. its also a very good price for what you get.

There really hasnt been much testing on rear wings yet. would it be better to get a GT-wing for the track? i havent the slightest clue, i need venders, customers and manufactures to do more testing.

power goes without saying and i know you all know what the options are. no need to go over that.

one thing i would also like to mention is heat. The r35 doesnt like it one bit. but the worst part about it, is racing on the track it needs a reduction in heat or it will not last a few laps. it depends also if you add alot of power or if you keep stock power. the engine oil will do just fine with stock setup, but adding 100hp or their abouts is going to need better cooling... esprit already did testing with the intercoolers and found the HKS GT570 kit benifits from a larger intercooler. zele and nismo took advantage of a differential oil cooler. garage saurus are working on a transmission oil cooler (zele already tried this but found issues with pressure drops).

the transmission has gimped from overheating on many R35's from excessive track use... so its a major downfall to racing.

weight you can remove the runflats or better yet, reduce the size of the wheels and make them lighter weight also, smaller wheels will allow for differnt gearing that will be faster on a race track. lighter brakes, lighter suspension, and most of all, lighter seats and exhaust. if your going to track the R35 alot, you may want to get steel exhaust, it will take more punishment than Ti, and if you go with a single out pipe, with no cats, it will reduce weight alot too. tho TI is lighter, it can be abused and is costly to repair, plus it can warp due to excessive heat, which the R35 is full of heat, hence why nismo manufactured a specific exhaust for the nismo R35, with air ducts that act as support for warping and cooling it off.


Well, this is my take from many of the tuners from japan to the usa. very little of this information is from myself, so if you see something wrong with what i have said, please make a comment for me to correct what i have said (maybe i just didnt explain it right tho). plus there is so much more you can do than just this.

[JRu17]

This is the first time I've heard anythin bad about the Endless brake fluid, I wonder if it hadn't been tightened properly and that let moisture into it not to mention why the calipers weren't painted anymore

As far as the "all street cars understeer" I felt no understeer in my Evo 8

[amfaster]

I dont think the guy wants to build a race car. He sounds pretty happy with what he has other than making it last longer and getting some better tires. I think someone needs to research additional brake cooling, maybe ducting underneath the car or through the front somehow, but it needs to be done.

And if you're going with anything smaller than 19" wheels I think it's mandatory that you'de need stiffer suspension or some REALLY meaty tires or you'll scrub the bottom of your car pretty bad based on the pics we've seen.

Even 600* rated fluid can end up with a mushy pedal, it probably didnt boil because if it did, you get foot to floor. CMP is hard on brakes, but not as hard as it used to be, driving style can have a big affect too, trying not to stand on the brakes is key. I think for the cost of replacements, he should contact someone that makes custom rotors. He can send them an old one and they'll make slotted rotors for him in the size he needs. You only buy the hat occasionally and it cuts down on costs because all you are replacing is the steel part of the rotor and attaching it to the hat. Less labor intensive too.

[STI2EVO2GTR]

Brake cooling ducts might help someone needs to make them

[tyndago]

As far as the "all street cars understeer" I felt no understeer in my Evo 8

Whats your experience on track to be able to say that your Evo 8 doesn't understeer ? How many laps ? Do you race ? Does your car have any modifications ?

Understeer is normally built into the chassis, but you can also exaggerate it in the way you drive. I have a couple of laps on tracks in Evo 8's and stock they understeer. You can flick them to get them to rotate and they do that well. The Evo is based on a fwd chassis with the rear wheels added in. Mitsubishi did a great job on the car, and I do like it, but it understeers factory. Put some suspension and a bar on it, and you can get it to rotate at will.