Warped Discs, R34 GTT

[V-Spec]

On my R34 GTT, the discs were warped as I can feel intense vibration everytime I brake hard. After which I got the disc skimmed and slotted as below.

After a couple of weeks, the sympton re-appeared. it's not as bad as the first time but the steering vibrates whenever I brake hard. It's annoying me to the max and my mechanic says it's a common problem with Skylines. Is that so?

Does any of you experience the same thing?

Would aftermarket rotors solve the trick?

 

[RERider]

what tyre size and rim width u got?

 

[V-Spec]

RERider, I'm running the stock rims. Tyres are 225/45/17. Stock size too.

 

[kaminari]

It`s common for most car when breaking hard n brake disc too hot.Most car in circuit use solution like :

1. Stainless steel braided brake hose.
2. Master pump stopper.

There is possiblity stering vibrate becoz of uneven braking, nt well skimmed brake disc?or non suitable brake pad (uneven tear). Changing new suitable heat range brake pad may solve ur prob.

 

[V-Spec]

How would stainless steel braided hoses help in this matter? Aren't it supposed to give a better braking feel coz there'll be no expansion in the hoses as opposed to rubber? Nuttin to do with juddering.....

Master pump stopper also increased brake feel via countering flexing on the firewall.

After skimming it was perfectly ok. Just appeared a few weeks later after that so I'll rule out uneven skim. Pads are new Endless units, changed together with the skimmed discs.

 

[kaminari]

yeah both of it for better braking feeling but stainless steel braided hose not only improve braking feel on ur brake pedal, but also protect high heating from brake disc as well which coz bubbling in ur fluid n lead to uneven braking force.

Since u have changed the pad, is either ur disc not well balance skimmed or occur whenever uneven braking force from caliper piston. Overheating? Worn out caliper?

 

[V-Spec]

kaminari, how would stainless steel braided hoses protect high heat from heating from brake disc?

I'm really clueless why it warped again. Would changing to an aftermarket one help? If those also warped there goes $$$ down the drain.

The disc should be well skimmed as it was OK for the 1st couple of weeks, if not it would have shown the moment I drive out from the shop. Worn out calipers? Which component specifically? I checked the piston rubbers and they are ok.

 

[satigue]

Hi Vspec,
1st was yr shocks.....and now this? whow....wat happened? been doing spirited driving izit? hehe....come join the 'sunny' club.....got 2 members already, driftmeister & myself:) car sure no problem one.

 

[kaminari]

satigue : How are u bro? Thought u want sell ur baby alrdy?heee

vspec:
Stainless steel braided hose constructed of PTFE (Teflon) core which covered with a nylon or kevlar braided sheath.Teflon doesn`t expand under pressure and doesn`t deteriorate with age.It also resists high temperature and chemically inert.

Before skimmed do u facing ths prob too? How abt ur brake fluids?Do u check the thickness wth digi caliper both side skimmed even or nt?U have to take note here, new brake disc, skimmed disc or brake pad takes at least abt 150km (depend brake force apply) to adopt each other. So can`t say it`s ok once after u skimmed.

worn out caliper always becoz of dirt or aging piston seal.Some ppl just might overhaul the caliper once change brake pads.Myb it cost u a lot changing the aftermarket disc, why nt u overhaul the caliper 1st n fit wth used disc. See the result 1st.

 

[V-Spec]

satigue, no more $$$ for a sunny la. Maintain one car also half dead oledi. Hahaha

kaminari, before skim yes I faced the prob, that's why i sent it for skimming. Brake fluids have yet to be changed but are in good condition. Nope, did not check the thickness of both rotors.

The piston seals you refer to is the rubber seals? If so any idea where I can get it and what's the part no. for the ER34? Thanks a mil!

 

[ManR34]

hey vspec....how hard is the braking?
issnt that the ABS kicking in?
cos when i really hard brake...lets say from 180km/h -> slowing down....i oso get that jerking feeling...but not so much vibrating on the steering...but jerking feeling of the ABS in action?

but if u are just normal driving and just braking hard and getting bad vibrations on ur steering wheel...its definately not a common problem wif skylines...i too am using endless 500 degree pads...so i think u should get new rotors...DBA disc brakes i had recommend, i think u can get them here, i am not sure.....

by the way i thought stock tyre size was 235/45/17 on the ER34? cos thats wat i have on mine car. its oso on stock rims too.
why its 225 with yours??

goodluck!

 

[V-Spec]

ManR34, braking is just hard BUT not hard enough for the ABS to kick in. It's not the ABS juddering coz the steering (and effectively the whole car) vibrates.

DBA 310mm rotors aren't available here yet. :confused_smile:

Your tyre size is 235/45/17??? Hmmmm..... stock specs is indeed 225.

 

[chris2000]

Hi Vspec,

Stainless steel braided hoses does not protect the fluid from boiling. Its a mis-conception. All quality PTFE/Teflon hoses braided in stainless steel are used to reduce expansion of rubber hose during hard braking, which in return give you better brake pressure line = better stopping power, more consistent pedal feel and prevent hose rupture at high pressure.

Street use normally use stainless braid only as the kevlar or carbon fiber braid are very light but also extremely expensive and also only used by Top Notch racing teams in F1, WRC and BTCC.

As for your vibrating problem, you have to look at two options. To evaluate your driving style to see if you need higher specs pads. Cause if you drive hard and brake hard you will need better pads. People only look at how good grip or temperature rating of pads but don't realize that pads actually help to remove heat away from the discs thus keeping it cooler.

And generally, higher rating pads or race pads will do these so you normally hear less warping problem on race cars. The set back is to use higher rating pads.

Option 2, is to look at your Disc Minimum Thickness. Min thickness of each discs is normally stamp on the disc or on your service manual. Because you have skimmed your discs, make sure its within the minimum thickness or else it will be dangerous and discs will just warped again after skim.

Its a pity that DBA not available for your 310mm size here yet. I just checked again and we only have the GTR34 and Z33 only.

 

[ManR34]

ManR34, braking is just hard BUT not hard enough for the ABS to kick in. It's not the ABS juddering coz the steering (and effectively the whole car) vibrates.

DBA 310mm rotors aren't available here yet. :confused_smile:

Your tyre size is 235/45/17??? Hmmmm..... stock specs is indeed 225.

OIC, like that sure get new rotors mate...

hey chris2000, can u fit 330mm rotors on the ER34 stock calipers/rims?

if yes, vspec u might aswell upgrade it, cos replacing the same size (310mm) doesnt really help that much as compared to if u got larger rotors (330mm), a much bigger difference in braking...or if u had 18" rims, get 355mm! hehe

yeah i tot 235 was stock specs, i guess the prev. owner change to 235 tyres...
do u know wats the biggest tyre size u can fit on the stock rims?