(not so) good vibrations

[slowmow]

Hello all,

Sorry for the noob questions, but here goes:

1) I can't keep wheel weights on at the track. I've tried tape (duct, Gorilla, and 3M foil), but the adhesives just melt. Next up is 3M high temp foil, but haven't tried that yet. The vibrations are diabolical when the weights inevitably fall off. I asked guys at the track, and got a range of answers from "use tape" to "I don't balance my track wheels because weights just fall off and the tire moves on the rim anyways, and you pick up rubber, etc.". Suggestions?

2) Last track day, in the last session, I got a clicking when under braking and turning left. I had enough time to quickly "play" with it, and adding steering or braking intensified the sound. I'm going to check the CV axle, wheel bearings/hubs. It sounded like front left...but hard to tell. Anything else I should look at? I had an off track excursion through a grassy field that was fairly smooth and uneventful (turn 10 at VIR).... relatively ... but you also jump FIA "gator" curbs at real speed there, which seems like it puts a beating on the car.

3) I keep getting "warped rotors" - I've read/heard that its likely pad deposits. I try to be vigilant about not stopping and holding the brakes when they are super hot, using the hand brake, etc. I try to take a cool down lap when possible, and cruise through the paddock for a few "laps". Ideas?

Thanks all... cure me of my ignorance.

[JD001]

Is it possible that you are "over" driving your car? Driving technique may come into play and driving to your car's capabilities..

[Jdmjunkie]

Are you constantly using Abs in every braking zone? That can also generate a lot of heat. Do you have brake fade issues?

[slowmow]

Originally Posted by JD001

Is it possible that you are "over" driving your car? Driving technique may come into play and driving to your car's capabilities..

Well, given that I went flying off the track over a blind hill... yes, that is possible. Ha ha ha!

But do you mean with the braking problem? Yes - that is possible too... I'm using Carbotech XP10's, and given the wear rate, experienced folks have said its time to step up pads. Maybe they are prone to depositing material, even once parked, at the temps they are reaching? No idea. The rotors go from new to heat checked to cracked fairly quickly.

As for technique, yes... I'm sure there are 1000 ways I can improve. Instructors and coaches I've had in the car said I am doing great on the brakes, so I don't think I am doing something hinky that might cause excessive temp/wear.

As for overdriving tires, probably. That's an area I don't really understand how to tell the difference between useful slip angle and tire shredding uselessness.

[slowmow]

Originally Posted by Jdmjunkie

Are you constantly using Abs in every braking zone? That can also generate a lot of heat. Do you have brake fade issues?

Sometimes I get brake fade, but usually only in longer sessions on tracks without longer periods between intense brake zones.

I don't think I'm into the ABS... definitely know what that fells like and try to brake just shy of it. Though, with the diabolical wheel vibrations and brake vibrations, the brake pedal feel isn't exactly easy to parse.

[strat61caster]

What brake pads do you use? You shouldn't be getting fade at all and a compound more track-worthy is less likely to build up deposits.

Are you cleaning your wheels before you balance them? Some techs are too lazy to clean off the area before sticking the wheel weights on and no tape will stick to grungy wheels for very long.

Which 3m tape did you try? Not all of it is created equal. I know the foil tape I've tried had subpar adhesive. Maybe some kapton is in order? You don't need the 600°F stuff, if you're wheels are getting that hot your tires are melted. Literally melted. 300°F is probably plenty, they might spike to 250°F in the most extreme scenarios but most of the time should be under 200°F, you want a stronger adhesive since it's the forces that are getting you, not the heat.

[Icecreamtruk]

Dont balance your track wheels, have someone who knows what the yellow and red dot on the sidewall of the tire means mount your track tires to your wheels.

[colin88]

Originally Posted by slowmow

Hello all,



Sorry for the noob questions, but here goes:



1) I can't keep wheel weights on at the track. I've tried tape (duct, Gorilla, and 3M foil), but the adhesives just melt. Next up is 3M high temp foil, but haven't tried that yet. The vibrations are diabolical when the weights inevitably fall off. I asked guys at the track, and got a range of answers from "use tape" to "I don't balance my track wheels because weights just fall off and the tire moves on the rim anyways, and you pick up rubber, etc.". Suggestions?



2) Last track day, in the last session, I got a clicking when under braking and turning left. I had enough time to quickly "play" with it, and adding steering or braking intensified the sound. I'm going to check the CV axle, wheel bearings/hubs. It sounded like front left...but hard to tell. Anything else I should look at? I had an off track excursion through a grassy field that was fairly smooth and uneventful (turn 10 at VIR).... relatively ... but you also jump FIA "gator" curbs at real speed there, which seems like it puts a beating on the car.



3) I keep getting "warped rotors" - I've read/heard that its likely pad deposits. I try to be vigilant about not stopping and holding the brakes when they are super hot, using the hand brake, etc. I try to take a cool down lap when possible, and cruise through the paddock for a few "laps". Ideas?



Thanks all... cure me of my ignorance.

Your not meant to run weights at the track. At least here in w.a. they are banned for safety reasons

Sent from my SM-N975F using Tapatalk

[86MLR]

Using drilled rotors? look for cracks.

Have you thought of ducting for the brakes?

Balancing? Correctly mounting the tyre, as stated above, will help, olot, also, have you tried Dyna beads? Im getting some for the wire wheels on my Harley, the physics seems viable.

Do you skim your discs when you change your pads? If not you should to clean off the old pad materials, and how do you bed in your brake pads.

[Dave-ROR]

Originally Posted by colin88

Your not meant to run weights at the track. At least here in w.a. they are banned for safety reasons

Sent from my SM-N975F using Tapatalk

Allowed in the US.

OP, aluminum HVAC tape generally keeps the weights on. Just make sure the wheel is clean first.

[colin88]

Originally Posted by Dave-ROR

Allowed in the US.



OP, aluminum HVAC tape generally keeps the weights on. Just make sure the wheel is clean first.

Isn't there a slight bit of concern that a weight is going to end up in someone's windscreen or a bystander ?? 200kmh lead essentially a bullet

Sent from my SM-N975F using Tapatalk

[Dave-ROR]

Originally Posted by colin88

Isn't there a slight bit of concern that a weight is going to end up in someone's windscreen or a bystander ?? 200kmh lead essentially a bullet

Sent from my SM-N975F using Tapatalk

In 20+ years of track days and racing I've never see that happen. I've seen at least 15-20 animal strikes on track during that same time though, including birds into windshields..

Bystanders, in lawsuit happy US, aren't usually that close to the track surface (ironically at a dirt roundy round track I have been hit, in the temple, with a bolt that flew off a race car.. that hurt!

As for windshields I'm sure anything is possible but it wouldn't be my primary concern.. especially when those large birds that weigh more a lot more than a 1/4 ounce wheel weight are just enough to shatter the windshield but not cause injury to the occupants.

[NoHaveMSG]

Originally Posted by slowmow

But do you mean with the braking problem? Yes - that is possible too... I'm using Carbotech XP10's, and given the wear rate, experienced folks have said its time to step up pads. Maybe they are prone to depositing material, even once parked, at the temps they are reaching? No idea. The rotors go from new to heat checked to cracked fairly quickly.

This is exactly your problem with brakes. Even running BBK I would get deposits on the friction rings when I ran XP10's and it gave the car that warped rotor feel. They would just smear all over when they got hot and are garbage above a novice level.

High temp foil tape works for me keeping weights on.

[slowmow]

Thanks to all that have commented and offered advice. Appreciation. I will try getting a shop to mount the tires using the red/yellow marks to achieve some better level of balance without weights, and use 3M high temp foil tape if weights are needed... and clean the bejeezus out of the wheels beforehand. I'll step up from Carbotech XP10s, probably to CSG's C2s.

Clicking under turning (especially when braking) sound like CV axle? I'll search previous posts/threads, but any opinions on Advance/Autozone aftermarket (much cheaper, guaranteed for life) vs. OEM vs. something meant for abuse? I'm doing ~12 track days a year, so longevity given wear and tear is a consideration.

Again, thanks all. Having a community of more experienced folks to get advice from is super valuable.