924Board.org

[benlg81]

Hi All

Had the afternoon yesterday blasting around mallory park as part of the ppc challenge and was wondering if anyone else has had these symptons after a track day and best ways to sort them before the next one or ust before driving in general.


The first one is the front grease caps leaked grease out of them onto the wheels not an issue just wondered if this is normal and how i should go about top it back up.

the second one is the brakes, they started to lose the pressure a bit but thats just down to the fluid which has been changed but only to dot 4. but the main issue is the high pitch noise now coming from the drivers seide all the way home it stoped if i just rested my foot on the brake pedal or braked it would stop then come back again, anyithing i should look out for when i take the wheels off later.

the last and main issue i hope will be easy is the gearbox/back end. after the track day it was fine but on the way home it developed a whine type noise which was apparent during acceleration and decelaration. i have only just changed the fluid could this simply be a case of toping it up now after having a hard time on track? or is it something else to look at?

cheers in advance for all help as i want to get back out there and have another go quickly

Cheers

Ben

[968rz]

#1. Normal, the high Gs are forcing the grease out. Try new caps or pack the bearings after every event.

#2. Get race pads for the front (track use only) and bleed the brakes all around (sometimes even during the event). The noise could be glazing on the rotors, check/replace the pads and machine them

#3. That one I'm not sure of with out hearing it.[/quote]
_________________
Rick
79 924 coupe Petrol Blue 3spd auto (wife's DD)
93 968 coupe Amazon Green 4spd Tip (my DD)

[924RACR]

On #1, I believe that's more likely heat causing your stuff to expand - are the caps popping loose? Mine have. Then again, maybe that's not the exact thing you're dealing with...
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Vince Ponz]

keep the rear brakes well adjusted.

You may have warped them so wait till they cool off raise the car on that side and rotate the wheel. One see if there is any brake residue on the rotor, do you hear a slight grinding on the high spot or all around.

On the track the fronts get a work out if the rears are not perfect. when you got off the track maybe you did not cool off the brakes.

Run ducts to the front for fresh air. Remove temporarily the side makers and run the ducts. Off the track put them back.
_________________
"Never let them see you sweat"
77.5 924 modified track car
79 931 Euro stock
88 924S SE
87 911 Targa stock

[benlg81]

the problem was there waqs no where to leave the car with no brakes on, the padock was on a slope,

will definatly look into some ducts for the future

think it was down to the fluid getting very hot. i have taken the pads out copper greased the backs and given the fronts a little rough up.

also re adjusted the back brakes hopefully everything else is fine.

checked the gearbox oil and it is stil very full comes out if you open the fill hole. so not checked if it is better now the oil cooled down will report back later.

also put the old standard 14's on as the front left 15" tyre has a mighty flat spot from the mother of all lock ups.

any ideas if 15 or 14 semi slicks are cheapest what do people run out on track?

[gohim]

For a little more accelleration, get some good low profile rubber for the 14" wheels and run them for track events.

The brake pads are probably glazed, and have probably transferred some melted material to the rotors. Take some high grit, low number sandpaper to the rotors and scrub the stuff back off (wear a dust mask). Rough up the front brake pads as well, to remove the glaze.

Check and adjust the rear brake shoes between runs to keep optimum brake performance.

Carry a set of wheel chocks with you so you can block the wheels when you park, and don't have to set the parking brake (which causes warping if set when hot).

Use a good grade synthetic wheel bearing grease to help prevent grease from melting and running out (I use Valvoline Synthetic Grease, and it has never run off or melted). Replace the grease caps for better seal and more tension to hold the caps in place. Seal the speed cable hole with silicon sealer.

What weight gear oil did you fill with?

[924RACR]

I haven't tracked with 4-bolt brakes, but gohim's exactly right on that last para for sure - matches exactly what I've been doing on the racecar.
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[peterld]

And get rid of your front brake backing plates - your brakes will love for it!

[benlg81]

the oil was fuchs 75w90 semi synthetic

is it an easy job to remove the backing plates? will it be ok for every day use as well?

is it a common issue with the gear box oil getting too hot and thin and creating a whine or am i using the wrong oil all together?

[Cedric]

I have the same problem with grease that drips out, but its not that much. I use castrol grease, it made it a bit better.

Why not just leave the car with a gear engaged and the car wont roll anywhere ?

Backing plates are an easy job, very easy. Just take of some bolts.

Go for some real brake fluid, like motul RBF600, its cheap and handles a lot of temperature.
_________________
1980 924 Turbo
www.instagram.com/garagecedric/

[Mahatma Gadhni]

I had some scratching noises from the back once after running my car really hard. It turned up to be a coil spring in the drum brake that got loose and caused the noise.
_________________
1984 924 2.0 NA

[John Brown]

Gohim and group have advised well. I've probably 'tracked' a 'stock' 924 with the original rear disks harder than anyone; so my $.02.

The front wheel bearings are very highly loaded plus the original small front brakes are adequate but between the two sources a LOT of heat. As Gohim stated; use a high quality synthetic wheel bearing grease.

It's not unusual for a street car to need bleeding of brake fluid more than once the first day you track it. The fronts once in good repair are adequate; the rear drums are not and never will be. If you continue to track the car the best you can do is take a good close look at wheel bearings and brakes front and rear.

Everyone (well - lots of folks) over here swears by Swepco 201 trans lube. Main point is use a quality synthetic lube. As in the case of wheel bearings the use of synthetic is because heat is the culprit.

When we finally quit racing the 924 with rear drums we were using up a set of rear brake shoes in less than a day. Track days shouldn't be quite so bad as all that; but gives you an idea what the future will bring!!
_________________
John
80 931 - #931 44Cup
99 Escalade - tows track cars
gone but not forgotten: original 924.org car - 82

[Cedric]

hmm, my rear shoes lasted at least a season. And that included lots of track hours. Always adjust the shoes so that they can have some room to expand while their getting hot. Or else you will have the dragging and that will burn them pretty fast. I tried some other solutions than stock for brake shoes. But i didnt do any different, i got more track hours out of the stock ones..
_________________
1980 924 Turbo
www.instagram.com/garagecedric/

[benlg81]

Hi all just a qucik update

drove the car too work today and the gearbox seamed fine no strange noises or feelings hopefully it was just a case of the oil getting too thin could this be right? if so what is the recomended oil for hard driving and track days as i dont want to put the box in any unneeded stress.

After scrubbing the pads ect they seam perfect again so thats also a bonus

just need to look for some tyres now and we're away again.

Ben

[Vince Ponz]

If you track the car and have the 4 bolt setup I want to mention that these cars are momentum cars. By this I mean stay off the brakes and prepare the turn without braking if possible. Keep the momentum up and you will be faster. When Bridgehampton was opened I would barely brake. Plenty of elevation changes and right turns. I would stay with early to mid 80s 911. Not down the straight but in the turns. [80,81,82s] It was a whole package to think about when driving at the track. Some places for us are better than others. Pick your spots to your advantage.
John Brown was at this track so he knows what I mean. Great track.
_________________
"Never let them see you sweat"
77.5 924 modified track car
79 931 Euro stock
88 924S SE
87 911 Targa stock