Need advice, overheating brakes at track

[flash968]

something many people fail to consider is the weight of their wheels and tires - this affects braking requirements dramatically - a couple of pounds of extra tire or wheel can make a HUGE difference in how much brake you need

upon looking at the shot of the white car in the corner, those wheels are probably extremely heavy

i would also say that you need a boatload more spring and swaybar

[aftermath]

One reason I posted the picture is that the whole stance of the car has changed with the tires. Other racers that know my car say my body roll is pronounced now and the pictures I have show a lot of squat out of the corners. I have way stiffer then stock springs and upgraded sways, but its obvious they are no longer enough.

[flash968]

the rear is showing the most need - from the amount of roll, it looks like you need to double that spring rate - if you only bumped up the front, then that would explain a lot of the braking issues, as you are probably pushing a lot more than you need to

[aftermath]

Im trying to recall details of the car, the fronts coil overs are 600lb and the rear torsion is 29mm. The sway are 28 front and 22 rear. Im trying to confirm those numbers but I cant find the email when I bought the car.

[Rasta Monsta]

Great googly-moogly, your front springs are far too stiff for 29 in the rear. Try 350 (maybe 400).

Totally explains the horrible stance in earlier pic.

[flash968]

yeah - front springs are too stiff for the entire rest of the setup

front sway bar is way too small for that spring too - a 32 would be better, but at least the 30mm M030 bar

based on the 292# wheel rate of the 29mm torsion, i would either add a 150# coil to the rear, or drop down to a 350# in the front

as it stands though, that car must push like crazy, and then snap power oversteer

[333pg333]

Originally Posted by 924RACR

Actually the point about better rubber means (assuming you do it right, your suspension balance is good, and you are using the extra grip) you can carry more speed THROUGH the corners.

Since you can go THROUGH the corner faster, you can enter the corner faster... which means LESS braking.

So, I understand the desire for better brakes, and nothing wrong with that - but I'm wondering if you're not getting the full benefit of the fresh rubber (or is it too old to stick well, if used?).

Vaughan, I think it's actually both symptoms that you find with better/bigger rubber. Yes you can carry more speed through the corners (although you induce more body roll as well...all things being equal), but coming up to hard braking areas puts more stress on the braking system as you are carrying more speed...in my experience anyway. As an example, I went from noisy push understeer on worn Nittos to sharp turn in and higher corner speed when only switching to Hoosier R80s in the afternoon. In only say 8 short laps I was getting brake fade and soft pedal where I'd previously not had any of that all day. So it's a dual edged sword in some cases.

[flash968]

yup

i think part of the problem is the unbalanced suspension - this would force you to brake harder than you would otherwise need to - this problem may not have shown up though until the larger tires came into play

[aftermath]

Reviving the thread as Im thinking about the car....

Im running Hawk Blue and I decided that Im at least going to try a more aggressive pad. My car is a mix of parts and Im never sure what will fit.

I tried to look up a more aggressive pad ( dt60 ) but I only found a match for the rear.

When I ordered brake pads a while back I spoke with a shop and sent them pictures, this is what they said...

"You have either early 944 turbo or 964 calipers F&R You need Hawk
HB170E650 brake pads', this part number is for the blue pad I recieved.

Anyone know a part number for something I should try? Ive heard from many people that a more agressive pad is what I need to match up to the rcompound tires I switched to this year.

[jpk]

Hawk numbers the pads by pattern (HB170) and thickness (650 = 0.65 inches) The letter represents the compound (E for Blue) G is the DTC-60 and U is the DTC-70

They do list an HB170/650 for the DT60 and DT70 compounds; look for a 1994 968 with standard suspension if they don't list it as an application for your car.