Prop Valve 4 Whl Disc Brake Avanti/interim update

[sbca96]

I know I got them to lock, but I dont recall which did first. I was
always under the impression that they rears should lock first, thats
what my Hawk did (as far as I remember). This paragraph explains the
reason the rears tend to lock first :

"Whether the car is equipped with front disc and rear drums, or has four-wheel discs, hydraulic pressure should be reduced to the rear brakes for several reasons. The single most important reason is because even under moderate braking, natural weight transfer reduces weight on the rear tires and moves the weight to the front. This unloads the rear tires, which makes it much easier to lock up the rear brakes in hard braking. Once the rear brakes are locked, the tires skid, which immediately causes loss of control."

Now I guess I need to get the Avanti out of the garage and see what
its doing now. I have changed it since that initial testing, it has
the 13" brakes up front now. My dad is visiting next week, so we had
planned on driving the Avanti around, he wants to try out the TKO. I
also want to get more video of it, maybe some of which lock first. I
know that the fronts are working, it nose dives quite well. I doubt
it would stink bug that much if the rears were doing all the work.

Jim, what did you find out with your Cobra setup?

Good info Jeff!!

Tom

[bige]

I finally got to the brakes. I was sidetracked replacing the constant pressure valve body in my TCI 200 4R trans but now with the 'going' handled I got back to the stopping.

I removed the proportioning valve and did not install the metering valve so I'm out there 'naked' with full pressure to the rear brakes. I checked the brake pressure at the rear calipers and it's the same 1000 lbs that I have at the master cylinder. Everything I've read tells me I should have 1,000 lbs to the rear brakes for them to work properly so for now I'm not going to limit their pressure. I used my pressure bleeder with a special adapter for plastic reservoir master cylinders.







With the drums and the Chrysler dual master I could not power brake the car past 1300 rpm without the wheels spinning and the emergency brake didn't do anything going forward although it held a little in reverse. I didn't try power braking up until the wheels broke loose but it went past the rpm that it would normally break them loose.

The test drive was, thankfully, uneventful. I couldn't due a DEEPNHOCK 60 to 0 slam on the brakes and hold on test however hitting them hard but not locking them up from about 45 mph did not produce anything but a straight, nicely modulated stop. A tire screeching "holy crap" test will have to wait.

ErnieR


On its way to a 15.097 Island Dragway Great Meadows NJ Spring 2006.

[DEEPNHOCK]

I like your incremental steps.
This way you know where it changed, and that makes it easier to change...
Oh, on the Yellow POS, my first 'heavy' brake application (that was over 50mph) was done at Osceola drag strip during South Bend '02.
Like yours..It stopped nice and straight[]
Nice work!
Jeff[8D]

The test drive was, thankfully, uneventful. I couldn't due a DEEPNHOCK 60 to 0 slam on the brakes and hold on test however hitting them hard but not locking them up from about 45 mph did not produce anything but a straight, nicely modulated stop. A tire screeching "holy crap" test will have to wait.
ErnieR