$5000 budget Mustang

[Ron S]

Don't know if anyone else that is running a full floating rear is experiencing the same issues I am. It seems the inner axle seals just won't stop leaking. These rears are unique in the fact that you pack the outer wheel bearings with grease, and seal the gear oil in the center section. They don't want the gear oil getting to the wheel bearings and cleaning the grease out of them. I have replaced the grease seals 3 times, and they just let the oil leak into the wheel bearings constantly.

It was so bad that on my AMX rear I machined the inside of the axle tubes to except Dana 44 front inner axle seals. Figured that is what the OEM did and it should work, but that didn't fix my Mustang.

On the Mustang I vented the center section, and each individual axle tube thinking they were building pressure blowing past the seals, didn't help. Glued the aluminum seal housing in place thought maybe it was leaking past the O rings, didn't help.

Several calls, and a bunch of investigation later this is what I found. Due to the cambered axles, Nascar uses these funky seals that have the ability to seal even when there is a fair amount of misalignment. It is a dual seal, in which you pack between the two seals with axle grease, installed them today, they seem really nice, will let you know how it goes.



http://www.sealsit.com/specs/axlehub.pdf

[Mike Holleman]

Ron, I'm running a double set of seals. One set just inside the inner tube and a second that fits further in the tube. I also put a baffled vent in the housing with the canister mounted up in the quarter panel. I think this combination fixed it.

[Ron S]

With all the working on the other car this poor car has been abandoned. Baer sent me a new brake set up before I went to optima, I never had a chance to adjust anything before it left for Vegas. Car slid all over the track, front tires locked up at every turn. Adjusted the rear bias as much as possible, but still not a lot of rear brake.

While getting ready for Motorstate I decided to check the front to rear brake pressures. The first check, pushing as hard as I could, showed 2100psi front/ 400psi rear. Don't know what they are supposed to be, but I know that's not right.

Decided to ditch the tandem master cylinder with the rear bias adjuster, in favor of a dual master set up. Drilling the holes in the firewall was a real pain, but I did get it done. Made an aluminum cover for that mess, powder coated it, and will assemble it tomorrow.

The original set up definitely never worked considering I've cracked 3 front rotors, and the rears look pristine. This definitely a case of too many irons in the fire, this should have been checked/corrected years ago, just had too much going on. Building the car is easy, sorting it is the hard part.

[andrewb70]

Ron,

It sounds like you need to do some further calculations. Aside from the line pressure to the calipers, you need to take into account the piston area of the front and rear calipers. Having such a difference in pressure may not be a bad thing (although I would still want to know why the huge difference) if the piston area of the calipers is sized accordingly.

Paging Ron Sutton!!!

Andrew

[Ron S]

Made a bunch of calls Andrew, just to find out what others pressures were, and what the percentage differences were. What we have determined is that there is already bias built in to the system because of the piston differences front to back. I'm going to start with a 3/4" masters front and back, and change if need be, after driving it. It has to be better then what I have.

[Crestronwizard]

"Building the car is easy, sorting it is the hard part. "

That's what I am dreading more and more each day.

[Z06killinSBF]

Shoot I'm just having a hard enough time building mine!

[Ron S]

Got the masters in place, will make up the lines tomorrow. This is getting stupid working on two cars at once, and posting crap.

[tommycomfort]

This is getting stupid working on two cars at once, and posting crap.

Yeah, but we appreciate you sharing your hard work. So, stop whining about it!

[Ron S]

But I / And I / But / OK

[HellPhish89]

But I / And I / But / OK

:Ron hangs head... slinks back to garage:

[rixtrix1]

:Ron hangs head... slinks back to garage:

And keeps turning out great stuff faster than everybody else!

[Ron S]

Was just finally uploading some pics on to the computer from Bob's event in Pittsburg. Thought they were cool so I would post a few. Some of the best pics I've seen of this car.

[Krazed]

Love seeing that thing!

How's it stopping now after the changes?

[Ron S]

At the Pitt event I took second on the road course, the brakes feel so much better. I can't believe I drove that car that way (and thought it worked ok) for that long. Still tweaking on the alignment a bit trying to get the camber where I'm happy with it. If you look in a couple pics the inside tire is far from flat which I can't think is optimum.

[andrewb70]

So Ron,

Give us a rundown of what ended up happening with the brakes. What MC sizes did you settle on? What were the resulting front and rear pressures?

Andrew

[Ron S]

I put the 2 separate masters on the car and started with 3/4f / 3/4/r. After checking the pressures with the balance bar in the middle. 3/4F-3/4R Masters. The pressures were 1050 rear / 950 front. Adjusting the bar I could get it 1200 F/ 800R and then reverse it 1200R/ 800F with just a turn of the knob. It did seem to favor the rear pressure wise, so I may change the rear to 7/8. After changing to 3/4f / 7/8r the with the adjuster in the middle the offsets got worse high in the front low in the rear. Ended up with 7/8f / 3/4r with 1050/1050 on pressures. makes no sense to me, but that is how it ended up.

[andrewb70]

I put the 2 separate masters on the car and started with 3/4f / 3/4/r. After checking the pressures with the balance bar in the middle. 3/4F-3/4R Masters. The pressures were 1050 rear / 950 front. Adjusting the bar I could get it 1200 F/ 800R and then reverse it 1200R/ 800F with just a turn of the knob. It did seem to favor the rear pressure wise, so I may change the rear to 7/8. After changing to 3/4f / 7/8r the with the adjuster in the middle the offsets got worse high in the front low in the rear. Ended up with 7/8f / 3/4r with 1050/1050 on pressures. makes no sense to me, but that is how it ended up.

It makes perfect sense. A smaller bore MC will give you MORE pressure.

Andrew

[wfo guy]

The pics are great, Ron. I hope everything else goes well.

[Ron S]

Someone just sent me this from the Speed Hunters web site. Article was on Ken Blocks 4x4 Mustang drift car. If you scroll down the article and get to the design inspiration board that they put together. There is a couple pics of this Mustang on there, one of the chassis, and one complete. Kinda cool


http://www.speedhunters.com/2014/12/...r-build-story/