Braided Brake Lines

[Frank Corkran]

All right, I'll play along.

 

Nothing in what you quoted prohibits your "suggestion". You can have all the stock/modified specified stuff for CMC, but add a pressure sensor to sample the rear line pressure. Then a radio signal would be sent to a remote hydraulic actuator attached to each rear caliper. If you used wires for the signal instead of radio waves, it would be similar to the Ford Integrated Brake Controller for trailer brakes. Nothing in what you quoted prohibits this.

 

What would make such a system illegal for CMC (without approval from the CMC Board of Directors) is a critical section of the series rules you didn't quote:

 

5. ALLOWED MODIFICATIONS

Other than those items specifically allowed by the rules, no other part or component may be modified, removed, or disabled. If there are any "questionable" or "gray" area modifications, the competitor shall contact the CMC Board of Directors for clarification before competition. Replacement parts must be original equipment manufacturer (OEM) or others of equivalent OEM specifications. (i.e. – OEM replacement parts from any retailer are allowed provided they meet OEM specifications and do not offer a performance improvement over the OEM part they replace.)

 

Section 5. ("Unless I specifically say you can, you can't.") is what makes CMC different from many other series - and has kept it true to it's original intent. See section 2. On the other hand, AI is more of a "Unless it's specifically prohibited - knock yourself out!" type of ruleset. But you can still get yourself into trouble playing in the "grey" areas around those prohibitions.

[jon dawes]

i knew that! i was just seeing if somebody else would catch it. . .er. . yeah!

[NorrFam]

Ok, Well. With all that being said I believe what I shall do since we are talking HPDE for now and at most TT in the future. I think I will get new rubber lines and anytime I think they need to be replaced, will do so. Cost is less, I will know what I've got and its basic limitations, and I can get them most anywhere, usually.

 

Thanks for all the input.

 

And Frank, I understood the concept of your words but not the implementation. No braided lines I have looked at were marked -3 AN or - 4 or anything else so I dont know how to tell one from another. I do recognize the different types of banjo bolts and that some require the 15* bend coming off the caliper.

 

Curious, given Jons reading of the rule book that allowed rerouting in some cases, 17" lines would not be long enough to allow for full travel of the shock. Reads like, get a 30" line and run it where you have to in order to miss anything that needs to be missed. Break out a batch of Colin's zip ties and have at it.

[Frank Corkran]

Ok, Well. With all that being said I believe what I shall do since we are talking HPDE for now and at most TT in the future. I think I will get new rubber lines and anytime I think they need to be replaced, will do so. Cost is less, I will know what I've got and its basic limitations, and I can get them most anywhere, usually.

 

Nothing wrong with that approach. The main advantage of braided lines is better feel/modulation due to a more rigid hose. This benefit is much more pronounced on the front than the rear, especially if you're running a brake bias that allows the fronts to always lock first - such as with a stock prop valve and/or more aggressive pads on the front than rear. Like I said, OEM lines are very rugged, just expand a little more under pressure than the braided lines.

 

And Frank, I understood the concept of your words but not the implementation. No braided lines I have looked at were marked -3 AN or - 4 or anything else so I dont know how to tell one from another. I do recognize the different types of banjo bolts and that some require the 15* bend coming off the caliper.

 

All the braided brake lines you've likely ever seen use -3AN Teflon lined hose (larger -4AN hose is used in a few applications). The hose assemblies (hose w/fittings on each end) meant as direct replacements for stock hoses (probably what you've seen) have end fittings crimped onto the body side that accept either an SAE Inverted Flare 3/16" tube with 3/8x24 nut or a DIN "bubble" flare 3/16" (4.8mm) tube with 10mmx1.0 or 12mmx1.0 nut. This fitting also usually clips into the body mounting bracket. There are adapters available that clip into the body mounting bracket like this hose fitting, but they mate to a stock flared tube w/nut on one side and a female -3AN hose fitting on the other side. There are also caliper adapters that are a banjo that mates to a female -3AN hose fitting. Now you can use a hose of the correct length with straight -3AN hose fittings on each end. These hose assemblies are available pre-made in various lengths for $12-$20 each. Or you can buy reusable end fittings, "olives" (sort of a crush sleeve) and hose and make your own. I'd recommend the pre-made hoses because a) the Teflon-lined hose is a pain to put the fittings on, and b) you don't have a means to pressure test the hoses at twice the working pressure. You don't want to discover you didn't get the ends installed properly when the hose pops out of the fitting during threshold braking.

 

Curious, given Jons reading of the rule book that allowed rerouting in some cases, 17" lines would not be long enough to allow for full travel of the shock. Reads like, get a 30" line and run it where you have to in order to miss anything that needs to be missed. Break out a batch of Colin's zip ties and have at it.

 

There may be a way to route a longer hose that doesn't kink the hose or foul with anything at some point in the articulation of the rear suspension, but now the expansion of your long braided Teflon hose may have as big an effect as the greater expansion of the much shorter stock rubber hose.

 

Another thing about the braided lines: the braid is what contains the hydraulic pressure. If you knick the braid, the inner Teflon tube will begin to extrude outward at that point. The inner tube is now thinner at that point, so this will continue until the inner tube finally ruptures - and away you go! The thick outer rubber jacket on the OEM hose isn't involved in containing the pressure, it's mainly for resisting cuts, abrasion, kinking, etc. If something rubs on the OEM line, you'll likely spot the damage to the outer jacket before it damages the inner pressure hose. Lastly, the SS braid acts like a file/hacksaw on anything it touches - such as a tire sidewall. The rubber line isn't likely to damage anything it touches - plus the factory went to a bit of trouble to make sure it wouldn't touch anything.

 

Keep the factory rubber flex lines in back, inspect them regularly and replace them when appropriate. Sounds like the "best" way to go for your street/HPDE car. And what will you do with the money you don't spend on braided rear lines (all together now)?

[jon dawes]

SPEND IT ON LIQUOR AND WOMEN OF ILL REPUTE? FUND REBEL GROUPS IN MICRONESIA? GO TO VEGAS? TELL ME TELL ME TELL ME, FRANK??????!!!!!!

[Frank Corkran]

Jon, if you don't know the correct answer to that question by now then I'm afraid there's no hope for you at all. Perhaps you'd enjoy collecting stamps of the world instead?

[NorrFam]

I dont know what to say Frank. Some how he keeps getting in the door.

 

I would spend lots of money on seat time if I had lots of money. Thats why I am working weekends for Laura so I can run other weekends.

 

Now if I just dont have any more offs in front of Chris I'll be ok. On DOT Rs I would a got around but on hot streets nope it just didnt happen. If you dont know what Im talking about .....never mind.

 

Thanks guys!

[jon dawes]

. .. hey i like stamps. . .

[Renntag]

there ya go. thats a cheap hobby for ya.

[Frank Corkran]

I would spend lots of money on seat time if I had lots of money. Thats why I am working weekends for Laura so I can run other weekends.

 

[Mr. Burns rubbing hands] Ex-cel-lent! [/Mr. Burns]

 

Now if I just dont have any more offs in front of Chris I'll be ok. On DOT Rs I would a got around but on hot streets nope it just didnt happen. If you dont know what Im talking about .....never mind.

 

Don't know about your off but answer me this: Are you in a big hurry now to go to R's so they hide your mistakes from you (for now)?

 

I guess I'll let Jon slide once again because:

a) he should fit right into the CMC group. If he behaves like this when sober...

b) I just finished watching the 2006 Nationals DVD that came in the envelope with my NASA Competition License. So I'm feeling charitable.

 

Edit: one of the video editors really must like Christian's '66 Mustang. Seemed like it's in nearly every AI/CMC race scene.

[NorrFam]

No Frank not in a big hurry for R's. I found a good street tire that suits me. It wasnt a tire problem. Like you said the R would have helped me escape but it was a mistake (for streets anyway).

 

I just tried to go too deep in the brake zone in 1 at VIR. If it had been lap one or two I might have got it but it was deep in the session. It was a drift off late in 1 and in a race would have been coming back on once I got things collected. In DE it was a sit and wait on the corner workers to let you go again. Thats where the cats set the grass on fire. If I could have kept going instead of sitting (going very slowly, watching the workers) I doubt the result would have been the same. No damage to the car, just scorched grass about the size of 2 or 3 cars. Didnt even know about the grass til I was getting checked in the pit.

 

Needless to say I heard about it good naturedly in the paddock once people figured out who caused black flag on the group. But we got back out for some more laps after.