Hey all,

So last year I had a WG line melt and blast me with all the boost I could make in a third gear pull. So I have my break-in complete and want to tune some boost into the equation.Since I do not want a repeat of this happening I am wanting to go with either hardline( brakline) or AN lines.

Anyone have recommendations on sizes for either?

Thanks, Dave

 

I'm personally using SS push-loc fittings and 1/4" brake line directly from my compressor housing to the WG port. When I up the boost I'll run the brake line from the WG to the boost controller solenoid. I can't comment on how well it works yet, although I expect it to be more than enough.

 

You've got a couple options. You can buy SS line (4AN is good) and all the proper fittings. If you have a Tial gate though it will be tricky because they are metric threads on the side. You can get stainless steel line, skip the fittings, and clamp it on a barb there with a hose clamp. You can run stainless steel to the side port and a separate line to the top port, using silicone or neoprene (fuel hose). That's what I do. The side port is the most important one, it supplies the air needed to open the wastegate valve.

also, set an overboost fuel or spark cut in your engine management system. While certainly not good for the engine, it's much preferable to overboosting. So for example if you have a PFC and want an 18psi fuel cut, set your boost level in the Commander or Datalogit to about 1.05 kg/cm^2. that will make the overboost fuel cut kick in somewhere around 1.25 kg/cm^2 or 18 pounds .

 

I've done aluminum tubing using -AN fittings at the compressor and wastegate and using tube sleeves and nuts on the lines. Easy to build, works well, and looks nice. You could do stainless line for a little more bling, it's just harder to flare. There are -4 fittings available that thread right into the Tial metric holes. Think Earl's has them.

Stainless braided line won't have much more, if any, temp resistance than regular silicone line.

Another option, easiest and cheapest, is insulated sleeves over the silicone line. I've used this in lots of areas with great success.

 

Thanks for the input everyone. I will be going with the hard lines. Is there a preffered size for that? I.D.? Standard brake line size etc..Is brake line sized in -AN?

Thanks again.

Dave

 

the -an hardline that Ludwig is talking about is aluminum line that you need to flare (37 degree) with a tube sleeve fitting.

The fittings I'm using in my TiAl WG are 1/4" NPT. It is not recommended, but the metric thread on TiAl's are close to pipe thread, I just ran a tap through the housing with it apart and use the push-lock NPT fittings to 1/4" brake line. I haven't ran it long enough to recommend it, but it's what I did.

 

I did an informal test on this matter to simulate the most extreme condition--hose touching hot exhaust. I took rubber vacuum house (Autozone stuff), silicone vacuum house (Hose Techniques), neoprene fuel/emissions line (normal Autozone), and stainless line. I have a very very hot soldering gun that is not actually meant for wiring and can glow red hot (like super hot exhaust piping).

I placed the gun on each one of them and tested how long it took for them to melt through. Rubber went first as expected. Silicone and neoprene fuel line lasted about as long, and if anything the fuel line lasted longer because it had a thicker wall. The stainless was practically invincible in comparison. I held that extremely hot gun to it for over a minute. It scorched the outside but it never melted through.

Try it yourself.

 

I believe you. Though the soldering iron is a fairly limited heat source. It's easy enough for the stainless braid to conduct the heat away from the pinpoint application area of the soldering iron to normalize the temp over a broad area.

 

Awesome! Somebody who has data instead of just an opinion. Was the stainless line rubber or teflon? The teflon has a higher temp rating.

Also BTW -- the banjo fittings on my Tial 44 WG use a M10X1.0 bolt. That's the same setup used on some brake calipers. A banjo to -4AN fitting should work.

 

i had extra ss braid from my fuel lines, so i ran them as my wastegate lines too. 5/16 to my tial 44m. doesnt feel exact, but it seals well with a worm gear.

 

I just ran 1/4 brake lines with 4an tube nuts on the end where my rear WG lines run under the manifold. It works flawlessly. I run a short section of rubber hose with AN fittings to connect them to the solenoids. This prevents the lines from vibrating as much and should keep them from cracking.

 

i definitely need to get a 37 degree flaring tool...

 

I use -4AN SS braided lines for my wastegate. Most wastegates use 1/8"NPT inputs so you can adapt to -4 pretty easily. Worth the money, too.

B

 

im confussed... so whats the prop id of line i should run for a 44mm wg? also waht size thread are you guys using to tap into the compressor housing?

 

1/4" line, same as -4

 

That's 1/4" OD, not ID. Tubing is measured in OD -- ID isn't usually referenced. For boost reference, the size of the pipe thread won't matter. 1/8", 3/8", 1/4" . . . all of them are large enough that they won't restrict flow through the 1/4" tubing.

 

I would be worried about the hard line failing at the fittings due to vibration work hardening that area over a period of time. I have seen copper lines do this on many occations on boilers at work and while I don't know how stainless would hold up, if it were my car I would run the hard line close and then a small section of hose on the end.

 

it was rubber stainless, the kind you usually assemble by hand (Earls etc).