Up pipe recommendations

Ok, so as moose said, I'm risking starting the Holy War of Uppipes here. I'm looking into an uppipe and right now I have my eye on the Crucial Uppipe. I know some of you have them already (slug and AthensWRX specifically) and I got good feedback on this pipe. Of course, everyone says that flex pipes are better because they won't break, crack, leak, etc. Does anyone with a crucial have leak, crack, breakage problems? If so, are these covered under the lifetime warranty Crucial offers?

Those of you with flexes, what flex do you have? Is it 321 steel or 304, painted, ceramic coated, etc? Do you have leak issues, fitment issues, cracks? What kinda of warranties are offered on your pipe?
I don't want to start a war of which is better unless you can honestly say "I had an ABC solid pipe, it leaked like no tomorrow and cracked in two years. Then I got a XYZ flex pipe 5 years ago, no problems since." If you have a pipe that contradicts the sterotype please tell me (My ABC solid pipe has never leaked in X years of install) etc.

I'm looking at a catless, so is your EGT sensor mount removed as well? Since it probably doesn't serve a purpose without the cat. Lastly, what kind of power increase did you see (if coupled with a dp/cbe/tbe please note that).

Thanks everyone!

 

I have a Perrin solid uppipe. It does not have an EGT bung so your sensor is eliminated. Honestly, there's no reason to keep the sensor if you ask me; it's only there to ensure that the temp is correct for the cat. Yes, you can read the temp via the ECU, but it's in a far less than ideal location and you're better off tapping the manifold if you are concerned about reading EGTs.

I haven't dynoed mine, but between it and the Helix DP I noticed full boost some 500RPM earlier and much smoother and even powerband. Feels less like a turbo car and almost naturally aspirated now.

The Perrin is 321SS, and has very pretty welds and thick flanges. I dig it.

There's a good thread going on ClubWRX about uppipes and leak statistics; there were some in there who have had both flex and solid for 20-30k miles without a problem. I think it's mostly in the install if you ask me (using torque wrenches, fresh gaskets, tightening in the right order etc).

Any uppipe will give you about the same feel and performance. Even a gutted stocker.

Just my $.02...

 

Alex here...dont get a solid pipe, always get a flex. If you want to save money, gut your own pipe and just use that to hold you over for a bit.

 

i have a gutted stocker and it has been great..not bad for a free mod..wish i would have done it to begin with..plus it has heat shields on it to keep the heat in the pipe where it needs to stay

 

I had a flex PDE on my WRX. Quality crafted and worked flawlessly. I plugged the hole with a bolt and did the resistor fix ($0.25). Never had a CEL.

A catless uppipe doesn't really add power, it allows your turbo to spool up quicker. ie. about 300 - 600 rpm sooner. Power comes from getting rid of downpipe cats and tuning.

Shameless plug... it's for sale in my for sale thread btw.

 

Is the stock uppipe flex or solid (i've never really looked at one)? Alex, you always say get a flex, but i've seen no evidence that this really is a better choice, even on the nasioc threads. Can you point me somewhere that verifies this claim?
Radon, you'd be amazed what a shameless plug will do sometimes. I didn't realize yours was for sale. $200-250 is about what I'm anticipating spending so that's right in my ballpark =)

 

the stock uppipe is a flex

 

go for gutted stocker, its worth it being free. thank you to kris for being my insperation to gut mine :banana:.

 

the only thing i dont like about gutted is the possible flow degradation... the pde flex uppipe has a constant diameter throughout the pipe (except for the tiny ~1mm gap for the flex section) and is very smooth inside... the gutted uppipe diameter goes from small to large and back to small... the first is better for good flow (at least thats what i remember from a fluids class i took a while back) but i dunno how much of a difference it will make in our applications... any MEs have anything to add to this?

 

please lets not start another flow rate war :gaysex: :gfight:

 

Yeah, we can argue about boundary layers, flow rates, surface roughness, heat dissipation until we're blue... until somebody dynos all the pipes on the same car on the same dyno, we just don't know.

Personally, I don't think there's any worthwhile difference between any uppipe.. the important piece is losing the cat, and they all accomplish that!

 

yeah, i know with my STI take off and gutted stocker i made 204/211 to the wheels and im damn happy about it so if that helps anyone at all, good, if not, oh well.

 

Found this info or propaganda... take it for what's it worth.

Performance Design Enterprises flex-joint turbo uppipe. Eliminates the first catalytic converter for improved throttle response and quicker turbo spool. PDE utilized computer modeling and stress testing in selecting the bellows used with this product to ensure a long service life! In addition, the flex construction features a tube in bellows design to limit turbulence for optimal flow. PDE's dyno testing shows this pipe makes more horsepower (approx. 4 hp on the same car, same day) than a catless Subaru uppipe.

Either way, I'd still get an accordian style flex as opposed to the braided kind. Lots of info on nabisco regarding the two styles.

 

bahahaha :keke:

 

According to Unabombers Uppipe thread on Nasioc, there is not evidence that a flex uppipe is any better or worse than a solid uppipe. It all depends on the install. All uppipes will net about the same gains, generally about 10 HP, spool up will generally occur about 500 RPM sooner. I have a Scoobysport Solid uppipe, it has a 25 year warranty and I have not had any problems with it as of yet. Install with a solid uppipe will be slightly harder, but not a whole lot.

 

In my opinion if you did not need a flex joint in the uppipe then why would subaru put on in. If you look on the inside of the PDE flex uppipe it is smooth with no funky jounts but it is a flex. I would recomened the pde or simply rip the pus out of your stock one. I dont know any body who has been unhappy with the gutted stock uppipe.

 

I'd wager a guess that they did it because of sloppy tolerances in the castings. That, and being able to slap it on easily without worrying about getting things perfectly lined up.

I agree re: gutted stock uppipe. Seems to work great. Would I do it if I had to do it over again? Probably not; the construction of my Perrin really appeals to me and I like shiny bits.

 

from what i've read subaru did it for heat expansion purposes, not flex or sloppy casting. That's from a Nasioc post so take it for what it's worth, maybe true maybe not. But if it's an accordian style flex then that makes sense to me.

 

That would make sense too. I don't know the heat expansion properties of whatever Subaru used vs 304 or 321 SS. Anybody?

 

i dunno what they used either. but i know 321 is a better high temp steel than 304. It's less likely to fatigue under mechanical loads at high temps, however it's corrosion resistance is lower (relatively, but not anything that will ever affect the life of the parts to a measurable scale)

 

the PDE is ceramic coated as well

 

I found some cool info on 304 and 321:
http://www.azom.com/details.asp?ArticleID=965
http://www.azom.com/details.asp?ArticleID=967

I like this about 321:
Applications

Typical applications include:

· Aircraft exhaust manifolds

· Expansion joints

· Bellows

· Furnace parts

· Heating element tubing

· Heat Exchangers

· Woven or welded screens for high temperature mineral processing

· Spiral Welded tube for burner pipes and flues

 

im still running stock uppipe, oh mine came catless stock :naughty: