AVO Metal HFC downpipe review

[camber]

I installed this a month ago or two ago and here's the review.

 

First thing that strikes you is the size of the cast bellmouth. It's big! I swear the bellmouth bigger then turbo but I guess that wouldn't suprise some people:lol:.

 

The pipe is a full three inches with a metal HFC near the bellmouth. The gaskets are very high quality and I swore the DP mouth gasket was OEM. It just didn't have an OEM sticker on its plastic baggy:lol:.

 

This DP will fit the stock catback and uses a adapter plate that has a lip to accomodate the stock donut gasket.

 

http://i13.ebayimg.com/01/i/000/90/b1/7b58_1.JPG

 

The install is the same as any other DP. However, screwing down the bellmouth to the turbo is a bit tricky due to its size(The bellmouth seems to flare out around the bolt heads). I found a 3/8 racket and standard socket couldn't be used on most of the bolt heads at the turbo to DP connection. I used a flexible gear rachet with a box end and open end and had to take the TMIC off to get enough sweep to tighten the bolts on that side.

 

http://ecx.images-amazon.com/images/I/41B63Z6MM4L._SL500_AA280_.jpg

 

When I first installed the DP, it slightly touched the side of my 6MT. I drove around like this for a bit and it did not rattle or cause any problems. However, I went back and slotted the hole in the bracket at the rear of the DP. I was able to get a few millimeters of clearance.

 

I reused the OEM donut gasket on exhaust adapter to the catback. However, I couldn't use the OEM spring bolts and used non spring bolts provided by AVO. Therefore, there is no more flex allowed in this TBE.

 

I haven't had any leaks or other problems with the DP. My girlfried says my car sounds a bit louder but I can't tell the difference. Sometimes, it smells a bit funny at start up but nothing obnoxious.

 

I bought this DP with the idea that I will upgrade to a twinscroll setup in the near future;).

 

BTW - RhinoRamps work on a stock height spec. B, with an RBS replica STI lip.

[camber]

Forgot to post up some installed pics. I'll do it later tonight...

[LittleBlueGT]

Nice to have a DP that will adapt!

[snow05gtRI]

i feel like that bracket causes pressure to go back into the DP. though i'm no MechEng so i dont really know flow that well. just feel like wide into small with no angling (from the looks of it, it's just flat, there's no tapering, just 3" on one side and 2.5" on the other, so there's a .5" wall on the DP side)

[camber]

Meh...

 

The exhuast adapter is a simple way of attaching the stock catback to a 3 inch DP. It's a nice addition for people that look to retain the stock catback and stops leak that people experience when they try to mate other flat flange 3 inch DPs to stock catback.

 

Give up a little bit of flow to stop potential leaks and smelly situations!

 

I thought the inclusion of the adapter(and quality gaskets) by AVO was a nice touch and is something not offered by some other competitors.

 

Personally, I'll be ordering a new 3 inch mid and Y pipe very soon but I haven't had any issues with the included exhaust adapter.

[pathfin9]

Any chance I could get you to post up some sound clips? Are using stock cans, or AVO?

 

Thanks!

 

-John

[camber]

Here are the pictures of the DP slightly touching the transmission and the used donut gasket on the exhaust adapter.

 

I think if I had a 5MT, it wouldn't have anywhere near touching. However, it was an easy fix to gain a bit of clearance.

[camber]

Any chance I could get you to post up some sound clips? Are using stock cans, or AVO?

 

Thanks!

 

-John

 

Right now its just the AVO DP mating to the stock catback exhaust.

 

Not really any difference in sound, maybe just a tad more noticeable unequal exhaust manifold, boxer rumble. Unfortunately, I don't have a good method of capturing sound.

[snow05gtRI]

yeah not saying it was a bad choice, i was just typing out my thoughts.

 

and i realize i didnt finish that sentence...i think i was gonna say could backfire but oh well. i might end up having to do this anyway (the bracket, exhaust I got is a 2.5" inlet) so let me know if you notice anything....

[Guest]

I use this downpipe with twinscroll bellmouth for my vf37 hybrid. This is a nice piece but the alignment of the pipe vs. the bellmouth left to be desired. The pieces were shifted somewhat. I enlarged the bolt holes on the pipe slightly for better alignment - making sure that only the gasket's metal ring protruded and no part outside the ring.

 

Older AVO downpipes shipped with crappy gaskets without metal ring and per what I read they would eventually would leak at the bellmouth to pipe joint.

[pathfin9]

Right now its just the AVO DP mating to the stock catback exhaust.

 

Not really any difference in sound, maybe just a tad more noticeable unequal exhaust manifold, boxer rumble. Unfortunately, I don't have a good method of capturing sound.

 

Oh ok, thats actually what I was looking at doing also. On a scale of 1 to 10 with 1 being stock exhaust, how would you rate the loudness?

 

Thanks!

 

-John

[camber]

I use this downpipe with twinscroll bellmouth for my vf37 hybrid. This is a nice piece but the alignment of the pipe vs. the bellmouth left to be desired. The pieces were shifted somewhat. I enlarged the bolt holes on the pipe slightly for better alignment - making sure that only the gasket's metal ring protruded and no part outside the ring.

 

I didn't have this problem with the single scroll bellmouth but I'll look out for this issue if I go twinscroll.

[camber]

Oh ok, thats actually what I was looking at doing also. On a scale of 1 to 10 with 1 being stock exhaust, how would you rate the loudness?

 

Thanks!

 

-John

 

1 out of 10.

 

Maybe, 1.5 out of 10 for more discerning people:lol:

[Guest]

I didn't have this problem with the single scroll bellmouth but I'll look out for this issue if I go twinscroll.

 

I think i had the same issue with vf40 style bellmouth as well, but never installed it or bolted to the pipe (just test fitted). Later I traded it for the twin scroll one.

 

Anyway, the bottom line it is a great DP, especially that it is upgradable to twinscrolls and doesn't neck down to 2.5" at the outlet. I wish they would put bung for o2 sensor on it. It would be near perfect then!!

[praedet]

I also wish the Cat was actually at the other end...

 

It doesn't have an O2 bung? My understaning is that w/ TS downpipes, the OEM O2 is moved to post turbo, so I would even want two bungs

[Guest]

I also wish the Cat was actually at the other end...

 

It doesn't have an O2 bung? My understaning is that w/ TS downpipes, the OEM O2 is moved to post turbo, so I would even want two bungs

 

The current twinscroll bellmouth (revised) comes with the bung for the "narrow" o2 sensor. I had to add one more in the pipe itself for a wide o2 sensor.

 

And, no I like the cat in front. Does not lower ground clearance (and potentially be fire hazard when you park on grass).

[SBT]

^ Good idea about keeping the cat heat away from the ground, but are there any issues with that same heat up close to the driveline (boots, joints, lines) and the intercooler?

 

How much OD dimensional difference is there between this cat and say the Perrin or Cobb HFC? Same, smaller, larger?

[BradyCat]

Your downpipe doesn't have the flex fitting like the one at FredBeans? Your's is what they call the metal 'race cat' right, not the ceramic cat? Maybe that is a new design or something? Anyway, that is the one I'll be going with in the not too distant future, nice write-up.

 

http://www.fredbeansparts.com/servlet/the-Subaru-cln-LGT-05-dsh-09-cln-Downpipes/Categories

[camber]

My AVO metal cat DP doesn't have a flex section. Neither does the stock DP but it does use the donut gasket joint(with the stock CBE) to flex or move. AVO pipe can use the same donut gasket with stock CBE with the 3" -> 2.5" adapter. However, you can't use the spring bolts which takes away the flex from that connection.

 

I'm guessing that this(http://www.fredbeansparts.com/servlet/the-1816/AVO-Subaru-Legacy-GT/Detail) is the metal cat DP due to the price differential. Just ask the guys at Fred Beans they help your out