CAT BACKED EXHAUSTS for subaru B4 2002

[Guest]

Hi fellow Subie's this is Subaru Ho

a debatable topic has been puzzling me, I have heard from local tuners and local mechanics that for my B4 2002, that the best cat back exhuast solutions will only be able to be a Half-Cat from the half way point and bolt to the exhuast because they reckon that anything more than that e.g Manifold and down pipe will kill the secondary turbo resulting in Secondary Turbo Failure. Due to the back pressure.

question: IS THE SECONDARY TURBO FAILURE TRUE? OR A MYTH?

[RSB]

For a start, anything forward of the cat is not a cat back exhaust. A cat back is just that. And the Cat referenced in that equation is the cat aft of the Y pipe, not the one in the down pipe.

As far as killing turbos goes, aftermarket downpipes have been known to kill early bd5/bg5 turbos due to overspool, but I understand it was fixed with the VF18/19 combo which was Pre B4. As for B4, i'm not overly familiar with their quirks.

Doing the exhaust properly can get you good gains in peak HP and reduce lag and VOD. Having a halfassed job can introduce you to a whole lot of financial pain :-)

[Guest]

Found this, would have to double check it would fit your car, mag and turbo told me this would be the one for my car (1999 B4 RSK)

http://www.drivenperformance.co.nz/scripts/prodView.asp?idproduct=890

[Guest keltik]

Wow thats a friggin awesome price for a full system!

Yes older models had issues with the primary turbos exploding.

If you do end up getting a full system, can someone do us a MASSIVE favour and get a dyno run before and after its fitted.

[Guest]

 keltik said:

Wow thats a friggin awesome price for a full system!

Yes older models had issues with the primary turbos exploding. -----I wasnt aware this had changed, i thought they still sh*ged the primary turbo if you freed up the exhaust too much im rapt if its no longer the case as thats the whole reason i havent planned on touching mine.

If you do end up getting a full system, can someone do us a MASSIVE favour and get a dyno run before and after its fitted. ----This would be awsomely valuable info for everyone

[pl0x]

 webup said:

My primary is dying after installing a big bore. BH GTB

Whistles alot and splutters sometimes under throttle.

You think it couldn't have just been a coincidence (sp?)

[Guest keltik]

If it works for 100,000km then dies shortly after fitting a new exhaust when primarys are known to get over stressed with new exhausts - thats a little too coincidental for me.

[pl0x]

but it could have been thats its 100kms old that killed it?, i wouldnt think puting just a big bore on would increase that much flow anyway would it?

[nzkaosnz]

my tt was on 240k km, and god knows what # motor, still had vf13/14 - put the full downpipe on, and turbos went fine for next 50k km till i sold it (went through 2 motors in that time tho ) Primary got a little whiney, but still went hard.

If you have a vf13 and it dies, shed a small tear, make an small offering to Zeus, then move on to something biggr n better like a vf18/vf21 or any of the new TT turbo's.

Up until that point - it goes HARD.

[Carbon]

Rage make a reasonably priced one for the B4, make sure you specify manual or auto. I had huge problems making mine fit, but Rage came to the party and paid to have it corrected.

[nzkaosnz]

rage was the brand i had fitted. The downpipes fit well, its just the Y-pipe can be a niggle.

[Carbon]

Yep, no problem with the downpipes, they just hang there ;-)

All of the angles at the bottom were totally wrong - pretty much had to make a complete new y piece

[nzkaosnz]

magoo ended up just making y pipe from scratch, turned out same price as rage list price for that piece

[Guest]

when i get the full exhaust, ill give it to make and turbo and tell them to make it fit

or go to Al's Mufflers

[Guest dcornie]

al's mufflers are really good done heaps for my mates car