I picked up a 15k mile VF39 from a fellow NASIOC member and noticed a small crack in what looks to be the usual place others have mentioned or shown.

What are the options? Can these be repaired and made reliable?

Do the cracks need to be fixed? As I'm sure there are plenty of stock STIs with them who don't know.

I appreciate advice and guidance. I tried searching but did not come across a definitive thread.

thanks.

04 sti vf-39 are showing cracks on the hot side of the turbo.

how repair?..guess you could have it welded, but doubt that.
just get a new hot side, why just up grade?

doesnt really hurt anything if the car is stock....

Sooner or later the crack will expand and start to leak, especially if you run higher than stock boost. I've got a cracked VF39, too. I've tried a whole bunch of tricks to fix it, but it's a bitch to work on and nothing seems to handle the heat it gives off. Welding does not seem to be a good idea.

Sooner or later the crack will expand and start to leak, especially if you run higher than stock boost. I've got a cracked VF39, too. I've tried a whole bunch of tricks to fix it, but it's a bitch to work on and nothing seems to handle the heat it gives off. Welding does not seem to be a good idea.

I'm not sure I agree that it will definitely expand and leak if you run stock boost - sort-of what you are saying. All the cracks I've seen do not leak. That being said, it would probably be a good idea to get a diff turbo, or at least a new exhaust housing, if you are going for high HP.

I'm going on distant past experience. This was a pretty common problem with the turbo on the Syclone and some Buick models. Eventually, they all leaked. I don't think it was pressure related. I think it's due to repeated metal expansion and contraction, in an area where the metal is thin or there are impurities.

I don't know anyone who has got the crack and just decided to leave it alone and see what it looks like in a year or two. I'm sure there are many, they just aren't coming here and talking about it.

Crap all these posts on cracked vf-39s... There's nothing you can do? like can you grind it out if it's small?

EDIT: I just saw a post from Jerry @ Deadbolt that said he is able to fix these if caught early, how I'm not sure...

any other options? arrgh I've been trying to buy a used VF39 (without the crack) I've already had 2 cancel 2 deals on buying one becasue of this. :(

can you just dremmel it out if it's small?

vf 30 housings bolt right up.

Yes a couple vf30's haev cracked, but the couple 30s over 4+ eyars in the states, vw allt he 39s in the apst year....



*edit, ok w t f was wrong with me when I typed that???:huh: :huh: grap on my typing

FP Green

If you port the wastegate hole to fix boost creep does that prevent the cracks?

I'm assuming thats about where the crack is, can someone verify this?

vf 30 housings bolt right up.

Yes a couple vf30's haev cracked, but the couple 30s over 4+ eyars in the states, vw allt he 39s in the apst year....



*edit, ok w t f was wrong with me when I typed that???:huh: :huh: grap on my typing

http://www.codemia.com/grap.jpg

If you port the wastegate hole to fix boost creep does that prevent the cracks?

I'm assuming thats about where the crack is, can someone verify this?

It's got nothing to do with boost creep. The metal is too thin in the area where the cracks occur. It's possible porting the waste gate could relieve some stress that's contributing to the failure. Can't hurt.

I know but I was saying if an STi owner were to port his/her wastegate hole to prevent boost creep, would that PREVENT a crack from forming.

I know but I was saying if an STi owner were to port his/her wastegate hole to prevent boost creep, would that PREVENT a crack from forming.

no. Its not stress related. Its a defect in the metal. Porting does nothing to relieve any stress anyway.

Darn... I was so in the market for a VF39... :mad:

What usually happens to "fix" cracks in wastegate flapper holes is to simply enlarge the hole to accept a larger wastegate flapper. You remove the material that is cracked, basically. A lot of DSM owners had this happen to their turbos-the problem is that the turbo is designed as a unit to be boosted to a certain level, thus creating a certain amount of heat.

You exceed the engineering tolerances for heat by turning up the boost and keeping it up. Lots of factors, including the material thickness and metal composition, lead to failures like these. The biggest factor is simply engineering these turbos to boost to less than 18psi consistantly.

This can be fixed if caught early because "new" cracks are usually smaller than "old" cracks.

Thank you!

You should really see this topic:

http://forums.nasioc.com/forums/showthread.php?t=758692&highlight=vf39+crack

I'd use it as a reason to upgrade...