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Discussion Starter #1
So I picked up a solid VF46 on ebay (I live on the edge) with ~10k on it.

I am trying to decide what other supporting exhaust mods I want.

I want to spool at ~3500; and I want to stay Fed legal if possible.

I am primarily thinking Perrin EL headers, uppipe to quicken to sppol time.

Do you all think it would be harmful to keep the OE DP?

I brainstormed this cockameimee idea considering the flow of install; while replacing the turbo, why not replace the whole system pre-turbo system?

Suggestions?
-RL
 

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if you want to minimize spool time, ditch the stock dp. if you want to change out uppipe and headers then that would be the time to do it, while the turbo is removed. good luck w/ your project!
^^^^^ Do this for best performance as far as "Fed legal" retain, or re-install stock DP for inspection, cut a bit of performance, then make sure you get an AP so you can undo the tune your car is going to run on for the stock map, just for inspection purposes, then reflash again after re-install.
 

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If you decide to go with a downpipe, be careful of the divorced bell mouth style dp's. The vf46 wastegate hits the separator that extends past the bell mouth on some dp models. The tdo4 wastegate is vertical and fits within the wastegate side of the divorced style dp, the vf46 wastegate is at a 45 degree angle across the separator and hits it. Either it won't even bolt up or if it does bolt up, the wastgate won't open. I cut the seperator flush and it worked fine.
Just trying to save you some time and aggravation... ;D
 

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If you decide to go with a downpipe, be careful of the divorced bell mouth style dp's. The vf46 wastegate hits the separator that extends past the bell mouth on some dp models. The tdo4 wastegate is vertical and fits within the wastegate side of the divorced style dp, the vf46 wastegate is at a 45 degree angle across the separator and hits it. Either it won't even bolt up or if it does bolt up, the wastgate won't open. I cut the seperator flush and it worked fine.
Just trying to save you some time and aggravation... ;D
was this with a LGT or 08/09 WRX dp?
 

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Doing the headers and uppipe would be alot easier while the turbo it off. I installed a Perrin uppipe when i swapped turbos. I think you should get a new downpipe too. Doesn't make sense to run stock DP if you are doing everything else. If you don't want to get a cat-back, i'de say go with a non-catted 3" DP.
 

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I'm not one to talk about doing things backwards, but swapping turbos before swapping downpipes is a little odd...

I would def, recommend you get a new one to get the most out of the turbo...

Our DPs aren't efficient enough to get the best out of the stock ones let alone the VF46...
 

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Discussion Starter #8
Our DPs aren't efficient enough to get the best out of the stock ones let alone the VF46...
I thought the 08 shared its DP with the legacy...

My understanding is if I swapped the VF46 alone, I'd have a Legacy engine. Am I incorrect?
 

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If you decide to go with a downpipe, be careful of the divorced bell mouth style dp's. The vf46 wastegate hits the separator that extends past the bell mouth on some dp models. The tdo4 wastegate is vertical and fits within the wastegate side of the divorced style dp, the vf46 wastegate is at a 45 degree angle across the separator and hits it. Either it won't even bolt up or if it does bolt up, the wastgate won't open. I cut the seperator flush and it worked fine.
Just trying to save you some time and aggravation... ;D
was this with a LGT or 08/09 WRX dp?
08/09 WRX DP divorced bellmouth. Any bellmouth w/o the divider/separator should be OK or if you are as cheap as me and like the erz/tsudo type, just cut and grind the divider/separator off a bit to clear the vf46 wastegate. I think the legacy divorced dp separator/dividers don't protrude into the turbo as far as some of the WRX dp's do. Just hoping that everyone checks that their wastegate can still open to prevent a catastrophic event... ;D
Hope it helps anyone thinking about the swap.
 

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Discussion Starter #10
If you decide to go with a downpipe, be careful of the divorced bell mouth style dp's. The vf46 wastegate hits the separator that extends past the bell mouth on some dp models.
What DP are you running? I was thinking of going with Maddad's shorty catless for 08/Leg/STI.
 

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I run the erz/tsudo dp, it wouldn't touch bellmouth to turbine, gapped about a quarter of an inch, divider hitting wastegate. I gave the turbo to a friend to run for awhile w/ the ap that I sold him and his indvidia divider/separator blocked the wastegate from opening even though it would bolt up. This was a vf40, same hotside as a vf46.
 

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08/09 WRX DP divorced bellmouth. Any bellmouth w/o the divider/separator should be OK or if you are as cheap as me and like the erz/tsudo type, just cut and grind the divider/separator off a bit to clear the vf46 wastegate. I think the legacy divorced dp separator/dividers don't protrude into the turbo as far as some of the WRX dp's do. Just hoping that everyone checks that their wastegate can still open to prevent a catastrophic event... ;D
Hope it helps anyone thinking about the swap.
Thanks, I do have a VF46 sitting in the basement currently. I was thinking about going w/ the Invidia but for a LGT. And there are 2 versions on the Invidia IIRC. The 1st ones did have the wastegate problem, but the new ones should not.
 
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