APS SR30 or VF34
04-15-2004, 09:53 AM
#16
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Subaru has been using IHI turbos for years. The IHI VF series turbos have been on STi's and WRX's for quite some time. Both turbos have their downsides. The APS is a gorgous turbo but on the other hand it cost a lot of money.
Again, this is something that comes down to your preference.
Again, this is something that comes down to your preference.
04-15-2004, 10:24 AM
#17
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iTrader: (12)
Join Date: Nov 2002
Location: bay area, CA
Posts: 440
Car Info: 02 WRX wgn full STI swap
I talked to a friend tuner and your right... though not sure what they were originally developed for, Suby and IHI go back a while. I'm going to edit those posts so I dont confuse anyone.
No question... the APS units are expensive. I can only express faith in longevity because I haven't run it yet. But you can tell that this is one very well built turbo with quality in mind.
The #1 reason I switched from the VF34 to an SR30 is Boost creep. TXS stage 4 with no cats proved too much exaust flow for the VF34's wastegate. Even with the wastegate wide open, there was so much pressure that it was easier for the gasses to push through the turbine causing over boost. Granted I want to hold the boost to what many consider low at 16.5-17psi. I'm tuning for mid range power and not peak HP #'s. I put on the APS TMIC... (you seriously could not fit a larger intercooler under the hood, this things huge). It didn't help the boost creep.
After lots of research, I found that this is very common with the VF turbos and was told the best solution was to port the wastegate or get this PUT THE CAT BACK IN AFTER THE TURBO TO RESTRICT THE FLOW! Do a search for "boost creep" for more info. Although porting the wastegate wouldn't be that hard, I decided that the VF34 was flawed by design and that if the best answer was to change that design or detune my car by choking it up I would shop elsewhere. I have been assured by master tuners and APS that ths is just not an issue with their turbos.
Sorry for the book... If you plan on keeping at least one cat (prefferably on the downpipe) this will not be an issue for you. However, if you choose to save the money and get a VF and you're running no cats... make sure you port the wastegate BEFOR you spend hours putting it in.
Ash
No question... the APS units are expensive. I can only express faith in longevity because I haven't run it yet. But you can tell that this is one very well built turbo with quality in mind.
The #1 reason I switched from the VF34 to an SR30 is Boost creep. TXS stage 4 with no cats proved too much exaust flow for the VF34's wastegate. Even with the wastegate wide open, there was so much pressure that it was easier for the gasses to push through the turbine causing over boost. Granted I want to hold the boost to what many consider low at 16.5-17psi. I'm tuning for mid range power and not peak HP #'s. I put on the APS TMIC... (you seriously could not fit a larger intercooler under the hood, this things huge). It didn't help the boost creep.
After lots of research, I found that this is very common with the VF turbos and was told the best solution was to port the wastegate or get this PUT THE CAT BACK IN AFTER THE TURBO TO RESTRICT THE FLOW! Do a search for "boost creep" for more info. Although porting the wastegate wouldn't be that hard, I decided that the VF34 was flawed by design and that if the best answer was to change that design or detune my car by choking it up I would shop elsewhere. I have been assured by master tuners and APS that ths is just not an issue with their turbos.
Sorry for the book... If you plan on keeping at least one cat (prefferably on the downpipe) this will not be an issue for you. However, if you choose to save the money and get a VF and you're running no cats... make sure you port the wastegate BEFOR you spend hours putting it in.
Ash
04-15-2004, 04:06 PM
#19
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iTrader: (12)
Join Date: Nov 2002
Location: bay area, CA
Posts: 440
Car Info: 02 WRX wgn full STI swap
if the turbo's out you just take apart the center clamp and exaust housing comes off as one piece of cast iron. Get yourself a dremel or a sanding wheel or twelve and go to town. Just dont take too much metal out.. the wastegate seal is floating and you need to make sure that you dont over port it and it still seals.
external wastegate would kick ****... doen't look too stock though. hehe
Who the heck am I to talk??? My new turbo is frickin RED!
Ash
external wastegate would kick ****... doen't look too stock though. hehe
Who the heck am I to talk??? My new turbo is frickin RED!
Ash
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