Subaru WRX Forum banner

1 - 5 of 5 Posts

·
Registered
Joined
·
3 Posts
Discussion Starter #1
So I bought a 2006 wrx wagon recently. It is supposedly tuned for 7psi (wastegate pressure) with a VF39 and no restrictor pill. I am wondering what will happen if I put the restrictor pill back in? Will I need to get it retuned? I was told that the previous owner detuned it when it had the original TD04, then put the VF39 in, replaced the vacuum lines as well as removed the restrictor pill so that it would only run at wastegate pressure, then had it retuned for the VF39. Pretty much just asking where to go from here. Any advice helps

List of mods:
VF39 Turbo
3" TBE
Cobb 2" up pipe
Gfb electronic boost controller
Injen CAI
Atermarket (ebay) bov - (switching back to JDM OEM bpv)

Thanks in advance.
 

·
Registered
Joined
·
477 Posts
Hey, welcome aboard!

I smell something iffy on the above information previous owner has provided.

Erm, the way one would "tune" for wastegate spring pressure (which by the way makes absolutely no sense to do on a vf39 vs stock turbo since it would be a drop in power) would be to directly connect a hose from the turbo compressor outlet to the wastegate actuator nipple completely bypassing the boost control system. If that's what's going on, something tells me that the person did this because they tried to run the turbo without a tune and it would not boost correctly (likely overboost) so as a last resort they gave up and hooked it up to spring pressure so the car doesn't overboost/fuel cut or some other weird boost control behavior.

My big question is... why would you DETUNE the stock turbo... and then put in a bigger turbo and detune even further...?

I would recommend the following:
1). Get your car fully serviced, check all hoses, belts, EVERY intake connection (especially ones after turbo including ones under the intercooler)
2). Run a compression test (or better yet a leak down test) to make sure your motor is safe
3). Talk to the ECU and look at what the learning view is currently doing. Is your DAM (IAM) value below 1? Is there significan't Fine Learning Knock? ARE YOU TUNED FOR THAT INTAKE? (those are all very important questions)

When you know your car is in good shape, I would start bringing everything back up online
4). Properly hook up the remainder of the boost control system
5). Set up a pro-tune appointment and hook up the boost control system to the turbo in their parking lot (or drive with zero boost until you get there)

So now the question becomes one of tuning. If you hook it up, you will need a tune (pro-tune to be exact since no off-the-shelf maps will run with your Intake and vf39... unless you go opensource and dig up a map on RomRaider forums, I'm sure there's a vf39 map for the 06 somewhere).

Keep asking questions and we'll answer!
 

·
Registered
Joined
·
477 Posts
I think the previous owner didn't get a tune after putting in the boost control solenoid. That's the only real logical explanation I can think of to hook up the turbo to spring pressure. Or "tune it down" from stock.... which makes zero sense at all since the car came with a tune FROM THE FACTORY that was designed to work well on ALL production vehicles.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #4
Hey, welcome aboard!

I smell something iffy on the above information previous owner has provided.

Erm, the way one would "tune" for wastegate spring pressure (which by the way makes absolutely no sense to do on a vf39 vs stock turbo since it would be a drop in power) would be to directly connect a hose from the turbo compressor outlet to the wastegate actuator nipple completely bypassing the boost control system. If that's what's going on, something tells me that the person did this because they tried to run the turbo without a tune and it would not boost correctly (likely overboost) so as a last resort they gave up and hooked it up to spring pressure so the car doesn't overboost/fuel cut or some other weird boost control behavior.

My big question is... why would you DETUNE the stock turbo... and then put in a bigger turbo and detune even further...?

I would recommend the following:
1). Get your car fully serviced, check all hoses, belts, EVERY intake connection (especially ones after turbo including ones under the intercooler)
2). Run a compression test (or better yet a leak down test) to make sure your motor is safe
3). Talk to the ECU and look at what the learning view is currently doing. Is your DAM (IAM) value below 1? Is there significan't Fine Learning Knock? ARE YOU TUNED FOR THAT INTAKE? (those are all very important questions)

When you know your car is in good shape, I would start bringing everything back up online
4). Properly hook up the remainder of the boost control system
5). Set up a pro-tune appointment and hook up the boost control system to the turbo in their parking lot (or drive with zero boost until you get there)

So now the question becomes one of tuning. If you hook it up, you will need a tune (pro-tune to be exact since no off-the-shelf maps will run with your Intake and vf39... unless you go opensource and dig up a map on RomRaider forums, I'm sure there's a vf39 map for the 06 somewhere).

Keep asking questions and we'll answer!
Hey thank you so much! I'm going to get a compression test done in the next week or two, I have had it looked over by a reputable Subaru specialist in my area and the only things he had found were leaking valve cover gaskets and exhaust manifold gaskets, which have since been replaced. Other than that though I'll have to do a couple logs and see what the numbers are looking like for fine learning knock and DAM. Thanks so much though, helps a ton.
 

·
Registered
Joined
·
3 Posts
Discussion Starter #5
Hey thank you so much! I'm going to get a compression test done in the next week or two, I have had it looked over by a reputable Subaru specialist in my area and the only things he had found were leaking valve cover gaskets and exhaust manifold gaskets, which have since been replaced. Other than that though I'll have to do a couple logs and see what the numbers are looking like for fine learning knock and DAM. Thanks so much though, helps a ton.
UPDATE: turns out that the previous owner put in the 3 port ebcs but did not get it tuned for it, so removed the restrictor pill to make it run on wastegate pressure.
 
1 - 5 of 5 Posts
Top