Hello all,
Well first off the questions I will ask are for a friend, I have a WRX and am not sure about some things with the 4G63 set up. Also I did a search and could not find much to help me. O.K. So we put on the GReddy intercooler kit with lower boost pipes and we are not sure of the way that would be the best place to re-locate the vac. line that goes to the T fitting. He has a factory boost gauge, and we tried to T it in with that and it made the gauge show no reading, we then put it after the BOV and befor the hard line, gave low boost (0.6 bar), then we put on the line that goes from the intake manifold to the FPR solenoid and gave us low boost too (0.8-9 bar). I'm not sure if the vac lines have any thing to do with the low boost, seems to me like the boost solenoid is not getting any pressure/reading and that would make it peak at like 9-10 PSI. right? Also I know the vac line we are using is a little bit bigger that what it should be, but all of the conections feel and sound tight. Also he has a forge motorsports recerc./ by-pass valve and the whole problem seemed worse with it on. And with the HKS SSQV w/ a recerc. kit (what we are using now), should it be stumbling or stalling? There are no boost leaks and the mods are:

HKS SSQV w/ reserc. kit
Downpipe
cat back exhaust
upper greddy intercooler pipes
greddy FMI w/ lower pipes
Cone filter intake kit

Any ideas or info would be great

 

Good luck. Get a MBC or a flash. First test for a boost leak.

 

That did not answer my questions.

1. best place to relocate the vac. line (see above)

2. why with recerc. bov the car will still stumbel and stall on deceleration

3. what else can cause low boost

The car feels smooth but will not boost.

 

Bump............... any other help with what I have would help, nobody else got GReddy lower I/C pipes?

 

Not sure what to tell ya. It is hard to get a picture in my head of what your working with. Take a few snap shots and post them up.

You are using a cone filter intake kit. What one? HKS, K&N, or just a cone filter with stock intake piping.

Dose the GReddy lower I/C pipe not have the nipple for the vacume line. Is that what the problem is? If so it is just like the Bushure Delux Lower I/C pipe.

I was told that you could tap into the new lower I/C pipe and reconnect the line or you can re-route the line.

I would recommend getting a MBC so you can bypass all the different connections. Let me know if this helps any. or ask a few more questions. there should be some info on the boards about your problem.

 

Get an MBC, my car was having low boost problems too, couldn't figure out why (thought it might have been timing issues)... regardless the MBC fixed it.

 

Well, I belive it is a K&N filter. And yes there is no nipple on the I/C pipe that comes off the turbo, I thought about tapping it in but that would be a waste of a great part if it does not work. Mostly I want to know what else I can tap that vac. line into (it goes to the T fitting that then goes to the waste gate and boost solinoid). But please read the first post. Also, why would I have him buy a MBC befor finding out what is wrong, I think it would cause more problems down the road. And what is the deal with the HKS SSQV?

 

I have no idea about the HKS SSQV. As far as a where to replace that line. I think you tried all the logical options. the boost guage line, the line at the front right of the valve cover. They should work. It has worked for many people with MBC. I think the problem still might be a boost leak. did it start to happen after the FMIC install? Try switching back to the OEM lower I/C pipe and see if that fixes it. Now that I think about it your problem might be the aftermarket vacume line the original OEM vacume line had a restrictor pill in it! that might be why you are reading low. Just something to check hope it helps.

 

Yep, I thought that was odd too, with HKS SSQV. As for the restrictor, that was the first thing I looked for since I did not see it (my WRX has one that is a big white connector, between the vac. lines), but then found out that it is in the lines on the EVO and found it. I had to squeez the line and feel for it, its right by the boost solinoid. And yes, this all started after the I/C install. What about the vac. lines to the T fitting being to big, can that cause this, like I said in the first post, the line feels and sounds good, but ya never know.

 

Bump.......need some more help/ideas

 

Bump........come on no one has any ideas?

 

to address your boost problems- There are two restrictors in your stock vacuum lines. They are not white nipples, rather they are metal "pills" that are actually in your lines. If you want high boost USING the stock solenoid, I recommend putting the stock vacumm lines back in their original configuration. You can get higher boost by removing ONE of the pills and still using the solenoid. I honestly can't remember which of the pills to remove, so you'll have to experiment. You NEED that one pill in order for this to work or else your boost gauge will show the same readings you are currentlyl getting. The pills can be remove by CAREFULLY using a coat hanger.

to address your bov problems- this is common when VTA. You can either recirc, try tuning it in some manner (reflash, safc, utec, etc..), or just deal with it.

hope this helps.

 

There is a restrictor in the hose that goes from the T to the Discharge pipe. If you changed this vacuum hose you will only get 9-11 psi of boost. Your only fix is to restore the restriction or get an MBC.

 

OK. I know there is the one in the vac. line going from the T fitting to the boost solinoid. But the other one I'm not sure about. Is there a diagram that I can look at to see where the other restrictor pill should be. The diagram under the hood is no help. Also the HKS SSQV is recirc-ing back to the intake.

 

And I also just thought about the fact that the GReddy kit comes with blue vac. line to replace/retap that line that should go from the T to the lower I/C pipe????? You think the kit is designed to only be used with a boost controller? Or it would have a pill in it. The other kid that did this part of the job said it would be to short, so he cut it up and we had to use normal vac. line from the hardware store.