boost problem???

[snowboard48]

Hey guys,

I have a v7 wrx, stock standard, but ive noticed when i boost it doesn\'t go that hard, and the bov only goes off slightly, i have checked for leaks and tightened everything and seems fine, idles fine.

I find when i put the same bov on my gtb it goes off really easy just by touching the accelerator, yet with my wrx i have to have foot to the floor and even then it just goes off,

Is this normal for a v7 wrx... does anyone know what the factory boost is? as my v7 sti went much much better.

Does anyone recommend just getting a external wastegate and running more boost?

[evljat]

I\'ve never driven one but I think it\'s safe to say that the v7 wrx would be pretty slow.

The BOV goes off easily on a GTB because the primary turbo spools pretty much at idle.

[Kiwi_Fozze]

check your idle seat pressure. the gtb runs more boost... if i remember correctly the wrx should be running around 10-14psi boost, the gtb runs a fair bit more.

check around for leaks around the ic joins as well.

[snowboard48]

Yeah i have checked everyone for leaks, actually stripped everything back and started from scratch. When i rev the car on idle the bov goes off pretty loud, but when im driving it doesn\'t sound like it goes off much at all, and not very responsive either?

I thought it might of been the bov, so i purchased a new wrx bov to eliminate that problem but i find the same again.

Im beginning to think that its just cause it doesn\'t run much boost from factory, feels like about 7-10psi, I guess im just use to driving Sti where the boost is normally at least 16psi.

Would anyone recommend getting a wastegate and running 1bar on it, or you think thats to much for the wrx in standard form?

[Guest]

1 Bar should be fine. I wouldve thought it would be at least 12psi like the V5/6. It sounds like its running internal pressure 9psi? like its in limp mode or something.

[Kiwi_Fozze]

the v5/6 only ran 10 standard. hang on, i\'ve got some v7 wrx maps here....

[Guest]

Mine ran 12 along with a couple others Ive seen and so did V5/6 foz.

[Kiwi_Fozze]

all my maps say the v7 wrx should be hitting about 13 psi peak (1.952 bar absolute)

boost cuts at 2.2 bar absolute, or about 17 psi.

so, if you wanted to run a tap or EBC, you should get a fair bit more response from the TINY td04 turbo, but at stock boost these are basically at the limit of their efficiency. you could go for a bigger VF series turbo and set it up to run on the stock system, you should have some noticable gains without even retuning.

do remember, these ecu\'s are reflashable too

my forester ran 10psi, limp mode was 7psi, as has been nearly every other v5/6 wrx or forester i\'ve looked at.

[Guest]

So internals 7psi? I knew it was 7 or 9. Both my V5 and foz were imports with TD04 and had 2.5" TB exhaust but most def 12psi without ebc/tap/external. Would hold boost right to redline also.

[Kiwi_Fozze]

mmm weird. my foz was the td04, standard exhaust right through, hit 10psi peak at like 2500 and tapered to like 7psi at redline. could be the exhaust making the difference lol

[snowboard48]

Yeah im not 100percent sure how much psi its running, but it feels like about 10psi.

Similar to my evo 7 that i had acouple years ago, I was told that the evo 7 came into the country running only 7psi as thats when the new emission laws came into place and that a simple return would wake them up.

So maybe this is the case with the v7 wrx also?

As for changing the set up and running different turbo etc, to be honest i would be better of just selling it and buying another sti. Case closed. lol

[Guest]

A VF and a tune could be had for under 1k or through a proper tuner 1.5k odd max. Agreed an sti is a lot more car at an extra 3-5k but still you would need to tune for the best result anyways. TD04 are shite back to back untuned with any VF.

Plumb in a boost guage and check what psi its running till then this thread is a tad silly lulz.

[snowboard48]

yeah all good, will suss out how much boost im actually running, if it turns out im running more than 10psi then something must be wrong cause the bov should go off much more than what it does atm, and it says that the bov im running is for cars running 10-25psi, so if im only running 7psi that would be why it hardly goes off.

Anyway cheers for your thoughts.

[Guest]

Curious as to what cfm the gtb is flowing at the same rpm as the wrx? TD04 is pretty small.

[Pappu1]

Out a gauge and see what u getting to

Also try this boost say 3rd gear to Abt 4000rpm and then let off and see if there is any difference in noise on bov

What sorta bov is it?

[snowboard48]

Ill go buy a boost gauge and connect it up.

I just brought a auto gauge wrx bov, designed for v7 wrx onwards.

Says that the bov is recommended for 10psi onwards

[Johnnynz]

 evowrx said:

Plumb in a boost gauge and check what psi its running till then this thread is a tad silly lulz.

Lol cant believe thread got that far without someone saying it.

Interested in the results.

Snowboard, if you put [ i m g ] at the start of your sig and[ / i m g ] at the end with no spaces it will show as a pic not just a web address.

[Guest]

 Johnnynz']

[quote name='evowrx said:

Plumb in a boost gauge and check what psi its running till then this thread is a tad silly lulz.

/quote]

Lol cant believe thread got that far without someone saying it.

Interested in the results.

Snowboard, if you put [ i m g ] at the start of your sig and[ / i m g ] at the end with no spaces it will show as a pic not just a web address.

I just gathered it had a boost guage not an arse guage that reads psi. I mean what car doesnt have one these days. Just make sure the bov is not venting at idle if not plumbed in.

[Johnnynz]

Stock v7 BOV will be open at idle. But it should run like balls if its not plumbed and on a stock ECU so probably not the cause.

If its running a completely stock setup as OP says it wont be very loud anyway surely? Boost gauge is by far the best way forward.

[Guest]

Quick thought theyre both running pod? or is V7 air box and legy pod?