SU Turbosmart - 10-20psi or 20-25psi spring for stock k04??

[dale_gribble]

My stock BPV was slowly losing its ability to hold boost with the Stratified Tune I am running until last week where it abruptly started leaking anytime I was on the boost.

Lex's tune has my k04 running at ~21psi @ ~4000 or so and tapering down to 19psi at redline.

I just received my SU BPV today with the optional spring.

My boost curve kind of runs on the edge of both springs which is why I am looking for feedback. Should I run the 10-20 or the 20-25? Is the spring rating based on max boost or where the turbo spends most of its time?

Help is appreciated. Thanks.

[Whiteboy]

I was wondering this myself...

[XerocX]

What color is the 10-20 spring?

[ms3blackmica]

The springs are all the same color, they just come with some paint on the side to mark them. 10-20 psi spring has green paint. 20-25 psi spring has pink paint.

I always had the SU TS BPV for 3 years now and always had the 10-20 psi spring. It caused issues for me when i started to run 21 psi. Boost would taper off earlier in the RPM range. I ordered the 20-25 psi spring and now boost is holding strong.

My opinion, its worth it.

[XerocX]

Originally Posted by ms3blackmica The springs are all the same color, they just come with some paint on the side to mark them. 10-20 psi spring has green paint. 20-25 psi spring has pink paint. I always had the SU TS BPV for 3 years now and always had the 10-20 psi spring. It caused issues for me when i started to run 21 psi. Boost would taper off earlier in the RPM range. I ordered the 20-25 psi spring and now boost is holding strong. My opinion, its worth it.

I am running my dual port vta using the Guardian Angel and it flutters in low boost and also in higher boost (surge?). I loosened the tension a little past where the red mark is and still get it. I heard by using a softer spring it eliminates the flutter. my boost is 19.5 psi. Any tips?

[ms3blackmica]

Originally Posted by XerocX I am running my dual port vta using the Guardian Angel and it flutters in low boost and also in higher boost (surge?). I loosened the tension a little past where the red mark is and still get it. I heard by using a softer spring it eliminates the flutter. my boost is 19.5 psi. Any tips?

I am not framiliar with the dual port.

I only have the TS BPV (only recirculates).

Lex could answer that for you.

[XerocX]

Thanks

[dale_gribble]

I ran the 20-25 psi spring. It was fine. It held boost with no partial boost flutter.

Thing is quieter than stock. I like it.

[fivefingerdeathpunch]

Originally Posted by dale_gribble I ran the 20-25 psi spring. It was fine. It held boost with no partial boost flutter. Thing is quieter than stock. I like it.

does yours hit boost targets? i tried using the 20-25psi spring when i was running 21psi and for some reason i was only able to hit 18psi or so with the stiffer spring

[dale_gribble]

Ya, mine was hitting boost targets no problem.

[nybe0010]

Originally Posted by XerocX I am running my dual port vta using the Guardian Angel and it flutters in low boost and also in higher boost (surge?). I loosened the tension a little past where the red mark is and still get it. I heard by using a softer spring it eliminates the flutter. my boost is 19.5 psi. Any tips?

I have the dual port as well and i experienced flutter in low boost when i was running recirc now i have no issues while im 50/50. Im curious as to whether or not i may need a different spring when i get a tune and run more boost, but maybe you could go 50/50 see if that solves it?

[XerocX]

Originally Posted by nybe0010 I have the dual port as well and i experienced flutter in low boost when i was running recirc now i have no issues while im 50/50. Im curious as to whether or not i may need a different spring when i get a tune and run more boost, but maybe you could go 50/50 see if that solves it?

I have my recirc hose plugged due to being VTA. I think I remember someone said they went with a softer spring and they had no flutter. I'm at 19.5psi and am wondering if the softer spring will hold that.

[nybe0010]

Originally Posted by XerocX I have my recirc hose plugged due to being VTA. I think I remember someone said they went with a softer spring and they had no flutter. I'm at 19.5psi and am wondering if the softer spring will hold that.

Alright well give that a shot and then let me know! Im going to be getting tuned pretty quick here and i may run into similar issues. Any particular reason you run VTA ive read around and ppl mostly only have negative things to say?

[XerocX]

Originally Posted by nybe0010 Alright well give that a shot and then let me know! Im going to be getting tuned pretty quick here and i may run into similar issues. Any particular reason you run VTA ive read around and ppl mostly only have negative things to say?

Yeah man, I installed a Guardian Angel for overboost protection (hit up Lex for more info) and it has an option to run your bov VTA with no ill effects on the car. It already saved my ass once too!

[nybe0010]

Originally Posted by XerocX Yeah man, I installed a Guardian Angel for overboost protection (hit up Lex for more info) and it has an option to run your bov VTA with no ill effects on the car. It already saved my ass once too!

damn thats sick plus you get all the noise even 50/50 is soo much louder than recirc. My AP showed me hit 23 psi and threw the overboost code when i was running a stage 1 map and i didnt have my internals in yet cut out like a mofo and scared the shit out of me. I saw the guardian angel on their site im looking into getting stratified i will probably end up getting it!

[XerocX]

Originally Posted by nybe0010 damn thats sick plus you get all the noise even 50/50 is soo much louder than recirc. My AP showed me hit 23 psi and threw the overboost code when i was running a stage 1 map and i didnt have my internals in yet cut out like a mofo and scared the shit out of me. I saw the guardian angel on their site im looking into getting stratified i will probably end up getting it!

Right on man! Check them out, Lex will answere all your questions, he helped me out a lot. I'm VERY happy with my purchase

[nybe0010]

Originally Posted by XerocX Right on man! Check them out, Lex will answere all your questions, he helped me out a lot. I'm VERY happy with my purchase

Sounds good will do !

[dale_gribble]

The softer spring is leaking on me around 20 psi. Piece of shit. The hard spring is too hard and I get some compressor surge and the soft spring is too soft now.

[Boost_creep]

FWIW, I've been running the softer spring at 20-21 psi for 2 years, and I love it.
No flutter, and holds boost like a champ!

[mituc]

I used the soft spring with a 24PSI tune and it was fine. I think the ability of the BPV to hold boost is not necessarily dependent on the opening pressure. When into boost you have the same boost pushing the piston into the closed position both in the cold pipe and the other hose connecting to the IM. So as long as the pressure difference does not exceed a certain value that would make the spring compress (14PSI for the softer spring and 20 psi for the stiffer one) the piston should stay closed.

If you guys have problems with the Turbosmart BPV holding boost check that rubber o-ring/gasket at the top of the valve. Over time mine got longer for some reason (probably because of the Turbosmart Oil I was using, or heat stress?) and I had a very hard time threading that cap back after I was lubing the piston. Last time I lubed the piston it took me 20 full minutes to put it back in place, and this used to take less than a minute. When I got back in the house I ordered a Cobb XLE which requires less maintenance thanks to the low friction material used for the piston coating.

[dale_gribble]

I have had the Turbosmart BPV with the soft spring for a while. Every oil change, I pulled it apart and oiled it. I just recently inspected it and it was fine. It seemed to do fine, but lately, I started hearing (and seeing in logs) the BPV dumping some boost over 20psi at peak boost. I am not sure what changed since I first installed it. I don't think this is a leak at the o-ring; I think the spring is starting to compress and leak under 20+ psi boost pressure. Maybe the spring is getting a little tired? I don't know.

Anyways, I put the higher rate spring on and we'll see how it does. It isn't fluttering at partial boost and is holding boost fine.

[mituc]

The spring gets indeed a bit softer over time but not too much and I still don't think it's a real issue.
I lubed mine every ait filter change which in my area has to occur at 3-5k km (2-3k miles), so a lot more often, and still the piston had some obvious wear marks on it.
I don't think mine was leaking (at 24PSI is becomes a lot more obvious), but eventually it would have. So pull the piston and take a look at it.

These are good valves, very easy to maintain and worth every penny. But sometimes they are just full of surprises.

So, OP, put the softer spring in, in my opinion you really don't need the stiffer one.

[dale_gribble]

I am OP. I did need it. Ok, I did some more research here. Street Unit must be retarded or using ricer math to come up with their spring ratings (10-20psi, 20-25psi). Everything you will read is that springs aren't rated for boost. Repeat: Spring ratings are not rated for boost. I'ts a pull type valve; the vacuum sucks open the valve. Therefore, the springs are rated based on the amount of vacuum the car produces at idle to ensure the vacuum can sufficiently open the valve. Springs are rated relative to engine vacuum reading at idle on a warm engine. They are not rated on how much boost they can hold.

Turbosmart offers 2 springs with their BPV made for our car; these are the two springs that SU sells with this BPV:

TS-0203-3002 BOV Kompact DP Spring-Pink (rated at 15-21 in/hg)
TS-0203-3003 BOV Kompact PB Spring-Green (rated at 10-16 in/hg)

Our cars typically idle at -10.5psi (~21 in/hg). Therefore, the Pink spring (15-21 in/hg) (the supposed 20-25psi spring) IS the correct spring for our cars. I confirmed yesterday that the spring has a little pink paint on it when I swapped it out. I am running this spring and it is working perfectly.

I find it very unlikely that SU ran spring rate tests and found some way to definitely rate the 'boost rate' of the springs.