Forge bpv. Which Spring/shim?

[booya620]

ok. I know there are random posts everywhere with what spring shimm combo people are using in their forge bpv. Mine is being shipped from su. I'm otherwise stock until Cobb ships their intakes out, which I'm not holding my breath on. I haven't seen a lot of: "I have a, b and c mods so I'm running spring red/blue/yellow with 0/1/2 shims". From what I have gathered most are running blue with 2, but no referral to what mods. I'm assuming intake maybe dp/mp. What do people recommend for stock? What should I look for when tuning the bpv with the correct spring/shim combo? Most of the 3 pages of threads I searched through are opinions on the best bypass valve, very little on actually tuning the forge. I did find this info on the forge site, but their recommendations see "off" from what others have suggested:

Valve Spring Tuning Kit

Now you can fine tune your Blow Off/Diverter Valve to the exact needs of your engine with this complete tuning kit.

Your valve tuning kit you will find four springs and three spacers.

The strongest spring is the red, followed by the blue, yellow and finally the green which is the weakest. The spacers enable you to fine tune the settings between two spring tensions if required.

We normally supply our valves, unless requested differently, with a spring that will match the tension of the manufacturer’s original fitment valve. However, as many owners undertake tuning modifications some may wish to re-tune the valve characteristics to suit a given application.

If you are finding that the valve is dumping more than required or you are loosing boost pressure it is normally an indication that a stronger spring is required. Conversely if the valve is failing to dump it may be necessary to install a weaker spring. If during this tuning of your valve you are faced for example with the red spring being to strong and the blue spring to weak, you can add the spacers to the blue spring to increase the tension by small increments, thus achieving a setting between the red and blue springs.

Valve Spring color coding

Green - 5-15 PSI

Yellow - 15-23 PSI

Blue - 23-30 PSI

Red - 30 + PSI

The above figures are estimates only and should only be considered as a guideline

Please note - fitting a stronger spring into a valve will not increase boost pressure unless existing pressure is being lost. Failure to allow the valve to operate by installing a spring which is to strong may cause damage to the turbocharger.

[booya620]

I you look above the blue seems to be rated for a much higher application than a stock ms3, at least according to their "guideline" numbers. But i haven't even heard of anyone running a yellow.

Blue, and try some shims.

[Sacrilicious]

you should run the spring color that best suits your boost level. if you're running stock boost, most people use blue + 2 shims...MAYBE yellow + 2 shims. as boost increases, more and more people switch to red + 0 shims.

[udontknowjack]

Originally Posted by booya620 I you look above the blue seems to be rated for a much higher application than a stock ms3, at least according to their "guideline" numbers. But i haven't even heard of anyone running a yellow.

i know someone running yellow from m3f...and hes like how it perform...1 yellow 1 shim....and his ms3 is with heavy modds....im gonna try that myself soon...

[diepanthony]

i thought the stock ms3 only boost at 15. so why is people running blue and up?? shouldent stock be using the green with shims?? im new to this whole thing and i myself just got the forge bpv and im trying to figure this out as well.

[NYpest]

I thought Pat@forge said that the spring rates were under rated for the ms3

Originally Posted by NYpest I thought Pat@forge said that the spring rates were under rated for the ms3

he did.

[Sacrilicious]

Originally Posted by MZRDISI4 She did.

yes, the spring ratings are off...blue is usually the spring to use for stock.

oh, and as a clarification, "patty@forge" is a guy...his name is patrick, so he's a dude!

LOL, patty just sounded like a girl.. my mistake.

[Sacrilicious]

Originally Posted by MZRDISI4 LOL, patty just sounded like a girl.. my mistake.

ya, i know, and i'm sure patty has a good laugh about it too!

[leadf00t]

Not trying to thread jack or anything, but I installed my Forge this evening and I went with just the blue spring and no shims. I am not getting any noise out of the BPV no ping, whoosh or anything. the car seems to be idling fine, and drove great. First to second shift seems smoother, but I've only had the car for a week or so. The smoother shift could be my imagination. Is this normal with a stock car, and just a Forge BPV ??

Yes.. the stock airbox muffles the noise. And the smoother shifting could be a result it holding boost better.

[silverspd3]

get a intake and u will hear all the lovely turbo noises

[Renzokuken]

I was running the red spring, but once I got my FMIC, it was too rough for DD so I put it down to the blue with 2 shims, now its much better.

[gtlaw]

Originally Posted by leadf00t Not trying to thread jack or anything, but I installed my Forge this evening and I went with just the blue spring and no shims. I am not getting any noise out of the BPV no ping, whoosh or anything. the car seems to be idling fine, and drove great. First to second shift seems smoother, but I've only had the car for a week or so. The smoother shift could be my imagination. Is this normal with a stock car, and just a Forge BPV ??

I have mine with the blue + 1 shim and I can just barely hear it when shifting in lower rpms. I think I'm going to switch to the yellow

the stock valve seems much harder to push in with your finger than the forge does, and my stocker defineitely wasn't leaking

[booya620]

Originally Posted by leadf00t Not trying to thread jack or anything, but I installed my Forge this evening and I went with just the blue spring and no shims. I am not getting any noise out of the BPV no ping, whoosh or anything. the car seems to be idling fine, and drove great. First to second shift seems smoother, but I've only had the car for a week or so. The smoother shift could be my imagination. Is this normal with a stock car, and just a Forge BPV ??

Did you try any other combo's to see if anything worked out better?

Did Pat from forge say how under rated the springs actually are? I guess I'll try to contact him and post the info I get up here unlees someone else posts it first.

[booya620]

I have mine with the blue + 1 shim and I can just barely hear it when shifting in lower rpms. I think I'm going to switch to the yellow

the stock valve seems much harder to push in with your finger than the forge does, and my stocker defineitely wasn't leaking[/QUOTE]

When tuning the forge valve should we be making it easier or harder to press the piston in? I need to get better background info on how a bypass vavle is supposed to work. trying to find a decent article on this online sucks.

[gtlaw]

I have mine with the blue + 1 shim and I can just barely hear it when shifting in lower rpms. I think I'm going to switch to the yellow the stock valve seems much harder to push in with your finger than the forge does, and my stocker defineitely wasn't leaking When tuning the forge valve should we be making it easier or harder to press the piston in? I need to get better background info on how a bypass vavle is supposed to work. trying to find a decent article on this online sucks.

the valve releases extra pressure when the throttle shuts, but the turbo is still spooling its kind of the opposite end of turbo lag. if there wasn't a valve it would put strain on the turbo because of the extra pressure backing up to the compressor.

I just switched to the yellow spring, and it seems much better. I can hear it decently now. without a boost gauge I can't confirm if its leaking or not, but I don't see why the springs would be under rated for the MS3 and not other cars that just seems stupid to me. the only explaination I could possibly see for that is if the MZR creates very high vacuum compared to other engines

[leadf00t]

[QUOTE=booya620;76425]Did you try any other combo's to see if anything worked out better?


No I just started with the blue spring since I dont have any other mods it seemed like the right way to go. It's hard to find any real useful information about the Spring configurations. I've been searching, and people will have different color-shim combo's from one month to the next when they reply to a post. You think ok he's using this combo & it works, then you read the next post thats a couple of months later, and he's running a different config. Sometimes their mods have changed, and sometimes they're the same.

[booya620]

I installed mine yesterday and I've been running the yellow spring no shims. I haven't noticed an issue with the spring not being strong enough for this car. I'm probably going to keep it this way until I get a boost gauge installed.

From the research I have gathered about bypass valves it seems that it's purpose is to allow charged air to escape while the throttle is closed during shifting, thus allowing the turbo compressor to keep spinning( at 130,000rpms appx at full boost). If there is no bypass valve or if the spring in a forge valve is set too high. Compressed air pressure will build between the closed throttle plate and the compressor. In turn, slowing down the turbine greatly reducing available horsepower.

when tuning the bypass valve the spring rate has to be low enough to allow the compressed air to vent or be recirculated, but strong enough to hold during high boost.
I'm assuming the best way to do this would be to use a boost gauge and go just beyond the threshold where pressure air is leaking through the recirculating valve.
Oh yeah! the shim goes between the piston and the spring, correct? Is there a psi rating increase per shim? I wish forge would have f*cking instructions in the box.

The yellow spring may seem like an improvement but you will actually read with lower boost over the blue spring.

[gtlaw]

Originally Posted by MZRDISI4 The yellow spring may seem like an improvement but you will actually read with lower boost over the blue spring.

I really don't see why. there is normally boost on both sides of the piston its only when theres a pressure difference it opens

[CMESCOOT]

Is anybody running a forge VTA? I know the standback will allow us to vent, but want some opinions before I go that route.

[08cosmic3]

I'm blue with 2 and a Cobb SRI and it sings. In fact I wish it were not so loud.

[ONLYA6]

I was running the yellow spring and according to my Dashhawk I did a pull in 4th gear and was boosting ~16.8 right after spool then tapering off to 16.0-15.8 at 5k

Tonight I put in the Blue + 2 shim and under the same conditions I am boosting almost almost exactly 1 lb more and not tapering off as much as before.

So that's my experience.

[oskinosmee]

I use red with no shims but i run 20 psi

[SgtP]

im at stock boost which is about 16-17 with my mods. i have the red in but havent driven the car since it has been put in. ill report back with my findings. i might go down to blue until i get the standback installed.

[gtlaw]

Originally Posted by ONLYA6 I was running the yellow spring and according to my Dashhawk I did a pull in 4th gear and was boosting ~16.8 right after spool then tapering off to 16.0-15.8 at 5k Tonight I put in the Blue + 2 shim and under the same conditions I am boosting almost almost exactly 1 lb more and not tapering off as much as before. So that's my experience.

thanks, I'll be switching before I go to the track.. I wish that damn ventpod would get done already

[Qluber]

blue no shims

[xandrake]

Originally Posted by Qluber blue no shims

x2 -- This is what Patty told me would work best with my mods.

[Crossbow]

If I'm not mistaken (from the other dozen or so forge threads), the original spring "psi ratings" are for the 1.8 engines from the Audi's. Since we are dealing with a 2.3 engine, the recommendations change.

As others said, on a stock ms3, the recommendation from forge was a blue spring, and to tweak with shims as needed.

I find that the blue spring works pretty well, but will let off extremely easily (not holding boost) in 1st and 2nd sometimes under light throttle applications. I was going to try a blue spring with 2 shims as per forum owner tweaks, but found my inner o-ring (in the cap was damaged). I contacted forge, and within 1 minute of my email being sent, received a reply asking for my address to send a replacement...talk about service!

[seige123]

running blue and loving it. I had been running the yellow and the stealership told me I was loosing boost. I put my stocker back on and they said it was fine. I went ahead and but the spring kit to change from yellow to higher spring rate. My problem with the stock is that it would jerk alot at take-off and with the blue sprimg on the forge valve my car feels like it has more power and does not jerk me off anymore during take-offs.

[Big Dog]

Holy thread revival Batman! Blue spring and one or both shims is pretty much standard to start.

[SternRitteR]

Well ive been running the yellow with 22psi now with no ill effects for months.
it holds boost and dumps just fine.

[Z32_MS3]

Blue with 1 shims

Edit: Just realized how old this thread is whoops !

[Chris1208]

I just put on my forge bypass/diverter valve and a cobb sf sri and currently running blue spring and 2 shims I can definitely hear the swoosh from the intake and valve makes a nice loud flutter noise sounds good so far. anyone on here know if I should run a different spring or anything?

[Easter Bunny]

Blue two shims.

[WAMBUSHHHH!]

Originally Posted by Chris1208 I just put on my forge bypass/diverter valve and a cobb sf sri and currently running blue spring and 2 shims I can definitely hear the swoosh from the intake and valve makes a nice loud flutter noise sounds good so far. anyone on here know if I should run a different spring or anything?

x2 on blue two shims...first post though? make that intro thread sennnn

[RedDevil13]

Blue+1shim for now. May change after I finish tuning.