Turbo flutter MMP twins
- Thread starter Jordi992
- Start date
Your boost PSI has nothing to do with the spring rate psi. One is positive boost pressure the other is vacuum state. They are not to be confused. You must know your specific car's vacuum level and get the spring that is congruent to that vacuum.
I ordered the black one ... I'll take Chris' word for it ... good enough for me.
Filippo
On the Tialsport spring - there are "aftermarket" springs ... fakes ... they say they are Tialsport and are not. If you want the real deal, buy from an authorized Tialsport dealer.
Unfortunately Tialsport is the land of fakes, yet ironically the company does not provide any way to search for authorized dealers or provide a dealer list - great way to promote a fake industry around their products. FWIW you can order on Amazon, but go to the listing of sellers for the product - Automods is an authorized vendor, $27 gets it to your door with Prime.
Filippo
Unfortunately Tialsport is the land of fakes, yet ironically the company does not provide any way to search for authorized dealers or provide a dealer list - great way to promote a fake industry around their products. FWIW you can order on Amazon, but go to the listing of sellers for the product - Automods is an authorized vendor, $27 gets it to your door with Prime.
Filippo
Last edited:
Well, I have a black and unpainted spring if you want to pay for shipping and packing I can send it for a reduced price. Let me know. I don't remember how much they cost, will look in my records.
VT
Screw that ... look at those GC lites to the right of the spring!
Filippo
Screw that ... look at those GC lites to the right of the spring!
Filippo
Rite of Spring? Isn't that Stravinsky?
Neil
For us guys that bought with 11 psi spring should we bother changing if not having any issues. Like could this help spikes on shift or help hold boost. Top gear and others have always pushed the heavier spring and I know just cause it works doesn't mean it's best im just curious what improvements the lighter spring could make if not having issues with current spring?
https://bmw.spoolstreet.com/documents/bov-setup-for-your-n54.30/
^^^ VTT's write-up on the BOV.
Filippo
^^^ VTT's write-up on the BOV.
Filippo
I think the confusion is because the springs are rated in psi, but they are talking about vacuum, which we typically (at least in the US) as inHg. 11 psi of vacuum is 22 inHg. You ideally want the spring around where the car idles at. If your car doesn't hit 22inHg when you shift, then yes, you should bother changing or you aren't getting it to open fully/properly/bestest. Don't forget that 1/4 source - that is a YUGE component for the Tial to operate correctly.
Yes and no. Everything is correct here except the idle part.
MHD monitoring shows -8.8 to -9.8 psi at idle depending on conditions. However let off the pedal completely above 2k rpm and it's consistently -11.1, -11.2 psi. Idle isn't high enough rpm for full engine vacuum. That's why IMO you should be running the 11 psi spring and only change it for a softer one if you have issues and everything else is done right.
But this is what I'm trying to get what is the benefit of heavier spring or lighter spring if they both open when you lift throttle? Is it a case of the lighter spring may not close fast enough when throttle blade opens again or the light one will keep turbos spinning faster on quick shift?
Lighter is better than heavier. The spring pushes the valve close against the cp air pressure. Therefore, a lighter spring will react and release faster than a heavier spring. Too heavy a spring and your BOV will not even open at throttle release.
