This isnt about MAF codes, its about the spring pressure in the TIAL Q's.

The old Tial 50mm BOV's worked great, and the spring normally used in teh EVO would be the PINK spring rated at -12.

When you go to Tials Website, you find that the Q dosent list the pink spring for -12psi anymore. it lists only for -11 psi and the -12psi is blank.

This also stands true for the QR but not the @lpha or 50mm models.


I ran the Tial Q with the pink spring and it leaked it would not hold 25 psi.

I took the same spring and installed it in a 50mm tial OG style and it worked fine.


if you look inside, the diaphram length is almost double in the Q making it obvious that the spring would not be as stiff in the Q as in the 50mm race valve.





So am I crazy, or did Tial replace the origional 50mm BOV with something that dosent work for EVo's and other high boost cras?

 

i have a 11psi spring in my Q. i boost checked it to 30psi with no leaks. would have gone to 40 but my coupler wouldnt stay on my turbo.

 

I also use the 11psi spring in my Q, no issues yet.

 

x2

I have the 11psi spring and the valve opens a tiny bit on neutral decel. It would probably be 'perfect' with another .5lb but i'm not using a MAF, so its not an issue.

 

I had a lot of issues when I first install the Q with stock maf...11 psi was too stiff and 8 psi the bov opened and closed whenever it wanted...10 psi is perfect...driveability is a lot better with the 10 psi spring...I plan on going SD soon so driveability will get even better...

 

with a 3 psi spring i haven't had any problems with leak checks to 35psi. The spring has no effect on the valves ability to hold boost, so if it's leaking you've got something screwed up.

 

i've got the q with the 11psi spring and no issues.

 

+1

 

what do you think it could be?

keep in mind i installed a old school 50mm in its place with the same spring, and its working like a champ.

 

yeah, sprig has nothing to do with a leaking BOV. you choose the spring according to your inhg at idle. you have a leak in your vac line going to the BOV or somewhere else.

 

Just replaced all the vaccum lines. But like i said, new old school valve works fine.

I love evo m. full of knowledge.

 

I use the tial QR with the 11psi spring and it works great. You have a boost leak from something else as some have mentioned. Check to make sure your bov is seated properly. I have this problem until it was fixed.

 

im very interested to see pictures of this setup in an Evo engine bay, and possible sound clips?

edit: nvm, here is a sound clip off youtube: http://www.youtube.com/watch?v=LvnSg2MJNvU

 

Now thats a quick evo.

 

thats compressor surge--^ has nothing to do with the bov

op..have you performed a boost leak test? simply replacing all lines is a waste of time. it could be a leak from a coupler, could be a leak from intake mani gasket, TB shaft seals, TB gasket, and all other vacuum lines. or the BOV might not be seated correctly. also make sure you have the right spring according to your inhg at idle. a spring in a q will react different in a old school and different in an alpha