12 psi with grainger?

[Dusted U]

Have an 87 Shelby daytona with 3 mods, no cat and a grainger valve, shimmed wastegate. problem is I cannot get over 12 psi. Do I need to shorten the spring in the valve or what are my options? i know that it had 12 psi all stock with the factory controller. A/F guage shows all is well at 12. I would just like a couple more psi.

[1985ShlbyChrger]

no need to stretch the spring or get a stiffer spring. both are easy to do, stretching the spring you can do with your ifngers and buying a new spring is easy, go to a hardware store and take your old spring with you, grab the same size spring just a little stiffer.

[GLHNSLHT2]

if the wastegate is shimmed and you're only getting 12psi I'd say the can is dead. try unplugging the vac line from it and carefully seeing if you can get over 12psi. If so then it's the grainger. If not it's the can. The can on my 87 died awhile ago. Wouldn't pull over 11psi with the 2.5 shoved under it.

[Dusted U]

i shortened the spring in the grainger and found my 2 psi. 14 on the stock guage through all the gears.

Rob

[Una]

After everyone told me you couldn't use a large can from a T1 Garrett, I swapped one onto my T2 turbo in California.. Works like a champ, I can get as low as 10psi, and as high as 25psi..

[cadmanspd]

I've got an early can on my TII Aries. Fits awesome.