More boost with Profec B

[CanadianTSi]

Just wondering if anyone knows any tricks to get more than 26psi out of a Greddy Profec B?

Thanks.

 

[daren_p]

Not sure if you have an origional B or the spec II or if this would even apply to those models but I know when the profec type S came out they had a software issue that was limiting the boost. With my evoIII I wasn't able to see over 20 psi with the high boost setting maxed. Sent it back for the software update & now see 20 psi with the high boost setting sitting half way.

Otherwise not sure what the limit is on the origional B but the spec II should be somewhere in the mid 40's. The way the profec works is its just a multiplication factor of your base wastegate pressure. Its something like 2-2.5 times, so if your actuator is 10 psi you will only get 20-25 psi out of the boost controller. The way to up your max is just to increase your wg pressure. If your running internal, tighten it up if its adjustable or shim it if it isn't. If your running external, time for a heavier spring.

 

[CanadianTSi]

Its the Original Profec B and I can run 18psi with it off, so it only gives me an Extra 8psi which is kinda weak...

 

[Staytuned]

Just wondering if anyone knows any tricks to get more than 26psi out of a Greddy Profec B?

Thanks.

More than 26psi?...are you looking for more knock or higher IDC's with your setup?

seriously though ditch the internal WG and the old school profec (if it is truly limited to 26 psi) and go external sprung for 20 psi and run the newer profec. I now get 25 psi at half the high setting.

 

[CanadianTSi]

You mean 106% IDC is high

 

[talont3t4]

Most boost controlers have a hard time running more then double the wastegate spring pressrue. I would switch out the spring to a higher one say 15Psi.

 

[Kevin Jewer]

Yes, the old skool Profec B will do double the spring pressure, or 26 psi, whichever is lower. I ran a 22 psi spring and still couldn't get over 26 psi. Has something to do with the strength of the solenoid or it's spring.

There was one way I was able to get more boost, but it's a hack at best, try it if you're really bored. I ordered an air pressure regulator from Mcmaster and installed it between a pre TB boost source and the "top" port of the WG. I put some pressure on that port to keep the WG closed. I want to say that the pressure on the top port equaled the amount I could go over 26 psi by, but I believe there some some loss there. In the end I gave up and went to a MBC on that car. I've run the newer Profec B (type s or something) and the HKS EVC with higher boost, they have solenoids allegedly good to boost in the low 40s IIRC.

 

[CanadianTSi]

Yes, the old skool Profec B will do double the spring pressure, or 26 psi, whichever is lower. I ran a 22 psi spring and still couldn't get over 26 psi. Has something to do with the strength of the solenoid or it's spring.

There was one way I was able to get more boost, but it's a hack at best, try it if you're really bored. I ordered an air pressure regulator from Mcmaster and installed it between a pre TB boost source and the "top" port of the WG. I put some pressure on that port to keep the WG closed. I want to say that the pressure on the top port equaled the amount I could go over 26 psi by, but I believe there some some loss there. In the end I gave up and went to a MBC on that car. I've run the newer Profec B (type s or something) and the HKS EVC with higher boost, they have solenoids allegedly good to boost in the low 40s IIRC.

Thanks alot Kevin.

Looks like I'll be upgrading to a Type S over the winter...

 

[daren_p]

Thanks alot Kevin.

Looks like I'll be upgrading to a Type S over the winter...

New Type S would be the way to go, I've run 22 psi with the knob set right around half way up and my WG is ~ 12psi, so you should have no problems seeing 26+ with 20psi base.