It's factory set at 10-12 psi but I'd like to lower it to 5-6 psi max. Does anyone know how to do it? Thanks.

 

You'll need a manual or electronic boost controller to do it.

But why would you even want to lower the boost on that turbo?

 

because it's going on my old b18a with stock internals.

 

Number One...you CANNOT, I repeat CANNOT lower the lowest physical setting of the wastegate with ANY type of boost controler.

Number Two...the 14b's wastegate is set up for 9psi stock...you work up from there, not down.

 

What actually controls the amount of boost? is it a spring inside the waste gate? if it is can I just replace it with a 5 psi spring? Well, if I can't use the 14b I might have to sell it and get a weaker T25 or T3.

 

Yes, it is a spring inside that controls the boost, although in that wastegate it is irreplaceable. The T25 (while flowing 100cfm less than the 14b) is set up to boost at 11psi stock, not 9psi like the 14b. Keep your 14b and use an external wastegate...solve all your problems.

 

I believe you can thread the actuator arm, Even bend it but I wouldnt go that route. What you want to do is have the flapper door open sooner, so threading the arm and extending the length of the bar will do this. Also I think the hahn racecraft sells something for the adjustment of the stock actuator--although it may only be for the T25.
A boost controller will only raise boost from where its set at the wastegate, you cannot lower it.

 

Yes, thread the actuator arm or buy one already done.

 

Just want to make sure which piece is the actuator arm: The one with the yellow or red arrow pointing to it? And any idea how much I have to extend it? Thanks.



[Modified by teg90rs, 4:31 AM 12/4/2001]

 

There really isnt any way to tel how far to extend it. Your best bet is just to thread it.
Its simple. Cut in 2. Buy rethreading kit. Probably 10mm or 8mm. Goto hardware store and find a long shaft nut.
This should do it. I would say turning it out maybe one or tow turns would change boost levels by a couple psi..

 

The red arrow points to the actuator arm.

Cut it, thread it, reconnect it with a nut.

Also, T25 wastegate is set to 7-8 psi. I know, I run it everyday.

Randy

 

i always thought by reducing the arm length the wastegate would not be fully closed all the time which results is lots of lag but also lower psi. shortening the arm does not make the wastegate open sooner....only the spring can do that.

ya...so can't the sring be changed?

 

Thanks for the help everyone.
I have the specs for the waste gate:
-supercharging pressure = 6.0-10.8
-waste gate valve opening pressure ~ 11.1


[Modified by teg90rs, 12:56 AM 12/5/2001]

 

so can you change the spring?