I have a Turbonetics Deltagate W/G which is about 2 years old so far and hooked up to my relatively new Turbonetics MBC, you know, the black plastic one. I have had thiss hooked up for quite a while, but recently, I have the need to notch it down to the minimum setting, shich should net me about 1-2.5 psi slipping by, right ? Well I played with it and noticed that my boost goes as far a 8 psi, maybe even 9, but I don't want to push it as I cannot supply the fuel right now. I want to limit my boost to minimum for right now, then 5-6 psi after while I am still getting parts... problem is, the MBC does not seem to be doing it's job ! I have heard some horror stories about the deltagate, could the WG be my problem, or is it the MBC, or is it both ?

I can't afford a new WG just yet (and I would go Tial) so I hope it ain't broken !

 

I've heard the turbonetics MBC is crap, I was talked out of it a couple months ago. I would just remove it, and go off of the wastegate spring for now to keep boost down.

 

take the 9psi spring out and replace with a 6psi and see if that holds - turning upside down doesnt work by the way.
you may have ruptured diphragm or MBC is leaking boost, maybe WG outlet not enough for all the exhaust, hondas really like to spool. costs like 8 bucks to replace diaphragm.

 

hMMM.... WG dumptube is like 2" wide, 14" long... is that too small ?

I'll look into the 6 psi spring too...

 

Are you saying that you tried to lower the boost level with an MBC on a 9lb spring? If your spring is 9lbs, then that's the lowest you can go on it, MBC or not. You need a softer spring.

 

So the spring leaves me no room for adjustment with the MBC ???? I mean, I never tried to turn it down this low with the MBC, but I followed the instructions (IE: back out screw as far as you can..etc...) So the 9psi spring can't go lower on the deltagate... what am I, stuck to buy the 6 or 7 psi spring ? Why did I spring $100 on an MBC then ?

What's the lowest spring avail for a deltagate ?

 

thats what i dont get.... if you got a 7lb spring... why cant u boost below it with a mbc? im sure you can adjust it lower than 7lbs. its a boost controller... not a boost controller for only boost levels higher than the spring on the wastegate. someone wanna explain why this is so?

 

Yeah, what he said dammit !??

Anyone?

 

An MBC modifies the boost signal to the w/g in order to control boost. It does this by placing a restriction on the boost flowing to the w/g in order to have the w/g see less boost, and thus keep it closed longer to hold more boost. An MBC can't modify the boost signal to be higher than it actually is(which would make the w/g open sooner and hold less boost), it can only restrict it. That is why you can't use a boost controller to dial in boost levels below that of the w/g spring.

 

You can't lower the boost below a WG's prespecified amount(the spring). ANY boost controller can only RAISE the boost above the spring's amount.

The only way you will be able to lower the boost any further is put in a differnet(less tension) spring in the WG.

 

what you should have done is get the softest spring....then with the mbc you can up the boost.

All the mbc does is fool the wastegate. but you can fool the spring.

get the softer spring keep the mbc then when ur ready up the boost.

spring is like 30 bucks?

edit: mbc can also spool you up faster....so dont think u wasted 100 bucks on one.


[Modified by Cramerox, 5:16 PM 5/29/2002]

 

I can only find a 7psi spring as the lowest... is there a lower boost spring than the 7psi unit ? Is there a trick to get the W/G to boost something ridiculous, say....1psi ? Sounds like a stupid question, but I have my reasons...

 

Hey anthony

 

I"M SURE that you could find a spring that will give 1psi. I really don't know how the boost will react, but I'm sure you could just find a super soft spring that matches the size of the normal wastgate spring.

I'm going to use an internal wastegate with my build up(not telling what turbo) and am setting it for 4-5 psi with a switch "off" then with the switch on, it will spool to a full 18 psi.

get good gas milage and reliability when I don't need the power. Then If some ricer punk comes up along, all I have to do is flip the switch and kill his ***. The Zydne takes care of the fuel/spark mapping changes.

 

Bryson where can i get more infon on the zydne ecu? im planning to run to boost settings also.

 

lowest available spring... 3 psi spring (green) turbonetics part # 10113... adjustable up to 5 psi by tightening adjustment bolt on top of gate... retail cost less than 10 bucks, so don't get ripped off...

 

Gotta call turbonetics to see who carries the 3 psi spring. Hell, if the MBC will allow me to up the boost I can keep that setup for a while b4 I need to swap for a better WG ! Dynamic turbo doesn't have it (of course !), anyone have an 800 # for turbonetics ?

 

so basically, when you install a mbc... you can only boost 7lbs and up. so much for boostin 5lbs daily once i get one. im just wondering why the spring will only allow it to boost 7lbs or higher. i know the function of the mbc...

 

Well you can't reduce the tension on a spring(only way is to make a new spring, or heat it ). you can only INCREASE tension for more boost.

Or in the case with a Boost controller, your limiting the pressure the valve see's to open.

say you have a 5psi spring in the WG now. You then throw in a MBC and tune it to see 10psi. you are limiting the pressure the WG spring see's by 5psi. So when the turbo spool's to 10psi the WG is actually only seeing 5psi, and it's opened fully.