If you run it in interrupt mode, it will allow quicker spool and it should hold boost a little better up top. However, you will need to have it tuned for, as you need to lower the wastegate duty cycle to prevent overboosting. I am using the Prodrive solenoid, which is very similar to the GM but it includes a wiring harness so you don't need to splice the wires.

 

Thanks.

I'm still unclear. Can this be used on a completely stock motor? If so, are there drawbacks? (other than overboosting)

 

heh.. overboosting sounds harmless... but will destroy an engine.. other than overboosting you will just not be making max power that you could be. you will not be running safe and will certainly have issues.

 

Great...I'll have issues. I already have issues (ex-wife). I'm trying to get some input as to what these 'issues' are or will be.

Ok. Let me try again, this time with a little background. I have owned and raced motorcycles for over 20 years now. My other car is a heavily modified 300ZX TT. I've owned and rebuilt a 1967 427 powered Sting Ray. I only say this because I want those that read this to understand that although I do not know much about the STi's motor, I do understand engines and what overboosting is, and what it can do and how it does it. And no, overboosting doesn't sound harmless. I'm familiar with too much boost (think 300ZX TT above).

I've learned that there are some cheap modifications for some vehicles and was curious about this GM soleniod thing. As an example: Some slight dremel work on the airbox of one of my motorcycles will get 3-4 dyno proven HP gains.

Why do it? Is it too risky? Will a stock motor benefit? In addition to potentially too high of boost pressure, is there anything else? Can the overboosting be controlled or prevented via tuning (a stock motored STi)? Is this a tuners trick, or is there some merit to it? Are there long term drawbacks? The first reply claims "quicker spool up". True? False?

 

dont waste your money on it.. ull end up replacing it down the road when you get a electronic boost controller.

 

the the GM solenoid will work fine and if you solder the resistor it will have NEAR the same impedance that the OEM solenoid has. (the perrin solenoid matches the OEM exactly) Configured in interrupt mode you will have quicker spool and you will be able to hold your WG shut longer. It is superior to the stock solenoid when used right.

You should only install an upgraded solenoid IF you have direct control over your wastegate duty cycles via a Utec or Cobb Streettuner.

also don't listen to this guy:

dont waste your money on it.. ull end up replacing it down the road when you get a electronic boost controller.

If you can control the wastegate duty cycles and are doing it with a utec or streetuner then you already have an "electronic" boost controller.

 

Awesome. Thanks for the useable information guys.

 

It "can" be used on some completly stock cars. If you are going to try it just be careful and watch the boost. If you are overboosting after you install it I would remove it until you have a proper way to control it. And it turns the factory/Utec into the same thing as an aftermarket EBC.

TMS

 

In comparing a solenoid (in my case the $90 Perrin EBCS) to just a simple wastegate spring mod ($3) ... the wastegate spring mod beats an EBCS hands down in terms of performance per dollar. In fact, if you know how to tune the stock solenoid then you can tune the stock solenoid to just about the same level of performance (on a stock VF39) as compared to a GM or Perrin solenoid. In all honesty, I wouldn't waste my money on the EBCS or GM solenoid. Plenty of people are using the stock solenoid on high power setups now. Why? Because people have learned how to tune the stock solenoid. You said you want little tricks that give power. IMHO, the solenoid is not one of them. A wastegate helper spring is. I got 200rpm quicker spool and it holds acceptable boost at redline (15lbs).

t

 

In comparing a solenoid (in my case the $90 Perrin EBCS) to just a simple wastegate spring mod ($3) ... the wastegate spring mod beats an EBCS hands down in terms of performance per dollar. In fact, if you know how to tune the stock solenoid then you can tune the stock solenoid to just about the same level of performance (on a stock VF39) as compared to a GM or Perrin solenoid. In all honesty, I wouldn't waste my money on the EBCS or GM solenoid. Plenty of people are using the stock solenoid on high power setups now. Why? Because people have learned how to tune the stock solenoid. You said you want little tricks that give power. IMHO, the solenoid is not one of them. A wastegate helper spring is. I got 200rpm quicker spool and it holds acceptable boost at redline (15lbs).

t

the spring is a cool mod for helping the wg stay shut... but an ebcs will help that flapper be more responsive so the WG can bleed off pressure sooner which is a different thing then trying to keep the wg shut.

 

the spring is a cool mod for helping the wg stay shut... but an ebcs will help that flapper be more responsive so the WG can bleed off pressure sooner which is a different thing then trying to keep the wg shut.

Again, this is my experience tuning my own car on a VF39. I understand the theory and agree. However, the reality was different when I actually got into doing my own tuning with regard to the VF39. I am not making this claim with regard to other turbos ... just the VF39. I've tuned the stock solenoid and the EBCS. Most people just talk about a tuned EBCS. Very few people talk about a well tuned stock solenoid and then compare it to a tuned EBCS. I've done it. Since this post is about the VF39, that is what I posted about.

t

 

I'll sell you a cheap EBCS... I just put in a Apexi AVC-R.

See post #6 for *my* experience. Also, listen to Tim (WolfPlayer).