legacycentral bbs

OK, I'm confused. I am trying to hook up my turbo and I'm a bit lost. I have shoehorned in a vf34 and I'm down to the vacume lines. Now there are 2 connections. One on the compressor side housind and one on the waste gate actuator. I think that on the factory setup these two connections go to two different places. BUT, on my vf34 these two nipples on the turbo were connected by a T and there was some brass thing in the vacume line like a restrictor of some sort. So I am confused. do I dismiss the whole T with the restrictor and just connect the two nips to the correct places in the car or what? Also, I have no idea where those places are lol. I have looked at some pics but none have enough detail to see the turbo area. Any help would be great. Thanks in advance

-Mike

Do you use the stock boost controller? If yes, then the lines need to go the the stock boost control solenoid in the same places the stock hoses would. If not, then they need to go to whatever other boost controller you use. You can ignore the T

Have you done any fuel system upgrades?

MK

I think the difference is due to the way factory boost control is done.

The early setup (I think it was used on all Legacies and Imprezas with the 90-degree compressor inlet) has a three-way boost control solenoid. Pressurized air travels from the compressor outlet nipple to the solenoid, and from there it travels either to the wastegate actuator or to the intake resonator. There's actually a restrictor in the hose going to the intake resonator.

The later setup (I think it goes with the straight compressor inlet) uses a 2-way solenoid which just bleeds pressure off to the intake. Pressurized air travels from the compressor outlet nipple to the tee, and then simultaneously goes through the solenoid to the intake or through a restrictor to the wastegate actuator. The restrictor makes the solenoid's pressure bleeding more effective.

If you want to try using stock boost control, do what MK said. Remove the hoses and tee that came on the VF34 and just set it up like stock (see [url]http://www.graphics.cornell.edu/~v/vacuum/[url] for a reference on how the stock stuff is plumbed).

But I'm not sure stock boost control will work right -- doesn't the VF34 have a nominal 9 psi wastegate setting? The stock turbo's wastegate opens around 5 or 6 psi. The difference would throw off the stock boost control's calibration, particularly since stock boost is supposed to be around 9 psi. So you'd probably be better off connecting the compressor outlet and wastegate actuator directly with a piece of hose than you would be if you used the factory boost control.

In any case, you're planning on running more than 8.7 psi on the VF34, right? Why not just install a manual boost controller?

magicmike wrote: I have shoehorned in a vf34

May we have some pics Please!!!!

ok here are some pics, http://photos.yahoo.com/mikem_75

As far as settings things up, I want to at leaste get the thing hooked up so it will work for now. I'm also putting in the all alluminum saab ic I picked up recently so I guess it would be ok to just do what you said vrg3, putting the compressor outlet directly to the wastegate actuator for now, I am getting the A'pexi AVC-R soon but I wanted to get the engine running for now. Will not using the stock boost control solenoid give me a check engine light or anything? As far as fuel system upgrades I have none for now, I'll worry about that once I get to raising the boost. It has been hard finding time to work on this project lately so I need to take one step at a time. Work is really kicking my ass lately. Thanks guys

-Mike

As long as you leave the stock boost control solenoid connected to the electrical harness, the ECU won't throw a trouble code. I'd suggest putting caps on the two sideways nipples too since you'd otherwise leave them exposed to the elements.

I need to buy that boost controller soon, anyone know where i can get a good deal on one? or does someone want to suggest a better alternative?

Build one. Ace Hardware should have everything you need to make your own... its just a valve that lets the wastegate actuator see more or less of the actual turbo pressure, controls whether it opens at or above the wastegate spring pressure.... let me see if I can find a writeup I found once before...

OK I couldnt find the exact writeup but I searched on Google for "DIY boost controller" and found many similar to this simple one:

http://www.z31.com/oboard/archives/view.pl?139

Probably cost you less than $10 with valve and fittings.

no no no, thank you for the reply but I want an electronic one. I want to get the A'pexi AVC-R. I like the features. I was wondering if anyone knew where I could buy one of those cheap or if there was something better. Sometimes people on here have connections so I thought I'd ask

I'd get a used A'pexi AVC-R off someone at NABISCO. They're always selling them and usually at a good price. If not there, I've seen 'em new on ebay for about $100 less then most shops and vendors have them for.

cool, I'll try that, thanks

damn those electronic boost controllers are expensive, just looking through the popular ones. Nice features to be sure... but damn thats expensive.

I can get a TD05-16g for less money than one of these....

well considering I spent 1000 on the turbo I think 400-600 on a control for it would be ok