SVO gets new Boost Conroller and Bypass Valve

[SchoolBoy]

So ever since I rebuilt the motor in my svo, and then adding the front mount intercooler two problems have plagued me.

The first being anything more than 14psi of boost and the car would detonate, pull timing and all around fall on its face. Its clear to me now that this is mainly caused by the head having been cut several times. Now the true remedy for this is either a thicker head gasket or a new head. While I have not had time to do the tear down, I only just recently picked up a back up head. {1-23-18, The real cause was excessive piston to wall clearance that resulted in a full rebuild} So in the mean time I need to just turn the boost down. Doing this with the Gillis bleed valve proved to be tricky as there was no happy medium between 10psi and 14-15. Also the Gillis would do its normal 1-2psi creep. This is when I decided to bite the bullet and buy a electronic boost controller.

The second problem came up after I built my front mount intercooler in the form of compressor surge and VAM flutter. It was getting so bad that when I lifted from low to medium boost levels on the freeway it would violently shake the whole car. Now I was still using the bypass valve that forced4 used to sell but for some reason it just wasn't venting the boost. I will also say that my placement of the valve probably played a roll in this. Had it been closer to the charge pipe if not directly attached to it this may not have been as big a problem. Either way I needed something far more sensitive and vented more.


So after doing some digging, a lot of youtube watching and poking around boosted import sites one name popped up a few times....GoFastBits After a few more evenings on the old internet, I could not find any negative reviews or failures of their products with one exception.... GoFastBits is based in Australia so tech support would be through email. I figured I would see if they could recommend a bypass or blow off valve that might fix my surging problem. Well long story short, the tech didn't just say "here use this," he actually wanted to hear my problem to help diagnose the issue. So I sent him two gopro videos that I took from under the hood. With that in hand he told me to use the T9301 bypass valve. http://www.gfb.com.au/products/blow-...ent-bov-by-gfb The key here was that my forced4 bosche bypass needed a pressure difference of 10 points to open vs the T9301 at only 5 points. An example being: if I boost to 3psi and let off, the bosche would need to see a vacuum of 7" before opening, the GFB only needed 2" to open. So I hopped on ebay and picked one up that was for sale in the usa NIB.


It was very well packed, looked nicely made, and all I had to do was rotate the vacuum nipple by following the instructions.

20150603_194916_HDR by Judge Dread, on Flickr

20150603_195035_HDR by Judge Dread, on Flickr


Compared to the bosche diaphragm valve this uses a metal piston.
20150603_195038_HDR by Judge Dread, on Flickr

20150603_195045_HDR by Judge Dread, on Flickr

20150603_195050_HDR by Judge Dread, on Flickr

This is after rotating the cap so that the nipple was pointing the way I wanted it.
20150603_200716_HDR by Judge Dread, on Flickr


My old Bosche setup...
20150603_200933_HDR by Judge Dread, on Flickr

20150603_200941_HDR by Judge Dread, on Flickr