Garrett T3 upgrade with FORGE CBV
Time for the next installment. In the summer of 2012 when Cheap Thrills hit the streets, I began twisting my Hallman MBC for increased boost
Well most of you know the result...addiction to boost, and the desire for MORE
Unfortunately, compressor stall happens. Here is a referenced thread with the dinky details of my introduction to this phenomenon:
http://forums.turbobricks.com/showthread.php?t=263667
I realized I had made a mistake in my turbo planning (but then I'm new at this
) ....when I upgraded to the old school Garrett T3, I had no bypass or "recirculation" valve for occasions where the throttle slams shut and 16 psi hits a brick wall. Well it was clear that corrective actions were necessary.
After consulting with the 7/9 brothers here, it appear that several had run the Garretts with either the old Pierburg valve, or had retro'd another recirc. valve. Many are available, but which one? Well FORGE had excellent feedback here and in various turbo applications, so I settled on that. Others know all too well that LH2.4 requires a CBV for optimum engine management.
A suggestion from a UK Bricker intrigued me....he fitted his 9 series with the old 740/760T Garrett hot side pipe which has the 28mm port to feed a CBV for recirculation and avoidance of the dreaded surge. Would it fit my 9 series? Based on other TBers, indeed it does. Thanks Crag!
Well FCP Groton provided the first piece, the suction inlet hose between the AMM exit and my T3 inlet. I ordered the 7 series part.....and albeit a little tight (had to stretch it a bit to the AMM exit vertically), but it fit, just like this:
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I was concerned about the PS belt cutting the recirc. hose, but it clears with some breathing room:
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In my (vast) hoarded collection of Volvo turbo parts, I'd picked up a factory FMIC and piping from a guy who tried to install on his Ford 2.3 Turbo...and gave up, selling it on CL for $25 for the whole setup. I thought wait a minute, I've got the right hot side pipe already! Cleaned her up and she fit the T3 perfectly:
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Well I needed the balance of the hot side pipe to the stock FMIC. So I measured out the length of the 760T pipe and cutoff one of my stock 9 series pipes to makeup the rest of the system. Took it to my buddy the machinist to see if he could weld an aluminum bead for hose clamp retention.....but we had a hell of a time getting the paint to remove (OE paint, hell for stout). I wanted to wire wheel off the paint/sandblast, but both would leave the surface improper for aluminum welding (in his opinion). I finally decided to forgo the hose clamp stop lip and just sandblast the surface for increased bite of my rubber coupling...which I had yet to source. Measuring the Volvo 760T pipe showed it was 52mm OD, and the small port for recirculation was 28mm OD. A quick Google search and I find HPS, maker of such custom couplings and hoses. They sell nice 52mm x 4 inch couplers for that very purpose (Amazon.com). I also bought a 28mm ID hose, 4 ply turbo boost duty rated, in a 12 inch length. I knew it would require cutoff (ended up shortening to 8.5 inches long) to connect the FORGE valve to the hotside boost source pipe.
All that said, here is my cutoff hot side pipe, post blasting for non-slip grip:
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Grabbed some nice new ABA clamps (Swedish, of course) and we've got a custom hot side pipe:
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I went double clamps for twice the holding power.....if my calculations are right, the joint will see around 60 lbs. force under 16 PSI with a 50mm ID section pipe (make your own calcs. & check me, please). I torqued those ABA clamps with my 1/4 drive ratchet & 7mm socket until they went "solid"....no more squirm of those 4 ply coupling & hose.
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FORGE has a good rep, builds a good product. I found this FMCL007P on fleaBay for $99 shipped to the door. My favorite color, black! Came fitted with the green spring, good for 5~15 PSI. Here she is installed:
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Well here is where it gets a bit tricky.....FORGE has 1" ports on their valves (25.4 MM), and the 760T pipe was 28mm. I decided to go with a 28mm HPS hose, and clamp her down onto the FORGE connection, as opposed to buying a 25mm HPS hose and stretching it over the 28mm connection on the hot pipe (the later might have worked, but I've hit that wall before trying to stretch a reinforced hose over bigger fittings). I put the 28mm hose into position and measured twice, then cut once to 8.5 inch OAL. I think it came out "just right".......take a look:
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Last, I needed the signal line from the intake, so when vacuum is sensed the CBV is open....and conversely under boost she stays closed. This hose with reinforced braided jacket and pretty damn heavy wall, is available by the foot from FCP. I want to say it was 5/32 hose, but don't quote me. It fit perfect on the FORGE valve and also at the intake manifold hose barb; both also fitted with the mini steel spring clamps to keep that signal hose connected properly. I even recycled one of the Volvo black plastic tie straps (used on the firewall to tie up hoses/wires) to attach the signal hose, clean and functional:
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Installed and torqued all clamps.....let her sit overnight and run the torque once more, GOOD to GO. The only thing left to do was a "wet test" as we say in the biz.....turn the HALLMAN MBC up a turn, and load test.
16 PSI again on my boost gauge, no annoying "turkey gobble" compressor surge, and smooth power. Mission accomplished.