Boost Creep Question
The pic above is terrible. Returning the w/g back into the exhaust at 90deg and so close to the turbine discharge itself is about the worst you could configure.
The entry to the w/g might be good, but everything else sucks.
And that rubber oil drain right beside the hot pipe ?? Nuts, that's asking for fire.
The entry to the w/g might be good, but everything else sucks.
And that rubber oil drain right beside the hot pipe ?? Nuts, that's asking for fire.
Earlier in the post he said a lighter spring was able to maintain 16psi to redline. So the gate isn't too small to control boost. He said it spooled slowly with the small spring. Which Is why I said to use the smaller spring with the grainger valve on the bottom port.
Thread Starter
9 Second Club
Joined: Jun 2013
Posts: 271
Likes: 0
Well I took the gate off and hooked it up to the air compressor and verified that the valve opens and closes 100% and properly. No holes in the diaphragm and no holes in the vac line. Also referenced it to the intake instead of the compressor housing. I also took the spring out before putting it back on and the valve closed with vacuum and opened with boost or pressure. Went a did a few test pulls and it still sees 15psi (I was by myself so I don't know exactly what rpm I went to as I was watching just the boost gauge and the road). What I need to do is get a passenger and find out if it will hold 15psi all the way to redline~6800, cause it was climbing slowly and not sure if it had leveled for a couple hundred rpm before I lifted or if it was still climbing. My next 2 steps are to try the grainger valve and also borrow someones 44mm wastegate and add it to the old port and see what happens.
Thread Starter
9 Second Club
Joined: Jun 2013
Posts: 271
Likes: 0
So if I buy another wastegate to put in my old location and run 2 gates am I able to mix the wastegates? Or do I have to buy another tial 44 so they match each other and can run the identical spring combos in each?
Thread Starter
9 Second Club
Joined: Jun 2013
Posts: 271
Likes: 0
Also if I can mix the gates does anyone know what v band gates will bolt right onto my existing tial 44mm flange? I know the precision 46mm gate will and I think I saw that the turbosmart 45mm will also, anyone know of any others or some other cheaper ones?
If the flange is the same size sure you can. Your just venting pressure. The system doesn’t care what brands of gate you run or what springs are in them. I’d suggest the same gate and spring pressure in each gate to keep things easy when tuning. This way you know each gate would do roughly the same amount of venting. Otherwise your gates will open/close at different pressures/heights.
Thread Starter
9 Second Club
Joined: Jun 2013
Posts: 271
Likes: 0
If the flange is the same size sure you can. Your just venting pressure. The system doesn’t care what brands of gate you run or what springs are in them. I’d suggest the same gate and spring pressure in each gate to keep things easy when tuning. This way you know each gate would do roughly the same amount of venting. Otherwise your gates will open/close at different pressures/heights.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
Thread Starter
9 Second Club
Joined: Jun 2013
Posts: 271
Likes: 0
I'd be happy with that. Where is your gate located? When we moved mine I thought it was to a good location and probably is, just surprised that the 44mm can't bleed enough exhaust off to even control say 12psi.
Been playing with the WG setup on my car since I changed cams. It reminded me of your issue. I run a single gate as well I think it’s a 50mm or right around there… hell I don’t remember. 10:1 5.3 with 1.10AR T4 S475. 83/74 wheel.
After installing my cam correctly boost jumped from 12psi at the lowest setting to 16. Car makes a ton more power now and I just spin on the street at these levels. So I needed a way to drop the boost down for street driving. I was running 2 springs in the gate with a “grainger” valve set to open around 10lbs with shop air. My MBC adjusted pressure to the top of the gate so I could run 12-20+psi with the old setup.
Now I removed one of my WG springs and hooked up a vac line directly from my intake with no grainger valve. When I road tested it, I would see 4-5psi in the lower rpm. Around 3800 rpm my WG is over run. At this point I would creep up slowly across the rpm range to 10+psi in the upper RPM. Now I put my grainger valve back inline with the lower port and I build boost quickly to about 10psi, the grainger valve opens, and then the WG spring holds it right around 10 to redline. My MBC is still hooked to the top port so I can add more boost for the track. I have a few other added bells and whistles that make this more complicated that I won’t mention. But I have about $30 worth of check valves, regulators, ball valves. All of which do basically what a nice Electronic boost controller would. In your case a nice EBC may be a third option.
Just a thought... let us know how it turns out.
My setup is a fugly "T" merge with WG priority on one bank. Pretty far from ideal...
After installing my cam correctly boost jumped from 12psi at the lowest setting to 16. Car makes a ton more power now and I just spin on the street at these levels. So I needed a way to drop the boost down for street driving. I was running 2 springs in the gate with a “grainger” valve set to open around 10lbs with shop air. My MBC adjusted pressure to the top of the gate so I could run 12-20+psi with the old setup.
Now I removed one of my WG springs and hooked up a vac line directly from my intake with no grainger valve. When I road tested it, I would see 4-5psi in the lower rpm. Around 3800 rpm my WG is over run. At this point I would creep up slowly across the rpm range to 10+psi in the upper RPM. Now I put my grainger valve back inline with the lower port and I build boost quickly to about 10psi, the grainger valve opens, and then the WG spring holds it right around 10 to redline. My MBC is still hooked to the top port so I can add more boost for the track. I have a few other added bells and whistles that make this more complicated that I won’t mention. But I have about $30 worth of check valves, regulators, ball valves. All of which do basically what a nice Electronic boost controller would. In your case a nice EBC may be a third option.
Just a thought... let us know how it turns out.
My setup is a fugly "T" merge with WG priority on one bank. Pretty far from ideal...
Last edited by Forcefed86; May 28, 2014 at 01:34 PM.
Thread Starter
9 Second Club
Joined: Jun 2013
Posts: 271
Likes: 0
Thanks for the input. Today I am borrowing another Tial 44mm gate from a friend temporarily to test out. I'll tee my ref line and run to the side port of that gate and add it to my old location with no spring. So with (2) 44mm gates and no springs hopefully I can control down to a very low boost level or maybe even 0. From there I will decide whether I want to just spend the money on another gate (if the 2nd gate fixes it) and have it fixed right and working proper no matter how I run the ref lines, or put together a grainger valve and test that option and see if I can get it to hold 15psi through redline with it.
Thread Starter
9 Second Club
Joined: Jun 2013
Posts: 271
Likes: 0
Well I was never able to get a hold of another tial 44mm to test with but I was able to borrow a jgs 50mm and learned they share the same flange. I don't know what spring was in the gate and neither did the owner and I didn't have any snap ring plier to open it to remove the spring so I just put it on by itself to see if maybe the 50mm gate by itself would do any better than the 44mm gate, ... it did not, same problem and had creep and let off at 17psi. Came back and added the other gate with no spring and this jgs50 with unknown spring and made a pull again, and finally I have a solution and it had no boost creep whatsoever throughout the entire rpm band of both 2nd and 3rd gear, it held 9-10psi fluctuating back and forth the entire pull, dead steady boost control which was really nice. So my new Tial 44mm I'll get tomorrow and spring them both for 12psi and bleed off whatever I need to hit 15psi. Just figured I'd update for others who may search this problem down the road.
