The last thing I checked was the plugs and none of them were wet from oil or wet period. The car has been running rich but nothing too bad.
Smoke when letting off throttle?
- Thread starter dan03mach
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The last thing I checked was the plugs and none of them were wet from oil or wet period. The car has been running rich but nothing too bad.
I have their twin kit.
Yep, same here. Hellion sent us the elbow fitting that goes into the turbos machined flat where you screw the feed line on, so that we could put NX jets in it to lower the psi feeding the turbos. I believe we used 20's. All three of the Hellion TT kits we did here locally were the same way.
Quite the opposite. I've never had a turbo car or seen one, BB or not, where a restrictor wasn't used. You're just asking for trouble by not running one, IMO.
Yet on the other hand, I just sent a thrust bearing turbo off a Supra back to Precision where the owner installed a .040 restrictor. The sheet came back saying "turbo failure due to lack of lubrication," I asked them what they recommended and they told me "beyond a 3an feed line, nothing." Here's a way to settle this, the owner here needs to call turbonetics and ask what restrictor they recommend for his turbo.
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You definitely need to use the right restrictor for the application, just as with anything else. I would never run a turbo with a wide open oil line to it, though.
I agree with you the OP needs to call Turbonetics and run what they recommend.
I agree with you the OP needs to call Turbonetics and run what they recommend.
Sorry, I'm just aggravated with this whole thing currently because I told the Supra owner at least 5 times to talk with precision about his setup and not just asshats over the internet, and see what they recommend for a restrictor before I install one for him. He told me he called them up, they recommended a .040 which I felt was a little small but I took his word for it. After the thing failed he comes back and says "Well I didn't actually call them, but it's what people were recommending." I would have spent less time actually talking to precision myself (vs the amount of times I told him to call) and I wouldn't have this son of a bitch clogging up space while he tries to figure out what turbo he wants now.
Out of curiosity, what do you personally use in Cobras as a restrictor when running thrust bearing turbos?
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The twin kits might be different then the single 76 kits. I know the twins use smaller turbos and are mounted lower so they have to use a scavanger pump. I'll call turbonetics or hellion and ask them.
I just called turbonetics and they said they don't recommend an oil restrictor on their turbos unless you are running over 90psi of oil pressure. So the open -4 feed line that I have going to my turbo is just fine.
I believe the pressure on start ups is between 80-100 psi and is some where in the 60's during normal driving. There was a thread posted on Modular fords that says what the pressures of our pumps are.
It may be possible that over time the pressure on the start up slowly took its toll on the turbo seals.
It may be possible that over time the pressure on the start up slowly took its toll on the turbo seals.
They are probably seeing over that on startups.
After speaking with a turbo design engineer he explained to me.......a possible cause for smoke on decel is a insufficent oil drain for the turbo. Keep in mind I have a ball bearing turbo which require less oil then a standard journal turbo, however both require a sufficent oil drain line.
He explained it like this........the seals on the turbine side of the turbo are similar to a piston ring. The seal has a gap at the top, if the turbo does not drain properly, on decel when large amount of vaccumm is created on the exhaust side, the excess oil sitting in the turbo is pulled past the turbine seal and causes smoke seen in the cars exhaust.
From what I've heard, oil drain lines should be a min. -10AN, -12AN is even better. They should be always on a downward slope to the pan with less then 90deg turns.
So........if you have a marginally sufficent turbo oil drain line and then add a little crankcase pressure, you've made the situation worse, and it's even harder for the turbo to drain.
By venting the valve covers to atmosphere and it smoked less on decel, you most likely let the turbo drain easier and stopped excess oil from being pulled past the turbine seal into the downpipe on decel. Many will say putting a restrictor in the oil feed line is a band-aid and the solution is a larger, more direct, oil drain line.
He explained it like this........the seals on the turbine side of the turbo are similar to a piston ring. The seal has a gap at the top, if the turbo does not drain properly, on decel when large amount of vaccumm is created on the exhaust side, the excess oil sitting in the turbo is pulled past the turbine seal and causes smoke seen in the cars exhaust.
From what I've heard, oil drain lines should be a min. -10AN, -12AN is even better. They should be always on a downward slope to the pan with less then 90deg turns.
So........if you have a marginally sufficent turbo oil drain line and then add a little crankcase pressure, you've made the situation worse, and it's even harder for the turbo to drain.
By venting the valve covers to atmosphere and it smoked less on decel, you most likely let the turbo drain easier and stopped excess oil from being pulled past the turbine seal into the downpipe on decel. Many will say putting a restrictor in the oil feed line is a band-aid and the solution is a larger, more direct, oil drain line.
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I am running a -3an line on mine. I bought a used turbo and had it rebuilt. I spoke to the guy who rebuilt it and did explain that the pressures are high on these cars and man, I do see 90+ while the car is cold and doesn't drop down for a while and even at cruise I see 50+. The guy that rebuilt my turbo said that he recommends restrictors or smaller lines when you see pressures over 60 psi. so he mentioned to try the -3an line first. And said, with the car running, disconnect the drain line and see how much oil comes out. it should dribble out and not pour out. if it pours out, that is way to much and a restrictor is required.
That being said, I haven't removed my drain line yet. I only have a couple thousand miles on my setup right now, but when the weather gets better I will try to remove the drain line and see what it does.
for comparison sake, both my past turbo cars I used the exact setup that hellion had in the kit and never had an issue.
That being said, I haven't removed my drain line yet. I only have a couple thousand miles on my setup right now, but when the weather gets better I will try to remove the drain line and see what it does.
for comparison sake, both my past turbo cars I used the exact setup that hellion had in the kit and never had an issue.
A .040" restrictor is good for a ball bearing turbo...but most people use a .065" on a journal bearing turbo. I've always used restrictors until my last turbo setup...and guess what? Blew the seal out of the turbo...these mod motors make a ton of oil pressure. My car idles at 75psi and anything over 2k rpm's she hits 100psi and then the internal bleed opens on the oil pump holding her steady at 100psi. Run the proper size restrictor for your particular setup and you won't have a problem. And yes drain line sizing and routing is VERY important. But your problems sound exactly like mine when the seal went on my turbo. First it was smoke on deccel...then it was under full boost.
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