gnathv
Full Access Member
It doesn’t take much exhaust leak to affect boost. It reduces drive pressure. Look for soot at that joint.
A turbo effects the boost, a leak will affect the boostANY leak will effect your boost.
My 93 was missing the cold air intake, sucking in hot air from the engine compartment.Also - I don't have the original air intake ducting (which was restrictive at the front opening anyway). The 4" snout on the factory airbox is just open under the hood. I also plan to build a cold-air intake with a piece of dryer duct, which should also help lower the temps a tad.
Thanks for the data. I also found a large intake-side leak (snail to intake gasket) by the blowby under pressure that sprayed onto the firewall padding! I'm sure that accounted for some of the improvement when I put the new CHRA in, but I'll never know how much, now...when your moving down the road the under hood air temperature is the same as ambient outdoor temp. Put a probe under your hood and see for yourself. When stopped the under hood temp does rise.
Another interesting observation: the oil pressure (sending unit at turbo oil inlet) is higher! It used to drop off the bottom of the gauge at idle when hot, which is 4 psi or less with that sending unit. (I have a variable sender with the resistor in the cluster jumpered, not the "idiot light without the light that Ford so thoughtfully provided). Now the pressure is well up on the gauge even at a hot idle. That means more oil to the rods and mains
I also noted that with 10 psi boost available (and still no smoke at full boost and wide-open, so I may be able to turn it up another 1/2 - 1 flat), the Facet 40285 pump can no longer keep up with the demand (Fuel Filter warning comes on) during a long pull, flat on the floor
I am planning to reinstall a new mechanical lift pump, and leave the Facet in series, after the mechanical pump. You can suck through the lift pump with no resistance, I checked I like having the Facet for easy priming and elimination of air after repairs, without cranking the batteries/starter to death. But it is marginal for stock boost/fuel and is overmatched with greater-than-stock boost.
If it still can't keep up with the mechanical pushing, out it comes!
Sounds like the WG is not the culprit.Thanks. I actually did wire it shut and it made only a small difference, not enough to risk running that way with no protection at all. My spring feels very strong too. I could apply variable air pressure to the actuator and watch the gate arm for movement, but that doesn't tell me how effective each increment of opening is...
I do have an adapter box to measure timing - but I don't own a dial-back timing light Could always calibrate the damper, I suppose. Or I might just experiment with a dime's width one way or the other from the current, allegedly correct, setting.
About the up-pipe joint - that pipe is at least 2" ID. Does a small (say 1/32") leak really affect boost that much? Even if it went all the way around, the total area of that gap would be a tiny fraction of the 3+ square inches of opening.
This is really interesting, I know everything got better when I got my intake hat seal leak-free.I had a small leak in my intercooler piping. I put 15lbs of shop air and used soap suds to find small bubbles at silicon connectors, it was small. It greatly improved response and added 4 lbs of boost. I’ll also beat the dead horse, when your moving down the road the under hood air temperature is the same as ambient outdoor temp. Put a probe under your hood and see for yourself. When stopped the under hood temp does rise.
No kidding, I know how an air leak works. My point was that the turbo passes most of the gas, a lot more than a 1/32" gap. What I'm interested in is the *percentage* losses.The reasoning is that it's air(compressible) and under pressure. So it will escape a relatively small gap much much faster than a liquid. Plus the hot side it pushing more PSI, up to double the cold side, and more pressure=faster and more drastic losses from a leak.
Now that is actually useful data. Mine is not as tight as that. I've got the wye shoved up as far as I can before tightening it down, and with a coating of Ultra Copper RTV.In my experience I lost 3 psi max with my up-pipe fitment not all that good and mine was tight enough that I could barely remove one half with the other side still bolted on.