my buddy has a 7.3 IDI. he decided to clamp off the wastegate line to see how much more power he can get out of the turbo. i was just wondering how long the turbo will last? he pulls heavy trailers every day and drives like a bat out of He** 24/7 . he was also kicking around getting/making an aftermarket air intake. any ideas? thanks
Turbo Question
- Thread starter TOTHEMAX!
- Start date
iirc...cylinder head liftoff occurrs above 15psi.
Freight_Train
Traitor to the brotherhood
is he in the southeast?If so,Tell him I am always interested in parts/project trucks with Grenaded engines!
icanfixall
Official GMM hand model
Tell him that any boost over 13 lbs is lost to heat. The turbo impellor will heat the intake charge past 300 deg. Why other than ego would anybody want to run like that? Just to say you did? He must have money to burn or dad gave him the truck. I really value what I have and try to take care of what little I have.
spencnaz
Full Access Member
- Joined
- Jul 26, 2006
- Posts
- 314
- Reaction score
- 0
A friend of mine had a custom 6.9 turbo install that put out over 40 pounds of boost. I dont know all the specifics on it, but it was a romper.
What killed that engine was a casting flaw that came from the factory that split the block in two along the crankshaft axis.
For a 6.9 you can make 8psi all day with no problems. Overboosting any engine is more a machismo thing than anything else, tis wasted energy.
What killed that engine was a casting flaw that came from the factory that split the block in two along the crankshaft axis.
For a 6.9 you can make 8psi all day with no problems. Overboosting any engine is more a machismo thing than anything else, tis wasted energy.
over 12 psi--even on a fac turbo engine--will normally melt down the pistons--which then destroys itself--or--if the block is weak--as he said--splits the block--either way--hes goofy in the brain---clean out the gene pool----
Ironman03R
Full Access Member
I've known people like that....good to have around if you wana get a good deal on something with a lot of new parts after they cant figure out whats wrong with it.
jauguston
Retired
Sassyrel,
Boost pressure does not melt pistons, heat does. If you keep the EGT at or below 1250 degrees you are not going to melt the pistons. I pull hills at 12psi all the time, 13 psi with the propane on. My EGT never gets above 1200 and I am not the least bit concerned there is danger. My engine is stock with a Hypermax non-pulse turbo, pump turned up 2 1/2 flat. and the Hypermax hood mounted cool air intake. Hypermax said a 6.9 can run 1250 EGT all day long. They also said on a '86 or later the stock head gaskets and head bolts are fine. They say the hood mounted cool air intake system reduces EGT by 200 degrees.
Jim
Boost pressure does not melt pistons, heat does. If you keep the EGT at or below 1250 degrees you are not going to melt the pistons. I pull hills at 12psi all the time, 13 psi with the propane on. My EGT never gets above 1200 and I am not the least bit concerned there is danger. My engine is stock with a Hypermax non-pulse turbo, pump turned up 2 1/2 flat. and the Hypermax hood mounted cool air intake. Hypermax said a 6.9 can run 1250 EGT all day long. They also said on a '86 or later the stock head gaskets and head bolts are fine. They say the hood mounted cool air intake system reduces EGT by 200 degrees.
Jim
Diesel JD
Full Access Member
I know guys around here see the 13psi range all the time, but shutting the wastegate actuator will blow up the motor, its only a matter of time. The boost by itself won't hurt anything in the range thata normal IDI turbo can get it, its the high egts that will hut the internals. The extra pressure will also cause head gasket failure sooner or later. On my truck, I'm not letting the boost get over 10-11 PSI I really hate replacing head gaskets!
Diezel_Cowboy
It's not like a real ***!
Bla Bla Bla Bla Bla...............All you worry worts give it a rest.
Boost doesnt blow up motors...........People do!
Just tell your friend to put in a pyrometer if he turns the fuel up and keep her below 1200 degrees. Then he will do just fine!
I say this because I have had my turbo waste gate plugged for 4 years with no problems. When put under load or pushing the pedal down it will peg my 15psi boost gage. Never had any problems with the turbo or engine BUT I do pay attention to the pyrometer and respect the 1200 degree mark.
Boost doesnt blow up motors...........People do!
Just tell your friend to put in a pyrometer if he turns the fuel up and keep her below 1200 degrees. Then he will do just fine!
I say this because I have had my turbo waste gate plugged for 4 years with no problems. When put under load or pushing the pedal down it will peg my 15psi boost gage. Never had any problems with the turbo or engine BUT I do pay attention to the pyrometer and respect the 1200 degree mark.
Suit yourself, but don't give risky advice to people who are looking for guidance. Yes, you can exceed the "recommended" boost, but only if your willing to accept the consequences if they arise. You know man, like I tell people I run WMO, but I don't RECOMMEND it. Hey, maybe that should be my new tag line too...
WMO doesn't kill engines, people do.
WMO doesn't kill engines, people do.
Mr_Roboto
Full Access Member
I've never met a wastegate valve that was not adjustable. I don't understand why you would eliminate something that was there for the safety of your engine.
Freight_Train
Traitor to the brotherhood
ok then,ask a old school ford Tech about the effects of too much boost.If I remember in the "Good ol days" when there were no wastegated turbos for our truck that the turbos were making so much boost to cause the wrist pins to woller out the holes and cause Catastrophic failure.That is the reason Ford said VOID when a truck would come in under warrentee with a aftermarket turbo and a damaged engine.....also the reason why Banks and ATS went Waste Gate.Too much boost and you will lift heads,Blow out gaskets,scatter pistons,and maybe even break head bolts if they are weak and you make a lot of boost.
