Overboosting??
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From: IOWA
Overboosting??
What is the maximum amount of boost that a 7.3L can handle before blowing gaskets? I'm running a performance flip chip, and when set at 110hp I can easily "overboost" according to the truck's computer. I think it's at 24 psi when my SES light comes on. I hit 27 psi easily, and could go well over that, but I let off so I don't blow anything up. It's usually hits there as a spike, jumps up hard and then I let off, I don't hold it for a duration. Can the engine hold up to 30 psi without any adverse affects, or should I be more careful and keep it under 24 psi according to the computer????
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From: Braham MN
I know that I read it somewhere in here, I just dont remember where, but I read that the heads can only take around 35 pounds of boost. as to what happens I dont really know and dont really wanna find out. as to what psi the head gaskets disappear i dont know either but figured I would pass on the 35 psi number to ya
Diesel rod
Diesel rod
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From: Braham MN
this is a direct quote from "Johns Diesel" i finally found something
Are you talking about too much boost for the turbo to handle or the engine? It's my understanding that the stock turbo can make up to 30 lbs of boost without problems and that the engine can handle up to 40 lbs of boost. Someone please correct me if I'm wrong.
Are you talking about too much boost for the turbo to handle or the engine? It's my understanding that the stock turbo can make up to 30 lbs of boost without problems and that the engine can handle up to 40 lbs of boost. Someone please correct me if I'm wrong.
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From: IOWA
I was wondering about the engine, but I assumed the turbo would be able to handle a lot more than what the motor could. If not, I'm curious about that as well. What you guys are mentioning I had an idea towards, but I'm not for sure.
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From: colorado
the factory garrett turbo is rated at 25psi, alot of people(incuding myself) run it up to 30 with no problems. the headgaskets start blowing out at aroud 40 psi, if you are running more than that you need to get the heads o-ringed to handle that much boost.
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From: Bridgewater, NJ
Folks just remember these engines where designed to run no more than 26 PSI Boost. The rods have been known to break between 28-30 PSI being powder coated not forged steel.
Don
Don
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From: colorado
Originally Posted by dm12578
Folks just remember these engines where designed to run no more than 26 PSI Boost. The rods have been known to break between 28-30 PSI being powder coated not forged steel.
Don
Don
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From: Lake Stevens, WA
Farmboy, how you doin? I will second that the factory turbo is good to about 25 psi. They do not have thrust bearings and the side loading at that psi will cause them to have a dramatically shorter lifespan. With that said, I have the clamp mod and have gone up to 28 psi intermittantly with no side effects 
. There are people on dieselstop blowing 40 psi on stock heads and bottom end. Where people get into trouble is when they start playing with the timing. Apparently that will break stuff quickly. 
Long story short, with stock turbo and stock injectors, you should be fine. Just don't mess with the timing. 
. There are people on dieselstop blowing 40 psi on stock heads and bottom end. Where people get into trouble is when they start playing with the timing. Apparently that will break stuff quickly. Long story short, with stock turbo and stock injectors, you should be fine. Just don't mess with the timing.
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From: Bonney Lake, WA
You should be able to venture into the mid 30's without any trouble at all. Your pcm will start to cut off the fuel when the boost exceeds 22psi, however. You can get around this by installing one of these. Install it into the line to the MAP sensor, between the guage fitting and the MAP sensor. Your gauge will still register the true amount of boost being made, but the MAP sensor won't see any more than 22psi.
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From: Lake Stevens, WA
Your gage will still register correct as long as you place place it on the map side of where you tapped in for the gage. I am sure you knew that, but thought I would throw it out anyway. Also, if you have a spare air pressure regulator laying around, those work as well for preventing defueling. That is what I am using
Also, if you have a spare air pressure regulator laying around, those work as well for preventing defueling. That is what I am using
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Originally Posted by dm12578
Folks just remember these engines where designed to run no more than 26 PSI Boost. The rods have been known to break between 28-30 PSI being powder coated not forged steel.
Don
Don
Hammer
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From: IOWA
Yea, same here. Makes me wonder why Ford went to the powdered metal rods instead of the stronger forged. I suppose they were cheaper to make.
Quadzilla-
I'm assuming that is just a relief valve that opens at 22psi, so the PCM will only see 22 psi and not defuel when it gets over that?
I may have to do like Fordnut74 and use an air regulator, or something cheaper that will do the same thing.
Quadzilla-
I'm assuming that is just a relief valve that opens at 22psi, so the PCM will only see 22 psi and not defuel when it gets over that?
I may have to do like Fordnut74 and use an air regulator, or something cheaper that will do the same thing.
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From: Lake Stevens, WA
It is all about the bottom line. IF the PM rods will hold the stock power, and are cheaper to make....
The A/P regulator works great, but by the time you buy the regulator and two nipples, not a whole lot cheaper. Just quicker. And I happen to have one laying around from old junk spray gun. If you do buy a regulator, make sure it is a regulator with a gage. there are some cheap ones out there that are nothing more than a small ball valve.
The A/P regulator works great, but by the time you buy the regulator and two nipples, not a whole lot cheaper. Just quicker. And I happen to have one laying around from old junk spray gun. If you do buy a regulator, make sure it is a regulator with a gage. there are some cheap ones out there that are nothing more than a small ball valve.