Stock VGT Boost Issues

[Cdiesel288]

Evening All,

Head studs were installed three days ago, so I turned my raceme up to max HP, timing, and quick spool, to check out some numbers.

I hammered down in 4th today, got up to 1033F EGT, and 35.5# boost; I let off as soon as I saw the boost number.

From what I understand, the stock VGT can push too high a drive pressure when the boost gets over 30#.

Is the motor good with head studs, or should I start looking at a new manifold & compound turbo setup sooner rather than later?

I know fuel won't keep up with the air when/if I do this, but drive pressures over a pound or two can be fatal for the motor, from what I have read.

Apologies if I'm missing something or not fully comprehending what I'm talking about.

Thanks for the insight.

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[Cdiesel288]

I should clarify, and I understand that head gasket failure isn't caused by high drive pressure.

I'm more concerned about exhaust valves, pushrods, and other things.

I also understand that the exhaust brake creates higher pressure in the manifold and against the valves themselves.

I've read too many conflicting "research" posts and articles, and I'd rather not make a fatal mistake, LOL.

Thanks again, folks.

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[Badger2078]

Subscribed.

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[CumminsForYa]

You should be ok, but there are no guarantees in head safety.

I'm still running stock head studs & I'm pushing 650hp, and I run the exhaust brake 24/7.

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[Badger2078]

550 all stock, and I'm looking to increase that number soon, though.

I wouldn't push it any harder the way I am.

My brother's truck approx 700 hp but 2 head gaskets in less than 1000 miles, and he is studded.

His stock VGT pushes 60+ psi.

The Tuning is way too wild, I think.

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[CumminsForYa]

Damn.

Bad draw from the factory.

I've gone thru quite a few clutches but haven't had any issues with the power plant.

Waiting till I upgrade my injectors and CP3 before I stud & mill mine.

I don't want to mess with the head while it's still working.

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[f18framer]

I use Rays tunes and run mine up in the 35 psi range with no ill effects.

I have heard, however, that the stock pressure sensor tops out at about 35 psi and won't read higher, so it may be more.

I have an analog boost gauge but honestly have never been able to see where it peaks out to see if it is true or not.

I do have head studs in, though.

I have the ARP 425s, if I remember right.

It is the lower grade ones, not the 625s, that cost 1000 bucks.

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[Cdiesel288]

I use Rays tunes and run mine up in the 35 psi range with no ill effects.

I have heard, however, that the stock pressure sensor tops out at about 35 psi and won't read higher, so it may be more.

I have an analog boost gauge but honestly have never been able to see where it peaks out to see if it is true or not.

I do have head studs in, though.

I have the ARP 425s, if I remember right.

It is the lower grade ones, not the 625s, that cost 1000 bucks.

I can say with accuracy that the stock sensor doesn't top out at 35.

I saw 38.9 yesterday and not to rag on anyone that goes with the 625s, but for years we ran the ARP 2000s.

I know there's a big difference in tensile strength of 225k psi and 285k psi, but I think the more significant issue is rapid pressure, not total stress.

Properly warm up the motor, and don't go from full throttle to zero, to full throttle to exhaust brake, and we should all be ok.

Besides, the 68RFE should die before our studs?

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