13bt - boost & EGT wisdom

[fireball]

I should know this, or be able to quickly find it, but am currently striking out on both.

Can the wise folks please let me know what the max recommended boost and EGT is on my 13BT? All stock with a 3" exhaust.

Finally got the old gal back together (with EGT and boost gauges and boost controller) and am heading west, want to make sure I can hold the pedal to the floor from Denver to Grand Junction

 

[Behemoth60]

Aluminum in your pistons will melt at 660C, according to the scientists.
I've heard some people say to keep your EGT's below 600C

 

[cruiserdan]

Aluminum in your pistons will melt at 660C, according to the scientists.
I've heard some people say to keep your EGT's below 600C

Measured where? Before or after the turbo? This has always confused me.

 

[jblueridge]

Mine is configured like yours. Hills cause egt rise to 550 C. Boost at these times maxes my 15psi gauge so maybe 18 psi boost. Tire pressure is 60psi which makes rolling the MTs easier.
I have no idea if I am causing damage.

 

[fireball]

The oem red light comes on around 15psi. I’m running 14psi right now. 550c is 1022f which is I believe a bit under the safe range.

But again I’m going by memory from 7yrs or so ago when I first bought the truck.

@OGBeno what say you?!

 

[Behemoth60]

Measured where?

Maybe it's time for new rules. Let's try this...

If you are a nervous ninny:
650C pre turbo
600C post turbo
continuous duty

You will never melt a piston at those temps.

But, have you ever measured a N/A 3B EGT? 700-800C is possible with a bit if fuel turned up. But the pistons are not melting. Why? Lower piston oil jets and intermittent duty. That's why. The exhaust gas temp is not the piston face temp. It takes time to heat soak the pistons, and the piston have cooling designed into them with those oil jets which extends that time.

If you are among the maxpower people, try this...

750C pre turbo
700C post turbo
For a 30 second duty cycle.

Ooohh this is so exciting.

 

[Behemoth60]

Hills cause egt rise to 550 C. Boost at these times maxes my 15psi gauge so maybe 18 psi boost.

I have a 30PSI gauge and with the wastegate pressure line disconnected, stock turbo and 2.5 exhaust I can get up to 21 PSI in the right conditions. The 'Red Light' is comforting assurance that my turbo is still making good boost.
And in case this was not already obvious, adding MORE boost and not adding fuel LOWERS your EGT's. Turning up your turbo is easy way to manage EGT's. When the boost blows out your 35 year old head gasket, replace it with an 11115-58050 and you will be good to go from there.

 

[cruiserdan]

Maybe it's time for new rules. Let's try this...

If you are a nervous ninny:
650C pre turbo
600C post turbo
continuous duty

You will never melt a piston at those temps.

But, have you ever measured a N/A 3B EGT? 700-800C is possible with a bit if fuel turned up. But the pistons are not melting. Why? Lower piston oil jets and intermittent duty. That's why. The exhaust gas temp is not the piston face temp. It takes time to heat soak the pistons, and the piston have cooling designed into them with those oil jets which extends that time.

If you are among the maxpower people, try this...

750C pre turbo
700C post turbo
For a 30 second duty cycle.

Ooohh this is so exciting.

Thank you Peter.

 

[Pacer]

Measured where? Before or after the turbo? This has always confused me.

Ben's is pre turbo, where it should be

 

[cruiserdan]

Ben's is pre turbo, where it should be

Except in the (admittedly rare) case where the probe tip breaks and grenades the turbo.

 

[FJBen]

I have a 30PSI gauge and with the wastegate pressure line disconnected, stock turbo and 2.5 exhaust I can get up to 21 PSI in the right conditions. The 'Red Light' is comforting assurance that my turbo is still making good boost.
And in case this was not already obvious, adding MORE boost and not adding fuel LOWERS your EGT's. Turning up your turbo is easy way to manage EGT's. When the boost blows out your 35 year old head gasket, replace it with an 11115-58050 and you will be good to go from there.

I can’t get close to 21 psi with my stock rebuilt ct26 turbo. I may try completely pinching the line off to see what happens. 15 is the max mine will do right now.

 

[Hulsty]

I used to run 19psi on my stock turbo and backed off at 750c EGT's. After a couple of minutes at those EGT's the water temp starts to rise and you gotta back off anyway.

 

[Dusten]

Maybe it's time for new rules. Let's try this...

If you are a nervous ninny:
650C pre turbo
600C post turbo
continuous duty

You will never melt a piston at those temps.

But, have you ever measured a N/A 3B EGT? 700-800C is possible with a bit if fuel turned up. But the pistons are not melting. Why? Lower piston oil jets and intermittent duty. That's why. The exhaust gas temp is not the piston face temp. It takes time to heat soak the pistons, and the piston have cooling designed into them with those oil jets which extends that time.

If you are among the maxpower people, try this...

750C pre turbo
700C post turbo
For a 30 second duty cycle.

Ooohh this is so exciting.

Except the difference pre and post turbo is never set

I'd add if you're a nervous nanny don't put your f***ing pyro post turbo