Engine/Transmission (1994 - 1998) Sky High EGT's! What's the deal?

[C. Harlan]

The only mods I have done was remove my AFC spring, and lengthen the arm on the wastegate to allow less boost. Would this cause me to have sky high EGT's? I couldnt even pull a hill yesterday with a BUMPER PULL Trailer and 3 ice chests on it without having to back out of it. It was 104° outside, but I do not see how that would affect it so much as to making it run 900° post turbo with 10 lbs boost... anyone have any ideas? I know I have no boost leaks otherwise I would not be able to get to the 40-41 psi I am seeing now. when I mash the go pedal the gauge goes and skyrockets... Someone give me some ideas please!! Thanks!



-Chris-

 

[Extreme1]

Why did you remove the AFC spring?

 

[C. Harlan]

Because I can.

 

[SEmerson]

I could hit 45 psi with 2 major leaks.



You added fuel and removed air. So EGTs will be up for sure.

 

[BPonci]

Check to make sure your wastegate is not creeping open to early. You need a certain amount of preload on it or you will lose boost response time and low rpm torque.

 

[britannic]

What was the reason for lowering the boost?

 

[JGheen]

Originally posted by SEmerson



You added fuel and removed air. So EGTs will be up for sure.

There's your answer... ...

 

[JGheen]

Originally posted by SEmerson

I could hit 45 psi with 2 major leaks.

With a "major" leak and that much boost you must be running twin turbos, right?

 

[Forrest Nearing]

he's got an HX40... it would appear that he lowered it down to 41psi.



Forrest

 

[BPonci]

Not having a fuel curve on the bottom end will make the egt rise very quickly.

 

[C. Harlan]

So shorten the wastegate arm back to where it was, and it should be more manageable?? That is what I think I am understanding... Is that what y'all mean??



-Chris-

 

[JGheen]

Just looking over your sig again, do you have any aftermarket injectors with those 191 DV's? With your timing up to 16*, only a #10 and an HX-40 pushing 40-41 psi, you should not be having those high EGTs. After looking your comments over again, how much boost are you seeing? Is it really 40-41? With the wastegate turned down I would think you should be seeing low 30's and that would definately bring the EGTs up since your not moving the air that you used to.

IMO, you want your wastegate to open at the very latest possible moment for max boost. Unless you want to set it at your desired boost level, but then you have to adjust the fueling down to accomidate your lower boost.

 

[1dslram]

You should set the wastegate at 38 - 40# of boost maximum. Now that you have air put the spring back in the AFC if you want faster fueling get the AFC spring kit, DON'T REMOVE the spring completely. After you get that far adjust the starwheel to get the preboost fueling where you want it. Keep the AFC housing full forward, unless you want slower fueling. This will get you in the ballpark and you can start fine tuning at that point.



Why the 191 DV's with the stock injectors or even aftermarket injectors these DV's push a lot of fuel at the low end and increase smoke and EGT's. This is a part of your heat problem.

Bruce

 

[SEmerson]

Originally posted by JGheen

With a "major" leak and that much boost you must be running twin turbos, right?

A hx35 to start with then a pdr hx40 before I found my leaks. The 45 was with the 35.

 

[JGheen]

Originally posted by SEmerson

A hx35 to start with then a pdr hx40 before I found my leaks. The 45 was with the 35.

How is that possible though, to get that much boost with a "major" leak or leaks with only an HX-35? Were you running a non-wastegated turbine? What is your definition of a "major" boost leak?