How to lower EGT

Krumby

Krumby

Active Member
So I just installed the egr delete kit yesterday in my l300 with the 4d56. Also installed the glowshift 3 in 1 put the probes in the delete kit. Drove to work I live on Maui and work on Haleakala about 8 miles up the mountain. Not that steep at that point. The egt read between 1200-1300 going up with rpm at 3000 and speed at 49 that’s all she has. Boost was at 8 psi tops I’ve seen 10 psi max so far and engine temp 185-191.
I guess the only way to get the egt down is exhaust and air. I don’t want to spend 600 on a snorkel does anyone make a better air filter system that breathes better (air filter is brand new) ?
2.5 inch exhaust here I come really didn’t want it loud but what else can one do?
 
Btw got the egr kit from sk66 on here I highly recommend it, well made and comes with everything you need even pre drilled from sensors if you choose. He’s very helpful
 
I've done all of that. IMO, the best thing you can do is increase the boost pressure to nearer 14psi; EGT's stay a little lower at the same throttle setting. You can do that just by reducing the length of the wastegate actuator rod and removing/blocking the over pressure valve (1" pipe plug). Not sure why that makes the difference it does because more boost pressure also increases the fuel delivery (unless the boost compensator tops out early?).

Next best would be a larger diameter free flow exhaust; EGT's take a little longer to climb, but they still get there.

Intake (filter/etc) is not a contributor unless extremely dirty/obstructed, and that would show up with other symptoms (heavy black smoke). Snorkel makes zero difference.

I'll let mine hit 1400 momentarily, and I generally sustain 1300 on prolonged climbs until I see the water temp start climbing to 3/4... then it's time to back off.
 
I echo sk66 here and I’ll add that if you tune it properly, you can increase your power and effectively lower your egts at the same speeds you’re traveling now.

There’s a great sticky in the L300 faq section here

I’m about 700-800f egts at 70 mph at around 3000 rpm and engine temps at 192 (ac off) on a flat now. I’d love to figure out a way to see temps at a known grade (come on google maps )
 
I agree with the advice above: increase your boost to 14psi and fit a clean air filter. The root cause of high EGTs is not enough air for the amount of fuel you're trying to burn. At Haleakala's 10,000ft there's not much air to begin with, so the engine needs all the help it can get.

sk66 said:
...more boost pressure also increases the fuel delivery (unless the boost compensator tops out early?).
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It does indeed top out at around 8psi. On a stock injection pump there's a white nylon spacer under the boost diaphragm which limits the plunger's travel. At 8-10psi the plunger hits the nylon spacer, and increasing the boost any further doesn't result in more fuel, just more air, which is good for EGTs.
 
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There was a noticeable drop in EGTs when I added a manual boost controller and upped it to 10 psi. Really only gets to 1250-1300 if I'm hammering it up a hill with 4 people in the back. I would try to get it above 10 but for some reason my overboost goes off very easily after 10/11psi. Think it's just a sensitive controller..

TL;DR - upping boost seems to make a difference in reducing EGTs
 
Krumby said:
How does one reduce the length of the wastegate actuator rod ?
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There’s a long adjustment nut on the actuator rod with locknuts on either end (all 10mm). Loosen the locknuts (one is reverse thread) and turn the long nut to adjust the effective rod length. Tighten locknuts back down when you’re finished adjusting.

Or just use a cheap manual boost controller that makes everything way easier to adjust and never look back
 
Do you mean like this ? I put this in and that’s it I can add more boost ?
 

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Yeah it fits inline between the turbo and the wastegate actuator. It limits the amount of boost the actuator “sees” allowing more boost to build up before it bleeds off.
 
Krumby said:
What is not the prettiest? The boost controller?
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Yes, the boost controller in the link. There are much prettier, much more expensive and more electronic options. But this does it. It will increase your boost from 8psi to around 14psi or whenever your overboost valve pops off. That introduces more air and can help bring EGTs down.
 
blank1024 said:
Yes, the boost controller in the link. There are much prettier, much more expensive and more electronic options. But this does it. It will increase your boost from 8psi to around 14psi or whenever your overboost valve pops off. That introduces more air and can help bring EGTs down.
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I bought this same boost controller. I don't know much about Diesels or Turbos; the Deli is my first foray. Any advice from your installation you could share?
 
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