6.0 Exhaust Upgrade

Harry · 08-10-2022, 06:52 PM

I have a 2008 6.0 that has EGT's that run up to 1200 when I am on long grades or full throttle . Has anybody changed to a 4" CAT back exhaust and found a reduction in EGT's. Open to any other ideas to keep them down.

SheepShagger · 08-10-2022, 08:04 PM

The cat and down pipe are the restriction, I can’t see how a 4” cat back system would improve EGT much when the cat and down pipe are still their, at 3” restricting the flow. While towing I guess you may see a very small drop. Simply removing the cat would net you better results than 4” cat back and keeping the cat.
I did remove my cat (I live in a state where their is no emission on diesel) and that alone improved my EGT.
4” turbo back and cat delete would net you best results.

ShuttlePilot · 08-10-2022, 08:22 PM

In my opinion, if you are less than 1300*F sustained, at full throttle or at least deep into the throttle, making lots of power, a little smoke but you can see through it, that tunes A/F mixture is about perfect in a 6.0. I understand the desire for lower EGT's but based on what your describing I think your doing just fine.

Removing the cat is probably the best bang for the effort then muffler in regards to EGT's. On mine it didn't make that much difference though.

- Eric

unreng · 08-11-2022, 01:17 PM

How much do you want to spend?

Harry · 08-11-2022, 01:29 PM

Money is not an issue if it resolves the problem long term.

unreng · 08-11-2022, 07:16 PM

In no particular order...

1. Cold air intake (if stock engine then stock air intake will work).
2. Remove restrictions in exhaust / upgrade the exhaust.
3. Upgrade turbo.
4. Upgrade to odawg s2r intake.
5. Tuning.
6. Relocate heat generators / airflow blockers from in front of intercooler/ radiator (trans cooler, steering cooler, condenser)
7. Water/ methanol injection.
8. Increase rpms when driving uphill.
9. Install BD diesel exhaust manifolds.

Twoxentrix · 08-12-2022, 07:52 AM

^^^^^^ number 8 is solid advise ^^^^^^
I find holding 2500-2600 RPM’s (sometime that means taking it out of OD) will keep the egt’s under 1050 on uphill grades.

Glenn P. · 08-18-2022, 10:09 AM

The question not asked here is where is your EGT sensor? Mine is tapped right into the exhaust manifold and 1200 egt with load on a long grade is typical, I try not to keep it pegged at that forever but it is in the normal range under those conditions. Now if your egt sensor is further downstream that could be something that needs to be addressed.

I did a cat delete and for me I noticed no difference in EGT levels, just my observations.

And I agree with Twoxentrix point, back off a bit and increase the RPM's in a lower gear if you are worried.

jwintersteller · 08-19-2022, 02:12 PM

I have a 4 inch CAT back exhaust and I found that it reduced my exhaust temps by 50 degrees across the board. I started out by building a 3 1/2" down pipe from the turbo that transitioned to a 4" pipe once it got under the van and deleted the CAT. This system dropped my exhaust temps 100 degrees across the board. I also installed a cold air intake that dropped the temps an additional 50 degrees. So the reason I now only run a 4" CAT back is I live in California and using the full system for about a 1 1/2 years, I had to reinstall the Cat and the original down pipe to pass the smog test. I noticed that the temps went up 50 degrees. But with the cold air intake and 4" CAT back I am still 100 degrees lower than I started. Plus with the CAT installed, there is less exhaust smell, it's quieter and believe it or not, my MPGs went up. So I didn't take it back off. FYI my temps generally run at around 800 degrees on flat and may get close to 1100 degrees on a hill if I'm pushing it. But mostly stays right at 1000 degrees. And my temperature sensor is mounted in the back of the driver's side exhaust manifold. As mentioned by others I also find switching off the overdrive when climbing a grade, may increase the ECT and EOT but lowers the EGT.

My exhaust mod is in this thread on the second page.
https://www.sportsmobileforum.com/fo...mods-7913.html

And this is the intake mod. BTW I still have the prototype/mockup if anyone wants to recreate this thing.
https://www.sportsmobileforum.com/fo...ake-10337.html

Hope this help,
Cheers

Twoxentrix · 08-20-2022, 04:12 PM

Quote:

Originally Posted by jwintersteller

And this is the intake mod. BTW I still have the prototype/mockup if anyone wants to recreate this thing.
https://www.sportsmobileforum.com/fo...ake-10337.html

Hope this help,
Cheers

You had my curiosity peeked so I followed the link - WOW! That's an amazing air intake you fabricated... You've got skills!