EGT and turbo size??

[Levi1a]

First time first gen. owner. Long time gear head. I purchased the truck to pull my trail rig. Engine seems to be in good shape. I assumed it was all stock when I bought it other than the fuel pin being turned already. I have slowly made needed repairs to he truck and just now decided to turn it up a bit. Mods are 90 degree turn of the fuel pin, one turn of the star wheel, smoke screw is down 1. 25 turns, and full fuel is right at one turn in. Unloaded 4th and 5th gear hammer down I am seeing about 20 psi of boost and I can make the egts hit 1200 if I want. Normal cruising at 60 mph 5th gear egts hang at about 800-900. 4th gear pulling hard long grades 6000 lbs. behind the truck the egts will hang right at 1100-1200 boost at about 10-15 psi. The truck will maintain 55. I usually try to keep em at 1100. I currently have a stock h1c with 21cm ex. housing. I would like to get some more air in the engine and try to drop the egts a tad without building crazy boost numbers. Question is an 18 cm housing swap worth it or should I go with a 16? I would like to keep the boost down to about 25 psi. Also am I correct to assume that more air will drop the egts? One more question. I see all kinds of post about acceptable egt numbers. Some say 1100 all day long never more than 1300 for a second or 2. Some say 1300 all day and peak at 1500 for a second. Sorry for the long post and thanks in advance for replies.

 

[Levi1a]

Bueller... ... . Bueller... ...

 

[Bob Beauchaine]

Since you did not say what size exhaust you are running I would say that the exhaust is probably stock. That being said if you want to run lower EGTs I would suggest going to a 4" exhaust. My first turbo upgrade was a 14 wastegated hot side and the 4" exhaust. Both the 16 and the 14 hot side are good for moving more air and that will help to your EGTs down.



Remember that a diesel is basically an air pump - air in (add fuel) air out.



The next was a PDR HX35 cold side. Then I added a "Banks" IC and TWorline 3. 5" turbo to intake manifold plumbing. I can not get EGTs over 950 running up Cabbage Hill with my current setup even when my 8000 lb trailer in tow. I can hit 1450 running on a dyno momentarilly but thats the higest I've ever seen. Normally I will be under 950. At 60 mph I will see about 800 in normal driving.



You can see my mods in my sig. You can also post your current set-up so we can all see what you are running.



BTW Welcome to the TDR - good to see a new member.



Bob

 

[Joseph Donnelly]

I compared the 16, 18. 5, and 21 cm2 housings some years ago. The 21 is horrible, high egt, sluggish spool up, etc. 18. 5 is good, but the best compromise is the 16 sq. cm. among those that fit directly (meaning non-wastegated; the wastegate adds 1. 2" to the length and pushes the downpipe against the heater box). BD and others sell the 16.

 

[Levi1a]

Thanks for the replies. I am running the stock down pipe into a 4" that turns out behind the cab. No muffler. Also I added a bhaf and ole smokey mount. What kind of boost numbers am I looking at with 16 cm non gated housing? Also the truck has a factory intercooler.

 

[Bob Beauchaine]

I am running a 4" 2nd gen down pipe. This eliminates the the 90 degree bends and I believe it improves exhaust flow. I wanted an exhuast brake and went with BD exhaust brake. The down pipe was installed by Rip (Source Automotive). The pipe was close enough to the heater box so I did wrap about a foot to keep from having any problems.



My PDRHX35 is running a 14 wastegated hot side. I also installed a boost fooler and it is closed right now.



I am running Snows Stage 3 analog W/M injection. The "T" that distributes to the W/M injection nozzels was replaced with a "Y" to improve flow.



Sometimes all the little things you do add up to push you to the next level in performance while still keeping egts under control.



Bob

 

[cerberusiam]

The amount of boost will depend a lot on the fuel screw and injectors. With the stock injectors and fuel turned up 30 psi is attainnable with a 58\16 turbo. Add injectors and 35 is about the top.

A 16 houisng is a cheap upgrade. A better upgrade is WG'ed 12 housing and a bigger compressor wheel. All depends on what you want to spend and what power level you want.

 

[Levi1a]

Thanks again for the replies. The truck now is a rocket compared to what it was, and I grin ever time I take it down the road. Honestly as of right now I don't want much more power than what I have , just would like to keep the towing temps a little lower, and get the turbo to light quicker. I am gonna look for a used 18cm housing and if I cant find one I will swing for a new 16. Thanks guys!!

 

[Joseph Donnelly]

If you add much fuel, the 12 cm2 housing will be on the small side of what is best. Even with stock 215 HP engines, I saw 25-30 HP improvement with the 16 over the stock 12.

 

[cerberusiam]

Now we get into the discussion and comparisons of what housing performs best under what conditions. There is a marked difference between a VE and P7100 when you start trying to compare HP gains on turbo configurations.



Max HP is read at the top of the fueling range which is in direct conflict with 99% of the usage scenarios. The bulk of the operation is around the 2000-2200 rpm range for normal driving and towing usage. This where we have issues with the smaller compressor larger turbine providing enough "good" air to control EGT's, boost is not the only factor here.



We want better air at lower pressures and that entails compressor and turbine changes, helps a lot with the spool to keep the smoke to a minimum also. A well matched 58\12 will out do a 56\16 at towing rpms when you start looking at spool and EGT's, the 56\12 will give lower DP and higher HP at 2800 rpms but that is not where we need it. Running stock injectors and just minor tweaks to the fuel supply it will be harder to spool a 16 housing that a 12. A 56 \12 will give great spool and pretty decent air in the towing range but be limited at a full tilt boogy. You have to pick and choose with a single where you want to be, or, go twins.



The difference of the turbo with a matched HP level will mean be able to roll along at 70 mph and 1000 degrees, or, 70 mph and 1200 degrees with less weight. The 3. 55 gear ratios do NOT help you in those conditions but that is another discussion.



The EGT's range that has worked for me for a long time is thus:



1250 and less - All day long



1300-1500 - 3 minites out of 5



1500-1800 - 1 minute out of 5



1800+ - About 30 seconds to melting things

 

[NJTman]

Here's a good article to keep in mind...

http://www.dieselpowermag.com/tech/0907dp_turbocharger_basics/viewall.html

 

[Levi1a]

Thanks for the info and replies guys. For now I dropped some money on a 16 cm housing. I really don't feel that with my minor fuel mods and HP desires that I can warrant dropping much more money into the H1C. I think when the time comes and the urge to push the ponies up a little more I will look for a hx 35.

 

[Levi1a]

Got the housing changed out today. First thing I noticed was the EGT's are about 100-150 degrees cooler. Spool up obviously is quicker. Also cleared a lot of my smoke up. Thanks for the push in the right direction