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Good read this am. You have some of the best troubleshooters on FTE giving advice. Here's my .02. Confirm through testing whether or not you have boost leaks. Granted you're seeing decent boost so probably not too bad if it is leaking but until you confirm you have none, it's kind of pointless to go on. The OEM CAC boots are okay, but some RiffRaff inserts ($40) and their thicker boots with Tbolt clamps eliminate that issue. Assuming no leaks, I would wager you'll still have an EGT issue due to the larger tires and stock turbo and exhaust. I agree returning to stock tune and performing some testing and datalogging would be a good start to see what is happening. IF that's not interesting, throw a 4" exhaust on and a high flowing intake. I don't know what the Volant specs are, but S&B is probably one of the highest flowing out there with the 6637 being the low dollar winner. Confirming the engine is working properly and allowing more airflow is pretty much all you can do until you start going down the path of increasing flow further with bigger turbo options.
Pressure drop across the cooling core? I'm one of the odd ducks who had my Boost gauges BEFORE the IC, and I had that to compare with the MAP sensor.
The only difference I saw in pressure is what you would expect from cooler air out being less voluminous than the hotter air pumped in. My Manifold Air Temperature was not much above ambient, so I had no reason to believe a bigger IC would help above and beyond what my 38R and CAI was already doing for me.
Perhaps it is a better designed stock intercooler that usual. A typical intercooler designed for stock power levels will usually show slight back pressure at higher boost levels (than stock I mean) and RPMS. Just out of curiosity, how high do you observe the boost on your pre-CAC boost gauge running evenly with the MAP sensor? It might negligible at lower boost but there is some at least in theory.
Mechanical boost and (pre CAC) and electronic boost showed no real discernible difference (up to about 28 PSI before the MAP sensor maxed out on stock turbo and injectors), but I couldn't log the mechanical boost to scrutinize it for subtleties.
When I had the stock turbo and injectors, the EBP far exceeded the MAP (about 15 PSI) on a hot tune at WOT. Now that I have the 38R and bigger injectors, I can tell you I have a specific gauge for the delta between MAP and EBP, and there's nothing more than a couple of PSI difference all the way up to 22 PSI (boost fooler now installed after I wiped out my MAP sensor with bigger injectors and turbo). The delta between MAP and EBP on a 38R is an oblique from the original topic, but it's noteworthy if somebody has any theories on this being a good thing or a bad thing in relation to CAC flow.
I can share my thoughts on the IC. I've looked at MAT, MAP, pre-IC boost, 0-80 times on different tunes and engine configurations, performance logs, and I even took a picture inside my IC:
The stocker quickly cools the air - that's why there's condensation on the surfaces (even though I live in the desert).
It does not fill with oil when one leaves the CCV tube leading to the turbo intake.
It flows as much air as any reasonable turbo you can put under the hood.
I would never in a gajillion years install a CCV vent to atmosphere. When I bought Frankenstinky with a CCV to atmo mod (1000 miles from home), I reconnected that to the turbo intake 36 hours later and 700 miles before I reached home. With all that condensate lurking in the IC, I'd rather there was some oil to accompany it - plus the CCV mod made the truck really stink.
In my view, not without considerable research, the IC is one thing we can leave alone - and move on to other mods/repairs in the truck for lower EGTs.
The CCV tube smells disgusting, except for when the oil is brand new. Then it smells like new motor oil.
About the intercooler: it seems to not be the huge choke point they tend to be on stock turbocharged engines (its pretty big after all). Yet some have claimed EGT drops by putting an aftermarket one in. And the plastic end tanks are not ideal.
A couple of years ago I authored a thread discussing intercoolers of different sizes and models and at the time the BRAND NEW not even on the street yet KC turbo vs. the GTP38R.
I believe the consensus was that the OEM 6.0 is good for about 25-50 degrees of cooker EGT's and the aftermarket 7.3 or 6.0 coolers are good for about a 100-200 degree drop. This was all with the modified stock or GTP38R turbos.
The cost of an aftermarket intercooler is not cost effective unless you have silly money to spend or just like swapping out perfectly fine for most uses equipment.
As we all know, I went the SXE route instead which garnered cooler EGT's and more power. If I had silly money, I would probably install a Mishimoto 6.0 cooler just so I could look at how shiny it was. But, I don't so I took the surefire method of being able to tow 12,000 lbs cross country and be done with it.
Yes the Mishimoto 6.0 version will fit the 7.3 and is a little larger as I understand it. Not sure why they even bother making a smaller 7.3 specific unit but I guess I'd have to ask them that. Upwards of 200* is pretty huge if true. And you know it will make the biggest difference under heavy boost and RPM loads as when towing in the mountains. Putt-ing around town probably not. What I like is the idea that I could swap the CAC fairly straight forward for a better one and maybe just stick with the modified stock turbo that I have, which I only spent around $850 on including the cost of the used van turbo. The intercooler would be ~$1000 I guess. I lost track of how much money I've spent on this thing a long time ago so it's not really about that. Just being a little contrarian. If it does what I need it to and comes in a little lower in total cost than a T4 kit that is nice too I suppose.
I agree that a 200 degree reduction is significant when only changing a passive part in the system. The intercooler will not change the limitations of the stock or modified stock turbo though.
The problem is two fold really...
The actual compression and air being forced into the engine and the ability to keep that air cool enough to keep the engine running efficiently. So, say $1000 for a good intercooler, boots to match the new nozzle sizes and whatever is decided on the turbo. Be it modified stock or a chosen flavor of the 38R. All of this can be resolved with new technology and advancements in forced air induction systems that were designed in this millennium.
I decided against the intercooler because I was already operating at the limits of the stock/modified stock turbo and there was nowhere to go.
I hope my thoughts are coming through properly for people outside my head to understand.
If your operating a stock size turbo beyond is efficiency range it is going to produce excess heat so you will see a more benefit from an aftermarket intercooler. However if you have a properly sized turbo to begin with it isn't going to produce all the extra heat so you would see much less benefit from an aftermarket cooler. Basically an aftermarket cooler is a bandaid and a properly sized turbo is eliminating the problem at the source.
Oh yeah. Ideally a T4 turbo and a better intercooler. T4 is still a little pricey for most guys (although getting more reasonable) and I don't like how there is still no downpipe available that will bolt up to the turbo on one end and the rest of a 4" exhaust on the other. Not that I know of anyway. A simple $100 adapter mates the non-wastegated Garrett turbine housings to any standard downpipe.
A t4 isn't the only option, drop in turbos like the KC38r have proven to do a very good job keeping egts down when towing. I plan on getting the 63mm version of the KC38r in the future.
A t4 isn't the only option, drop in turbos like the KC38r have proven to do a very good job keeping egts down when towing. I plan on getting the 63mm version of the KC38r in the future.
The GT38R or the KC38R might have gotten the job done, but the SXE definitely would get the job done. I couldn't take the chance at the time and I am glad I didn't.
From what I understand there have been some major changes to the KC line since a year ago, but I still see catastrophic failures happening from time and a lot if less than pleasant reviews.
I went with the old adage of doing it right the first time.
Bennyhick2 or someone else reading this may not need to choose the same path as I did, but it was the right path for me and it certainly cleared up any problems I had towing heavy. Now I'm looking to get rid of my EGT gauge. Even though I use a hot tune on stock AD 255,000 mile injectors to tow the 12,000 lbs camper around the country.
Intercoolers, drop in turbos, tow tunes, single shot injectors, hybrid injectors, etc... are no longer on my checklist of things I think about... PMS 100% cured...
I believe I have said my peace and hope this thread brought some answers or at least some options to the table for Bennyhick2.
Having built and running a T4 on my pickup I still want to try out the KC300x 63/73. My wife has an Excursion that would be a good candidate for one. Actually, keep an eye out for a build thread popping up...Can you say Excursion body swap?
KCs new line of the turbos they just came out with a few months ago, are better designed than what they had before they are based on the SXE turbo line. They did some high elevation testing on a 7.3 towing 12K with 200/30 injectors and never saw over 1100* egts. The T4 setup works great also if you have the extra cash, KC has done a lot of testing with the T4 SXE turbos as well, they used that as a baseline to design their current drop in turbos.
07-13-2019, 09:14 AM
