T4/SXE vs. KC38R - Decision has been made...
 

I have made my decision after much internal debate and with the advice and guidance from many FTE members. I would like to thank Akcooper9, The Brad, SRBF150, White Buffalo, Brian42, Brandon_oma#692 and Y2KW57 for answering my questions, concerns and dealing with my indecisiveness during this period of strife within my brain.

July 2019 Edit: I have created a thread with the entire parts list I used. The thread can be viewed by clicking this link: https://www.ford-trucks.com/forums/1...arts-list.html

April 2020 Edit: After reading all 1000000000000 pages of this thread, if you still have questions or concerns go to the post in this link: https://www.ford-trucks.com/forums/1...l#post19209098

***DISCLAIMER START***

I am in no way an expert on the 7.3 or any other engine for that matter. Many on this forum are experts and may have something completely different to add to the post. I have learned a lot after buying my truck just over 4 years ago. I like to make how to videos and help others learn from my experiences, and that is what this post is about.

Take it for what it is worth, which is free information.

***DISCLAIMER END***

My choices are listed below in order to obtain an efficient and reliable truck to haul our 5th wheel around the country for the next 50 years or so…

Choice 1 – T4/Borg Warner SXE 364.5 with OEM injectors

Choice 2 – KC38R with 160/80 PIS injectors

Each of the choices has its own advantages and disadvantages and I have selected the one that works best for my application. I am posting the results of my decision here to help someone decide when faced with a similar decision. Be it my chosen path or the opposite path that is up to them because it is their time and money.

Considering each of the choices being the same in at least three ways.

First, the selling of the OEM parts due to the parts not being needed any longer after the upgrade has been completed. For the T4/SXE kit this includes the pedestal and up-pipes, where the KC38R upgrade is more limited to the OEM turbo itself.

Second, the overall price when considering all of the major parts. Each of them will require a few minor things like T-fittings or what not, but these are the high dollar items. My cost figures are below.

https://cimg3.ibsrv.net/gimg/www.for...5cde292fc2.jpg

Third, the upgrades will involve similar amounts of time and labor to accomplish. A drop in turbo like the KC38R does take a bit of work to get the collector lined up even though it is relatively simple. The T4/SXE kit has more pieces, but goes together much easier as an overall process.

In my opinion, the goal of a turbo system is to create clean and efficient power for the driver of the vehicle. By clean and efficient I am referring to exhaust back pressure (EBP), manifold air pressure (MAP) and exhaust gas temperature (EGT) readings when the truck is working for a living. The ratio of 1:1 when comparing EBP and MAP is the key and the most efficient way to keep a turbo and intake system healthy and working at the top of its game reliably. Maintaining the ratio as close to 1:1 is optimal in order to make good clean power while keeping EGT’s lower and well below 1250-1200 degrees.

Operating in the 1200 degree range is OK and within safe temperatures for the 7.3, but lower EGT’s while maintaining the same power and speed is what I am striving for. Again, this is accomplished with a 1:1 ratio between EBP and MAP with a well running engine as I understand it.

Based on PCM data logs from other users (KC38R and T4/SXE alike), videos, testimony, countless hours of reading and images I have made my choice that the T4/SXE setup is the best way to maintain a 1:1 ratio when towing heavy. This is across the board when looking at various injector applications. All the way from the OEM 140/0 to hybrids at 238/80 to 180/80 single shots. The EGT gauge in a T4/SXE setup is not even considered a useful tool any longer because the EGT’s are well below what they should be monitored at.

My other consideration, the KC38R is a great drop in replacement and capable of making a lot of power and boost. Although, a good amount of fuel is required to spin it up to speed (even with the .84 A/R for the ZF6) which means that larger injectors are also required to keep the turbo operating at optimal performance. During this educational journey, I have learned that boost is not a measure of power or efficiency, not exactly anyway.

Mistakenly I was under the impression that boost was related to power and I should be pushing as much as I could, but I was wrong. Boost is only a measure of the pressure the intake system is sustaining and when dealing with larger boost numbers, other hardware upgrades should be considered like valve springs, billet plenums and what not. My goal is not to obtain 30+ PSI of boost when towing. My goal is to obtain ~25 PSI of boost with lower EGT’s and maintain substantial power when towing.

When boost reaches higher levels in the OEM turbo, heat builds quickly and EGT’s climb. The power curve dies off quickly when getting above 25 PSI and it starts working against the heat it is creating itself. A Garrett 38R or the KC38R are good ways to reduce the heat while building boost, but again boost is not the goal here. On the contrary for me…

The OEM turbo even when modified is not the right answer for me, as I have come to realize. It has done a great job, but I am ready to take the next step toward efficiency.

I have zero interest in reaching boost levels above 30 PSI while towing heavy while maintaining efficiency and reliability. To each their own, but for me I do not want to run on the ragged edge of performance for this engine for the next 10 years when driving this truck. The engine was designed to work in the 20’s when regarding boost and if I can obtain that PSI level and low EGT’s with bolt on modifications, then that is my path forward.

This brings me to the T4/SXE setup. The Borg Warner SXE is a great platform that has nearly revolutionized the turbo scene. Even the KC38R is designed after the SXE platform, but as a drop in turbo. The SXE is rebuild-able, replaceable in halves and easily swapped out if/when the need arises. If I decided that the .91 A/R was not right for me, I can change that one part out for a smaller or larger A/R at a fraction of the cost to competitors. The turbo runs very efficiently and is considered the benchmark among a lot of communities.

The fact that I can keep my OEM injectors with the T4/SXE setup and obtain a similar performance level that I would with the KC38R and 160/80 injectors is ideal for me and a huge consideration. If I ever have a problem with the Hydra chip, tuning or an injector it is much easier to find a replacement OEM Alliant injector or simply unplug the chip and continue on my way. The extra hardware and mounting that the T4/SXE requires compared to the drop in KC38R is minimal when talking about custom tuning, modified PCM and swapping injectors.

The swapping of the pedestal, oil line, up-pipes and Intercooler tube can be a bit daunting to to think about for some owners, but others of us have done this already. Each of these parts I have changed, refreshed or upgraded on my truck already. Just because I am putting in a flat pedestal designed by CSD instead of an EBPV delete pedestal designed by Garrett does not make it much different in my mind.

The mounting hardware for the T4/SXE is different because the orientation of the turbo is different, but this is where some of the efficiency gains come into play. The intercooler tubing is simple, that is just piping. When you really get down to the nuts and bolts, the T4/SXE install is really quite simple.

The cost of the T4 kit is one big factor for people like me, but as you saw from my own personal cost chart they are nearly identical. Take into factor the OEM parts that will be up for sale, the T4/SXE kit actually comes in cheaper by a decent margin. Then take into account the performance and efficiency differences, well it is what it is...

The gains from the SXE turbo are superior to the KC38R in my opinion. This and the fact that I can keep the boost levels low, the EGT’s low and maintain a high level of performance and longevity is what led me to decide on the T4/SXE setup.

I have not committed any funds yet, or know when I will purchase the kit from CSD and Liberator Turbo, but I would suspect it would not be too much longer. My wife and I are in a drastic change in lifestyle at this point and I just don't think it is the right time. Soon though...

Comments and thoughts are welcome. I hope someone can take away a bit of information from this, even if they disagree with it.

Thanks for hanging out and hopefully you can take something away from it that will help you in the future. :-drink :-drink :-drink

Well stated Sous and it seems that some folks at KC agrees:

https://cimg8.ibsrv.net/gimg/www.for...c39e724562.jpg

:-hijacked

One thing I never mentioned is it is nice seeing MADE IN USA stamped in the side of the turbo. No clue what the actual percentage is but they better be labeling products correctly. We all complain about lack of jobs here and go buy the cheapest thing we can from China or Taiwan.

Back on topic.

Sous send me your mailing information and I'll send you out insulation sleeving for the oil supply hose.

Wow , you have done your homework !..

Thank-you..

All I will state is..

I don't see how stock injectors and a much better turbo will ever compete with 160/80's and a KC on a performance level..

Kyle

Kyle, thank you. I always try to exhaust all of the options available before making a decision.

Comparing the KC and 160/80 injectors to the SXE and OEM injectors is comparing apples to oranges. Maybe that is why it has taken me this long (more than 6 months) and a lot of reading to make up my mind. Based on what I have seen and read, the T4/SXE running on OEM injectors will perform great. The T4/SXE running on larger injectors like the 160/80's will run great.

The KC running on OEM injectors will do well, but not as good as the SXE. The KC running on 160/80's will do well, but the boost levels are higher than I am wanting to go for my application.

This is not to say that someone else isn't perfectly fine with pushing 35 lbs or more of boost into their engine, but that is not me. Even then, referring back to the 1:1 ratio, high boost numbers is not where I want to be. I am not looking for the best bang for the buck, I am looking for the best application for reliability and efficiency and I think that the right combination for my application is the OEM injectors with T4/SXE. This combination offers the most "fail safe" features out of the available options in my opinion.

I am not looking to smoke tires or run 75 MPH up a grade towing heavy, I am looking for longevity of the system as a whole.

Maybe I am wrong and the OEM injectors paired with the T4/SXE system is not the way to go. Although, I know of at least 1 person (OEM injectors with T4/SXE towing heavy) running this combination and they have sent me very detailed information showing the efficiency of the setup. The way I see it is that changing a good portion of bolt on equipment is a more reliable method to achieve the goal than changing internal engine parts, chip programming and possibly PCM programming.

Again, this is just me and my best shot at what I think will work for my situation.

Very nice..
I wish you luck and I am sure you'll keep us posted on the way

BTW - I don't see liberator turbo "on-line"

Kyle

Thank you sir, I wish you and anyone else that has chosen the 7.3 lifestyle luck.

Liberator Turbo (spelled liber8rturbo) is an Ebay retailer that has managed to create a customer base by providing Borg Warner turbos for a discounted price. I personally know of at least 3 complete turbos that have been purchased from them with great success.

I think you will be happy with your decision. One thing though the cost of the injectors you listed on the KC38R are brand new. Another option would be rebuilds at 1300.00 +-. I just took my truck off the rollers yesterday with my new fuel system and other things and it made 560 rwhp 1143 ft/lbs. Egt's are much better. As you said the T4 system is suited better for your application with stock injectors. But for performance both system's are very similar and have the same potential. Pick your poison.

Thank you, I think I will be happy as well.

I listed both sets of injectors as new prices both for the Alliant and the PIS. Frankly, I have seen too many stories about troubleshooting remanned injectors and I don't want to mess with it. To me personally, it is worth the extra money to get new injectors that will last 250K+ miles without having to be pulled again. Even Rosewood who is a premium re-builder has problems once in a while, it is the nature of the business.

Pick your poison is a great way to put it.

Great results for your truck, I am glad you seem to have gotten it nailed down.

I couldn't agree more! You get to the point where you've always got the hood up instead of driving it (or right after).

I think you've made the right decision going with the T4. The cost offset with stock injectors and selling off the OEM pieces left over makes it even more palpable.

The scale of performance, reliability, and longevity is impossible to balance but I think you're on the right track to do it. If I had the option I would go the T4 direction for a better turbo but "The Man" has a differing opinion. My rebuilt stocker is great but limits the new sticks but, like you, I'm not interested in hanging out above 25 psi. In my conservative mind I consider that the "ragged edge of performance" you mentioned. The 7.3L has a legendary image of reliability and I'd like mine to live up to that so I'm as calculating as you when it comes to pieces and parts that go on it.

IMO the less you do inside (e.g. non-stock sticks) will help it last longer. Plus you already have programming that you like (I'm not sure if there are any tuning adjustments for adding a beefcake turbo) so it seems like a great fit for maximum benefit with minimal disturbance.

Be sure to post your progress with the kit when you get it so we can live vicariously through you! :-X22 :-X04

That's exactly why I went new. I only wanted to go in there once!

Brian, you have been a great source of information and advice. You have also been a sounding board many times that most of the other FTE members have not been subjected to. I appreciate your thoughts in this thread and your guidance because you and I do think a lot alike.

There are no tuning changes required when changing out the modified OEM turbo for the T4/SXE kit. Frankly, I am hopeful that I can stop using my "heavy tow" tune and just use my "daily drive" tune for everything. Then I will only have 2 real tunes to switch between which are daily drive and high idle once in a while. We will see what happens though.

As for keeping the FTE up to speed with how things go. I have intentions of doing an install video similar to how I did the OUO traction bars install video. From un-boxing all the way to the first start up.

Regarding the new injectors, that is the only path forward for me in the injector category. Again, if I can keep the internals and heart of the engine as close to OEM as possible but tow a heavy trailer up a grade in 4th or 5th gear at 900-1000 degrees of EGT's, that is a win in my book any day of the week.

Interesting update Sous, thanks for the information and I look forward to hearing how it goes. However, I cringe at the thought of doing up pipes but I know that they'll come apart a lot easier if they have to be done again.

Mark, the 15 year old (at the time) OEM up-pipes came off without a hitch on my truck because it was a Louisiana truck. No rust, no issues really. I installed Dorman up-pipes and when I put the T4 kit on from CSD it comes with up-pipes that are a breeze to install compared to the standard 7.3 up-pipes. I will then turn around and sell the standard 7.3 up-pipes in the FTE Marketplace to recoup a bit of cash.

Everything about the T4 kit is easier regarding mounting, it just takes more time because I have to remove all of the standard parts it replaces on the 7.3.

Great choice Sous, that would be my next step after I get the tranny fully built lol.... Its going to be awhile.