Backstory: my partner and purchased a 4/98 F350 long bed crew at an estate auction a month and change ago with 350k on it. We'd been looking at trucks for towing vintage machinery, general hauling, and using the bed to camp in, and thought this would fit the bill (plus two of my siblings own or have owned 7.3s and know a lot about them). Plus the price was far far less than the going rate for these trucks.

Since then I've been in the process of getting the rig in reliable shape, which has included an major (costly) rebuild of the front end and steering and replacing all the fluids. I've also replaced the thermostat, CPS, EBPS and tube, MAP sensor tube, torqued all boot clamps, and added an AIS and Hydra (the PCM has an abysmal hypertech tune on it).

The Problem: After fixing the above I purchased the Forscan app and have been monitoring vitals to see if there are any more issues that need addressing. I noticed that MGP/boost never exceeded ~12 PSI regardless of tune. I put together a boost leak detector, set compressor regulator to 10 PSI, and hooked it up to turbo inlet. Ended up finding leaks around the sensors on the spider, but worst was the plenums. It looks like they'll need to be replaced, which means I need to remove the turbo.

The problem with removing the turbo is that means disconnecting it from the up pipes. My brother said the stock up-pipes aren't leaking... likely due to corrosion making a tight fit. I'm dubious that they'll stay sealed up if disturbed, and I'd hate to go through all this effort only to find that the up-pipes are now leaking after putting everything back together. Additionally, I don't want to purchase new E99 up-pipes for the stock turbo because...



It's seen better days.

The Solution: Given that I'm now looking at replacing so much of the turbo system, I'm figuring I might as well bite the bullet and replace it with a T4 system that will far surpass the performance and longevity of what's already on the truck. It will also provide some room for making better use of AC 160s when it comes time to replace the stock ones. This will also give me a change to do preventative maintenance on the fuel lines, fuel bowl seals, valve cover gaskets and harness, injector bolt torque.

The Questions: Many others have done the hard work of blazing a new trail with T4 systems on 7.3s and documenting their findings; there's a lot of information out there to guide me, and I've been doing as much research as I can.

I still have a few questions I need help on:

• In terms of my needs, in the foreseeable future it'll see use towing trailers filled with heavy vintage machinery, but most of the time the rig will be used for daily driving and road tripping/camping. I also live in a city on a very busy street (more like highway), so I generally need to be able to accelerate quickly from a stop. Some truck facts that may come in to play: stock exhaust, stock rear differential gearing, stock tire size, 4R100 w/shift kit.
  
  It seems like the S363/68/.91 is considered the ideal choice for a 7.3 with stock-med sized injectors, and provides best balance between broad power availability, amount of power, and EGT. I'm ready to pull the trigger on it, but would like to double check with the brain trust here that it'd be a good fit for my usage and driving style, as well as having room to grow for future AC 160 injectors? Would, for example, a 364.5/68/.83 be a better option?
  
• The kit. As far as I know, there's Irate, Obsession, and CSD.
  • CSD seems to offer the best value @ 1500 bones but I've heard of fitment issues; if there's a problem in this regard I'd have to contend with haggling and shipping for a replacement. It looks like the kit only has driver side intercooler pipe... assuming I'd re-use my passenger side pipe?
  • Obsession's kit seems the nicest (includes a lifetime warranty on the cast pedestal), and they have one on the shelf that I could drive over and pickup, but it's 2600 clams at the moment (does include all necessary boots and clamps... "everything you need to mount on an E99 except plenums"). Turbo seems to sit farther forward than other options.
  • Irate's is economical at ~1700 whatevers, and I could pick it up in person, but I get the impression it offers less value than CSD's, and has some quirkiness when it comes to the oil lines(?).​​
  • I plan on retaining the use of the AIS and CCV... unsure whether certain kits are more compatible than others in this regard.
    
• Where is the go-to source for the super core and housings now? The previous place seems to've gone out of business, and I really don't like the idea of having to pay a grand or so for the turbo.

Would greatly appreciate some feed back per my questions, and if you have any additional observations or things I should be considering that I may have over looked, please feel free to volunteer your thoughts!

Once I start pulling triggers and making headway, I'll document my progress here so that it may be a resource to others who end up venturing down a similar path.

 

Great thread coming!

 

You have done your research, so I won't bore you with details. I want to make sure you saw the thread linked below where I spelled out exactly what the T4/SXE conversion cost me.

T4 / SXE Parts List

In addition to that list, there are many other FTE's threads at the bottom of the first post.

You had some questions and concerns, hopefully what I say below will help you out.

I absolutely loved my 364.5/74/.91, but as you said, I think the 363/68/.91 is dead nuts accurate the right turbo for a 7.3L running on stock injectors to mid sized.

A friend of mine just last weekend installed a CSD T4 kit on a 4R100 truck and said the fitment was great. Nothing needed tweaking or adjusting. I do like the Irate Y-pipe better, but I do not like their oil return at all. That is my personal preference though.

The CSD Y-pipe is a bit wider than the plenums, but I just re-installed the CSD Y-pipe 2 weeks ago and had it mounted with boots in their proper locationsin 60 seconds. I then installed the clamps and it was good to go.

No need for the passenger CAC tube with the CSD kit, the OEM tube is utilized.
EDIT: Based on the comment below by ESwift, he is probably right about the E99 CAC tube being optional, he has an E99 so he would know better than I.

Obsession is nice looking and a good kit. I preferred the less clamps and union points that CSD offered, but they each have their advantages. I read recently where the Obsession kit has the oil supply line routed toward he firewall like the Irate kit where the CSD is toward the radiator.

Each has little differences and methods of installation.

CSD will put a CCV port in for you upon request, that is what I did. Others installed the OEM CCV port and fashioned their own out of the provided tubing for the intake. You can see me hooking up the CCV port in my installation video. I don't know if the other builders will include a CCV port or not.

@RacinJasonWV has shown us the AIS flows enough air for the 363 and 364.5 SXE.

@ESwift just bought a 363 last week and might be able to recommend a retailer. Another 7.3L owner I know bought one from Elite Race Fab late last week and I know of another 7.3L owner bought one from LM Performance a month or so ago.

I am NOT a sponsor, vendor, promoter or paid employee of any of the businesses I have named above. I simply relay information in an effort to help people make an informed decision.

 

Wow. That was a lot of good detailed information. You have really done your homework and it shows.

I won’t remember all the points so I’ll just hit a few I can in the order they pop into my mind.

First off I think the Irate kit hot pipe will NOT work with retaining the CCV tube and AIS as I have done. Eswift has told me this but I don’t have first hand knowledge. I do know the CSD kit will work in this regard.

The fitment issues with the CSD (which I have complained about) are probably overstated. Overall it it a good kit. The main beef is the fact that a few minor tweaks would make a huge fitment difference. There shouldn’t be any reason to send anything back. My only real issues were with the Y pipe and downpipe. Both workable. The hot CAC pipe doesn’t completely line up with the turbo which doesn’t matter but makes the longer boot Sous recommends a great upgrade for just a few bucks (if you can find one).

The CSD kit reuses your factory cold pipe. No issues there.

Turbo size….
​​​​​@brokestroke and @ESwift have ran the .83 housing with 73mm turbine. Both guys prefer the 363/68. I will let them speak for themselves on the matter but my opinion is the 68mm turbine is what you want with stock-ish size nozzles.

I feel like the EBP will stay in a better place with the 68mm vs using the 73mm with a .83 housing, which is kind of a bandaid fix to make the 73 work at lower rpm.

For what you’re planning to do I wholeheartedly recommend the 363/68/.91, and my guess is Brokestroke will likely say the 363/68/.83. It may be better but I haven’t seen any data for EBP with that combo.

Check out the turbo matrix thread for some driving impressions. It’s still a work in progress but the more people add to it the better it will get. I hope you will consider adding your opinions when the time comes. https://www.ford-trucks.com/forums/1...l#post19726786

I’m excited to see how your thread evolves.

Edit: Sous types faster than me… and if you haven’t seen it, there is a CSD kit install write up that haS the goal of working like an instruction sheet. https://www.ford-trucks.com/forums/1...l#post19273513

 

I would say, call irate, see if they will leave out drivers side pipe and intake pipe, and give credit for them towards their plennums that you will need since you have an e99, then buy a csd drivers side cac pipe($75, last I bought one, he sells em seperate, tell him irates sucks and you want his, that will make him smile), and do the 45° elbow (trimmed a bit) and a coupler to retain oem ccv center piece and use any intake from there.
I like irates down pipe and y better, the oil drain is good as well, maybe actually easir then csd, the irate oil drain runs behind turbo, it is a good fit, tons of clearence to cab, so no worries about rubbing.

Turbo, without a doubt a 363/68 .91 would be my top choice.
Elite Racing Fab is best price right now. Plus it is veteran owned and operated, and great to deal with.

 

Since the E99 has smaller injectors, check out the S363/68/.83. It should be a perfect match for the smaller injector and perform very well. It could run so great with the E99 injector you wont need 160/0s.

 

What intake are you wanting to run? If I get time to finish assembly this evening I can take a pic of how the Irate drivers side cac pipe would route and then the csd. I prefer the csd, main reason is because the Irate will not allow the use of my s&b intake

 

Eric, my understanding is he will utilize a currently installed AIS intake.

Priuslover, I am running the SXE with an AIS but want to provide one word of caution. My CCV is vented to atmosphere right now. So just keep an eye on it to make sure it doesn’t pull too much vacuum on the CCV and suck more oil than it should. By the results of my vacuum gauge testing I don’t foresee this to be an issue but wanted to share this information since I haven’t tested the AIS with a stock CCV setup.

Sous, I believe Eric was talking about the hot side CAC. The Irate version will not work while using factory CCV, or at least not the S&B intake. Eric prefers the CSD hot pipe due to this reasoning. I think the stock cold pipe should be fine but Eric please correct me if I’m mistaken here.

 

Missed the ais part..
the passenger side cac pipe from Irate is really nice, it has a bead formed in to help hikd the cac boots, but Sous was right, it isnt needed, the oem one in good condition works fine. One thing I tend to see is the oem e99 cac tubes tend to be deformed from people over tightening the boot clamps, the e99 cac pipes are aluminum, vs the l99+ are steel alloy

 

Andrew Arthur also builds T4 kits that work off the stock downpipe and builds them to work with the stock CAC pipes. He will also accommodate anything custom or out of the ordinary since he builds these for each customer.

Andrew is a great guy to work with and customer service is top notch.. Most likely going to go with his kit when I pull the trigger on a 363/68/.91 to go with my AC's.

 

I love the thought of using the “stock” downpipe, or in my case it would have been the 4” magnaflow.

I’m not sure about the hard line for oil feed. It looks nice, but vibration and heat expansion… a leak/crack there could be very bad.

I also feel like those T4 bolts should be studs like the CSD kit. It would make it much easier to tighten IMHO. You might request that when ordering.

I was impressed when I spoke with Andrew while trying to figure out a solution for my “under the turbo” issues. He seemed like a good guy and I would like to give him business. Plan to get some tunes from him eventually.

 

I just went through this, a spiral of upgrades. I am running 180/30s, an irate T4 kit, 364.5/.91 housing. My turbo seems to work well but I have 4.88 gears so I am always running 2400-2600 rpm so I would take the advice on a turbo setup from someone running factory F250/350 gears not 450/550 gears like myself.

The irate kit is good, but the hot side IC piping doesnt line up perfectly to the turbo. It was problem free for 3k miles and then I lost the boot. I found out Sous's recommendation on a longer boot and that will fix it. I am not sure if this is irate alone or other T4 kits as well.

Fitting the intake isn't the best either. I am probably just complaining though....Overall it is a good kit and it transformed the performance of my truck. I would buy it again. If they put in a longer boot on the hot side IC piping I would give it 10/10.

 

As these kits become more popular, I am pleased to see more kits being offered. I would venture to guess since there is no down pipe or CAC tube in the kit, the price is more in line with cost vs benefit.

Although, if these are one off creations based on customer desires and expectations, that could bring the cost up a bit. Did Andrew give you a rough cost estimate or range? If it is near $1500 or less, then that could make it much more appealing than $2000+ for those looking for a T4 kit.

Same thoughts on the down pipe and I see where AA clocked the turbine outlet a bit to be more in line with the Garrett OEM turbo outlet. I would be interested to see the OEM passenger side fuel line fitment on the AA pedestal.

The oil feed looks good and well made, it looks a bit tall from the image, but that may be because I don't have a point of reference other than the compressor housing. I would be concerned with the proximity it has to the up-pipe and compressor housing until I saw more details via pictures or in person. I trust that he has done his homework though.

I believe it was Jake (Khan) who mentioned an OBS owner that had a fire due to his oil feed line routed toward the firewall. I would have to go back and look. Since discussing the method of installation of the oil feed line in another thread, I prefer the CSD radiator side method the most. There is plenty of clearance in all directions from the outside of the hose.

As for the turbine flange mounting bolts, absolutely prefer studs over bolts through the holes. After installing two T4 turbos utilizing both methods (turbine + super core and turbine then super core) I can say without a doubt studs would be my preferred fastener.

I have been recommending AA as an option since he came onto the tuning scene a while back. I am a member of a Minotaur Tuning forum for educational purposes and see him posting there.

I have no personal business experience with him though as I am on OEM injectors and happy with the standard PHP tunes.

Great thread so far and the sharing of experience and information should prove useful for a long time.

 

Interesting use of a hard line for the oil feed. Angling the turbo like that might have solved my vane actuator cowl clearance issue also. I wonder if this makes it look enough like a factory system for the CA guys to pass inspection.

 

Great review and thank you for sharing your thoughts on fitment and quality.

I am pleased to read you were able to utilize the longer boot. That was originally AKCooper9's idea, but I did have to dig and find the boot details when the original source stopped selling them.

I would agree the CSD hot side pipe could use a bit of angle adjustment mating to the compressor outlet, but with the longer boot the CAC tube clears the alternator and the high pressure steering hose joint. So, overall I am very happy with the CSD kit.

It is not perfect or OEM fit, but rarely are aftermarket kits or parts. The minor issues can easily be forgiven for the performance benefits garnered when going with a T4 kit.

Even though the 364.5/74/.91 had me a bit under the turbo, it was miles better than the MST. No more downshifting, no more running 30+ PSI boost, no more watching the EGT gauge constantly, no more messing with OEM turbo collector clamps, etc...

The kit and turbo cost me $1700 and change after it was all said and done, but sometimes you have to pay for nice things.