About time is right. I've owned this truck for three years now and hadn't done any obligatory turbo upgrades yet.
It was a big year for my truck getting repainted recently and now the new turbo setup and supporting accessories.

That said, I thought I would post a review of the recent upgrades I did to my truck. If you see the length of this and you know you don't have the time or interest to read it, no problem, and feel free to exit from here. I just enjoy doing these things and maybe it will help some of those who are researching this in the future.

As you can see below, it includes the following:
E99 - L99 setup (pre-owned setup I purchased from a forum member. The parts had 6K miles on them.)[/I]
-38R turbo
-Deleted EPBV pedestal
-Bellowed up-pipes
-FRX
-HPX

Of course we all like pics so here's a couple for reference.









Goal:
I've owned my truck for a while now and have been happy with the TW tunes however, it used to get hot EGT wise partly due to the leaking factory up-pipes. Whenever I'd tow, especially, I'd have to monitor my EGT gauge like a hawk looking for its next kill. In the higher tunes it would also get fairly smoky too when you're weren't in boost and stabbed the throttle. Even without being tuned, I've always been content with the power towing on the highway. Where I wished the 7.3 made more power is down low in the powerband like for driving around town but I've ultimately come to realize and accept that it's not its realm there. I'll say the 7.3 is fast and not "quick." That's OK. What I wanted was for much lower EGTs and a little boost- (pun intended) in performance. I would say that I achieved that goal with the new setup. It really works quite well.

Driving it:
The first thing I noticed driving it for the first time as I pulled out into traffic after giving it a little stick was the absence of smoke in the rearview. I then pulled onto the freeway which consisted of a fairly steep hill with a sharp corner at the top. As I shifted through the gears, guess what, NO SMOKE again!! I was in disbelief. None. I then round the corner and really get on it in 4-6 gears. It felt like a sports car, and felt sooo wrong because of it at the same, lol. Before I knew it, I was actually redlining it in 6th gear!! I looked down and holy crap.... I'm turning 3600 RPMS in overdrive! Never done that before. The engine just runs soooo smooth and content now all the way through and feels so much more FREE. The speed is deceiving now simply because it revs so much more freely up top that it seems to secretly accelerate on you because of it.

The truck just has power. Pulling hills and grades is absolutely nothing. You pass people left and right like they are standing still without having to press the pedal down further. Here comes this diesel truck at only a quarter throttle passing you up steep hill. Stupid really. As I said, it feels so wrong in a truck of this girth. Going from 50mph to 85mph is nothing.
Getting into boost: One thing you will learn in this review is that I have always despised the stock turbo. I've pretty much hated the performance of it. It seemed to always have a mind of its own when it was going to light and was not predicable. You always had to drive around that thing and when you wanted it to boost, you really had to work hard at it to get it to. Anyway, I digress it was apparent the 38R seems to be more "alive" requiring less effort from you to "ask" it to work. It seems to run more linear and pull a lot smooth throughout the entire powerband too. The lag time down low with the old turbo was absolutely pathetic; I hated it. This new one, you stab the throttle down low and it actually feels like it's building up to something whereas the old one there was nothing.... just all motor. Zilch. Notta. The other point I might add about the stock turbo was that it was like it would only boost for a second then it was all over with. It was like "whoosh" and then you'd be all out of boost. The new one seems to carry it's boost a lot further and is now "whooooshhhh." It seems more usable, if you will, and actually carries itself vs. the other one that only seemed to work like a light switch. I also needed to run, for the first time, an OCR. Yet another thing I disliked so much about the factory turbo was the little boost that it created. Now the boost gauge is actually alive in active, lol. There was no way the stock turbo would get anywhere near throwing an overboost code but the leaking up-pipes were probably doing it a big disfavor there.

EGTs?
The EGTs, depending on the scenario of course, are a solid 200 degrees cooler all around. Substantial difference. I'm very happy about that lower EGTs. For example, while going up a certain hill in 4th gear at 35-40MPH it would always read ~800 degrees. Now it is reading ~600 and it's almost erie driving around and seeing the needle read much lower on the gauge; it really is. I can actually drive and take my eyes off the EGT gauge and not see it acting like a second tachometer.

The sound:
Ohh, the sound. Things have changed quite a bit. Basically like I'm standing behind a jet airliner. I've read the threads, watched several YouTube videos, and went into this with a preconceived consumption of what to expect. No doubt this turbo sounds like a 737, it does, but not unless you listen for it when you're driving normally. Even with the radio on a low setting, you're not really going to hear it when just driving around. The sound of the engine still out muffles the sound, for sure. When you get on it though, the sound comes alive for sure and sounds like a big rig but it's what you want to hear and not a bad sound. The intake has a completely new growl too that was never there before. My truck has never really had the famous "7.3 growl" (as I call it) but it has it now it does like never before. It was missing. It really sounds like two completely different trucks when you get on it now. The note from the straight pipe exhaust is actually louder than it was before which I'm sure is due to the EBPV delete. It sounds like BURB BURB BURB BURB along with somebody blowing a high pitched whistle through the exhaust when it's on high idle in the morning. I was expecting in cab noise of this turbo to be overwelming, crazy, while just cruising around in stop and go traffic but it's not the case at all. About the only thing I liked about the stock turbo was that it had a nice sound through the exhaust. The 38R has a higher pitched sing in comparison through the exhaust vs. that is more pronounced.

FRX & HPX kits:
While I did both the FRX and the HPX, I can't say which made the more noticeable difference or if it was a combination of the two. When I first fired it up, I could tell the engine was a little quieter at idle. Anything but idle I would say is just about the same though in terms of sound however. I will say though the noticeable tick from the #8 injector is completely gone. Like, all the way gone which is really awesome. In terms of starting faster like some have reported with the FRX and HRX? I don't think so. The chip is what cut the start time in half the time compared to when it was un-tuned. The throttle response down low is a little crisper/sharper right off the bat and is more response I'd definitely say. The fuel pressure is reading about 4-5 lbs higher than before. It was about ~63 PSI before and now is reading ~67-68 PSI.

Basically now the truck feels a lot more "airy" vs. before it felt like it almost got too much fuel down low in the higher HP tunes and got hot. I like how I can now stab the pedal going up a hill and look in my rear view mirror and see blue sky and not a black cloud like before while in a hot tune. The truck really runs great and seems very happy with the new setup. I can't wait to get a trailer behind it. Overall, a success.

 

So, another wasted weekend aye...😈 .... Congrats man, on your new found glory. Wish I can say the same

 

I remember the first time I heard that 737 sound... loved it. Like you say, it's not overwhelming (with the proper intake - which the 6637 is not on this list) - but it makes the inner caveman all giddy.

Very informative write-up with a lot of detail.

 

ARW, what injectors and intake are you running.

I enjoyed the read of your thoughts and experiences with the 38R. Thank you for taking the time to provide as much information as you could.

 

I second what has been said already. I, like Sous, am interested to know what else lies under the hood.

 

are you getting rid of the E99 spider? I need on for my son's truck

 

Thanks man! It was a long time coming and something I had to save up for.

Thanks Tugly. You are right, it definitely makes you all giddy.

Hi Sous,

My pleasure. The injectors are stock.

The engine is pretty much stock other than the listed mods above, a Tony Wildman chip and a gauge pack.

I may do larger injectors down the road but my biggest fear would be going back to high EGTs again.

Yeah, I have the E99 setup for sale. There has been some interest already in the spider but I'll let you know if it falls through.

 

I find it very interesting that the 38R makes such a difference on a mostly stock truck. I assume you upgraded the intake to an AIS or S&B or something else of that flavor?

Based on your thoughts about the swap, I may be getting the KC38R in a shorter time than I originally planned instead of waiting to do the injectors and turbo at one time.

200 degrees cooler is a remarkable difference and could be considered the best bang for the buck. I don't have any problems with towing EGT's on the heavy tow tune from Gear Head, but 100-200 would be great just for peace of mind.

 

To really take advantage of it from a performance standpoint, larger injectors would need to be had of course but you will notice a difference regardless. It helps that it's a ball bearing turbo to compensate some for spool up. Coming from an E99 setup that had the smaller 2" intake plenums, too, the engine is moving a lot more air than it did before. The up-pipes were leaking and I also did the EBPV delete as well, which not a substantial thing, is supposed to be good for a few drop in degrees as well. Combine all that with a bigger turbo and exhaust housing and it all added up to a solid drop in EGTs. If your up-pipes aren't leaking and you just put the bigger turbo on, you probably won't notice as big of a drop as I did but there will be something noticeable for sure. From a driving standpoint, the engine just feels a lot more free and revs out quicker; almost like it's free revving at times in neutral. Before it felt more restrictive, almost like you were driving with the parking brake on at times in comparison if that makes sense.

The intake on mine is a 6637 filter mated up to a K&N duct pipe as you can see in the photos- I've always ran this setup.

 

I doubt that he's avoiding your question but you did ask twice...I don't know what it is exactly but you can see it in his pics up above. ^^^

 

Like I said above, it's a 6637 filter mated attached to a K&N intake duct pipe.

 

Actually, I am a jackass and did not see from the pictures that he was running the 6637 open air filter.

 

Good review! I agree the 38R is a nice performing bolt on turbo. Probably what the truck should have come with if they could have made it quieter.

Having had a 6637 and the 38R for a short period of time I will say it was an absolute screamer. Could not take it for very long and anyone who rode in the truck was shocked how loud it shrieked. Got the S&B and that tamed it down enough to be ok but still louder than stock. The larger injectors I'm running may have contributed to this I suppose.

With a 6 speed, I can only imagine the fun! What gears are you running with the 37's?

 

Yeah, it's very much a "guys truck" so not worried about such things like noise too much.

Yeah, it's a lot of fun to drive. Still got the stock 3.73s for now; may go to 4.10s in the future but I don't mind turning the lower RPMs on the hwy.

 

You would be shocked to know how much the stock truck is held back by the engineers for this reason or that.

Stock turbo, stock tune (which defuels if you exceed 22 PSI boost), and stock injectors - but plenty of air in/out mods (boost far right):





This is what happens when modified fuel is rolled into with a 38R (red line attached):