wanting to dump 38r

lincolnlocker

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Its funny you mention this. I have been pondering this same thing.

SO MANY people have zero issues with the 38r (or variants of it). Towing with no issues and spools awesome. Then you have some guys that have EGT issues and say it spools like a turd... then they go T4, fixes all the issues, and they love it.

I have always wondered if when they go "t4" they fix all the boost/exhaust leaks because everything is brand new, which is part of the previous problem and now why they have zero issues.

I have never met anyone that has not had some sort of boost/exhaust leak when having turbo issues. If they ever stop by the shop it takes me about 5 min to find a leak (usually they have multiple leaks). These 15-20 year old truck parts will leak and go bad. It is funny because the most common thing I hear is "wouldn't I notice if I had a boost/exhaust leak"?


I just don't see it being possible that the performance of the box 38r can vary so much... it has to be tuning, health of truck, or leaks. But that is just a theory.
i have said the exact same thing for years.. i had that problem.. just a measly 200° rise in egt and i took soapy water to the entire charge side of the system and found my plenums to be leaking... twice... and i run my dually in one tune no matter what i was doing.. the hottest tune it has.. i could run a buck twenty with my 36 foot 5er on the back and just hit 1400°

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KCTurbos

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i have said the exact same thing for years.. i had that problem.. just a measly 200° rise in egt and i took soapy water to the entire charge side of the system and found my plenums to be leaking... twice... and i run my dually in one tune no matter what i was doing.. the hottest tune it has.. i could run a buck twenty with my 36 foot 5er on the back and just hit 1400°

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Not trying to be a jerk... but I guess the guys with good luck could just have bad pyros. Just saying that would explain it.
 

Addicted4

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What temps are you actually seeing? I should have asked this earlier but 1200 isn't hot but 1400 is. Towing 10k lbs at 70-75mph isn't in my liking, 65 tops for me or less. If these is the case your gear ratio vs tire size vs mph/rpm could be your issue. 4.10's tow better all around imo or drop tire size.

My truck for instant is a 4.10 with 35" tires I setup for dd/tow and run 65 at 2k roms so it's in its sweet spot 18-2k depending on 60-65mph.
 

psduser1

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A lot of true statements here.
My 00-manual- I tow everything on gh s hot street. Only trouble is high load, low rpm, and not while accelerating.
My 01-auto- is completely the opposite, lol. 4.10s, 235/65/16s, and it'll run up to 1400, empty, if you want.
Replaced boots, uppipes,etc, when we had the engine out about 35k miles ago, with no apparent leaks. Just have to drive that one by the pyro.
Those two trucks have very similar everything, performance-wise, so I don't know what gives. Gave up caring, for now. At some point, though, I will swap those two turbos around, just to see if that is the difference.
The ex is brainless, better than stock. Still with stock injectors though, so not really in the same game.
 

superpsd

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Likely a combination of issues. I can drastically lower or raise EGTS by jacking around the SOI mapping without no other changes. Of course that also plays a part on how the turbo spools up.
 

psduser1

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Likely a combination of issues. I can drastically lower or raise EGTS by jacking around the SOI mapping without no other changes. Of course that also plays a part on how the turbo spools up.

That is a fact. However in my case, the 01 has had three different tuners over the last four years, with no notable difference. No live tuning, just thru the mail.
 

mikeeg02

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I'm one of the few that had a 38r, bellowed pipes, checked and tested boost leaks until I was blue in the face, and was unhappy with its performance. The biggest boost leak i had ended up coming from the IAT sensor, between the brass and the plastic where the sensor was, and it took 15+ psi to show. I did replace it, and couldn't find another leak. No difference.

I went to a 366sxe and can't say enough good things about the swap. I can run a much hotter tune (and actually thr second hottest tune I have )
and still not exceed 1250* in any condition, empty or grossing 24k. With 238/100s, and a tired old motor at 280k miles. Judging off my experience with this turbo, I would not want to go any larger for the same or smaller injectors. I'm running a 1.0 exhaust housing, and run 1:1 up to 40 psi. Loaded doing testing I was able to make 15+ psi smoke free at 1500 rpms. The 369 May spool almost as fast, but unless you had it gated and ran a .9 housing, I fear your happiness may not be as great as mine is. But I could be wrong.

Having said that, most of my complaints in the 38R was feeling like it hit a plateau above 2100 rpm (which I've since learned was probably mostly because the gate was too tight), and the noise. It didn't spool badly, but it never came up as fast as my 366sxe. And that's important to me being a manual tranny.
 

lariat 7.3

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Just curious at what rpms are you having "egt" issues? Locked in OD at 60mph going 1700rpms?

unless im spinning 2200rpm plus its "falling" under the turbo. So it's either sit there at 65 spinning 2500 rpm+ or let it drop into OD and lug it AT 70+. Iguess its just the nature of the beast? I feel like im killing it running those rpms
 

mikeeg02

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unless im spinning 2200rpm plus its "falling" under the turbo. So it's either sit there at 65 spinning 2500 rpm+ or let it drop into OD and lug it AT 70+. Iguess its just the nature of the beast? I feel like im killing it running those rpms

Heres a couple of fun videos with a 366sxe, 238/100s, supporting mods and a 6 speed.

This is all heavily loaded (24k scale verified) But look at them gauges. Neither video exceeds 1200 degrees, and both are being stupid, pulling grades starting way low in rpms. The second video starts at 1500. Both were rolling in and smoke free. The first video starts a little higher in rpms, but gauge view is better.

https://www.youtube.com/watch?v=SZNacIg_cPY

https://www.youtube.com/watch?v=powB5VLW0_s
 

mikeeg02

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This one has boost:backpressure guage, red is boost, green is back pressure. Sorry for the amateur video recording. Hell I had to get a youtube and have someone show me how to use it to share them.


https://www.youtube.com/watch?v=OAdEvM3WVf8


All of these videos are on ge@rhead's #5 street fury. (Second highest file)

DRW, 3.73 gears, 235/85-16 tires.
 

psduser1

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This one has boost:backpressure guage, red is boost, green is back pressure. Sorry for the amateur video recording. Hell I had to get a youtube and have someone show me how to use it to share them.


https://www.youtube.com/watch?v=OAdEvM3WVf8


All of these videos are on ge@rhead's #5 street fury. (Second highest file)

DRW, 3.73 gears, 235/85-16 tires.
Stop it, you're killing me!:thumbsup::cool::mad::cool:
I think the options are way better on your platform, and I wish the sxe had been out when I put my truck together!
Lariat7.3- 2500 rpms isn't killing your truck, by any means. If you don't mind spending the money, there are better options out there, other than the 38r.
 

lariat 7.3

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Stop it, you're killing me!:thumbsup::cool::mad::cool:
I think the options are way better on your platform, and I wish the sxe had been out when I put my truck together!
Lariat7.3- 2500 rpms isn't killing your truck, by any means. If you don't mind spending the money, there are better options out there, other than the 38r.

i just want something that preforms well. It's amazing how well these newer trucks can pull the same loads effortlessly for the most part. I should've never driven one :drool:
 

mikeeg02

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i just want something that preforms well. It's amazing how well these newer trucks can pull the same loads effortlessly for the most part. I should've never driven one :drool:

Maybe I didnt make it obvious, but my truck is an '01, 7.3, 6 speed. And in that tune there isnt any condition (loaded or empty) I can make the truck exceed 1250*, loaded or empty, basically making my gauges not necessary and more for reference. With your 80% nozzles, it should be even cleaner then mine. If those videos dont make you want to convert, (seeing as your sig looks like you have all the rest of the supporting mods) then Im not sure what would.

And after all the performance gains, you can actually hear yourself think as compared to the 38R.

I have a S&B enclosed intake, and I sound deadened it as much as possible to quiet up the 38R. Dropping in the s300 really dramatically quieted things up. And then once I figured out a muffler combo to get rid of drone, its like a stock truck inside the cab. I couldnt ask for more, its my dream truck. :drool::drool: Specially now with my aluminum flat bed. Its my 500hp sleeper. :pullover:
 

lariat 7.3

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Maybe I didnt make it obvious, but my truck is an '01, 7.3, 6 speed. And in that tune there isnt any condition (loaded or empty) I can make the truck exceed 1250*, loaded or empty, basically making my gauges not necessary and more for reference. With your 80% nozzles, it should be even cleaner then mine. If those videos dont make you want to convert, (seeing as your sig looks like you have all the rest of the supporting mods) then Im not sure what would.

And after all the performance gains, you can actually hear yourself think as compared to the 38R.

I have a S&B enclosed intake, and I sound deadened it as much as possible to quiet up the 38R. Dropping in the s300 really dramatically quieted things up. And then once I figured out a muffler combo to get rid of drone, its like a stock truck inside the cab. I couldnt ask for more, its my dream truck. :drool::drool: Specially now with my aluminum flat bed. Its my 500hp sleeper. :pullover:

Oh it sure does make me want to swap over. If i tried that with the loads i pull, about 17k it would be 1400*+
 

mikeeg02

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With your injectors I'd do a 364.5 with the larger exhaust wheel (74mm IIRC) and a 1.0 housing. But that's my opinion. Based off my experience. You may get away with a 366 like I have, and I'm very happy with. I'm just unsure how our nozzles differ, and wouldn't want to suggest a turbo you'd be under more than not.

That being said, my 366 fits my injectors (238/100s), 6 speed and my driving style very well.
 

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