38r to sxe

[psduser1]

That sounds similar to mine empty. I may get a little better than that, but it usually picks up rpms. Loaded heavy and the right grade are what it takes to make 15+ at that low rpm. Though obviously I don't recommend that for anything other than testing. What turbo do you have under there anyways?

38r, 160/100%, zf6, 3.73, and 34" tires.
This wakes up about 1600 +/-. I'm usually towing at 21-2200 rpm. Fifth gear, or sixth, depending on the roadway (state hwy two lane or freeway).

 

[bigfords]

I thought so. But I couldn't remember. When I had my 38r, I think 4-5 was possible. But nothing more with out making a lot of smoke. Mine didn't really want to come to life closer to 17-1800 IIRC.

Mikeeg was both your 38r and 366sxe runs with the same tuning, I think you said GH last we talked.


Sent from my SM-G920V using Tapatalk

 

[mikeeg02]

Both had ge@rhead. I had both stock Injectors and 238/100 hybrids with this 38r. I got my best fuel mileage with stock Injectors and the 38r. Squeezed out 18.5 mpg once. Best with hybrids was 16 once. 15.5 avg. With hybrids and sxe I average 16-16.5.

My old truck was heavy. ~9k on average. And I drove it for about 200k after i put in a set of 175/146s and a 38r. It was a good running truck, but an auto. This manual truck didnt much care for the 38r. No tuning revisions on my daily file (#5) between turbos. My all out file got fixed, it had some excessive pulsewidth issues that needed dialed in. I didn't realize it until some time after the swap.

 

[lariat 7.3]

Are you happy dumping the 38r for the SXE? I'm not sure what size tires you were running with it but mine on 35's with 238/80s doesnt spool till about 2000 rpms. Just doggy in general. So now the debate is a 364.5 or a 366 and what housing, looking for spooling down low and cool egts

 

[mikeeg02]

You couldn't pay me to go back.

 

[lariat 7.3]

I can sell the 38r and associated stuff to recoup most of the cost. I'm tired of the lagginess and redic high egts.

 

[mikeeg02]

With the 35s, and if you prefer to tow between 60-70 mph, I would do the 365.4, 74mm, 1.0 housing and call it a day. Enjoy.

 

[lariat 7.3]

DD 90% yow 10% if even that much.

 

[mikeeg02]

I unless you're looking wanting those last couple potential horses, with 35s, I would stand by my above statement. The brad has almost the same setup and is thrilled with it. Only differences he has are 200/80s and a .9 housing if I remember correctly.

 

[CarportMechanic]

Are you happy dumping the 38r for the SXE? I'm not sure what size tires you were running with it but mine on 35's with 238/80s doesnt spool till about 2000 rpms. Just doggy in general. So now the debate is a 364.5 or a 366 and what housing, looking for spooling down low and cool egts

I dont wanna talk you out of an SXE turbo cause that is the rout id like to go eventually but I do believe you have sumthin going on if your truck dont spool til 2000 RPM.

On a 6% grade going 50mph in 6th gear kinda lugging it at 1500 rpm im pushing 8-10 psi unloaded. I do have a fair amount of haze lugging it like this but definitely not a thick black cloud. By 2000 rpm im in the 25psi range.

Your 238's should be building more boost.

3.73's on 35's

 

[mikeeg02]

I dont wanna talk you out of an SXE turbo cause that is the rout id like to go eventually but I do believe you have sumthin going on if your truck dont spool til 2000 RPM.

On a 6% grade going 50mph in 6th gear kinda lugging it at 1500 rpm im pushing 8-10 psi unloaded. I do have a fair amount of haze lugging it like this but definitely not a thick black cloud. By 2000 rpm im in the 25psi range.

Your 238's should be building more boost.

3.73's on 35's

8-10 @ 1,500 on a 38R is a good deal. I thoroughly leak tested everything on my truck, and couldn't quite get there. And that one came to life around 1,800. I agree that 2,000 seems a little high. Some have said over the years slight changes happened to the 38R, and some worked better than others too . Maybe I got a hungover Monday turbo. My old one worked similar, but on my old auto truck, it was harder to pay attention to spool up in normal driving. Unless in OD and lugging it.

 

[psduser1]

So I made my little trip.
Weights as listed above,I tried tried the low rpm pulls.
Fourth, fifth, or sixth, pretty much the same results.
Thousand rpm, flatfoot, it was a blackout, lol.
About 1300 rpms, it was definitely cloudy!
At 1500, there was a distinct haze.
At 1600, just a light haze, and clearing up, as rpms climbed.

Basically zero boost at a thousand rpm, at 1300, the needle was off the peg, and at 1600, it was headed to the sky, lol.
Didn't seem to matter what gear, by 1700, it was almost perfectly clear out back.
This is with a stock hpop, 100% nozzles, and Matt's tuning for reference.

Personally, 15 psi at 1500 means squat to me, unless a guy could turn that into 5 psi at 1000 rpms, because 5 psi was enough with my setup to clear up the smoke. I was gaining speed at 1000 rpms, it was just dirty! In other words the turbo was out of its effective range. If the sxe line can make boost at 1200 rpms, that's worth doing! And I'm genuinely interested, because this setup does have it's limits.

 

[The Brad]

What were the EGTs?

 

[LakeBum]

I just put a s364.5/74/.91 in with stock injectors. Have no issues spooling, building boost or EGT issues. Worth every penny.

 

[psduser1]

Never over 1250.
Granted, these weren't long steep grades, just relatively short pulls. Thirty seconds to a minute and 1/2 or so. By then, rpms were near 1900-2k, and outside the questionable rpm range, so to speak.
I don't think there is enough fuel commanded to worry about below 1800 rpms, in my experience.
With a decent mid, or big oil setup, smoke would be much lighter, as well, fwiw.

 

[ghohouston]

I do not understand the 38r complaints, other than noisy. There has to be another underlying issue imo. Leaking up pipes, leaking boots/intake plenums, up pipe to turbo not fully flush with each other, bad map sensor, ****ty aftermarket comp wheel, etc. SOMETHING has to be up. 38r's may be old technology, but they are tough, good working turbo's.

 

[superpsd]

Well look at this way. Quite a few including Irate says the S369sxe alone spools about as fast as a 38R. Considering the sxe flows a ton more air and a larger compressor wheel to let a large diesel breathe. It's a simple no Brainer improvement. More air and Less backpressure equals lower EGTs and More power plus less chances of overpowering an exhaust valve spring.

 

[LakeBum]

SOMETHING has to be up. 38r's may be old technology, but they are tough, good working turbo's.

You nailed it, they are simply that...old technology. Unfortunately until one has jumped to an sxe and seen (not heard) the difference in what it can do, one wont understand.

 

[LakeBum]

But I can't tell you how they compare exactly to a genuine SXE t4 turbo because we have not tested it back to back. And even if we did then there would always be the "nay sayers" about how something was not done right, tuning wasnt right, probably had a boost/exhaust leak, etc (on both sides)

Thoughts on sending The Brad, Mikeeg02 or the likes (with tried and true sxe experience who left a 38r for greener pastures) a turbo, pedestal and up pipes for the back to back comparisons?

 

[psduser1]

I do not understand the 38r complaints, other than noisy. There has to be another underlying issue imo. Leaking up pipes, leaking boots/intake plenums, up pipe to turbo not fully flush with each other, bad map sensor, ****ty aftermarket comp wheel, etc. SOMETHING has to be up. 38r's may be old technology, but they are tough, good working turbo's.

I tend to think that, as well.
Definitely a solid turbo.

You nailed it, they are simply that...old technology. Unfortunately until one has jumped to an sxe and seen (not heard) the difference in what it can do, one wont understand.

Sounds awfully condescending, lakebum.
I don't think anyone would say the 38r is better than a newer design. Anyone who spends anytime researching their turbo purchase , both on paper, and in action will agree that the sxe outflows the garret. That is a fact.
Doesn't mean the garret doesn't have it's place in the world.
I find it ironic that tuning problems are often chalked up to "each truck is different", get that rationale goes out the window when hard parts issues come up, lol.