Too much boost?

[Lt.Dan]

Hey guys, I've been doing a lot of reading about future mods for myself, injectors and turbo to be specific. Reading into what injector I want to step up to, and what turbo to match with said injector. I think I've decided on a 180/30 or 200/30, and a KC38r to go with it. But then started looking into how big of an injector to go with the stock turbo, and I stumbled upon some guys saying the stock turbo shouldn't be pushed past 25psi? Some saying dont go past 35psi? And some saying 40psi will make it come apart pretty quickly?

I've got stock AB injectors, all in great shape (had them all bench tested), with the stock turbo with the WW2 and a 360* rebuild kit, and a stock HPOP. (I just ordered a T500 pump last week). And in the 80hp tune from PHP, (their canned tunes) I have seen it build 34psi of boost repetitively, unloaded, on flat ground.

Now, am I already pushing the stock turbo with stock injectors? Seems like I need to do a turbo before I do anything else...

What do you guys think?

 

[rusty1161]

The 38R won't mount up to an OBS without new plunums, wye, pedestal, I/C pipes, up pipes and downpipe, at the least. For my money, and what I did was go T4 SXE turbo and an Irate kit. This gives you more options for turbos and probably is pretty dang close price wise. And no chasing parts on Craigslist or the classifieds. Irate has one sale a year at Thanksgiving if you want to save the most dough.

Rusty

 

[Lt.Dan]

KC Turbo makes a bolt in KC38r for the OBS now.

https://kcturbos.net/collections/7-3-powerstroke/products/94-98-obs-kc-tp38r-turbo

I'm just curious more about the stock turbo than the upgrades though. I know the uprgrades wont happen for quite some time.

 

[rusty1161]

KC Turbo makes a bolt in KC38r for the OBS now.

https://kcturbos.net/collections/7-3-powerstroke/products/94-98-obs-kc-tp38r-turbo

I'm just curious more about the stock turbo than the upgrades though. I know the uprgrades wont happen for quite some time.

I forgot about that one. Sounds like a good setup, especially if you intercool it.

You should be fine with you stock turbo/injectors. I'd be more concerned with EGT's than too much boost with your upgrades to the turbo.

Rusty

 

[Lt.Dan]

My EGT's right now are somewhat manageable. But i wont know for sure until i get my T500 pump in, and get it hooked up to a trailer. Right now with the stock pump, its throwing a code for low ICP, and EGT's get up to 1100* pretty fast, and then creep up higher and higher until i lift my foot out of it. I can get it to 1400* pretty easily, but I believe the low ICP is the cause for that. If its not, im going to try and piece together and intercooler kit for it.

So if I go to a 175/30 injector with the stock turbo, will it create too much boost for it to handle? And what about the motor itself? It maybe be rebuilt with new gaskets and head bolts, but no studs. The motor is only good for about 40psi right? Or am i thinking about this the wrong way? Will the turbo still only spool around the same even with a bigger injector?

 

[Magnum PD]

Why no head studs? You can run the turbo like your doing just worry about longevity

 

[Lt.Dan]

I didn't see the need for them at the time. Before the motor went out, i was lucky to see 23psi, loaded, going up a hill, so I thought even with more mods I probably wont get up into the high 30's. But I guess that was the wrong thinking, hahaha.

How long do you think the turbo will last being used the way it is? And what If I stepped up in injector size as well?

 

[Magnum PD]

Just depends on how hot the turbo gets and how well balanced it is. Some People haven't had long term luck with the WW2.

 

[Lt.Dan]

Do you mean how hot the turbo gets, as in EGTS being high, or oil temp being high? Or a combination of both?

I never had mine balanced as it said they came "prebalanced" should I pull it and have it done?

I guess A turbo rebuild isn't really that hard, or expensive, assuming it's not catastrophic.

 

[Magnum PD]

EGT's.

Pushing the turbo beyond its limits is on borrowed time

 

[Lt.Dan]

So what would you recommend is a safe EGT range? I'm guessing it's lower than 1250*? That way I at least can get as much life out of it as I can.

Thanks for all the help bud

 

[Magnum PD]

That's doable.

 

[superpsd]

I have never seen my Pyro beyond 1200° but I also do not tow heavy. Hotter tempatures makes things cracks like the injector cups.

 

[MeTo]

I have never seen my Pyro beyond 1200° but I also do not tow heavy. Hotter tempatures makes things cracks like the injector cups.

Unless you drive like an old women or your Pyro needs calibrating? I say BS. Have you actually tested it's accuracy?

When was the last time anyone has heard of anyone testing and calibrating the accuracy of their Pyros? Or have checked
the margin of error (independent and combined) in their readout and thermocouple?

Mine was off by -83 F. For fun, I compare the temp indicated on my EGT readout and the outside temp on the overhead console,
when I start it for the first time each day.

 

[Jomax]

My max egt I'd let it get to when I had my 7.3 towing was 1350.


Sent from my iPhone using Tapatalk

 

[MeTo]

It's not uncommon for pullers or drag racers to see 1600, but we are talking seconds here.

 

[Lt.Dan]

Yeah, I do know that aluminum does begin to MELT at 1250*. Now at 1250*, it does take a long time, but it will happen, so the higher the temp, the faster it will. Thats why pullers are getting to 2000* for a couple seconds without much damage (that they know of).

Unless you drive like an old women or your Pyro needs calibrating? I say BS. Have you actually tested it's accuracy?

When was the last time anyone has heard of anyone testing and calibrating the accuracy of their Pyros? Or have checked
the margin of error (independent and combined) in their readout and thermocouple?

Mine was off by -83 F. For fun, I compare the temp indicated on my EGT readout and the outside temp on the overhead console,
when I start it for the first time each day.

How do you calibrate a pyro? Mine is probably off lol

 

[superpsd]

Unless you drive like an old women or your Pyro needs calibrating? I say BS. Have you actually tested it's accuracy?

When was the last time anyone has heard of anyone testing and calibrating the accuracy of their Pyros? Or have checked
the margin of error (independent and combined) in their readout and thermocouple?

Mine was off by -83 F. For fun, I compare the temp indicated on my EGT readout and the outside temp on the overhead console,
when I start it for the first time each day.

The only checking I had done was at idle with an uncalibrated IR thermometer. The Pyro kit is a few years old Autometer. When I have seen 1200° I typically ease up. Usually pulling the passes lighty towing I see those numbers. If I had hooked 10K up and pulled I am sure it would be higher. Ive been making changes to SOI and have been able to make huge changes in how it drives, how hot it gets, and how the turbo spools...I have yet to tow much with the S369. As for SOI or timing I found having an aggressive timing map increases noise of course as well as drastically lowering EGTS at the expense of not enough hot gas to drive a larger turbo. Too conservative timing caused hot EGTS and great spool up. Too much aggressive timing created black smoke and too little Grey haze clouds upon throttle in. Start getting the timing just right and the sucker spools Great with reasonable EGTS and is pretty clean out the pipe as well as nice response and reduced noise. Running the 200% nozzles has been cooler running then the stock nozzles.

Also no I don't drive like an old woman. The all aluminum 12' camper trailer I built usually weights about 2K once loaded up. Although the aerodynamics of a brick (I will be adding a rounded nose) With that trailer I can pull the passes at 70/80 easy constantly passing truck after truck that are pulling mammoth campers that have them pulling at 60/65. My thermostat cracks open at 176° with the IR thermometer and my EOT hangs around 180°. Pulling hard long grades it will climb to 210° EOT

 

[thatdude]

I have never seen my Pyro beyond 1200° but I also do not tow heavy. Hotter tempatures makes things cracks like the injector cups.

That's pretty cool. I've seen past 1500 a few times. Only issue I had on that engine was valve float and a few cracks on 4 of the fuel bowls but that's a pretty normal 7.3 problem. Still made good compression before I ripped it apart.

 

[Lt.Dan]

So to bring back up part of my original post, Now i've got the T500 installed, with some Swamps custom tunes in it. And in the extreme mode, I'll see it peak at almost 38psi. Towing a small trailer in the light tow tune, in 3rd uphill It stays a steady 24psi at 65mph.

Is it normal to see this much boost with stock injectors and a pretty much stock turbo? Not exactly sure what is going on, but I'm reading all over that guys with the exact same mods, if not more, are struggling to get 25psi?