Building compounds

Back woods · Mar 18, 2017

Hello everyone, new here but not new to 7.3s. Have a 95 powerstroke I would like to build some mile towing compounds for. I've got a 2000 7.3 parts truck that I plan on robbing parts from. Planning on swapping the IC, plenum, spider and turbo. Turbo is stock GTP38 with a WW2 and ATS ported housing. Going to port the internal WG and cross port the divider. Not looking to make over 425hp. Yes that is easily obtained with a good single but I want to build compounds. Stock injectors for now but will likely swap a 17* pump, super duty injectors or possibly 160s.

Trying to decide which atmospheric turbo to use. This is a budget build so I have 3 turbos in mind. All eBay off brand China copies. S475 1.32 AR. K31 billet 1.32 AR or a Holset HT60. Feel like the K31 would fit the bill the best but am slightly unsure. Looking for fast spool and boost under 40psi.

threegenpowerstroke98 · Mar 18, 2017

There's a guy hanging around the forums who used a garret 4202 over top the tp38 with beans 180/100 and tuning who did about 425-450 if I remember right. keep in mind that stock turbo don't like over 25-7 ibs of boost so using a stock turbo as a primary will be a limiting factor. Also when fueling you're looking at about 2-2.2-1 hp-cc of fuel ratio so keep that in mind when choosing injectors.

emev0l · Mar 20, 2017

I don't think it's worth it, BUT, I wouldn't mind seeing you try triple stock turbos.

08strokin · Mar 20, 2017

sub'd

euroford · Mar 21, 2017

Most of the threads i've found discussing compounds on the 7.3 have devolved into bunch of posts just saying "your stupid, put a T4 on it and be done", but I honestly see some validity to the concept. Especially if your a DIY guy who's going to do all of your own fabrication. You might just be able to get a lot of air in that motor for a fairly minimal investment, and i know i'd have fun just doing the tinkering and fab work.

Very interested in following your build progress, it would be great if you can post some photos and etc. as you go through the process.

I can envision how most of this could be laid out pretty reasonably, mostly i'm curious about where your source oil pressure and drains for the atmospheric turbo.

Making something like this, especially with your low-ish boost goals, you'll want to have good control over the wastegates. I'd prowl around ebay for a used HKS or Greddy electronic boost controller, they are pretty cheap and even the older ones work very very well. I've been using and HKS EVC3 for about a year now and its a great gadget that I scored for under $200. I'm surprised more diesel guys don't use these.

threegenpowerstroke98 · Mar 21, 2017

I've done some gogling out of curiosity and it seems like the holset has been done before with the stocker. s475 would be a good turbo too, lots of support for anything borg warner. I would suggest waste gating around the tp38 though so as not too risk over spooling it. If you haven't already you should read into the turbo maps of the turbos and find which ones best compliment the turbo map of the stock turbo. Also head studs might be something you might want to consider. simple peace of mind.

Back woods · Mar 21, 2017

Not 100% sold on this but I may run a GTP38 with a ported internal gate. If not I am leaning toward an external gate on the TP38. Unsure if the 1.15ar would be worth it though.

mtsnowrunner · Mar 21, 2017

S364.5 SXE and done. Make 450-500 HP easily and do anything you want with it.

bruce · Mar 22, 2017

An s362 with an s480 would be pretty cool but no way I'd mess with a stock turbo.

JDelaney · Mar 22, 2017

mtsnowrunner said:
S364.5 SXE and done. Make 450-500 HP easily and do anything you want with it.

That right there is hard to argue with!

superpsd · Mar 22, 2017

If you are going to use the TP38 I would upgrade to the 360° bearing.

emev0l · Mar 22, 2017

bruce said:
An s362 with an s480 would be pretty cool but no way I'd mess with a stock turbo.

A 62 alone would probably be enough lol, a s362 with a T6 s475 would be more then plenty. Sounds like he's looking for super low budget though.

emev0l · Mar 22, 2017

Used T6 s475 for sale in the classifieds right now for $500

http://powerstrokearmy.com/forums/showthread.php?t=77296

euroford · Mar 23, 2017

superpsd said:
If you are going to use the TP38 I would upgrade to the 360° bearing.

Agreed. I think the 360deg bearing is a great upgrade. Inexpensive, easy, good maintenance that a stock turbo probably needs anyways, and at least in my experience appears to solve many of the issues with the TP38 turbo's.

I rebuilt mine with a 360 deg.kit that i scored on amazon for $36 bucks, along with a WW2, ported 1.0 housing, turbosmart actuator and electronic boost controller. I've been beating on it for about 50,000 miles since I went with the bigger hybrid injectors and it sees 30-35psi 50+ times a day and 45-50psi when i hit the drag strip a couple times a year.

I'm not saying the TP38 is any kind of great turbo, its not, but i've come around to think the 360deg bearing upgrade might solve its worst weaknesses.

I didn't expect that turbo to last very long, but its actually served me well and spools really quick on my ZF6 truck.

thatdude · Mar 26, 2017

threegenpowerstroke98 said:
There's a guy hanging around the forums who used a garret 4202 over top the tp38 with beans 180/100 and tuning who did about 425-450 if I remember right. keep in mind that stock turbo don't like over 25-7 ibs of boost so using a stock turbo as a primary will be a limiting factor. Also when fueling you're looking at about 2-2.2-1 hp-cc of fuel ratio so keep that in mind when choosing injectors.

I made more than that with the same injectors and a modified H2E. That's horrible

Back woods · Mar 27, 2017

Mocking things up with an old H2D. Thinking about going with an Hx55.

threegenpowerstroke98 · Mar 27, 2017

My suggestion would be to put it over where the old passenger side battery is with the intake directly off the turbo and put the battery behind the drivers side battery where the intake is currently. Way more space and less lines in the way. That's always how I had imagined doing it.

Back woods · Mar 27, 2017

Shooting for minimal under hood modifications to fit the second turbo.

pwrstrk01 · Mar 29, 2017

I had a tp38/gt4202 twin set up on my truck made 472/860 @ 1200* liked it a lot. changed out the 4202 for S475 that set up worked great too. now I have a GTP38/S475 setup. I have ran .84 1.0 and 1.15 exhaust housing, no waste gate, cross drilled a 1.0 gtp38 factory style waste gate, a 38 mm waste gate, a 44 mm waste gate, gated the atmospheric turbo. I have played with this set up a lot of different ways, listened to a lot of people say that their singles will out perform it, they made more power with a single blah blah blah... I now have a GTP38, with a billet WW2, 360* thrust, 1.0 housing and a 38mm external waste gate and a 475 with a billet wheel, 360* thrust, 1.25 T4 exhaust housing and I finally upgraded to 3 inch intakes. I haven't had this truck on a dyno in 4 years so I have no idea what it is making for HP, but I know that this set up is the best it has ever ran. makes 45 psi boost and 48 psi drive pressure. I can put a truck on my 30ft flat bed and pull anywhere I want in MT and not have to worry about looking at the pyro..EVER! now I didn't build this truck for all out horse power I built it to tow and it does that very well. I will also add that if you are just looking for towing set up GTP38 (with a cross drill factory waste gate on a 1.0 housing)/475 set up will do really well until you get over 30-35 boost then the back pressure climbs very quickly to 60+. Also the 3 inch intakes help tremendously with off idle power, don't mess with any factory ones save some money and buy a set from irate. I think that's about it let me know if you have any questions I will try and get some pictures up in the next couple weeks

thatdude · Mar 30, 2017

threegenpowerstroke98 said:
My suggestion would be to put it over where the old passenger side battery is with the intake directly off the turbo and put the battery behind the drivers side battery where the intake is currently. Way more space and less lines in the way. That's always how I had imagined doing it.

agreed on the turbo location but I would actually move both batteries to the frame. There's plenty of room to do so.