Different Turbo's???

bigblu78 · #1 (**permalink**) 10-02-2006, 08:02 PM

I know about all of the kits that are out there for the 6.9 and the 7.3. What about fabbing up your own turbo set up??? I know that a lot of fabrication would be needed, ie manifolds, mounts, exhaust, etc... But how possible and how logical would it be? The reason I am asking is because I have all the means to fabricate the system but I lack the knowledge needed in turbo-charging a 7.3. I would hate to blow my truck up because of something stupid.

What kind of boost can be run?
Is an itercooler needed?
What are safe EGT temps in a 7.3?
What is spooling and how does this different in turbo's?

Thanks guys...

brownieboy525 · #2 (**permalink**) 10-02-2006, 08:25 PM

this is just my oppinon but i think you would be better off with just buying a whole turbo kit. with the amount of time youll spend on fabing everything and hunting down parts plus the individual pieces you need will probably run you about the same as a kit. with a turbo kit safe boost is no more than 12psi. an intercooler is not needed with only 12 psi when you start building higher boost than an intercooler is needed. Egt should be less than 1200 degrees above that and you start to melt down pistons.

Dave Sponaugle · #3 (**permalink**) 10-02-2006, 08:32 PM

I would keep the boost under 15 PSI on a stock 7.3 engine.
An intercooler is not needed.
Pistons start to melt at 1250 degrees, so 1100 or 1150 is about tops except for very short times.
Spooling is the turbo winding up to higher RPM's which creates more boost.

Several people have asked about building their own turbo setups, one guy did it and blew his up.

Several of the parts for the turbo mount and exhaust would be rather hard to make.
My ATS has a cast piece for the mount that does double duty routing the oil back into the engine from the turbo.
Also the up pipe to the turbo from the exhaust manifolds is in a tight place, that would also be hard to fab up given the clearance around the area you have to work in.

bigblu78 · #4 (**permalink**) 10-02-2006, 08:33 PM

I know the kit is the best bet for simplicity. I have a couple of good turbo that I have gotten off of wrecked trucks from work. This is what has brought up this idea to fab up a system. I know the basics of turbos and how they work but I don't know the do's and don'ts of getting this to work on my truck.... I am afraid of not getting enough oil to the turbo, producing too much boost etc....

Thank you for the number that you have given. One question, is going over 12 psi of boost a engine killer without an intercooler or is it that the 7.3 with stock specs just not able of handling over 12 psi??? I thought the intercooler was just a method of helping cool down the charged air... Also.. is the only way to control boost via wastegates?

brownieboy525 · #5 (**permalink**) 10-02-2006, 08:59 PM

even with an intercooler over 12- 15 psi will hurt your motor. its not the heat its that the compression ratio is so high. an intercooler does drop the temperture of the boost but thats not the issue with running over 12-15psi

bigblu78 · #6 (**permalink**) 10-02-2006, 09:37 PM

I appologize for the lack of knowledge I have here... I have read and read but I am finding that of course every set up is engine specific.... So here is what I have...

I have a Switzer turbo (do not know the model without going out and looking at it) that I have found will put out up to 22 psi of boost. Now.. to play it safe, i would like to cut this down to say 10 psi of boost. This is done via the wastegate correct?? Or is this impossible to lower the boost... This turbo also has two places for lines to be installed. I assume that this is oil inlets and outlets... Next question.. Is it safe to assume that I can connect the inlet line to an oil port on the motor and plumb the return line to the oil pan? Or do I need to pump oil to the turbo??

The exhaust fabrication will be tuff but doable.

Now for this other little killer... EGT's

If all of this was to work and I was able to get everything set up and working pushing 10 psi of boost and my EGT's get really high... How can you go about getting them lower???

I would love the challenge of putting this together and pulling it all off. Maybe impossible but sitting on these turbo's and still having my lathargic (sp) IDI is getting to me.

Thanks for the helping me out here guys. I may sound a little nuts and ignorant here but I am a firm believer that more pride can be takin in building rather than buying..

brownieboy525 · #7 (**permalink**) 10-02-2006, 09:50 PM

the questions about the turbo i can not answer. but the question about lowering egt all you have to do it take your foot out of it.

bigblu78 · #8 (**permalink**) 10-03-2006, 09:04 AM

Thanks for your help brownieboy525. I am going to look into the turbo's I have some more this evening and see what I can come up with as far a numbers...

Spectramac · #9 (**permalink**) 10-03-2006, 12:13 PM

What are these turbos off of? Unless the engine was similar in size it most likely won't work. I'd look for one off a DT466 IH if I was trying this from scratch. There may be some others from smaller engines that could work too. I wonder how 2 (or 3) old 2.3L turbos would look under the hood?

I guess you could rig up a blow off valve instead of a wastgate if that was easier.

You are right about the oil plumbing. Just run a line from the engine and then dump it back in. You just have to make sure the dump line goes downhill the hole run so it flows well. That way oil won't back up in the turbo and start to smoke.

bigblu78 · #10 (**permalink**) 10-03-2006, 02:52 PM

One of the turbo's is off of an older Kodiak truck that had a small CAT motor... The other is in fact off of a DT466. I would love to put the entire 466 in my truck but there is just not enough room and trans/transfer case issues really hold you back. (Maybe a future project.) Like I stated before, I know that I can buy a kit and be good to go but I would much rather fab up a system. I have driven a couple 7.3 idi's that have had the Banks kit and I was not at all impressed. Don't get me wrong, there was a great improvement but I believe that more can be done. The truck that I am putting this on is not a daily driver but I would like to keep still keep the reliability up. Therefore I am trying to keep in the "Safe" zone as far as boost and EGT's

lumbermansvo · #11 (**permalink**) 10-03-2006, 08:20 PM

Quote:

Originally Posted by Spectramac

I wonder how 2 (or 3) old 2.3L turbos would look under the hood?

The 2.3L guys are putting Holsets o their cars now. They get them off the Dodge Cummins engines.

One guy had his SVO running with a VNT turbo of a 6.0L PSD. He took it off before he started his Volvo DOHC head swap. The turbo will make its way back on after the Volvo swap. He plans to make kits for both the Volvo swap and the VNT turbo w/controller.

Dave Sponaugle · #12 (**permalink**) 10-03-2006, 11:24 PM

You will need to add both a boost gauge and a pyrometer.
Larger exhaust and no muffler helps to lower EGT's.
Cool air helps to lower EGT as well.

ATS relocated the oil pressure sending unit and gets the oil supply there for the turbo.
They also relocate the CDR and use the hole in the valley pan where the CDR was for the oil return.

High boost will take out your head gaskets first most likely, 12 pounds of boost on a 7.3 raises the compression ratio to 39 to 1. New head gaskets and head studs let you run more boost, milling the pistons down to lower the stock compression ratio lets you run even more.

That does get expensive though.