my moose boost spools quick. not that i have low boost but with a bigger pump i would think mid to high 20 psi range is doable.
Turbo talk
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david85
Full Access Member
I'm no expert at this point, but 0.7 compressor side seems to be pretty common among the established IDI kits. Exhaust A/R can be around 0.7 for wastegated, while .85 and up are seen in non-wastegated kits.
Right now, I have my eye on a 0.7 compressor and 0.63 turbine GT35 turbo but I'm not ready to pull the trigger yet. They can be had for fairly cheap though.
Right now, I have my eye on a 0.7 compressor and 0.63 turbine GT35 turbo but I'm not ready to pull the trigger yet. They can be had for fairly cheap though.
david85
Full Access Member
Running the numbers for your setup (7.3L, 3000RPM redline), it would show peak efficiency between 2400-2500 RPM with 26.5 PSI @ 2500. Now this is all still theory, and under ideal conditions, which presumes enough fuel/exhaust flow to permit this kind of boost.
The MooseBoost turbocharger also seems to have an unusually wide efficiency island compared to other turbochargers out there.
Do you have any numbers for how much boost you have at say, 1500RPM, 2000RPM, 2500RPM? I'm curious to see if my numbers are anywhere near the ballpark.
this is a pretty good write up on the turbo i have.
https://www.oilburners.net/threads/introducing-moose-boost.64346/
https://www.oilburners.net/threads/introducing-moose-boost.64346/
FordGuy100
Registered User
A/R is just a ratio and varies with housing sizes. A .7 AR T3 housing is different from a .7 T4
Y’all need to be easier on yourselves, years of testing and plenty of products already exist that match our displacement. Look at what the 7.3 psd market uses and read the reviews that those guys have on different turbos. Do you see 7.3 psds with hx35 swapped on? What about hx40s? No need to go into unfamiliar ground when there’s an almost identical displacement engine that has a ton of aftermarket out there.
Ever heard of timesrts? They work great for larger studs. I did a bbc427 7/16" to 1/2" studs. Super strong.
Iin the lower compression subject I built and olds 350 DX, remember those?: They are also IDI engines,
I took .062 thousands off the pistons. Turbocharged it. Was around 16.5 to one ran great. Started easy. It was in a Chevy half ton pickup,turbo 400. It would fry the tires.
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Iin the lower compression subject I built and olds 350 DX, remember those?: They are also IDI engines,
I took .062 thousands off the pistons. Turbocharged it. Was around 16.5 to one ran great. Started easy. It was in a Chevy half ton pickup,turbo 400. It would fry the tires.
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vegas39
Full Access Member
I had an olds diesel about 20 years ago, would love to find another one.
I get a kick out of how many people to this day, still think it was a converted gas motor. It was not! It was built on the same assembly line as the gasser to save money on tooling, hence the reason it is darn near identical. It's also the reason it didn't end up with enough head bolts.
If GM would have thought a few little things through, I feel it would have ended up being a great motor.
7.3s came with 1/2” head bolts from the factory. If you’re going to upgrade to a different thread size on a 6.9 then doesn’t make sense to go with anything other than the 7.3’s thread. Already been proven that you don’t need to decompress these engines and doing so is very detrimental to their performance. You’re comparing apples to oranges here
david85
Full Access Member
I used to rag on those 5.7 diesels as much as the next guy but I'm starting to soften my stance a little. Still not enough head bolts, but at least it was all iron, unlike some of the V6 Diesels GM offered with pot-metal heads (yes, I realize aluminum heads can be done right, but GM didn't get it right!).
Once in a while I've seen guys on YouTube building them up and 5-10 PSI is the most I ever heard of.
Macrobb
Full Access Member
As far as up-sizing the 6.9 head bolts, the problem is simply drilling the hole... straight. Yes, if you have a mill big enough, it would be easy, but that's expensive. The goal, therefor, would be to come up with a way to do it with a small drill press or hand-drill.
Talk is cheap bro, horsepower...
Not so much. I had a long conversation with R&D on this subject, he is one of the most knowledgeable guys out there on building Idi engines, he has one that's up in the 400 how range. And it took a Lot to get it there. Have you looked up the prices of his parts??? While they are reasonable for the quality of the components, it's in no way cheap. You will never get an honest 250 HP to the ground with a stock turbo and a 110 pump. It takes a serious parts list to get there.
Pump, injectors, cam, a good turbo,degree the cam (advanced)
Manifolds,intake and exhaust, charge air cooler, valve springs and retainers etc. Studs for the heads which are over 500$. Then the stock rods are questionable at that power level.
A set of reworked power stroke rods will fixtures that with machine work.
Another 600$. Chaching. His turbo kit is $3999. It's all there, but you still have machine work and labor to add up.on top of the required parts list.
I am considering this set up for my 88 7.3. parts alone are over 7K. My point is this, for that kind of money a guy can buy a 6.0 delete the egr, add some tuning, and have way more power for the same investment.
If you doubt my word call R&D yourself. Have a realistic conversation with the man that has done all the real world testing and development of IDI performance.
Not a shade tree hotrodder.
He has all the Dyno results from years of experience and failures.
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Not so much. I had a long conversation with R&D on this subject, he is one of the most knowledgeable guys out there on building Idi engines, he has one that's up in the 400 how range. And it took a Lot to get it there. Have you looked up the prices of his parts??? While they are reasonable for the quality of the components, it's in no way cheap. You will never get an honest 250 HP to the ground with a stock turbo and a 110 pump. It takes a serious parts list to get there.
Pump, injectors, cam, a good turbo,degree the cam (advanced)
Manifolds,intake and exhaust, charge air cooler, valve springs and retainers etc. Studs for the heads which are over 500$. Then the stock rods are questionable at that power level.
A set of reworked power stroke rods will fixtures that with machine work.
Another 600$. Chaching. His turbo kit is $3999. It's all there, but you still have machine work and labor to add up.on top of the required parts list.
I am considering this set up for my 88 7.3. parts alone are over 7K. My point is this, for that kind of money a guy can buy a 6.0 delete the egr, add some tuning, and have way more power for the same investment.
If you doubt my word call R&D yourself. Have a realistic conversation with the man that has done all the real world testing and development of IDI performance.
Not a shade tree hotrodder.
He has all the Dyno results from years of experience and failures.
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Your right on the smoke on a cold start David, it's a trade off though. I had a luminosity probe timing meter that went into the glow plug hole, so it was possible to get your fuel pump timing dialed in. With some degreeing of the cam and advanced fuel timing that took care of a lot of the smoke on start up. It would have some until you RPM it up a little, and water temperature comes up. But once warm it is much quiter, more responsive, and then you can build some serious boost. Diesel power is all about airflow. Lower compression let's you cram a lot more air in the cylinder, then you can give it more fuel.and.... it takes a lot of stress off of the crank and rods . Balancing the receip assy can do wonders for power and reliability. I've built both 5.7 &6.2 gm engines using this same stategy. And it really makes them up.
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79jasper
Chickenhawk
I think macrobb knows plenty about r&d's products. Lol
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