BD Diesel Turbo on 7.3L Power Stroke
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The Garrett GT38 turbo that came installed by the factory on most 7.3L Power Strokes works fine for completely stock rigs. But the minute an exhaust, intake and a healthy tune is added it runs into problems. Under heavy load the turbo surges and the wastegate simply isn’t strong enough to control the boost. This surging puts excessive lateral load on the rotating mass which beats up on the bearings eventually leading to turbocharger failure.

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THE FIX

BD Diesel has a fix for this in the form of their Turbo Thruster II. BD’s charger features a 33 percent larger than stock, has a 66/88mm 12-blade compressor wheel and a ported compressor housing to increase flow and control surging. The ball bearing center housing with BD’s sintered brass 360-degree six-pad thrust bearing reduces spool time while increasing service life. To control the added boost BD uses a larger and more robust wastegate controller.

The Turbo Thruster II GTP38 is available in two versions; one of which is California emissions compliant. The only difference between the two turbos is the turbine housing’s AR. The California legal version simply has a tighter AR (0.84 vs 1.0) for increased low rpm boost.

1. BD Diesel Performance’s Turbo Thruster II GTP38 for the 7.3L Power Stroke.

1. BD Diesel Performance’s Turbo Thruster II GTP38 for the 7.3L Power Stroke.

2. The Turbo Thruster II GTP38 features a larger, ported compressor housing for increased flow and to control surging.

2. The Turbo Thruster II GTP38 features a larger, ported compressor housing for increased flow and to control surging.

Turbo Thruster

3/4. BD Compressor Wheel and Housing vs. Stock Compressor Wheel. Equipped with a 12-blade, 66/88mm compressor wheel, the BD turbocharger flows more air and won’t surge like the stock one will. Looking at the new BD wheel compared to the stock wheel it’s amazing to see how far turbo technology has come in the last 13 years.

3/4. BD Compressor Wheel and Housing vs. Stock Compressor Wheel.
Equipped with a 12-blade, 66/88mm compressor wheel, the BD turbocharger flows more air and won’t surge like the stock one will. Looking at the new BD wheel compared to the stock wheel it’s amazing to see how far turbo technology has come in the last 13 years.

5. BD offers this turbo with one of two exhaust housing ARs. Simply speaking, the lower the AR is, the faster it will spool. But while the 0.84 AR turbo spools quickly, it will won’t perform as well as the 1.0 AR will on the top end. Unless you spend all your time in stop and go traffic, we recommend the 1.0 AR.

5. BD offers this turbo with one of two exhaust housing ARs. Simply speaking, the lower the AR is, the faster it will spool. But while the 0.84 AR turbo spools quickly, it will won’t perform as well as the 1.0 AR will on the top end. Unless you spend all your time in stop and go traffic, we recommend the 1.0 AR.

UNEXPECTED UPGRADE

Adding this turbo to this particular 7.3L has been on the list of modifications for quite some time but two days before leaving for the SEMA show we heard a “chirp” from under the hood while passing a semi-truck. Upon further inspection the factory installed GT38 had failed and the compressor wheel was rubbing on the compressor housing. With roughly a quarter-inch of play from the rotating mass, our hands were forced. Time for that new turbo we’d always wanted!

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BD’s charger features a 33 percent larger than stock, 66/88mm 12-blade compressor wheel.

We called up BD and had them overnight us a Turbo Thruster II. As soon as it hit the front door we headed down to our local truck shop, Pick-Up Parts in Mission Viejo, California, and started tearing apart the 2001 Power Stroke. It was a crazy rush to get it done and we made it with just enough time to load the truck and leave for the SEMA show. DW

6. Removal of the stock charger requires removal of about a dozen parts and can be done with simple hand tools.

6. Removal of the stock charger requires removal of about a dozen parts and can be done with simple hand tools.

7. The first part we removed was the turbo inlet tubing and air intake.

7. The first part we removed was the turbo inlet tubing and air intake.

8. We found it much easier to remove the crankcase breather assembly and turbo inlet tube together rather than fighting to compress the rigid inlet tube to get it out from between the turbo and breather.

8. We found it much easier to remove the crankcase breather assembly and turbo inlet tube together rather than fighting to compress the rigid inlet tube to get it out from between the turbo and breather.

9. Next the MAP (Manifold Absolute Pressure) sensor and bracket were removed using a 10mm socket wrench. Pulling the two together allows for much needed room to remove the cold side intercooler pipe. At this time we also disconnected the water methanol injection lines as well as boost signal lines for the trucks gauges.

9. Next the MAP (Manifold Absolute Pressure) sensor and bracket were removed using a 10mm socket wrench. Pulling the two together allows for much needed room to remove the cold side intercooler pipe. At this time we also disconnected the water methanol injection lines as well as boost signal lines for the trucks gauges.

10. Intercooler boots came next. Pulling the individual intercooler pipes is tricky and requires creative thinking. We found it easier to slide the cool-side tube forward and down below the intercooler outlet, rotate it 45 degrees counterclockwise and then remove. Note: Full removal of the intercooler pipes is not necessary but allowed us more room to work.

10. Intercooler boots came next. Pulling the individual intercooler pipes is tricky and requires creative thinking. We found it easier to slide the cool-side tube forward and down below the intercooler outlet, rotate it 45 degrees counterclockwise and then remove. Note: Full removal of the intercooler pipes is not necessary but allowed us more room to work.

11. The 7.3’s intake manifold (a.k.a “intake spyder”) must be removed to access the turbo. Seen here the wastegate control solenoid is unplugged, and removed. Two lines (green from the intake, red from the wastegate), a single electrical plug and an 8mm bolt are all that need be disconnected.

11. The 7.3’s intake manifold (a.k.a “intake spyder”) must be removed to access the turbo. Seen here the wastegate control solenoid is unplugged, and removed. Two lines (green from the intake, red from the wastegate), a single electrical plug and an 8mm bolt are all that need be disconnected.

12. Here the intake air heater is being unbolted. The air temperature sensor and a couple boost lines were also removed from the intake spyder.

12. Here the intake air heater is being unbolted. The air temperature sensor and a couple boost lines were also removed from the intake spyder.

13. The Garrett GT38 turbo uses a V-band clamping setup on all positive pressure ports. This one seals the pressurized air coming from the turbo to the intake spyder and later going to the intercooler. Removal requires loosening the clamp and popping the individual pieces of the clamp free with a small pry bar.

13. The Garrett GT38 turbo uses a V-band clamping setup on all positive pressure ports. This one seals the pressurized air coming from the turbo to the intake spyder and later going to the intercooler. Removal requires loosening the clamp and popping the individual pieces of the clamp free with a small pry bar.

14. The intake spyder feeds the heads through two boots going to each intake runner. Loosening both clamps on each boot allowed for easy removal of the intake spyder.

14. The intake spyder feeds the heads through two boots going to each intake runner. Loosening both clamps on each boot allowed for easy removal of the intake spyder.

15. With the intake spyder removed we could finally start freeing the wasted factory turbo.

15. With the intake spyder removed we could finally start freeing the wasted factory turbo.

16. With the intake out we now had two open intake ports. We crammed a few clean rags in their openings to make sure no foreign objects would make it into the valves and ultimately the combustion chamber, wreaking havoc.

16. With the intake out we now had two open intake ports. We crammed a few clean rags in their openings to make sure no foreign objects would make it into the valves and ultimately the combustion chamber, wreaking havoc.

17. At this point two V-band clamps on each exhaust port and a pair of bolts are all that secure the Garrett Turbo to the 7.3. Removing the downpipe clamp was fairly simple. We loosened the clamp and popped each steel V-band piece free with a pry bar. The clamp on the back side is another story. It’s a huge pain to access. We ended up using multiple prying “instruments” and a 3-lb sledgehammer.

17. At this point two V-band clamps on each exhaust port and a pair of bolts are all that secure the Garrett Turbo to the 7.3. Removing the downpipe clamp was fairly simple. We loosened the clamp and popped each steel V-band piece free with a pry bar. The clamp on the back side is another story. It’s a huge pain to access. We ended up using multiple prying “instruments” and a 3-lb sledgehammer.

18. Here’s the 7.3L Power Stroke sans turbo.

18. Here’s the 7.3L Power Stroke sans turbo.

19. Overall size-wise, the two turbos aren’t that different looking. The obvious difference being the massive air intake on the BD Turbo Thruster II versus the tiny stock opening that’s nearly half the size.

19. Overall size-wise, the two turbos aren’t that different looking. The obvious difference being the massive air intake on the BD Turbo Thruster II versus the tiny stock opening that’s nearly half the size.

20. The stock GT38 turbocharger with upgraded compressor wheel. Once out we noticed roughly a quarter-inch of play in the turbo’s center rotating assembly. There was so much play the compressor wheel was actually hitting the housing. If left in the vehicle much longer this turbo would have soon sent shrapnel into the engine causing catastrophic failure.

20. The stock GT38 turbocharger with upgraded compressor wheel. Once out we noticed roughly a quarter-inch of play in the turbo’s center rotating assembly. There was so much play the compressor wheel was actually hitting the housing. If left in the vehicle much longer this turbo would have soon sent shrapnel into the engine causing catastrophic failure.

21. The OEM turbine outlet flange must be removed and reinstalled on the new BD Diesel turbo.

21. The OEM turbine outlet flange must be removed and reinstalled on the new BD Diesel turbo.

22. We used an 8mm, 12-point box end wrench to remove the bolts holding the flange to the turbine housing.

22. We used an 8mm, 12-point box end wrench to remove the bolts holding the flange to the turbine housing.

23. With the turbine outlet flange off the new Turbo Thruster II we can see the wastegate. During rapid defueling, such as gear changes, this gate opens diverting exhaust pressure (a.k.a. “drive pressure”) away from the turbine and out to the down pipe. This helps save the turbo from damage when boost air is not needed by the engine.

23. With the turbine outlet flange off the new Turbo Thruster II we can see the wastegate. During rapid defueling, such as gear changes, this gate opens diverting exhaust pressure (a.k.a. “drive pressure”) away from the turbine and out to the down pipe. This helps save the turbo from damage when boost air is not needed by the engine.

24. Before installing the new turbo we replaced the oil supply and return O-rings with new ones supplied by BD. All the gaskets, as well as new turbine outlet flange bolts, we needed were included with the BD Turbo Thruster II.

24. Before installing the new turbo we replaced the oil supply and return O-rings with new ones supplied by BD. All the gaskets, as well as new turbine outlet flange bolts, we needed were included with the BD Turbo Thruster II.

25. Installation was simply the reverse of the removal process. The only difference is the use of BD’s turbo inlet tube instead of the stock part. The intake on the turbo is way too large for the stock inlet tube. The new BD inlet tube bolted up in the stock location with ease.

25. Installation was simply the reverse of the removal process. The only difference is the use of BD’s turbo inlet tube instead of the stock part. The intake on the turbo is way too large for the stock inlet tube. The new BD inlet tube bolted up in the stock location with ease.

Results:

The maiden voyage went off without any problems. This turbo took a bit more drive pressure to spool, which was expected. First of all it’s a bigger unit, but the reduced spool time is mainly due to the looser exhaust housing AR compared to the one on our stock turbo. But once it spool’s and is producing boost the truck accelerates hard. From 2,000 rpm and up the engine really comes alive. Under low rpm, heavy load there is zero compressor surge and not once did we hear the wastegate bleed off drive pressure (reducing turbo efficiency and boost) as the stock one had on a regular basis.

We’re impressed with this turbocharger so far but we’ll be beating on this turbo over the next year to give it a good, hard test. Just another step done in the 500rwhp goal direction for our 7.3L Power Stroke. Next issue we’ll be throwing some 238/80 injectors, valve springs, studs, and push rods at her. Dyno testing will be happening as well. Stay tuned.

SOURCES:

BD Diesel Performance

800.887.5030

DieselPerformance.com

Pick-Up Parts of Mission Viejo

PickUpPartsMV.com