We’ve all seen them, we’ve all been tempted, but quite frankly, those low-buck off-shore turbos available online just seem too good to be true. Case in point, the $163 GT45 clone offered by www.ebaystores.com/dnamotoring. I mean really, just how much power can a turbo that sells for just $163 really be worth? That’s like two weeks’ worth of lunch money, for Chrissakes. It must surely self-destruct the moment you start the motor, or at the very least, offer considerably less than the advertised power level. In our case, none of these things came to pass, though it should be mentioned right off the bat that we did not perform any type of long-term durability test. Simple power testing, even at variable power and boost levels, does not guarantee years (or even hours) of trouble-free service.
After posting the results of this test online, we did get feedback from a number of enthusiasts who have run this turbo successfully for many years on the street and strip, so at least we know some of them work well. We figure that even if you get limited service life, paying another $163 for more turbo fun still represents a good deal. This, of course, assumes the turbo doesn’t take out your motor along with it!
Now that we have the disclaimer out of the way, the important question on the table was just how much power was one of these GT45 clones really worth? We know that the inexpensive turbos available online come from China, where labor rates are much lower. Lower labor rates mean lower cost of production, which in turn mean lower pricing to the public. Many of the online sources sell the turbo seemingly at or near their cost, which only means a better deal for consumers.
Like any other turbo choice, ours was based on two criteria: power production and cost. (For guidance choosing turbos, click here.) We looked for the best combination of the highest power potential and price. The GT45 clone seemed to fit the bill, as these were advertised online with power outputs ranging from 600 hp to as high as 800 hp, depending on the seller. Though many sources offered this same turbo, the pricing varied by over $200 in some cases, and even varies from day to day from the same manufacturer. The best price we found for the GT45 clone on the day we searched was from DNA on eBay. A little research time spent behind the old keyboard goes a long way!
The cold side of DNA’s GT45 clone turbo featured a 0.66 A/R, a 69mm inducer, and a 98mm exducer. The hot side included an 88mm inducer, a 77.5mm exducer, and 1.05 A/R. (What does all this mean?! Click here.) The turbine housing also featured a divided entry, though it was run with an open T4 turbo flange. Our turbo was shipped sans oil fittings, meaning we had to come up with our own oil feed and drain fittings. For the oil feed, we simply tapped the existing oil feed to accept a standard 1/8-pipe fitting. A standard aluminum, two-bolt drain fitting was run in conjunction with a brass pipe fitting. Obviously, it was necessary to install a drain fitting in the oil pan. Since the test was to measure the power output of the turbo itself, we did not include the costs of these fittings or intercooler, or any other part of the motor in the $163 description (get those comments rolling).
To maximize the power potential of the turbo, we decided to run as much boost as it would support, at least at the power peak. This meant combining it with a suitable intercooler. The turbo was run through an air-to-water cooler from ProCharger, capable of cooling much more power than our low-buck turbo had the potential to produce. It’s always better to have more cooling and need less, but in our testing the cooler was run with 85-degree dyno water and not ice water (which would produce even more power).
To run this test, we also needed a suitable test motor. Luckily, we had our handy dandy, boost-ready 5.3L from Strictly Performance (SP) handy. Essentially an enhanced stock-bottom-end (SBE), the SP 5.3L featured a stock block and crank combined with Gen IV rods and hard anodized (cast) pistons. The combo also featured extra ring gap. Topping the lightly augmented short-block was a set of Katech-ported 706 heads secured by ARP head studs. For this test, the SP 5.3L was also sporting a FAST LSXR intake and Summit Stage 4 camshaft. Originally designed for an NA application, the Stage 4 Summit cam featured a 0.625/0.605-inch lift split, a 234/247-degree duration split, and 113-degree LSA. Basically, this 5.3-liter was one healthy LM7, even before adding the boost. This would allow us to easily test the flow and power limits of the DNA turbo. Need more proof? Run in naturally aspirated trim, this 5.3-liter exceeded the 500hp mark by pumping out peak numbers of 502 hp at 6,500 rpm and 432 lb-ft of torque at 5,700 rpm. Now it was time to install that $163 turbo!
In preparation for the DNA turbo, we removed the Hooker headers and replaced them with stock truck manifolds. The manifolds were swapped and aimed forward to work in conjunction with a custom Y-pipe designed to feed the single turbo. In addition to the 3-inch V-band fitting, the Y-pipe also featured a pair of flanges to accept Gen 5 waste gates from Turbo Smart. The DNA turbo was installed on the awaiting 3-inch V-band fitting using a V-band T4 flange adapter. Installation of the turbo also required the use of oil feed and drain fittings, a 3.5-inch exhaust, and channeling all that wonderful boost through the ProCharger intercooler.
It is important to note, all testing (both NA and boosted) was run on pump E85. With 89-pound FAST injectors, we had a combination capable of withstanding 1,000-plus horsepower levels. Now the question was, how far would $163 worth of boost take us? After starting at just over 5 psi, we increased boost 1-2 pounds at a time (see the second boost graph), until we eventually reached the flow limit of the DNA turbo. Running a peak of 10.6 psi at the power peak of 6,100 rpm, the turbo 5.3L produced a maximum of 793 hp and 795 lb-ft of torque. The $163 turbo could produce more boost at lower engine speeds, but simply ran out of available flow to increase the boost pressure at the power peak, but don’t get it twisted. Any turbo that makes nearly 800 hp for the paltry sum of $163 is going to be plenty popular. If you’re that greedy, you can always get two!
On The Dyno
Power Vs. Boost
We ran the eBay turbo at a variety of different boost levels. We started the test at just 5.3 psi, then slowly ramped up to the eventual peak boost reading (at the power peak) of 10.6 psi. The boost pressure actually reached as high at 14.0 psi in the middle of the power curve on the 10.6-psi run, but the turbo simply could not sustain that boost level at higher engine speeds. Check out the minimal gain at the top of the rev range between the 10.0- and 10.6-psi runs. Big power (torque) gains occurred lower in the rev range, but the turbo ran out of steam on the big end.
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