Product Review: Banks Power Upgrade

RVers Online October 1998

Dodge/Cummins 5.9L 12-valve turbo-diesel trucks

Banks Stinger®-Plus System

We get quite a stack of email here at RVers Online. Since we’re a completely non-commercial site and consistently refuse paid advertising, we occasionally sense that some of our readers’ comments praising a particular campground, product, or service might have been sent along with the hopes we’d publish the item in our “Mailbox”. Sometimes it’s pretty obvious. An email praising the XYZ Campground, signed by a reader whose return address is “” is quite easy to spot.

One of the products that readers seemed to comment on favorably is the Gale Banks power upgrades for towing vehicles and motor homes. Since we’d recently acquired a new Dodge dually with the stock Cummins engine, we decided we’d find out ourselves, and report our real life experience back to our readers. Since no one was paying us to do this, we’re of course entirely free to tell it the way it is. Which is what we think our readers really want to hear. We’ve read lots of product reviews in publications such as Trailer Life. But since they receive advertising dollars from the company whose products they’re testing, we’ve often wondered whether their objectivity might be a bit clouded.

But let’s give Trailer Life and like publications high marks for having the articles written by persons who have a complete understanding of the mechanical theories which are behind many of these products. Here we have a product review by a person who knows very little indeed about WHY such products do or do not work as advertised. But we think we’re entirely competent to tell, using just plain, non-technical English, WHETHER the product works — and if so, how WELL it performs.

With that bit of background, let’s look at our experience and its outcome.

What We Did

We were generally aware that Gale Banks Engineering makes power upgrade products for all the major gas and diesel tow vehicles, and for most if not all major brands of motor homes. They offer a variety of packages, giving the RVer an opportunity to choose the most economical upgrade option, or simply go for a full package offering the most power. When we first contacted Banks through their 800 number, we told them we had just purchased a new Dodge Cummins, and that it was among the first of the 215 HP engines, rated at 440 pounds of torque. We were advised that the performance data they had was based on the previous generation of Dodge Cummins engines — those with a factory rated horsepower in the 180 HP range. Ours is a five speed manual transmission, 4WD, and with a 3.54 axle. The only modification we’d made was to add a Pac Brake.

Since they had no data on the newest 215 HP Cummins, they offered to do some testing of the before and after horsepower and torque at their R&D facility in Azusa, CA. We couldn’t resist, and opted to install what is called the “Stinger Plus” system on our new truck. It involves the replacement of the components of the air intake and exhaust systems which Banks Engineering has found restrictive. It includes the Banks Quick-Turbo turbine housing and boost actuator. And the new OttoMind fuel calibration plate sees to it that the fuel delivery matches the improved engine airflow. Like all Banks products, it is designed not to disturb the factory warranty; and while we have no intention of expressing an opinion on the complex issue of “warranty” here, we did manage to find a website ( which some readers might find of interest on this subject.

Along with two motor homes and another truck scheduled for “surgery” the following day, we “camped” at the Banks facility the night before. At their request, we came in early for the purpose of putting our truck through its paces, both on the dyno, and in road testing, the afternoon before the package was installed. By late afternoon we got the basic “before” data on a computer printout. We had fully expected a test report showing that the “before” power ratings were below factory specifications — making it just a bit easier for the “after” tests to be impressive. But to our surprise, we found that the HP rating came out at an incredibly close 214.5; and the torque, rated as 440 at 1600 rpm, actually tested out at 450.7 pounds at 2300 rpm. At 1600 rpm, where it should have been highest, it registered 432.3 pounds — just a bit below the factory specification. The maximum “boost” recorded during the testing was 21.5 pounds. We found this interesting, in that the ’94 Cummins we’d just traded in had a boost gauge, and topped out at 16.

We were impressed not only with the numbers, but with the exhaustive efforts the engineers expended in getting fully credible data. From simply observing the process we knew that whatever the “after” numbers turned out to be, they would be both reliable and accurate.

A Chat with Gale Banks

During the afternoon Stephanie and I met with Gale Banks. He is a most pleasant and articulate individual, who has an obvious passion for both power and perfection. After a tour of the Banks facilities, where we had a chance to see some of their “space age” R&D projects, I asked Gale a few questions that I though might be of interest to our readers.

1. Without being technical, what does the “Stinger Plus” package really do? In a nutshell, it’s all about getting air through the engine faster and more efficiently. This may sound simple, but there are many components used in the stock manufacture of vehicles which are chosen according to cost, not performance. To keep a competitive retail price tag on the vehicles we purchase, there is always a tradeoff between cost and performance — and the sum total of these choices is what makes a high quality, well engineered, and more expensive set of components capable of delivering significant increases in what we as drivers feel as “power”.

2. What about dyno testing — we’ve read elsewhere that in “just 5 minutes” you can get some really useful data by running your vehicle through the dynonometer. Our own observation was that the testing took well over an hour. According to Gale, unless the test is done thoroughly and exhaustively, the data is not something that should be considered reliable. He pointed out that it takes at least 5 minutes just to warm up the engine; and then another 5 minutes to run it on the dyno so that the dyno equipment is fully lubricated and not offering an artificial resistance that can bias the results. According to Gale, he would not place much credence in dyno testing which was not done with the same care and precision that we saw in his R&D facility. While this isn’t the point of this article, we found that observation interesting…

3. What about weight ratings — does a power upgrade mean I can tow something that’s heavier than the factory ratings advise? Decidedly not! Gale explained that the factory ratings are based on three factors — power, braking, and suspension. Since the “power” rating is only one of these components, increasing power alone will of course have no effect on either braking or suspension. We think this is an extremely important point for RVers to understand. We suspect there are too many RV or truck sales persons who may suggest to a potential buyer that the easy way to get around the factory weight ratings is to simply get a power upgrade. If anyone is qualified to comment on this issue, it’s Gale Banks. And his answer on this point is unequivocal.

The Test Results (Theirs):

Late the following afternoon the test results on the Stinger Plus installation were completed. Again the dyno testing was a thorough and time consuming process. In fact our trip log now shows that during the time we were at the Banks facility our truck was driven 60 miles. The road testing took only perhaps 20 minutes. So most of those miles were done on the dynonometer.
The “after results” were again given to us both as a computer printout and as a graph. The most significant numbers are these:

1. Horsepower results showed an increase from 214.5 at 2500 rpm to 276.1, also at 2500 rpm — a gain of 28.7%. The highest percentage increase in HP occurred at 2100 rpm, where the rating increased from 168.9 to 230.5, or 36.5%.

2. Torque increased from a maximum of 451.1 @ 2300 rpm to 585.7 @ 2400 rpm — a gain of 30.6%. The highest percentage increase in torque occurred at 2100 rpm, where the increase went from 422.3 to 576.4, or 36.5%.

3. Boost (a gauge of turbo efficiency) increased from 21.5 to 31.

The Test Results (Ours):

We are entirely confident in the accuracy of the numbers that were furnished to use by the Banks R&D engineering group. However, our predicate for doing this review is that while charts and statistics are important, what does it “really feel like”?

In two words we’d say —”VERY impressive”. The normal “diesel lag” seems to have been significantly diminished. With an overall power increase of approximately 30%, it feels like driving a completely different truck. With its new, high efficiency muffler, it even sounds different going down the road. Sure, you’d still know it’s a diesel, but it has a certain authoritative tone under acceleration. The power difference isn’t just “sort of”. There’s no mistaking the substantial difference in acceleration and towing. Towing up a hill is often now done using a higher gear. For example, on our southbound winter trip (before the Banks upgrade) we towed our 29′ Alpenlite slider down I-5, and encountered 4 or 5 spots where we just lost power going up some of those long steep grades in 4th gear — forcing a downshift into 3rd gear while we crawled over the tops at 30-35 mph. On the return trip (upgrade installed), we sailed over those same summits with 4th gear providing all the power we needed to maintain highway speeds. The temperature and pyrometer readings both stayed well within the normal range at all times.

We even did our own very non-scientific before and after testing. Our “towing test” (Stephanie was not keen on subjecting our household belongings to this one) was using 4th gear under full load, and accelerating from 40-60 mph. It seemed to take forever in the “before” test. We clocked it at 25 seconds. In the after test, we clocked it at 16 seconds on the precise same roadway under virtually identical outdoor conditions. We didn’t do this to try to prove anything — good or bad. We simply wanted to see what our own set of “objective facts” would tell us. What it told us is that we feel as power really IS power.

We also did some testing of the truck without towing. We’ve not yet found a suitable place to replicate those tests, but we’ll amend this report with those additional results once we’ve been able to complete them. We shall also report on fuel economy when we’ve logged sufficient “after” miles to be able to roughly quantify our findings. We’ve kept a detailed log of the trucks first 8,000 miles, computing the light and towing mileage with considerable care. Our preliminary observation would be that the “after” mileage surely has not suffered from the installation; and preliminarily we think we’re seeing a trend towards an improved mpg of something on the order of approximately 5%. That’s encouraging because we’d have to confess we’ve done a bit of “acceleration” that we didn’t do before — simply because we couldn’t! It seems as if we need to experiment with some new driving techniques that don’t just “use more power”, but which “use more power efficiently”. With less lead on the pedal, the results may improve further.


We are completely satisfied with the outcome of this project. We’re not sure whether it validates our premise that high tech product reviews can be successfully undertaken by those who are technically challenged, but at least minimally articulate.

By way of summary, we assume that some installations would probably result in even greater power increases; and we’d guess some would likely not quite reach our results. Given the fact that our engine tested at or better than factory specifications before the installation, we started from a fairly strong power base. We suspect every engine has its own characteristics. In our case, we’ve found that the maximum torque is at a much higher rpm than advertised (a Dodge/Cummins issue), and is likely a result of the way the governor is set for that engine. If we can find a way to correct that situation, we’d like to — because at 2000 rpm we’re already going about as fast as we’d normally travel in 5th gear. And that of course means we’ll seldom have an engine speed which will be able to take advantage of the engine’s highest rated torque. (We wonder whether other owners of the same engine have a similar issue but may not be aware of it…)

Our installation, being done at the factory by highly skilled technicians, was probably as good as it gets. Moreover, since that’s what they do everyday, they appear to be able to accomplish the work within the time scheduled. We think major work such as this, if not done at the factory, should be done by a highly qualified specialist — one who’s reputation is built on quality and “after-sale service”, not just on a high advertising budget and sales volume.

Cost is of course a consideration. We could have chosen the basic “Stinger” package, rather than going to the full “Stinger Plus” — and we still would likely have achieved some very significant increases in power. However when we recently purchased the new Dodge dually (not an inexpensive event), had the salesman told me that for an additional 5% in the price I could have the same truck but with 30% more power — I’d have done it in a heartbeat.

We can of course only document this single experience, involving only one of many Banks products. But we’ve done so as objectively as possible, and we will update this report with any significant new findings we may make. If “very impressive” best describes our sense of the new power we have for towing those high mountain passes through the Cascade mountains in the summer months, it describes as well our impression of Gale Banks, the good team he’s put together, and the quality of the product now installed in our truck.

Some months after we installed the Stinger Plus package, a third and final component was made available. We subsequently installed this product, the TwinRam air intake system. Our review of the TwinRam is contained in a later article, which you can access by clicking here. This later article includes detailed spreadsheet data showing the dynonometer results for our engine (i) stock; (ii) equipped with the Stinger Plus; and (ii) equipped with Stinger Plus and the TwinRam.

NOTE: We’ve made no effort to list here the extensive lineup of Banks products for all trucks and motor homes; or the performance data that Banks Engineering has available for each. Readers wanting more information can send questions or information requests to a designated Banks representative via email to

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