We recently teamed up with the people at TorqStorm Superchargers and Holley when we found our ’72 Monte Carlo sleeper project, nicknamed Snake Eyes, was without…well, any modifications making it a sleeper. It did have a hopped-up 383ci stroker going for it, but not much else. Since the obvious answer to making more power quickly is boost, we decided Project Snake Eyes was going under the knife for a whole host of upgrades in preparation for a bolt-on supercharger kit from TorqStorm. You can read that step by step installation, here.
While it’s true, the TorqStorm blower is a completely bolt-on affair, it does require some ancillary support to function properly. As for Snake Eyes, it lacked anything that would aid the blower’s goal of forcing more air and fuel down the gullet of our 383ci.
In the following article, we’ll cover all the accessories involved with making our bolt-on blower a truly functioning power-adder.
To start, we made a call to our buddy Chris Beardsley at TorqStorm. Chris ran down the modifications absolutely necessary for a project like ours, and some of those additional mods you can make to get the most out of a system.
Before we got into the particulars, Chris explained the process he goes through with a customer looking to add some boost to their build. “Let’s say a customer calls us and says, ‘I’ve got a (insert make) V8 that’s under 400ci, it’s carbureted, and I’d like to add a blower.’ Well, assuming it didn’t come with electronic ignition, fuel pump, etc. there are some absolute must-haves to add before bolting on a blower.” We’ve listed those below.
Fuel Tank: At Mr. Beardsley’s recommendation, we started our project at the rear of the car with the tank. Since we’d be running a return fuel line, this was mandatory – our stock fuel tank wasn’t equipped for such a setup. We’re glad we dropped the crusty old gas tank out of the Monte, since our next “must-have” was an electric fuel pump and filters. We didn’t want any sediment or old fuel cycled through our new pump, filters, or carburetor. We ended up replacing it with a low-buck generic fuel cell we sourced on eBay.com. This also afforded us the opportunity to mount the cell in the trunk and cut some holes in the rusty floor – ratty muscle car points achieved.
Electric Fuel Pump: Chris told us, “you have to get rid of the mechanical fuel pump. They just won’t create the fuel pressure we need. When you’re running carbureted fuel pressure in a blown application, the fuel pressure needs to adjust based on the boost level. If you are going to add eight-pounds of boost, you need a fuel pump capable of creating 15-pounds of fuel pressure under boost.” Essentially, that meant we needed a fuel pump capable of “climbing in pressure,” so to speak. So, when it came time to move fuel from inside the cell to our carburetor and back, we installed a 160 gallon-per-hour Quick Fuel in-line pump and pre-and post-filters. That amount of power might sound like overkill, but let’s just say we were thinking ahead toward future mods.
Boost Referenced Fuel Pressure Regulator With Return: We asked Chris to explain the finer points of fuel pressure regulation with regard to boosted applications.”We use 8 pounds of boost as a pretty generic number. That’s what our single supercharger system typically makes, but there are people making much more than that with our twin system. Regardless, the same rules apply if you’re making 20 pounds [of boost].
It comes down to maintaining base fuel pressure on top of our boost number. If our base fuel pressure is seven-pounds, and our boost pressure is eight-pounds, then we need 15-pounds of fuel pressure. It remains the same if your base fuel pressure is seven [pounds] and you’re making 20 pounds of boost – you’ll need 27 pounds of fuel pressure.” A good point to note is, this applies to turbo stuff as well, it’s not just blower related.
For those of you who were in math class a long time ago, it’s relatively simple. The boost-referenced fuel pressure regulator we got from QFT is designed to operate within four- to nine PSI. It came pre-set at seven PSI, and it worked well for us right out of the box. Since it’s boost referenced at a one-to-one ratio, the math is easy. In our case, we are making eight-pounds of boost pressure and our base fuel pressure was set to seven-pounds out of the box. Without a boost-referenced regulator, the seven pounds of fuel pressure would not be enough to supply the carburetor which is seeing eight-pounds of boost pressure, thus requiring 15-pounds of fuel pressure.
By connecting a vacuum line from our carb hat to the fuel pressure regulator, the same eight-pounds of boost pressure the carburetor is seeing is also delivered to the regulator. This forces the regulator to overcome eight-pounds of resistance. It does so by pressurizing the diaphragm housing of the regulator with eight-pounds of additional fuel pressure, totaling 15-pounds.
Working in conjunction with the diaphragm spring, the regulator allows more fuel pressure to be fed to the carburetor, thus ensuring the float bowls never run dry and the engine operates unimpeded.
Blow Through Carburetor: Ah, the pièce de résistance – the blow-through carburetor. The crown jewel for our setup was selected, along with the rest of our fuel system components, from Quick Fuel Technology’s catalog of parts. Ours happens to be an 850CFM unit capable of working with forced induction applications.
Chris advises his customers to work with a custom carburetor builder to craft a blow-through setup that is tailor-made for each powerplant. He likes to start with a 4150-style, double-pumper, no choke carburetor, much like the QFT unit we selected, and build it to accommodate whatever they need – be it alcohol, E85, methanol, or simply gasoline, like ours.
Fortunately for us, the QFT unit sports all of those specs and more than accommodates the eight-pounds of boost we’re throwing at it. When we reached out to the folks at QFT, they broke down what sets our purpose-built Q-series carb apart. “They’re engineered for the dragstrip to combat the g’s experienced during hard launches. They’re equipped with notched floats and secondary jet extensions, and the high-flow aluminum main body isn’t just lightweight. It also features recessed air bleed cavities for improved air-flow.”
“Additionally, the die-cast venturi are machined to exacting tolerances for improved throttle response. Billet metering blocks ensure a uniform fuel curve, while throttle-bodies enhance durability. For those days when track conditions vary from one pass to the next, the QuickLink system makes adjusting the secondaries easy on models equipped with mechanical secondaries.”
Colder Spark Plugs:
Rounding out our list of “must-haves” is a set of colder spark plugs. Chris explained “colder spark plugs are just going to keep you away from detonation longer. Technically you could run without them, but you’re risking excessive detonation if you don’t. Some people will argue that you don’t have to have them, but it’s a damn set of spark plugs! throw ’em in and give yourself cheap insurance.”
We elected to go with a set of cheap Autolite 46-series spark plugs. That’s one heat range colder than what we’d previously had in our small block. We’ll likely go back and replace them with some platinum or iridium units once we’ve got the whole system dialed and we’re sure they won’t end up fouling.
At this point, with all the aforementioned modifications in place, the blower could be on the car, running, driving, and making power.
So, let’s get to the bonus round, where we really start making power with our bolt-on blower. These are the optional items a person can implement to get the most out of a system – be it a blower, turbo, or nitrous.
Chris shared a list of seven optional items he says will really wake a system up.
- Solid Ignition System: A high-output coil or MSD BTM box. (Boost retard is a secondary, but will aid you.) A high-output coil or multiple spark discharge box will do the trick. Users should add the ignition strength because that alone helps create a more efficient system. It’s most important to get away from the old round coil and points ignition. You’ll want to install an electronic ignition, good distributor, good coil, and good plug wires.
- If you’re upgrading the whole system, you’ve got to look at a high-output ignition box. Later, if all your I’s are dotted and T’s crossed, and you’re looking for things to do, boost retard ignition timing helps you build a better power curve on top of a power curve that was already pretty good. Ignition components are more important, but both will aid you in making more power. Of course, if you’re going to run your system without a boost retard control module, you’ll have to set your timing to a predetermined amount of advance.
- Boost and Air Fuel Ratio Gauges: A wideband air/fuel ratio and boost gauge aren’t mandatory, but they are important tools for understanding how the whole system is working together and how to start making other tuning changes based on what they’re telling you. You could run the car and it would work, but it’s a good idea to add them to give you some supporting knowledge. “If you’re going to base your timing off of the amount of boost you’re making. Like, if you need to remove one-degree of timing for every pound of boost, then you need to know how much boost it makes on your particular engine. The wideband also allows you to monitor the health of your engine and prevent it from running too lean or too fat – lest you have pre-ignition or excessive knocking.
- Your weather, camshaft, heads, engine size, and rpm are all factors which change the boost number. Until you measure it on your own vehicle, you won’t know what it is. From there, you can make your decisions on octane selection, total timing advance, blower speed, etc. It will also tell you where your fuel pressure needs to be. So, you can run without one, but it’s really a necessity for fine-tuning the system. You also need it for measuring consistency (it’s a good tool to tell you if the car is acting funny and why. If you’re used to making eight pounds of boost and for some reason it’s running sluggish and only making six pounds – maybe the belt is slipping, the tensioner is worn out, etc.
- Boost Retard: While still running on pump gas, a supplemental boost retard, if you don’t already have it in your ignition box, allows you to have full timing advance through the beginning part of the power curve, stripping away only the amount of timing that is replaced by the incoming boost pressure. So you don’t pull it all the way out quickly.
- Octane: By increasing the level of octane in your fuel, you can leave more timing in. Giving yourself that variable timing control, you can now play around with fuel quality instantly and adjust the timing to adapt to the octane. You could feasibly pull out about half as much timing, or if you run E85, you can use your adjustable timing controller to make more power.
- Blower Speed: Assuming you already have aluminum heads, headers, and an intake manifold the next step is to see if you can increase the blower speed with a pulley change. By increasing the speed at which the blower spins, you up the amount of boost pressure – effectively making more power. Talk to Torqstorm, they’ll hook you up with the best pulley option.
- Larger Air Filter: “The way we build our supercharger systems, every head unit uses the same filter, and in certain vehicles, there is room for a larger filter. Basically, the biggest filter you can fit will help your blower breathe better which makes more power.
- High-Flow Carb Hat: We’ve seen gains as much as 50 horsepower just by changing the carb hat. The biggest thing that it can do is change the distribution from front to back. Normally it creates a centrifugal effect on the air, which means the rear of the carb gets the best flow. With a taller carb hat, it distributes to the front much better. The front two cylinders are furthest away from the back of the carb. 60-percent of the air is in the back and it’s only feeding four cylinders.
- With a taller carb hat, the overall airflow into the engine is the biggest gain to be had. Although, the better flow comes at the cost of hood clearance. For Snake Eye’s cowl hood, that’s not a problem, but for people who want a stock appearance, it’s something to consider.
In the end, we installed a cheap fuel cell we got from eBay and plumbed new fuel lines. The fuel is now fed through an entirely new fuel system from Quick Fuel Technology and Holley, including a billet bypass regulator, 160gph fuel pump, pre- and post-pump filters, and an 850CFM blow-thru carburetor.
The ignition system was also upgraded with a new HEI distributor and boost retarding ignition box From Holley (6BTM). We added a new fuse and relay panel to accommodate some of the added circuits, which we wired the new fuel pump and ignition box to. We also simplified the factory wiring harness by de-pinning and re-pinning it with only the necessary wires. Since we were cleaning and upgrading the electrical system already, it made sense to mount a remote starter relay in the engine bay as well.
While we were working in the rear of the car, we took some time to add a remote fuel filler on the sail panel of the Monte and relocated the battery and master cut-off switch to the trunk.
And, of course, we bolted up the new supercharger from TorqStorm which required us to relocate and connect several vacuum lines.
We still have some fine-tuning to do before we get it back on the dyno for our “after” numbers, but Snake Eyes is back terrorizing the streets. Stay tuned to check out the next installment when we add some much-needed stopping and handling performance with a complete brake and suspension overhaul!
Until next time…