TorqStorm Centrifugal Supercharger Kit

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https://www.ebay.com/itm/TORQSTORM-S....c100012.m1985

Has anyone installed this supercharger kit on a 385-series powered Cobra? The add states that a 79-93 Fox Mustang style alternator must be used, and that Powermaster offers a V-belt alternator (part number 170781) or a serpentine belt alternator (part number 17735). However, it doesn't state that TorqStorm offers crankshaft pulleys that will support either V-belt or serpentine belt drives for the accessories (alternator, water pump, power steering).

Any comments about this supercharger system would be greatly appreciated.

[olddog]

I looked around on that page to try to find same details on what the blower is and some specs, but failed to find anything. If it is centrifugal, which most of what I have seen in the past is, the pressure is proportional to rpm squared. This means that at low rpm you get almost no boost. You are above 50% of your rpm before there is enough boost to matter.

So, you are going to have a very steep torque curve in the upper rpm. I have seen truck engines that make good low end torque and then run out of breath at the midrange, end up with a nice torque curve with these type blowers. However if you have a good set of heads and cam that make good power in the upper rpm to start, these type blowers will give you a torque curve that looks like a mountain on the way up. Not so much fun on the street.

The other two things I noted were the plumbing. One, there is no heat exchanger, to cool the compressed air. Depending on the air temp and compression ratio you cannot go above about 5 psi without cooling or you will get detonation. Two they are not enclosing the entire carb. It looks like the bowl vents are under the hat so it would work, but it is more likely to push fuel out every place it can find. Also you need to control fuel pressure. If you have 5 psi of boost you need 5psi more fuel pressure to get it into the bowls.

$3600 will make a lot of power from a 385 series engine. Not sure I would go down this road. Give it a lot of thought.

[cycleguy55]

Torque build starts at lower RPM than you might think, and sooner than the Vortech on a SBC test.

Single Torqstorm on a 383 CID SBC: Comparison: Testing a TorqStorm | Moore Good Ink

Double Torqstorm on a 427 CID SBF: Our Ford Boss 427 Gets Twin TorqStorm Superchargers - Hot Rod Network

Rather than a blow-through Demon carb, why not a FItech blow-through EFI - more money, but way more tuneable: Go EFI 8 1200 HP Power Adder – FiTech Fuel Injection

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https://youtu.be/ICTUSEED2KM

I found this video of a carbureted small block Chevy 372 being dyno tested. Both runs were on pump gas. First test: naturally aspirated. Second test: TorqStorm single centrifugal supercharger.

Horsepower improved from 460 @ 6400 rpm to 678 @ 6200 rpm, a 47% gain. They didn't specify the engine's static compression ratio, or how much boost was applied. For that sized engine, the 3.25" driven pulley will make 6-8 psi of boost, and the 2.98" driven pulley will make 8-10 psi of boost.

On one of the webpages I visited, TorqStorm states that their system is designed for use on stock or slightly modified engines. I guess everyone has their own opinion on what a "slightly modified engine" is. In my book, a carbureted 372 cid engine that makes 460 hp is not "slightly modified".

[cycleguy55]

https://www.youtube.com/watch?v=EHg2uqJvLOk&t=2s

Comparison of Weiand Roots-type blower and Paxton centrifugal blower. The Weiand produces more torque at lower RPM, but less HP at higher RPM. The Paxton produces less torque at lower RPM, but more HP at higher RPM. None of this is a surprise.

Comments:

• While Paxton and Torqstorm are similar designs (belt driven with step-up gearing) I have no idea how they compare in torque / HP curves on a given engine
• Centrifugal superchargers produce less low RPM torque than Roots or twin screw blowers, but that's should be more of an issue for heavy vehicles or towing than it is for Cobras. It's easy to over-power the rear tires on a Cobra - is there any real reason to make it even easier?
• Low boost (5-8 PSI) superchargers seem well-matched to a lower compression engine as an alternative to replacing the rotating assembly - though packaging will always be an issue in a Cobra.

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Way back in the day, I had a stock 1985 Camaro Z28 with a carbureted LG4 305 cid engine. I wasn't at all impressed with the performance of the car, so I ordered a crate 350 from Racing Head Service (RHS) -- a relatively inexpensive engine with a cast crank, 8.5:1 cast pistons, stock rods, cast iron heads with 1.94"/1.50" valves, Comp Cams 280 Magnum camshaft. I installed headers and dual exhaust, and a 172 cid B&M roots blower setup and Holley 650 carburetor (almost identical to the Weiand blower setup seen in the Engine Masters video shown above). The small roots blower was easy to install. The assembly stayed completely out of the way of the other accessories. The blower drive pulley was simply bolted onto the crankshaft in front of the existing accessory drive pulley. Intake manifold and carb installation were fairly simple, but there were two issues that I had to deal with in order to complete the installation. 1) The carburetor linkage had to be modified because the carburetor sat higher in the engine compartment. 2) I had to cut a hole in the hood because of the added height of the blower, about 6 inches.

A centrifugal blower would solve the height problem by placing the blower pump to the side, however, as mentioned in the video, there are some significant added expenses involved (e.g., the need for a blow-through carburetor, and a boost calibrated fuel system, possibly with the addition of a high pressure electric fuel pump). And then there's the issue of interference with accessories like the alternator and power steering pump, etc. It appears that centrifugal supercharger kits come with one-piece crankshaft pulleys, meaning that you'll have to obtain a pulley that has the correct belt types in the correct places to run all the accessories.

Overall, it seems like a roots-type blower is cheaper and easier. And now there's a more efficient version, the screw-type compressor made by Eaton. Those make more power with less heat than the old style blowers because they don't beat up the air as much while compressing it.

It'll be a tough decision. I really like the look of a blower sitting atop the engine, but I'm not too fond of the idea of driving a Cobra around town that has a carburetor and an air cleaner sticking out of the hood.