A Proud History of Boost

A couple summers ago I took a drive in my father’s ’48 MG TC. It had been 10-15 years since our last encounter, but the deep exhaust tone and supercharger whine were exactly as I remember. You see, Moss Motors’ founder, Al Moss, started selling aftermarket supercharger kits back in the mid 50s, and my father was one of his early customers. The Shorrock vane style supercharger mounted on my father’s car has been there for over 50 years. It was installed before I was born.

Goldman’s 1948 TC

On my sixteenth birthday, my father almost sent me down to the DMV in that car for my driver’s test. Sadly, he figured they might not be willing to give the test in a car with the steering wheel on the wrong side, so I wound up in Mom’s Honda instead.

MG TC shorrock supercharger installed in mid 50’s

With freshly minted driver’s license in hand, I embarked on a life long love affair with supercharging. My first taste of competition was in the old man’s blown TC at a parking lot gymkhana. I managed to beat Al Moss himself in the “cart sprung” class, and still have the plaque to prove it.

The age of Shorrock and Marshall Nordeck MG supercharger kits faded with time, but they are considered highly collectable today. So much so in fact, we ultimately believed there was room in the market to build a whole new kit. In 2000 we introduced our own take on an MGT supercharger kit.

At the time, our in house engineering capabilities

Moss’ original MG T-Series Supercharger sold from 2000-2004

were limited, but fortunately we were in partnership with some very talented supercharger kit designers. Using some cut and welded manifold parts as patterns, and the engineering knowledge of our partners down in Los Angeles, we managed to get workable castings. My one personal contribution to the concept was the insistence we incorporate a “sneeze valve.” Fuel injected engines may never backfire, but carbureted engines do, and the prospect of bent throttle shafts, or supercharger rotors being suddenly driven in reverse didn’t sound like a good idea. The resulting valve design is incorporated in all our British supercharger kits.

The Moss kit was based on an old school roots type Magnacharger supercharger. It was well received, and sales were beyond expectations. Everything was going great until our supercharger vendor, upon receipt of a new purchase order, told us there were no parts left to

Sneeze Valve

build blowers. To our dismay, it turned out the superchargers were being assembled from new old stock parts, and there was no tooling on which to make more. Whoever originally sourced the blower managed to miss that important detail, and so the Moss MGT supercharger kit quietly disappeared.

In those days, we were also hip deep in the market for modern superchargers, producing kits based on Eaton components for the likes of Ford, Mazda, Honda and Chrysler. We had partnered with Oscar Jackson and Harry Sanders of Jackson Racing, for design and engineering work on the modern cars. In working with and learning from them, our in house capabilities steadily improved. They helped us turn our cut and weld mockups into the necessary engineering drawings and patterns to make saleable castings.

As we hired new engineering talent, supercharger kit

Miata Supercharger

design became a wholly in house affair. Our first generation MGA/B kit was redesigned and improved, and we added Spridget, TR250/6, and TR3-4A kits to the mix. Pretty much everything supercharger from 2005 on has been designed right here in Goleta.

Some have claimed our whole supercharger program is nothing more than an expensive trip down memory lane, with the sole purpose of eventually producing a supercharger for your author’s personal Triumph TR4. I emphatically deny that. (I’m not under oath here, right?) All kidding aside, a well-engineered supercharger kit retains all the easy drivability one would expect from a stock car, while adding enough power to keep up in modern traffic. As an owner, having a little added wow factor under hood is a nice touch too.

On left is our original manifold from 2000. On right is our new manifold for 2012

Since the demise of our original MGT kit, folks have been asking, “When will you bring it back?” Well, the answer is now. The easiest way to create a new kit would have been to steal the design from Moss, but rather than dredge up our previous kit, we decided to go ahead and start from scratch. Our Chief Engineer, Jason Davis, has produced a beautiful new inlet manifold. Although largely similar in appearance to the old design (after all, there’s only so many ways to skin a cat), Jason applied some deep thinking to his new part. For example, the blower is ever so slightly offset from the centerline of the ports, because air doesn’t just flow from the center of the blower’s outlet port, but rather is concentrated a little to one side. By moving the blower, he’s centered the air entering the plenum.

Supercharger is slightly offset for best airflow

It’s pretty crazy for a large company to invest in something as esoteric as an MGT supercharger kit, but maybe, after being steeped in a lifetime of supercharged sports cars, the owners of Moss Motors just want to produce a little bit of fun. It’s great to be a part of a company that has a history of making products that sales alone don’t necessarily justify the development expense. Passion plays a important role in the decisions we make here too.

Prototype Supercharger on our TD pickup


'A Proud History of Boost' have 27 comments

  1. July 25, 2012 @ 5:47 pm Richard May

    What are the 0-60 times of a stock TD, and TD II, and with an added supercharger??


    • July 26, 2012 @ 8:24 am carlbergs

      Richard, I can’t tell if you wrote this tongue in cheek or not. The fact is, we have not run our stock TD, or our supercharged TD in a 0-60 challenge. A stock TC-TD would generally have a 0-60 time of 20-22 seconds. What we can tell you is the 40-50% increase in power makes for a more spirited drive. Holding highway speeds, especially up minor grades is easier and if you have a 5-speed conversion the power the supercharger adds with the 5-speed gearing makes it a car that’s easy to motor in.


  2. August 10, 2012 @ 2:34 am collette

    Existe t-il un e adaptation pour TRIUMPH VITESSE MK2? MERCI


    • December 7, 2012 @ 10:22 am stuursmad

      Collette, this comment was posted in response to your question:

      Bonjour Colette,
      J’ai lu votre demande s’il existe un kit compresseur pour la triumph vitesse. Moss vend un kit compresseur pour la TR6 qui a le même bloc moteur que votre vitesse. Il faudra peut-être prendre un carburateur plus petit pour votre voiture, mais le kit s’adaptera à votre moteur.
      ( voir dans leur website Triumph TR250-6, sous “performance”.

      Bonne chance,
      Bertrand de Decker



  3. August 15, 2012 @ 1:35 pm Tom DeBardas

    My dad had a new ’53 MG TD. Eventually he installed a Shorrock supercharger. He ran 0-60 times with it, but I don’t recall the results. Interesting story though, I was with him in the TD on some low traffic road when an XK 120 coupe slowly started to pass us. My dad, with ego intact, decided that this was just not right and eased up along side the Jag. To make a long story short, by the time the Jag got tired of the game and very quickly left us in the dust, the MG spedo read 90 miles per hour. Not too shabby.


  4. August 30, 2012 @ 5:47 am Jose V Vargas

    I just installed the supercarger on my 1953 TD. I could not be happier. I bought it the day Moss announced they were available. I live at 8000 feet above sea level (Bogota, Colombia) and now I have enough power for pleasant and aggressive driving ! I just love it.


  5. August 31, 2012 @ 4:38 pm Marcel Charity

    Is there a supercharger kit that will fit a North american 1978 Triumph Spitfire 1500 ?…From what i’ve read it’s the same engine as the MG Midget 1500 engine, would’nt one of these kits bolt on directly??.

    Either that of it’s time to convert it to europeen specs with the hi-compression pistons and dual SU’s…


    • September 6, 2012 @ 10:45 am stuursmad

      Unfortunately this is an easy one to answer…
      We only have a supercharger kit for the 1275 motor.

      But don’t lose all hope, our line of supercharger applications has a tendency to expand around here.


      • December 2, 2012 @ 7:51 pm Johnny Flame

        I saw a kit on E-bay a couple of years ago. it used a Weber down draft manifold and a stromberg carb. The guy that was selling the kit showed it installed in a Spitfire, and he assumed it would also go into a Midget. It’s on only installation question involved the battery, not a big deal with a small battery.
        This kit was priced around $3000 us, and had I had the money then, I’d be blowen today! I only wish I’d noted the model supercharger included. I’d be engineering this myself.
        Blowing a 1500 has been done, and like the 5-speed convertion for the 1500, Moss Motors will need to hear a lot of us scream before they get around to it. I’m not buying the 5-speed kit and minilite wheels until someone blows my Midget! It this screaming loud enough?


  6. September 21, 2012 @ 11:57 pm ROUMAGNAC

    Good day,

    Would it be possible to mount your supercharger kit to an MG TF 1250 ?

    Best regards


    • September 24, 2012 @ 12:40 pm carlbergs

      We are currently working with a Moss Distributor who is installing the system on his personal TF. As expected the top of the carburetor and others various parts are hitting on the top hood panel. Other areas are interfering with the hood brace and front hood handle. He says the problems are not stopping him from moving forward but he is not sure if the fixes will be something that we can replicate in a kit that we can sell. This happened on our first system we offered back in the early 2000’s which wasn’t offered for the TF for the same reasons.


      • December 5, 2021 @ 7:26 am charles lovein

        RE: blower on TF.
        I have a TF with the 1500 engine, and would like to know what other mods would be neccesary in order to make a kit like this work.

        Thank you for your time,
        charles lovein


  7. October 26, 2012 @ 10:46 am Scott Pierce

    Hello! I am looking for a Supercharger for a 69 Series 2A Land rover- 2.25 4 cyl.
    Can I fit something you sell to it?? It is petrol and just not built for the highway obviously.

    Thanks! I can adapt an SU carb-


  8. November 3, 2012 @ 3:46 pm frank opalka

    I used to have a Judson blower on my MG-TD, it helped a lot


  9. December 3, 2012 @ 6:17 pm William

    The supercharger, 5 speed and 4.55 rear end, have made a remarkable difference in my 51 TD. I installed a new Petronics Ignition and electronic fuel pump as extra measures for longevity and smooth modern operation. I’m the second owner (1964) of this beautiful little car. It will be passed on to Son and Grandsons. I hope they enjoy it as much as my wife and I have.


    • April 25, 2014 @ 10:01 pm Dick Mason

      William: It looks like you and I have identical ’51 TDs with the 4.55 rear axle gearing, Moss 5-speed trans, Pertronix ignitor, and I’ve just finished installing the new Moss-Eaton supercharger. Ya Hoo! What a difference!!

      Question: I’m hearing a noticable chatter/rattling noise coming from the vane housing area of the supercharger. Most notable at idle, and probably still there as rpm goes up but there’s so much other noise emitting from that old lump of a motor that it gets lost in the racket. Is that noise from the blower vanes normal??



  10. March 11, 2013 @ 6:17 am GRUSS

    J’habite en France. Je souhaiterais me procurer pour ma MG TD 1952 les kits suivants :
    – un compresseur MOSS
    – une boîte 5 vitesses FORD SIERRA + kit de montage
    – amortisseurs arrières hydrauliques
    – barres de torsion anti roulis
    Pouvez-vous me dire où m’adresser pour me procurer ces pièces et à quel prix ?
    Merci de votre réponse. Cordialement
    Claude GRUSS


  11. June 24, 2013 @ 3:00 pm John Douglas

    My first car was a 1947 TC…it came as a kit of parts in tea chests, plus the chassis and major mechanicals and bodywork, for £50 in 1966, when I was 20. Did a full rebuild on the beast and fitted a self-modified cylinder head and a Shorrocks supercharger kit. I could get wheelspin changing into third!! I bought the blower from the Exchange and Mart for £7-12s-6d and all the fittings from Allards in Putney. Had to search through a huge pile of castings to find the manifolds…. Learned a lot from that machine, she was good for almost 110 mph…loved the banshee wailing of the blower with the boost gauge at 7psi. Wish I still had her! However, the 1982 Lotus Esprit Turbo helps to make up for it…..


  12. December 12, 2013 @ 6:57 pm Holland Simms

    Have you considered making an adapter to use the supercharger with the MGB cross flow head that you sell? I noticed the TR3-4 supercharger is for mounting on a engine with right hand side induction ports.
    I have been considering that cross-flow head, roller valve train and perhaps boring the engine 40 over with 8.0 compression and using the high boost pulley. The engine is a late 65.I noticed you have 60 over pistons can that block really safely be bored that much or would it be best to sleeve the bores?
    Thank you


  13. January 13, 2014 @ 6:41 pm Ron Fiore

    Great article…………I purchased my ’49 TC in 1967. When purchased, it was fitted with a Shorrock supercharger. You are correct, the whine on the unit was musical. (Please refer to my “mossmotoring” article regarding “The Way We Were” movie car.)

    Unfortunately, when the engine was turned off, the oil contained in the oil line, would drain into the unit, creating a cloud of white/blue smoke about the size of a Home Depot, when the car was re-started.

    Because of this unliveable phenomenon, the unit was removed and replaced with twin SU’s.

    Although this remedied the problem, I have always wanted to re-install the supercharger (still sitting under my work bench).

    I have considered installing a solenoid-type valve, which would close off the oil line, when the ignition was turned off (thereby eliminating the oil drain-down problem), but have thought that another solution might present itself.

    Any suggestions ?

    Many thanks,

    Ron Fiore


  14. April 3, 2014 @ 4:00 am Jeff Liroff

    I’m interested in getting a Moss S/C for my ’61 Triumph TR3A. I won’t do the installation myself so what I’d like to find out is how many hours a very experienced & competent mechanic who’s never done an installation of your S/C before should need to do the installation?

    Also, how long will it take from order placement to order fulfillment for the low-boost unit to fit my TR? I inquired a few years back and the wait was many months at that time. Is it still like that?




    • October 19, 2014 @ 3:48 pm Tr3ASC

      hey Jeff,
      I too have a TR3A(1960) & am interested in the moss S/C.
      Wondering how your supercharger project went?
      My engine is strong & I believe, can endure the s/c , but I’m also installing a 1976 tr6 OD tranny.

      Any pearls of wisdom?

      Thx. & best regards,

      Guy Pierce


  15. July 18, 2015 @ 10:17 am John pumo

    Hi all I have a 1974 tr6 with a supercharger on it. It was recommended I put a bigger pully on it to get more boost. Any thoughts? Thanks for the input


    • August 11, 2015 @ 7:13 am John Jervis

      hi John,

      I have a Supercharger on my 1972 TR6 and I am looking to get some more boost from it. I am waiting for a larger crankshaft pulley to arrive which will mean the S/C turns about 13% faster, also I have the “super boost” conversion which is a smaller pulley for the S/C so it runs faster driven by the cranshaft pulley. My engine is a stock CP with 9.5:1 compression so I have already fitted a water/methanol injection kit as the heat generated by the extra boost will probably roast the pistons. Heat is what you will need to watch for because the detonation will quickly scrap the pistons/bores etc. I have altered a few other things to help the engine run cooler in the cylinder head area. Hope that helps.


  16. September 18, 2015 @ 7:22 am Wayne McDonald

    How about offering a mirror image copy of the TR6 unit for my MGC-GT?


  17. June 2, 2020 @ 3:31 am nissim buchnik

    hello friends
    i have a mg TD 1951
    and i have a jadsone super charge not instol
    i need the double puly that goes on the engine
    can you help?
    best regards nissim


  18. June 18, 2023 @ 2:57 am Larry Leonard Gray

    I have a Triumph TR7. Don’t laugh!

    What are the chances of a Moss Supercharger or even a turbo charger?


    L. Gray


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