Following the article we published last January on an M.A.G.-supercharged Volkswagen, we have received many enquiries, while details of other “souped-up” VWs have been coming at us thick and fast!
Before we discuss some of the claims made, it is ironical to note that, whereas formerly we were often accused of bias in favour of the German beetle, we had only to remark, when introducing the M.A.G.-blown version, that one of the shortcomings of the normal VW is its sad lack of any real performance, to be inundated with indignant letters defending the VW, which, these correspondents pointed out, can more than hold its own with other cars of similar size! Therefore, we hasten to point out that when we made this comment we were thinking in terms of the sort of performance sporting motorists expect; figures have appeared in Motor Sport previously which show how effectively the VW disposes of other small cars. In this respect, we have been taken to task for the poor figures we gave in the January article for the maxima in the gears of the normal VW. We have consulted our notebook again and find that what we quoted were the speeds at which the VW’s owner deemed it prudent to change-up in order to secure maximum acceleration on the timed runs. It is well-known that higher absolute maxima are obtainable and a fair comparison in this respect between the M.A.G.-blown VW and the normal 1957 VW we pitted against it would be: s/c VW: first, 16 m.p.h.; second, 45 m.p.h.; third, 69 m.p.h — Normal VW : first, 16 m.p.h.; second, 40 m.p.h.; third, 60 m.p.h. (speedometer errror corrected). Incidentally, the manufacturer’s recommended figures are, respectively, 15, 30 and 45 m.p.h. Although some readers think the driver we timed changed up early at 47 m.p.h., in view of the VW’s ability to reach or even exceed a genuine 60 m.p.h. in third, his acceleration times do not appear to have suffered. For example, we recorded 0-50 m.p.h. in 20 sec., 0-60 m.p.h. in 33.1 sec., and the standing-start 1/4-mile in 23.7 sec. The Motor gives figures, for a 1956 de luxe VW, of 18.2 sec., 32.4 sec., and 23.5 sec., respectively. The Autocar, testing a 1958 de luxe model, quotes 22.4 sec. from 0-50 m.p.h. (car not timed to 60 m.p.h.) and 24.6 sec. for the s.s. 1/4-mile but, although VWs do not require running-in, it is known that the car they had was new and stiff, resulting in pathetic figures. Yet, if The Motor and The Autocar figures are averaged we get 0-50 m.p.h. in 20.3 sec. and the s.s.1/4-mile in 24.05 sec. These are so close to the Motor Sport figures that we feel justified in using ours as a basis of comparison between normal and “souped-up” VWs.
Now let us consider some of the claims made for these modified cars. The Service Garage of Rhos-on-Sea sends us a cutting front the North Wales Pioneer concerning a 1956 convertible model with Arnott supercharger. For this VW a top speed of 98 m.p.h., 0-50 m.p.h. in 11.5 sec. and 0-60 m.p.h. in 15.8 sec. are claimed, and the Service Garage tell us that the 100-m.p.h. speedometer now fitted is probably 5 m.p.h. fast at around 90 m.p.h. The engine is said to reach 5,500 r.p.m. in third gear, equal to 80 m.p.h., and many will fear for its crankshaft. Modified suspension and Michelin “X” tyres render the cornering safe and if we read this local paper’s report correctly the compression-ratio has been raised to 8.0 to in spite of the forced induction. Fuel consumption they put at approximately 27 m.p.g.
The Services Garage of Colchester inform us that they have the agency of the American Judson vane-type supercharger installation for the VW, and the manufacturer’s leaflet they have sent to us quotes a maximum speed of 85 m.p.h., 0-50 m.p.h. in 10.2 sec., 0-60 m.p.h. in 15.5 sec. and 29 m.p.g. The Judson gives a boost of 6 lb/sq. in. and weighs 17 lb. (maker’s figures). This installation costs £80 fitted, or £90 for a Karmann Ghia.
Here it is opportune to remark that V. & F. Monaco Motors of London are able to supply the M.A.G. supercharger installation, which costs £96 fitted.
A new two-carburetter conversion for the VW is the A.V.C. made by Adams (VW) Conversions of Herne Hill and fitted by Abbey Garages. This employs two Solex 28 P.C.J. carburetters on A.V.C. induction stubs, using a semi-rotational tubular throttle linkage and choke operation by rod and angled arms. The A.V.C. conversion costs £45, fitting extra. Acceleration figures claimed for it are: 0-30 m.p.h. in 6 sec., 0-40 in 9.7 sec., 0-50 in 13.8 sec., and 0-60 m.p.h. in 21 sec., with 35 m.p.g. cruising at 70 m.p.h. and over.
We have not so far been able to test all these conversions and the only way to check the claims made for them is to check the speedometers and time the cars over a measured distance. We hope to do this for the Judson-blown car and an A.V.C.-converted VW In due course.
Meanwhile, we are able to publish authentic performance figures for the Rally Equipment two-carburetter conversion, about which some controversy arose in the correspondence columns in Motor Sport last month. This conversion in Stage II form comprises an additional Solex carburetter, inlet manifolds, petrol filter, air cleaners, petrol pipes, throttle linkage, balance pipe, jets and gaskets, the price of the kit being £38 10s. The choke is dispensed with on this installation. Rally Equipment claim 0-60 m.p.h. in 20.5 sec. from this conversion, which they import from Germany. When tested by The Autocar, a 0-60 m.p.h. time of 35.8 sec. was quoted, but two monthly motor journals published figures of 0-50 m.p.h. in 17.3 and 16.8 sec., and 0-60 m.p.h. in 21.5 sec. and 20.9 sec., respectively.
We took away for test the Rally Equipment 1958 VW, standard except for its two carburetter conversion. It had a Halda Speed pilot, stop-watch holder, screen-mounted Helphos swivelling interior spotllamp, Butlers reversing lamp, its switch sensibly incorporating an indicator light, small Union Jacks on the scuttle sides, and a London Rally transfer (the last-named causing other drivers to breath on one’s back window!). The car was shod with normal Michelin tubeless tyres.
We took the car to the same carefully measured mile where the M.A.G.-blown VW was timed. Timekeeper and watch were also the same. The figures obtained are compared with those for a standard VW and the M.A.G.-blown VW in the table below, and from these we deduce that of the other journalists who tested the car one was unduly cautious and the other two failed to allow for the fact that the car’s speedometer was reading fast. We make this statement after carrying out some significant experiments. Timing the car from rest to a genuine 60 m.p.h. (the speedometer going to 65 m.p.h.) but changing up at the speeds indicated on the speedometer, gave a time of 36:0 sec., which compares with The Autocar’s figure of 35.8 sec. and indicates extreme caution on the part of their tester! Timing the car from 0 to a speedometer 60 m.p.h. gave a mean time for runs in both directions of 20.3 sec., which is within one-fifth of a second of Rally Equipment’s own figure and close to the 0-60 figures published by two monthly motor journals, the time of 20.9 sec. for the slower run being exactly that quoted by one of these journals — verb sap.
Having satisfied ourselves as to how other testers came by their unhappily inaccurate figures, we timed the car to corrected speedometer readings (it was 4 m.p.h. fast at 50, 5 m.p.h. fast at 60 m.p.h.), with the result, shown in the table, these, for comparison, being shown with the figures published in our January issue. It is obvious that the supercharged car began to leave the two-carburetter car behind from 50 m.p.h. onwards and whereas at the end of the s.s 1/4-mile the latter showed an indicated 62 m.p.h. in third gear, the M.A.G.-blown VW was indicating 66 m.p.h. at the same point, and the normal VW a speedometer speed of 58 m.p.h. The Rally Equipment car gave true maxima of 16 m.p.h. in first gear, 45 m.p.h. in second and 67 m.p.h. in third gear, the speedometer reading 20, 50 and 73 m.p.h., respectively. When carrying out the acceleration tests we found it better to change up at indicated speeds of 18 and 48 respectively, in first and second gears. Some clutch slip intruded towards the end of the timed tests.
Although not so impressive as the blown VW and subject to some optimistic claims (readers must form their own opinions about claimed performance figures for other VW conversions not yet tested by this paper), the Rally Equipment conversion gives an improvement of over 8 sec. in acceleration to 60 m.p.h. over the standard VW, which is commendable, especially in view of the competitive price of this kit. This improvement is very usable on the road and brings no snags with it — the throttle action and noise level are indistinguishable from those of a normal VW. ln a distance of 560 miles it proved entirely reliable. Petrol consumption — running on premium but, not super, fuels — was 29 m.p.g. including performance testing, improving to 34 m.p.g. in normal usage. Starting from cold was hesitant due to the absence of choke.
Incidentally, twice recently while driving VWs we have been rammed up the back bumper in traffic by B.M.C. people, first by a Morris Minor at Victoria, then by an Austin A30 in Vauxhall which may or may not mean something! — W. B.
Acceleration Table: Normal 1957 VW — Rally Equipment 2-carb 1958 VW — M.A.G s/c 1958 VW
(Speedometers corrected for optimism.)
0-50 m.p.h.: 20.0 sec. — 16.0 (16.7) sec. — 15.7 (15.8) sec.
0-60 m.p.h.: 33.1 sec. — 24.4 (24.5) sec. — 21.0 (21.1) sec.
s.s 1/4 mile: 23.7 (23.7) — 22.8 (23.0) — 21.7 (21.7)
(Figures in parenthesis are means of runs in both directions)