For nearly 10 years we have been taking the attitude that the performance of a given sports car must be evaluated with due allowance for its engine size. The only trouble is that everyone seems to want more. The MG is a perfect example: no sooner had they come out with the "A", offering truly competitive performance for a 1.5 litre car, when along came our readers asking for more. Personally, we feel that 0 to 60 in 14.2 seconds and a top speed of 97 - 100 honest mph (which the stock MGA does) should satisfy anyone.
The truth is that although sports cars are gradually becoming accepted for what they are (maximum performers for a given class), there are still many people new to the sport who do not understand. Inevitably, since the MG is the lowest-priced sports car, it becomes susceptible to the wiles of the sorcerer, in the case Judson of Conshohocken, Pa.
Judson say that their supercharger offers 50% more power. though the car does indeed take on a new character, the truth is closer to 25%. However, even that much of a boost is well worthwhile, as shown by the tabulation which appears in the next column.
This order of improvement, plus a comparison of other data, indicates that the
|
Judson supercharger gives the MG a very close equivalent to 25% more torque and boosts the peak horsepower from 72 to 90, and no more. But the point is that performance is improved as if the 1.5 litre MG engine were enlarged to 1.9 litres.
|
|
Stock |
Judson |
|
0-30 mph |
4.5 |
3.8 |
|
0-60 mph |
14.2 |
12.5 |
|
0-80 mph |
29.0 |
25.0 |
|
Standing start |
|
|
|
1/4 mile |
19.6 |
18.1 |
So, the advantages of a Judson supercharger are stated factually in terms of performance gain - what are the disadvantages? In the first place, supercharging is a matter of degree. It can give fabulous power gains by using plenty of boost, but it is high boost pressures which have given supercharging a bad name. The Judson MG kit is designed to give modest manifold pressures of about 5.5 pounds per square inch maximum.
Then we must consider the fundamental principles involved. Judson superchargers are the vane type, which means positive displacement. This type of supercharger gives its performance gain at all speed, which is important.
Continued on next page
|
