Piaggio Original

19.4 HP @ 7080 rpm
19.6 Nm @ 6850 rpm
For its relatively small HP performance is very torquey.
Price: approx. 110 DM

Sito plus

20.3 HP @ 6750 rpm
21.8 Nm @ 6370 rpm
More torque, in comparison to the original Piaggio. But not much more powerful. Probably will be some km/h faster, since between 5000 rpm and 8500 rpm it has 1 to 2 HP more than the original Piaggio.
Price: approx. 120 DM

Kegra / JL

22.7 HP @ 7160 rpm
22.4 Nm @ 7030 rpm
The Kegra convinces neither with performance, or with torque. Still worse however, the area of highest performance is much too narrow a power band. It is by far the worst English racing exhaust on the market! (if it still is)
Price: approx. 500 DM?

Leo Vinci

26.9 HP @ 8230 rpm
23.3 Nm @ 7960 rpm
Clearly, it winds up quickly, almost too quickly. Its power band is also not very even. Will not be as tractable and easy to ride as some good English systems. At low revs does not go well. With 5500 rpm it has 13 HP (PM Evo here already has 18 HP!).
Price: approx. 130 DM

Polini

24.3 HP @ 8060 rpm
21.4 Nm @ 7930 rpm
Again a typical Italian. As with the Leo Vinci there is good HP, however the available power is simply too narrowly spread. Unfortunately at low revs (as with the Leo Vinci) simply EVERYTHING is missing.
Price: approx. 120 DM

Simonini

26.0 HP @ 7640 rpm
24.0 Nm @ 7500 rpm
The Simonini resembles very much the Leo Vinci and Polini. It has the advantage that it indicates always 2 HP more up to approximately 7600 rpm. It can be driven somewhat easier than the Leo Vinci and Polini. Its power band is also not the broadest. The PM Evolution is better because it a broader power band and has more torque. Given the selection between Polini, Leo Vinci and Simonini, the Simonini is the best choice, although all are not so good- however for the money?
Price: approx. 180 DM

No longer made
No Photo available

PSP 2000

23.2 HP @ 6350 rpm
27.4 Nm @ 5730 rpm
The PSP supplies torque over a broad power band. However here the with high engine speedness and the maximum performance lets require. Only which one can make with this exhaust is too secondly in the third course the burner highly to drive without to switch. It cannot do that well - more in addition. It turns even still fewer like a Piaggio original exhaust. High rates are to hardly expect it HP are missing there and it probably hardly such a long translation give
Price: No longer manufactured.

Zirri

25.4 HP @ 8310 rpm
21.9 Nm @ 8050 rpm
The curve resembles the TFF (PM old), however unfortunately shifted 1500 rpm toward higher revs. Thus it becomes difficult for normal traffic.
Price: approx. 270 DM?

RZ Evo LH 2000

27.2 HP @ 7500 rpm
27.0 Nm @ 6740 rpm
This exhaust and the following RZ leave almost nothing to be desired! Absolute top class!
Price: approx. 530 DM

RZ Mark One Right Hand

27.9 HP @ 7850 rpm
27.5 Nm @ 6780 rpm
Super high torque! Broad power band. Maximum performance and still all this in the correct speed range! It was actually for a long time the secret tip among the specialists. The looks are a matter of taste, because it is a right hand exhaust and flows under the motor.
Price: approx. 540 DM

(SIP say the muffler can fall off after long use - Bill.)

PM Evolution

25.0 HP @ 7410 rpm
25.9 Nm @ 6405 rpm
Decent performance at relatively small revs. Broad power band from 6000 rpm to 8000 rpm. This power curve is exemplary (which does not mean however that it is the best exhaust here). Here one can only say: Good selection, however still not enough to be the best, since for that 2 to 3 HP are missing.
Price: approx. 520 DM?

SIP Performance

27.5 HP @ 7620 rpm
26.9 Nm @ 6860 rpm
Yes! And again a direct hit. Performance, torque, the number of revs and the width of the power band speak for itself! The RZ Mark One right hand has the same and even somewhat more, but the SIP is carried left instead of on the right which makes the SIP performance a genuine alternative (not to forget the Evo 2000). The PM evolution it topped only scarcely. The SIP Performance is made by English exhaust guru John Lomas. Made of stainless steel.
Price: approx. 540 DM. Polished 590DM

Taffspeed Mk4

29.1 HP @ 7910 rpm
26.7 Nm @ 7450 rpm
Also not bad! Despite the high maximum performance the PM Evolution outweighs it strongly in the power band. From 5500 rpm to 7500 rpm there nothing at all, does not go. SIP performance and RZ Mark One right hand can be ridden better because of their beautiful power band.
Price: approx. 630 DM

TFF PM

27.2 HP @ 7810 rpm
24.9 Nm @ 7520 rpm
Performance-wise higher than the PM Evolution. But also here the number of revs are somewhat too high and the power band unfortunately not as broad as it should be. The curve resembles the SIP performance. Unfortunately shifted almost exactly 1300 rpm to towards higher revs. That makes it no longer easy to ride. PM learned from it and developed the PM Evolution.
Price: approx. 550 DM?