White One Racing Torque and RPM Vespa Box Exhaust | TEST

The world of Vespa box exhausts is constantly evolving, meaning our previous box exhaust tests are now well out of date; thanks to a plethora of new models from the main tuning houses. In addition, lots of smaller outfits are making their own submissions.

One such enterprise is White One Racing (W1R for short) who have developed exhaust systems for the various largeframe PX125/150 and 200 models. Damiano from W1R offered us two of his PX125 exhausts to test – in ‘Torque’ and ‘RPM’ varieties – to test on a pretty basic T5 engine with a Malossi 172 kit fitted. 

This engine, with standard 24mm carb and uprated oil injection pump, was my go-to for long-distance Cannonball races from Munich to Pordenone in Italy. With 18-litres of fuel on board and fuel economy of 10 miles per litre with the throttle to the stop, it meant that crossing the Austrian Alps from Germany to Italy could be done without refuelling.

Dreadnought in Munich in 2002 – an elephant for crossing the Alps

The eagle-eyed amongst you will have spotted that PX 125 exhausts do not natively fit the Vespa T5. All that has changed now; thanks to an adapter from BGM which bolts to the T5 barrel and provides a PX-like stub for any PX-fit exhaust to clamp around.

BGM’s adaptor stub to fit PX125/150 exhausts to T5 cylinders

My T5 172 has always been fitted with an ancient Taffspeed Mk4 exhaust which was probably the most adaptable expansion chamber for the P-range. It seemed to work on every engine, whether kitted or not. On the T5 it worked relatively high up the rev range; making peak power at 7,250 rpm and revving on to 9,000 rpm in the lower gears. As a result, it needed to run quite short gearing; only the standard 20T clutch cog or 21T when used with a windscreen that you could tuck behind.

The cost of shifting the power higher up the rev range is a lack of power and torque at low revs. If the engine isn’t singing like a fisted choirboy then the scooter isn’t moving.

Enter the Performance Box

There are performance box exhausts for every sort of engine now; many offer significant advantages over expansion chambers in terms of ground clearance, quietness, ease of fitting and rear wheel access. They are also useful in countries where the standard look of an exhaust is important.

Where box exhausts score less well is in terms of tone and style.

When it comes to performance, the old rule was that expansions usually made more power but over a narrower rpm-range; whereas boxes usually had a wider spread but lower peak power.

Lately, that has changed with newer box exhausts even rivalling old expansion chambers for outright power. 

W1R boxes have 9-segment cones in 0.8mm steel

White One Racing Boxes

These have grown from a technical development of Damiano and Francesco for W1R which is commercialised by the online store 10Polici. All the W1R boxes are made in Italy.

The two versions for each model differ only in the first part of the downpipe length. The Torque one is 40mm longer at the stub. Lengthening the downpipe makes the Torque exhaust work slightly better at lower revs.

How do they perform?

We managed to fit the W1R boxes to our first T5 172 for test. Alignment of the PX pipes using the BGM adapter was more difficult than it usually is for a dedicated T5 exhaust.

Compared to the Taffspeed exhaust both the W1R boxes made power much earlier in the rev range which equates to a significant increase in torque at lower revs.

I was quite impressed with the output because the gain in torque only comes with a small loss in peak power. Of the two, it was the longer ‘Torque’ box that performed best on this engine in terms of peak power, but as everything in tuning is a see-saw; the cost of this is reduced over-rev. 

What are the W1R boxes useful for?

One problem with a low-torque, high-rpm engine is that elevated engine rpm inevitably means high wear and high fuel consumption. 

If you can get more torque at lower engine rpm then you can run taller gearing. Then you can travel at similar speeds but using less fuel and causing less wear to the engine. If you do not change your gearing then you will simply go slower if you use an exhaust that does not rev as hard.

Changing gearing by a small amount on a PX-series engine is quite easy, simply by substituting the primary drive cog in your clutch. Where our test engine ran 20T, you would need to run 22T to achieve a decent top speed.

In the past, you would never consider fitting a box exhaust to a large-capacity or high-power engine, not only because it looks and sounds less sporty, but also because the standard 16mm outlet tube dimension can be restrictive enough to cause heat build-up in the cylinder. W1R have thought of that, and produce ‘+’ versions of all of their exhausts which have a 19mm outlet.

W1R provided graphs for a tuned LML 125 engine fitted with an RD reedvalve, a long-stroke Quattrini M1X kit and a 36mm PHBE carb. This comfortably produced in excess of 30hp.

Or, to put it more simply, you can now make a very practical Vespa touring engine with all the convenience of a box exhaust.

A 19mm outlet lets the heat out better

Other Points

• Both spring hook and normal clamp fitting options at the cylinder (springs not supplied)
• Black coating only lasts minutes on the downpipe (as with pretty much every other box exhaust) so expect rust or regular re-coating
• Sound is louder than a standard exhaust but not unpleasant
• The retail price for these boxes is €205-€209; depending on version

The stand spring touched the downpipe on Theresa’s T5 Classic

Exhaust paint: Gone in 60 Seconds – like pretty much every other exhaust. This is after 500 miles use…

VIDEO: Francesco explains the details of the W1R boxes. ‘Padella di corsa’ translates roughly to ‘racing frying pan’.

Words and images: Sticky

Dyno Testing: Diablo Moto