Last month we embarked upon the start of a series of dyno testing articles, covering the clubman style exhaust systems that are available for the Lambretta models. This month we move on to Part 2 of the series, to look at more of the available contenders…
With so many kits on the market, in such a variety of cubic capacities (typically 175cc-230cc) and with a host of cranks which implement the ability to move port specifications about, and many ported/tuned engines out there, we had to decide what to choose as a donor machine for testing on. In an ideal world we would test every pipe on every kit, at all different crank/carb/porting levels… but in reality that is simply not possible.
Luckily, local scooterist Rob Shaw had his latest build to offer, that was just run in and available for the job in hand, so he fetched it along and mucked in with the testing. It’s a cast GT186 kit that’s built onto a 60mm stroke crank making it 193cc. It’s received a small porting tweak and cylinder head rework that brings its performance up to a healthy figure more akin to that of a 225cc motor.
It runs through a 28mm Dellorto PHBH carburettor. This engine will be great, as its power range and application is very common: a ‘high-teens’ bhp cylinder, using a clubman pipe, Delly carb and built for touring at a pace higher than a standard engine, but without going OTT on race parts. That description covers a lot of engines out there! So this is perfect.
The next chapter
Continuing on from last month’s testing of the AF range of clubman exhausts, we now move further afield with offerings from the Scootopia Clubman to the Tino Sacchi Ancillotti in both long and short header pipe versions, and another Italian offering from Gori with their Racing version. As before each test meets a strict and repeatable testing regime, for accuracy of results worthy of comparison. The dyno graphs display each pipe tested in red, compared to a standard SX200 in blue and a JL3 expansion pipe in green, as our upper benchmark providing us with some useful indicators that most riders can relate to.
First on test this month is this tidy pipe kindly sent to us by Scootopia for testing, which arrived in bespoke packaging, along with all the fittings and fixings, and with what appears to be a good chromed finish two-piece header pipe. This should help with ease of fitment, which is exactly what it did, fitting up with no issues on our example. An online search found them to be available at around £95 on average. This exhaust had an internal diameter of 38mm on the header pipe connection, and a 19.5mm internal diameter on the outlet. Producing 17.55bhp at a low 7300rpm, which is close in terms of peak rpm to the expansion chamber, also with a good torque figure of 13.2lb-ft at 5800rpm. So all-in-all this pipe is a very good low rpm performer, which should make for a nice setup on a rally scooter .The pipe was also one of the quieter ones, which is a relevant consideration these days.
TINO ANCILLOTTI CLUBMAN: LONG 2-PIECE HEADER
An online search found this exhaust priced on average at around £170 and upwards, our test example was provided by a customer, so not new but still came with both header pipe options that have been in use during its production. This exhaust also had an internal diameter of 38mm on the header pipe connection, with a 19.5mm internal diameter at the outlet. Power readings showed 16.58bhp at 7000rpm with a torque figure of 13.1lb-ft at 5100rpm. Unsurprisingly, both figures were very close to that of the similar looking Scootopia version, Mechanically, this was another good fit but this had been modified by its last owner on the chaincase bracket to make it separate from the main body, so ignore that feature on the photo. Again, this exhaust was also one of the quieter ones.
TINO ANCILLOTTI CLUBMAN: SHORT 1-PIECE HEADER
Similar pricing to the two-piece and same body as before but this model with this short type of header pipe which makes for an interesting test. Header pipe and outlet sizes were the same at 38mm and 19.5mm internal diameters. In terms of power, this exhaust was making 19.72bhp at 8500rpm with a torque figure of 12.6lb-ft at 5900rpm… what a difference a header length makes! Moving peak power along the rev-range by 1500rpm, and increasing power by over 3bhp at peak. Fit and sound was as before, but the change of operating rpm between the two types would require different gearing to capitalize on this difference. On average gearing, 1500rpm extra equates to a theoretical increase of around 15mph in top gear — if the engine can pull it, a consideration for all pipe choices.
GORI RACING 48
These exhausts represent a major change in the tests in terms of pricing, moving up to an internet researched price of circa £280. That is up to three times the price that a lot of others we tested were priced at, but does tie in with the typical price charged for a full expansion chamber exhaust. Like an expansion this one has a small silencer attachment, so is supplied with something a little extra for the money. This ‘extra’ brings the noise level down well, and I would call it noisy without it on. This pipe actually belongs to Rob, the test scooter’s owner, and he has owned it for a few years now, having had it on a standard cylinder first, then later also on a BGM 225 cylinder, and now this… his GT kit. So this pipe certainly seems to have stood the test of time and miles, which is another consideration when looking at the first seemingly expensive RRP.
Rob told us: “It’s certainly had some use.” and then commented on how good the fit is, saying “it just slips straight on”. Originally sold in a high-temp clear lacquer finish, Rob had changed it to silver powder coat at some point… that’s not fared too well with the heat, so ignore that on our test pipe photo. Header pipe size at the box connection had a 46mm internal diameter, with an outlet size of 20mm internal diameter. The power results were pleasing at 19.99bhp at 7700rpm, showing useful over-rev to 8500rpm, and actually revved right on to 9600rpm. Torque was also good 14lb-ft at 7300rpm.
Red: Scootopia Clubman. Blue: Tino Ancillotti — long header. Green: Tino Ancillotti — short header. Purple: Gori Racing 48.
So this month the Gori showed itself to be a good performer at all power levels, and a bit of kit which fits well and can stand the test of time. Certainly in terms of ‘bang for buck’ it’s not the cheapest exhaust, and given the price difference it may not be everyone’s first choice. The Scootopia pipe shows strong mid-range performance and at a more favourable price, so that may sweeten the deal for many. Finally, the Tino Ancillotti in short-header format shows a top-end (8k-9k rpm) power range similar to the Gori, but for less money… although it was lacking in the 4k-6k rpm range as a consequence.
This chart displays the results showing the power output of each pipe at each 1000rpm step from 4000-9000rpm. The sub 3000rpm results are left off the chart as the throttle-roll-on nature from the sub-3000rpm dyno start run starting point does not settle fully until around 3500rpm.
|GORI RACING 48||8||12.8||15.2||18.2||19.4||14.6||19.99|
POINTS MEAN PRIZES
Of the four exhausts on test this month, I’ve chosen to award four points for the highest performer at each rpm range and max bhp, down to three, two, and one for the lowest, so highest points shows the best performer. The first column shows results over the entire rpm range 4000 to 9000rpm, I then added another column to show the best performer at 4000 to 6000rpm, as an indicator of low-mid rpm performance, and finally… I then added another column to show power at 7000 to 9000rpm, as an indicator of the high rpm results.
4K TO 9K
4K TO 6K
7K TO 9K
|1 CORI RACING 48||24 POINTS||9 POINTS||11 POINTS|
|2 SCOOTOPIA||19 POINTS||9 POINTS||8 POINTS|
|3 TINO ANCILOTTI-S||18 POINTS||4 POINTS||10 POINTS|
|4 TINO ANCILOTTI-L||14 POINTS||7 POINTS||10 POINTS|
In the next instalment we take a look at the BGM Clubman, a Mito reverse, a Ron Moss clubman and the latest Gori GP50. Got something else to test? We’d like to hear from you ASAP so we can include it.
Words & Photographs: Darrell Taylor
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