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Discussion Starter #1
i was looking at the F4 wiring diagram for the 2005 bike, and it had a system called TSS on it, which is only on the Tamburini at this point.

i didn't know what it was, untill now. it's a varible length intake system. it's not very sophisticated, but it's a first on a production motorcycle. btw, LOTS of cars use similar sytems.

here's a VERY good description by Kevin Cameron (MIT grad) of Cycle World. it's posted elsewhere on the net, so i've pasted it below. i've also included a link to the full review of the tamburini, which i belive is also on this forum.

alex

TSS, Intake tract trickery

Variable-length intakes such as the MV Tamburini's Torque Shift System make us think of Formula One or of the last of the racing Mercedes 300SLRs, but the concept is useful wherever engine torque must be maximized across a range of rpm.

First, some physics. When a piston drops on its intake stroke, a deep vacuum of about half an atmosphere is immediately created in the intake tract. This propagates from the piston crown toward the intake's open end—the bellmouth—at the local speed of sound (fast!). When it reaches the end, atmospheric pressure rushes in to fill that partial vacuum, creating a reflected pressure pulse that crashes back down the intake pipe as a wave toward the valves. If our wave returns to the cylinder just before the intake valves close, the pressure in that wave will be added to the pressure in the cylinder, making a denser charge that equals higher combustion pressure and increased torque.

Often there is not room on a motorcycle for intake pipes of the necessary length, so the designer will allow the intake wave to make two or more trips up and down a shorter intake pipe. Each reflection of the waves loses some of its intensity, but compromises are the engineer's stock in trade.

By using an intake pipe of ideal length for the desired rpm, a torque gain of the order of 10 percent may be achieved—but only across a limited rpm range. To have both a robust midrange (the Tamburini's peak torque on the CW dyno comes at 8700 rpm) and strong top end calls for having two different intake lengths. This is just what TSS delivers. The MV's four throttle bodies have short, permanent bellmouths suited to top-end power, but a set of moveable extension bellmouths is carried on a pair of linear bearings. Below 10,000 rpm, these extensions are in place, creating a longer intake tract that boosts torque. Above 10,000 revs, a Pierburg pneumatic actuator (run on engine vacuum) snaps the extensions up and out of the way, shortening the intake tract to boost breathing and thus power on the top end. This is a two-state system—it is not progressive—as the extensions are moved in or out of use within 0.15 of a second.

Because the change of intake length is carried out at an rpm between peak torque and peak power, where the engine's torque is less dependent upon intake length, torque at the "shift" point does not change greatly.

A similar two-state variable intake length system was used in Superbike racing by Honda on later RC45s, but this does not violate MV's claim that TSS is a first for a production motorcycle.
— Kevin Cameron


http://www.cycleworld.com/article.asp?print_page=y&section_id=12&article_id=22&page_number=1
 

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Interesting post, Alex. I would have been skeptical of the benefit, but after putting aftermarket Graves Velocity Stacks on my R1, I can attest that intake length really made a big difference, especially in midrange. Having a variable length intake system would seem to be ideal.
 

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Discussion Starter #5
here's a great photo of the system
http://www.cycleworld.com/article.asp?section_id=12&article_id=22&page_number=3

you can clearly see the shaft for the actuator between the #2 & #3 intake trumpets. the base of the system has a set of rubber seal rings which seat against the lower stacks in low-rpm operation.

pretty cool stuff. now when will someone come up with a variable length intake?

alex
 

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All that trickery doesn't seem to produce much BHP increase as against the standard 1000. :rolleyes: I presume it isn't about all out BHP, rather throttle response at certain RPM. The new 1000R has more or less the same max BHP as the Tambo with TSS. Perhaps those on the forum who have owned or ridden both (Tambo and standard 1000S) can tell us if they think it's worthwhile? :grin:
 

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Very nice post, cristal clear !

I've learn...and understand something today ! TX.
 

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There was some talk of more rpm and hotter cams to go with the new 06 Senna and R, but it would seem the bhp changed just enough to account for the RG3 on them. The fueling on my 05 is notchy I should get the new injection under warranty. :mad:

The Veltro comes with Tss right, how bad can it be.
 

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john said:
All that trickery doesn't seem to produce much BHP increase as against the standard 1000. :rolleyes: I presume it isn't about all out BHP, rather throttle response at certain RPM. The new 1000R has more or less the same max BHP as the Tambo with TSS. Perhaps those on the forum who have owned or ridden both (Tambo and standard 1000S) can tell us if they think it's worthwhile? :grin:

The idea is more available throttle control and torque at a wider range of revs rather than outright bhp..otherwise they'd just throw on a fixed set of stacks like the standard bikes.

I've ridden a standard 1000 and a Tamburini on our local twisties and it is a wider or 'fuller' range but the MT had mid/RG3/eprom and 1000 was standard so it's hard to be sure what was what exactly.
 
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