MNR Vortex RT Hayabusa

Need help from a fellow owner, something to air - discuss away!

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Weathers
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Re: MNR Vortex RT Hayabusa

Postby Weathers » Thu Jun 13, 2019 7:53 am

David T wrote:How do those different length trumpets work? Not seen that before.


I thought the same thing - interesting.

Nearly there Lee! Will be amazing once she’s up and running. Which track are you testing on?

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Re: MNR Vortex RT Hayabusa

Postby jeffw » Thu Jun 13, 2019 10:01 am

Different length trumpets are used on the bikes to fatten out the torque curve, effectively two cylinders are tuned for torque and two for top end.

Most of the BEC installs I've seen do away with it and just have the same trumpet length for each cylinder.

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David T
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Re: MNR Vortex RT Hayabusa

Postby David T » Thu Jun 13, 2019 11:13 am

jeffw wrote:Different length trumpets are used on the bikes to fatten out the torque curve, effectively two cylinders are tuned for torque and two for top end.

Most of the BEC installs I've seen do away with it and just have the same trumpet length for each cylinder.


Interesting.

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leegav
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Re: MNR Vortex RT Hayabusa

Postby leegav » Thu Jun 13, 2019 5:39 pm

Different trumpet lengths do exactly what jeff said.. I did toy with this idea on the tiger with the AT power throttles. Rich at RLM advised its a good idea for me as i ise the car on both road and track. We will adjust on the dyno to get it spot on for how i use the car. Jenvey do an adjustable itb trumpet set you can buy so you can adjust as much as you like.
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Re: MNR Vortex RT Hayabusa

Postby greenwoo » Thu Jun 13, 2019 7:51 pm

Guessing that bikes may be more receptive to the different lengths. Shows how different things work/don't on full engines set ups....i have adjustable trumpets on mine to do just that and it made the grand sum of bugger all difference...whether they were at 80mm or 90/100 or 120mm. Kind of surprised me after the article i'd read on Dave Walkers site, but i suppose so many things are variable, and so many 'experts' have their own opinions with little consensus; straight vs tapered, radius vs .....

I lost track a bit Lee, what will this engine produce - i recall it was already built to a high spec, so guessing that they already have a good idea on power?

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Re: MNR Vortex RT Hayabusa

Postby Crunchie Gears » Sat Jun 15, 2019 5:30 am

Brilliant Lee :D

Same tech questions here and power expectations :D

Cannot wait to see you enjoying the car.

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Re: MNR Vortex RT Hayabusa

Postby leegav » Sun Jun 16, 2019 7:51 pm

Mark did you adjust the trumpets and see on the dyno the results or just going off how the car felt... I read that article too and he pretty much said there should be a massive difference.. These itbs came off a grass track car with the owner been running hayabusas for some time.

Power should be 240+ at engine and 210+ at wheels.
Car will weigh 470 ish kg almost 200kg lighter than the tiger and 50 more horses. .pretty sure when i had the tiger corner weighted it was 660kg.
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Re: MNR Vortex RT Hayabusa

Postby greenwoo » Sun Jun 16, 2019 9:05 pm

@ Lee, tried them on the dyno and in parallel played with cam timing, made bugger all difference. But I guess every set up will be different in terms of responsiveness to that kind of thing.

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Re: MNR Vortex RT Hayabusa

Postby leegav » Mon Jun 17, 2019 8:30 am

that is interesting!!. il see if i can get print outs when they do the power runs and post them up to see if it makes a difference on the bec..
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Re: MNR Vortex RT Hayabusa

Postby Crunchie Gears » Mon Jun 17, 2019 8:38 am

Whatever Lee :D It is going to be super quick :? 8-) :lol: :lol:


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